title
stringlengths 1
251
| section
stringlengths 0
6.12k
| text
stringlengths 0
716k
|
|---|---|---|
Audio file format
|
Short description
|
thumb|Audio file icons of various formats
An audio file format is a file format for storing digital audio data on a computer system. The bit layout of the audio data (excluding metadata) is called the audio coding format and can be uncompressed, or compressed to reduce the file size, often using lossy compression. The data can be a raw bitstream in an audio coding format, but it is usually embedded in a container format or an audio data format with defined storage layer.
|
Audio file format
|
Format types
|
Format types
It is important to distinguish between the audio coding format, the container containing the raw audio data, and an audio codec. A codec performs the encoding and decoding of the raw audio data while this encoded data is (usually) stored in a container file. Although most audio file formats support only one type of audio coding data (created with an audio coder), a multimedia container format (as Matroska or AVI) may support multiple types of audio and video data.
There are three major groups of audio file formats:
Uncompressed audio formats, such as WAV, AIFF, AU or raw header-less PCM; Note wav can alternatively use compression.
Formats with lossless compression, such as FLAC, Monkey's Audio (filename extension .ape), WavPack (filename extension .wv), TTA, ATRAC Advanced Lossless, ALAC, MPEG-4 SLS, MPEG-4 ALS, MPEG-4 DST, Windows Media Audio Lossless (WMA Lossless), and Shorten (SHN).
Formats with lossy compression, such as Opus, MP3, Vorbis, Musepack, AAC, ATRAC and Windows Media Audio Lossy (WMA lossy).
|
Audio file format
|
Uncompressed audio format
|
Uncompressed audio format
One major uncompressed audio format, LPCM, is the same variety of PCM as used in Compact Disc Digital Audio and is the format most commonly accepted by low level audio APIs and D/A converter hardware. Although LPCM can be stored on a computer as a raw audio format, it is usually stored in a .wav file on Windows or in a .aiff file on macOS. The Audio Interchange File Format (AIFF) format is based on the Interchange File Format (IFF), and the WAV format is based on the similar Resource Interchange File Format (RIFF). WAV and AIFF are designed to store a wide variety of audio formats, lossless and lossy; they just add a small, metadata-containing header before the audio data to declare the format of the audio data, such as LPCM with a particular sample rate, bit depth, endianness and number of channels. Since WAV and AIFF are widely supported and can store LPCM, they are suitable file formats for storing and archiving an original recording.
BWF (Broadcast Wave Format) is a standard audio format created by the European Broadcasting Union as a successor to WAV. Among other enhancements, BWF allows more robust metadata to be stored in the file. See European Broadcasting Union: Specification of the Broadcast Wave Format (EBU Technical document 3285, July 1997). This is the primary recording format used in many professional audio workstations in the television and film industry. BWF files include a standardized timestamp reference which allows for easy synchronization with a separate picture element. Stand-alone, file based, multi-track recorders from AETA, Sound Devices, Zaxcom, HHB Communications Ltd, Fostex, Nagra, Aaton, and TASCAM all use BWF as their preferred format.
|
Audio file format
|
Lossless compressed audio format
|
Lossless compressed audio format
A lossless compressed audio format stores data in less space without losing any information. The original, uncompressed data can be recreated from the compressed version.
Uncompressed audio formats encode both sound and silence with the same number of bits per unit of time. Encoding an uncompressed minute of absolute silence produces a file of the same size as encoding an uncompressed minute of music. In a lossless compressed format, however, the music would occupy a smaller file than an uncompressed format and the silence would take up almost no space at all.
Lossless compression formats include FLAC, WavPack, Monkey's Audio, ALAC (Apple Lossless). They provide a compression ratio of about 2:1 (i.e. their files take up half the space of PCM). Development in lossless compression formats aims to reduce processing time while maintaining a good compression ratio.
|
Audio file format
|
Lossy compressed audio format
|
Lossy compressed audio format
Lossy audio format enables even greater reductions in file size by removing some of the audio information and simplifying the data. This, of course, results in a reduction in audio quality, but a variety of techniques are used, mainly by exploiting psychoacoustics, to remove the parts of the sound that have the least effect on perceived quality, and to minimize the amount of audible noise added during the process. The popular MP3 format is probably the best-known example, but the AAC format found on the iTunes Music Store is also common. Most formats offer a range of degrees of compression, generally measured in bit rate. The lower the rate, the smaller the file and the more significant the quality loss.
|
Audio file format
|
List of formats
|
List of formats
File Extension Creation Company Description .3gp Multimedia container format can contain proprietary formats as AMR, AMR-WB or AMR-WB+, but also some open formats .aa Audible (Amazon) A low-bitrate audiobook container format with DRM, containing audio encoded as either MP3 or the ACELP speech codec. .aac The Advanced Audio Coding format is based on the MPEG-2 and MPEG-4 standards. AAC files are usually ADTS or ADIF containers. .aax Audible (Amazon) An Audiobook format, which is a variable-bitrate (allowing high quality) M4B file encrypted with DRM. MPB contains AAC or ALAC encoded audio in an MPEG-4 container. (More details below.) .act ACT is a lossy ADPCM 8 kbit/s compressed audio format recorded by most Chinese MP3 and MP4 players with a recording function, and voice recorders .aiff Apple A standard uncompressed CD-quality, audio file format used by Apple. Established 3 years prior to Microsoft's uncompressed version wav. .alac Apple An audio coding format developed by Apple Inc. for lossless data compression of digital music. .amr AMR-NB audio, used primarily for speech. .ape Matthew T. Ashland Monkey's Audio lossless audio compression format. .au Sun Microsystems The standard audio file format used by Sun, Unix and Java. The audio in au files can be PCM or compressed with the μ-law, a-law or G.729 codecs. .awb AMR-WB audio, used primarily for speech, same as the ITU-T's G.722.2 specification. .dss Olympus DSS files are an Olympus proprietary format. DSS files use a high compression rate, which reduces the file size and allows files to be copied and transferred quickly. It allows additional data to be held in the file header. .dvf Sony A Sony proprietary format for compressed voice files; commonly used by Sony dictation recorders. .flac A file format for the Free Lossless Audio Codec, an open-source lossless compression codec. .gsm Designed for telephony use in Europe, GSM is used to store telephone voice messages and conversations. With a bitrate of 13 kbit/s, GSM files can compress and encode audio at telephone quality. Note that WAV files can also be encoded with the GSM codec. .iklax iKlax An iKlax Media proprietary format, the iKlax format is a multi-track digital audio format allowing various actions on musical data, for instance on mixing and volumes arrangements. .ivs 3D Solar UK Ltd A proprietary version with DRM developed by 3D Solar UK Ltd for use in music downloaded from their Tronme Music Store and interactive music and video player. .m4a An AAC or ALAC encoded audio file in an MPEG-4 container. In Apple's iTunes Music Store, M4A is used to represent a downloaded music file that is unprotected. .m4b An Audiobook / podcast extension with AAC or ALAC encoded audio in an MPEG-4 container. Both M4A and M4B formats can contain metadata including chapter markers, images, and hyperlinks, but M4B allows "bookmarks" (remembering the last listening spot), whereas M4A does not. .m4p Apple A version of AAC with proprietary DRM developed by Apple for use in music downloaded from their iTunes Music Store and their music streaming service known as Apple Music. .mmf Yamaha, Samsung A Samsung audio format that is used in ringtones. Developed by Yamaha (SMAF stands for "Synthetic music Mobile Application Format", and is a multimedia data format invented by the Yamaha Corporation, .mmf file format). .movpkg Apple An Apple audio format primarily used for Lossless and Hi-Res audio files through Apple Music. Also used for storing Apple TV videos..mp1MPEG-1 Layer I Audio.mp2MPEG-1/MPEG-2 Layer II Audio .mp3 MPEG-1/MPEG-2 Layer III Audio .mpc Musepack or MPC (formerly known as MPEGplus, MPEG+ or MP+) is an open source lossy audio codec, specifically optimized for transparent compression of stereo audio at bitrates of 160–180 kbit/s. .msv Sony A Sony proprietary format for Memory Stick compressed voice files. .nmfNICENICE Media Player audio file .ogg, .oga, .mogg Xiph.Org Foundation A free, open source container format supporting a variety of formats, the most popular of which is the audio format Vorbis. Vorbis offers compression similar to MP3 but is less popular. Mogg, the "Multi-Track-Single-Logical-Stream Ogg-Vorbis", is the multi-channel or multi-track Ogg file format. .opus Internet Engineering Task Force A lossy audio compression format developed by the Internet Engineering Task Force (IETF) and made especially suitable for interactive real-time applications over the Internet. As an open format standardised through RFC 6716, a reference implementation is provided under the 3-clause BSD license. .ra, .rm RealNetworks A RealAudio format designed for streaming audio over the Internet. The .ra format allows files to be stored in a self-contained fashion on a computer, with all of the audio data contained inside the file itself. .raw A raw file can contain audio in any format but is usually used with PCM audio data. It is rarely used except for technical tests. .rf64 One successor to the Wav format, overcoming the 4GiB size limitation. .sln Signed Linear PCM format used by Asterisk. Prior to v.10 the standard formats were 16-bit Signed Linear PCM sampled at 8 kHz and at 16 kHz. With v.10 many more sampling rates were added. .tta The True Audio, real-time lossless audio codec. .voc Creative Technology The file format consists of a 26-byte header and a series of subsequent data blocks containing the audio information .vox The vox format most commonly uses the Dialogic ADPCM (Adaptive Differential Pulse Code Modulation) codec. Similar to other ADPCM formats, it compresses to 4-bits. Vox format files are similar to wave files except that the vox files contain no information about the file itself so the codec sample rate and number of channels must first be specified in order to play a vox file. .wav IBM and Microsoft Standard audio file container format used mainly in Windows PCs. Commonly used for storing uncompressed (PCM), CD-quality sound files, which means that they can be large in size—around 10 MB per minute. Wave files can also contain data encoded with a variety of (lossy) codecs to reduce the file size (for example the GSM or MP3 formats). Wav files use a RIFF structure. .wma Microsoft Windows Media Audio format, created by Microsoft. Designed with DRM abilities for copy protection. .wv Format for wavpack files. .webm Royalty-free format created for HTML video. .8svx Electronic Arts The IFF-8SVX format for 8-bit sound samples, created by Electronic Arts in 1984 at the birth of the Amiga. .cda Format for cda files for Radio.
|
Audio file format
|
See also
|
See also
Video file format
Audio compression (data)
Comparison of audio coding formats
Comparison of video container formats
Comparison of video codecs
List of open-source audio codecs
Timeline of audio formats
|
Audio file format
|
References
|
References
Category:Digital container formats
|
Audio file format
|
Table of Content
|
Short description, Format types, Uncompressed audio format, Lossless compressed audio format, Lossy compressed audio format, List of formats, See also, References
|
Antipope Victor IV
|
Two
|
Two antipopes used the regnal name Victor IV:
Antipope Victor IV (1138)
Antipope Victor IV (1159–1164) (1095–1164)
|
Antipope Victor IV
|
Table of Content
|
Two
|
Area 51
|
Short description
|
Area 51 is the common name of a highly classified United States Air Force (USAF) facility within the Nevada Test and Training Range. A remote detachment administered by Edwards Air Force Base, the facility is officially called Homey Airport or Groom Lake (after the salt flat next to its airfield). Details of its operations are not made public, but the USAF says that it is an open training range, and it is commonly thought to support the development and testing of experimental aircraft and weapons systems. The USAF and CIA acquired the site in 1955, primarily for flight testing the Lockheed U-2 aircraft.
The intense secrecy surrounding the base has made it the frequent subject of conspiracy theories and a central component of unidentified flying object (UFO) folklore. It has never been declared a secret base, but all research and occurrences in Area 51 are Top Secret/Sensitive Compartmented Information (TS/SCI). The CIA publicly acknowledged the base's existence on 25 June 2013, following a Freedom of Information Act (FOIA) request filed in 2005, and declassified documents detailing its history and purpose.
Area 51 is located in the southern portion of Nevada, north-northwest of Las Vegas. The surrounding area is a popular tourist destination, including the small town of Rachel on the "Extraterrestrial Highway".
|
Area 51
|
Geography
|
Geography
|
Area 51
|
Area 51
|
Area 51
thumb|Area 51 viewed from distant Tikaboo Peak
The original rectangular base of is part of the so-called "Groom box", a rectangular area, measuring , of restricted airspace. The area is connected to the internal Nevada Test Site (NTS) road network, with paved roads leading south to Mercury and west to Yucca Flat. Leading northeast from the lake, the wide and well-maintained Groom Lake Road runs through a pass in the Jumbled Hills. The road formerly led to mines in the Groom basin but has been improved since their closure. Its winding course runs past a security checkpoint, but the restricted area around the base extends farther east. After leaving the restricted area, Groom Lake Road descends eastward to the floor of the Tikaboo Valley, passing the dirt-road entrances to several small ranches, before converging with State Route 375, the "Extraterrestrial Highway", south of Rachel.
Area 51 shares a border with the Yucca Flat region of the Nevada Test Site, the location of 739 of the 928 nuclear tests conducted by the United States Department of Energy at NTS. The Yucca Mountain nuclear waste repository is southwest of Groom Lake.
|
Area 51
|
Groom Lake
|
Groom Lake
Groom Lake is a salt flat in Nevada used for runways of the Nellis Bombing Range Test Site airport (XTA/KXTA) on the north of the Area 51 USAF military installation. The lake at elevation is approximately from north to south and from east to west at its widest point. Located within the namesake Groom Lake Valley portion of the Tonopah Basin, the lake is south of Rachel, Nevada.
|
Area 51
|
History
|
History
thumb|Nevada Test Range topographic chart centered on Groom Lake
The origin of the name "Area 51" is unclear. It is believed to be from an Atomic Energy Commission (AEC) numbering grid, although Area 51 is not part of this system; it is adjacent to Area 15. Another explanation is that 51 was used because it was unlikely that the AEC would use the number. According to the Central Intelligence Agency (CIA), the correct names for the facility are Homey Airport (XTA/KXTA) and Groom Lake, though the name "Area 51" was used in a CIA document from the Vietnam War. (the full declassified document is mirrored at Wikimedia Commons) The facility has also been referred to as "Dreamland" and "Paradise Ranch", among other nicknames, with the former also being the approach control call sign for the surrounding area. The USAF public relations has referred to the facility as "an operating location near Groom Dry Lake". The special use airspace around the field is referred to as Restricted Area 4808 North (R-4808N).
Lead and silver were discovered in the southern part of the Groom Range in 1864, and the English company Groome Lead Mines Limited financed the Conception Mines in the 1870s, giving the district its name (nearby mines included Maria, Willow, and White Lake). J. B. Osborne and partners acquired the controlling interest in Groom in 1876, and Osborne's son acquired it in the 1890s. Mining continued until 1918, then resumed after World War II until the early 1950s.
The airfield on the Groom Lake site began service in 1942 as Indian Springs Air Force Auxiliary Field and consisted of two unpaved 5,000-foot (1,524 m) runways.
|
Area 51
|
U-2 program
|
U-2 program
thumb|"The Ranch" with U-2 flight line ca. 1957
The Central Intelligence Agency (CIA) established the Groom Lake test facility in April 1955 for Project AQUATONE: the development of the Lockheed U-2 strategic reconnaissance aircraft. Project director Richard M. Bissell Jr. understood that the flight test and pilot training programs could not be conducted at Edwards Air Force Base or Lockheed's Palmdale facility, given the extreme secrecy surrounding the project. He conducted a search for a suitable testing site for the U-2 under the same extreme security as the rest of the project. He notified Lockheed, who sent an inspection team out to Groom Lake. According to Lockheed's U-2 designer Kelly Johnson:
The lake bed made an ideal strip for testing aircraft, and the Emigrant Valley's mountain ranges and the NTS perimeter protected the site from visitors; it was about north of Las Vegas. The CIA asked the AEC to acquire the land, designated "Area 51" on the map, and to add it to the Nevada Test Site.
Johnson named the area "Paradise Ranch" to encourage workers to move to "the new facility in the middle of nowhere", as the CIA later described it, and the name became shortened to "the Ranch". On 4May 1955, a survey team arrived at Groom Lake and laid out a north–south runway on the southwest corner of the lakebed and designated a site for a base support facility. The Ranch initially consisted of little more than a few shelters, workshops, and trailer homes in which to house its small team. A little over three months later, the base consisted of a single paved runway, three hangars, a control tower, and rudimentary accommodations for test personnel. The base's few amenities included a movie theater and volleyball court. There was also a mess hall, several wells, and fuel storage tanks. CIA, Air Force, and Lockheed personnel began arriving by July 1955. The Ranch received its first U-2 delivery on 24 July 1955 from Burbank on a C-124 Globemaster II cargo plane, accompanied by Lockheed technicians on a Douglas DC-3. Regular Military Air Transport Service flights were set up between Area 51 and Lockheed's offices in Burbank, California. To preserve secrecy, personnel flew to Nevada on Monday mornings and returned to California on Friday evenings.
|
Area 51
|
OXCART program
|
OXCART program
thumb|A 1966 Central Intelligence Agency (CIA) diagram of Area 51, found in an untitled, declassified paper, showing the runway overrun for OXCART (Lockheed A-12) and the turnaround areas (CIA / CREST RDP90b00184r000100040001-4)|alt=
Project OXCART was established in August 1959 for "antiradar studies, aerodynamic structural tests, and engineering designs" and all later work on the Lockheed A-12. This included testing at Groom Lake, which had inadequate facilities consisting of buildings for only 150 people, a asphalt runway, and limited fuel, hangar, and shop space. Groom Lake had received the name "Area 51" when A-12 test facility construction began in September 1960, including a new runway to replace the existing runway."OSA History, chap. 20, pp. 39–40, 43, 51 ... "OXCART Story" pp. 7–9 (S) (cited by "The U-2's Intended Successor")
Reynolds Electrical and Engineering Company (REECo) began construction of "Project 51" on 1October 1960 with double-shift construction schedules. The contractor upgraded base facilities and built a new runway (14/32) diagonally across the southwest corner of the lakebed. They marked an Archimedean spiral on the dry lake approximately across so that an A-12 pilot approaching the end of the overrun could abort instead of plunging into the sagebrush. Area 51 pilots called it "The Hook". For crosswind landings, they marked two unpaved airstrips (runways 9/27 and 03/21) on the dry lakebed.
By August 1961, construction of the essential facilities was complete; three surplus Navy hangars were erected on the base's north side while hangar7 was new construction. The original U-2 hangars were converted to maintenance and machine shops. Facilities in the main cantonment area included workshops and buildings for storage and administration, a commissary, a control tower, a fire station, and housing. The Navy also contributed more than 130 surplus Babbitt duplex housing units for long-term occupancy facilities. Older buildings were repaired, and additional facilities were constructed as necessary. A reservoir pond surrounded by trees served as a recreational area north of the base. Other recreational facilities included a gymnasium, a movie theater, and a baseball diamond. A permanent aircraft fuel tank farm was constructed by early 1962 for the special JP-7 fuel required by the A-12. Seven tanks were constructed, with a total capacity of .
thumb|upright|An A-12 (60-6924) takes off from Groom Lake during one of the first test flights, piloted by Louis Schalk, 26 April 1962.|alt=|left
Security was enhanced for the arrival of OXCART and the small mine was closed in the Groom basin. In January 1962, the Federal Aviation Administration (FAA) expanded the restricted airspace in the vicinity of Groom Lake, and the lakebed became the center of a addition to restricted area R-4808N. The CIA facility received eight USAF F-101 Voodoos for training, two T-33 Shooting Star trainers for proficiency flying, a C-130 Hercules for cargo transport, a U-3A for administrative purposes, a helicopter for search and rescue, and a Cessna 180 for liaison use, and Lockheed provided an F-104 Starfighter for use as a chase plane.
The first A-12 test aircraft was covertly trucked from Burbank on 26 February 1962 and arrived at Groom Lake on 28 February. It made its first flight 26 April 1962 when the base had over 1,000 personnel. The closed airspace above Groom Lake was within the Nellis Air Force Range airspace, and pilots saw the A-12 20 to 30 times. Groom was also the site of the first Lockheed D-21 drone test flight on 22 December 1964. By the end of 1963, nine A-12s were at Area 51, assigned to the CIA-operated "1129th Special Activities Squadron".
|
Area 51
|
D-21 Tagboard
|
D-21 Tagboard
thumb|The D-21 mounted on the back of the M-21. Note the intake cover on the drone, which was used on early flights.
Following the loss of Gary Powers' U-2 over the Soviet Union, there were several discussions about using the A-12 OXCART as an unpiloted drone aircraft. Although Kelly Johnson had come to support the idea of drone reconnaissance, he opposed the development of an A-12 drone, contending that the aircraft was too large and complex for such a conversion. However, the Air Force agreed to fund the study of a high-speed, high-altitude drone aircraft in October 1962. The Air Force interest seems to have moved the CIA to take action, the project designated "Q-12". By October 1963, the drone's design had been finalized. At the same time, the Q-12 underwent a name change. To separate it from the other A-12-based projects, it was renamed the "D-21". (The "12" was reversed to "21"). "Tagboard" was the project's code name.
The first D-21 was completed in the spring of 1964 by Lockheed. After four more months of checkouts and static tests, the aircraft was shipped to Groom Lake and reassembled. It was to be carried by a two-seat derivative of the A-12, designated the "M-21". When the D-21/M-21 reached the launch point, the first step would be to blow off the D-21's inlet and exhaust covers. With the D-21/M-21 at the correct speed and altitude, the LCO would start the ramjet and the other systems of the D-21. "With the D-21's systems activated and running, and the launch aircraft at the correct point, the M-21 would begin a slight pushover, the LCO would push a final button, and the D-21 would come off the pylon".
Difficulties were addressed throughout 1964 and 1965 at Groom Lake with various technical issues. Captive flights showed unforeseen aerodynamic difficulties. By late January 1966, more than a year after the first captive flight, everything seemed ready. The first D-21 launch was made on 5March 1966 with a successful flight, with the D-21 flying 120 miles with limited fuel. A second D-21 flight was successful in April 1966 with the drone flying 1,200 miles, reaching Mach 3.3 and 90,000 feet. An accident on 30 July 1966 with a fully fueled D-21, on a planned checkout flight, suffered from an unstart of the drone after its separation, causing it to collide with the M-21 launch aircraft. The two crewmen ejected and landed in the ocean 150 miles offshore. One crew member was picked up by a helicopter, but the other, having survived the aircraft breakup and ejection, drowned when sea water entered his pressure suit. Kelly Johnson personally cancelled the entire program, having had serious doubts about its feasibility from the start. A number of D-21s had already been produced, and rather than scrapping the whole effort, Johnson again proposed to the Air Force that they be launched from a B-52H bomber.
By late summer of 1967, the modification work to both the D-21 (now designated D-21B) and the B-52Hs was complete. The test program could now resume. The test missions were flown out of Groom Lake, with the actual launches over the Pacific. The first D-21B to be flown was Article 501, the prototype. The first attempt was made on 28 September 1967 and ended in complete failure. As the B-52 was flying toward the launch point, the D-21B fell off the pylon. The B-52H gave a sharp lurch as the drone fell free. The booster fired and was "quite a sight from the ground". The failure was traced to a stripped nut on the forward right attachment point on the pylon. Several more tests were made, none of which met with success. However, the fact is that the resumptions of D-21 tests took place against a changing reconnaissance background. The A-12 had finally been allowed to deploy, and the SR-71 was soon to replace it. At the same time, new developments in reconnaissance satellite technology were nearing operation. Up to this point, the limited number of satellites available restricted coverage to the Soviet Union. A new generation of reconnaissance satellites could soon cover targets anywhere in the world. The satellites' resolution would be comparable to that of aircraft but without the slightest political risk. Time was running out for the Tagboard.
Several more test flights, including two over China, were made from Beale AFB, California, in 1969 and 1970, to varying degrees of success. On 15 July 1971, Kelly Johnson received a wire canceling the D-21B program. The remaining drones were transferred by a C-5A and placed in dead storage. The tooling used to build the D-21Bs was ordered destroyed. Like the A-12 Oxcart, the D-21B Tagboard drones remained a Black airplane, even in retirement. Their existence was not suspected until August 1976, when the first group was placed in storage at the Davis-Monthan AFB Military Storage and Disposition Center. A second group arrived in 1977. They were labeled "GTD-21Bs" (GT stood for ground training).
Davis-Monthan is an open base, with public tours of the storage area at the time, so the odd-looking drones were soon spotted and photos began appearing in magazines. Speculation about the D-21Bs circulated within aviation circles for years, and it was not until 1982 that details of the Tagboard program were released. However, it was not until 1993 that the B-52/D-21B program was made public. That same year, the surviving D-21Bs were released to museums.
|
Area 51
|
Foreign technology evaluation
|
Foreign technology evaluation
During the Cold War, one of the missions carried out by the United States was the test and evaluation of captured Soviet fighter aircraft. Beginning in the late 1960s, and for several decades, Area 51 played host to an assortment of Soviet-built aircraft.
thumb|left|HAVE DOUGHNUT, a MiG-21F-13 flown by United States Navy and Air Force Systems Command during its 1968 exploitation
Munir Redfas defection with a Mikoyan-Gurevich MiG-21 from Iraq for Israel's Mossad in Operation Diamond led to the HAVE DOUGHNUT, HAVE DRILL and HAVE FERRY programs. The first MiGs flown in the United States were used to evaluate the aircraft in performance, technical, and operational capabilities, pitting the types against U.S. fighters.Steve Davies: "Red Eagles. America's Secret MiGs", Osprey Publishing, 2008
This was not a new mission, as testing of foreign technology by the USAF began during World War II. After the war, testing of acquired foreign technology was performed by the Air Technical Intelligence Center (ATIC, which became very influential during the Korean War), under the direct command of the Air Materiel Control Department. In 1961, ATIC became the Foreign Technology Division (FTD) and was reassigned to Air Force Systems Command. ATIC personnel were sent anywhere where foreign aircraft could be found.
The focus of Air Force Systems Command limited the use of the fighter as a tool with which to train the front line tactical fighter pilots. Air Force Systems Command recruited its pilots from the Air Force Flight Test Center at Edwards Air Force Base, California, who were usually graduates from various test pilot schools. Tactical Air Command selected its pilots primarily from the ranks of the Weapons School graduates.
In August 1966, Iraqi Air Force fighter pilot Captain Munir Redfa defected, flying his MiG-21 to Israel after being ordered to attack Iraqi Kurd villages with napalm. His aircraft was transferred to Groom Lake in late 1967 for study. Israel loaned the MiG-21 to the US Air Force from January 1968 to April 1968. In 1968, the US Air Force and Navy jointly formed a project known as HAVE DOUGHNUT in which Air Force Systems Command, Tactical Air Command, and the U.S. Navy's Air Test and Evaluation Squadron Four (VX-4) flew this acquired Soviet-made aircraft in simulated air combat training. As U.S. possession of the Soviet MiG-21 was, itself, secret, it was tested at Groom Lake. A joint Air Force-Navy team was assembled for a series of dogfight tests.
thumb|HAVE FERRY, the second of two MiG-17F "Fresco"s loaned to the United States by Israel in 1969|alt=
Comparisons between the F-4 and the MiG-21 indicated that, on the surface, they were evenly matched. The HAVE DOUGHNUT tests showed the skill of the man in the cockpit was what made the difference. When the Navy or Air Force pilots flew the MiG-21, the results were a draw; the F-4 would win some fights, the MiG-21 would win others. There were no clear advantages. The problem was not with the planes, but with the pilots flying them. The pilots would not fly either plane to its limits. One of the Navy pilots was Marland W. "Doc" Townsend, then commander of VF-121, the F-4 training squadron at NAS Miramar. He was an engineer and a Korean War veteran and had flown almost every Navy aircraft. When he flew against the MiG-21, he would outmaneuver it every time. The Air Force pilots would not go vertical in the MiG-21. The HAVE DOUGHNUT project officer was Tom Cassidy, a pilot with VX-4, the Navy's Air Development Squadron at Point Mugu. He had been watching as Townsend "waxed" the Air Force MiG-21 pilots. Cassidy climbed into the MiG-21 and went up against Townsend's F-4. This time the result was far different. Cassidy was willing to fight in the vertical, flying the plane to the point where it was buffeting, just above the stall. Cassidy was able to get on the F-4's tail. After the flight, they realized the MiG-21 turned better than the F-4 at lower speeds. The key was for the F-4 to keep its speed up. An F-4 had defeated the MiG-21; the weakness of the Soviet plane had been found. Further test flights confirmed what was learned. It was also clear that the MiG-21 was a formidable enemy. United States pilots would have to fly much better than they had been to beat it. This would require a special school to teach advanced air combat techniques.
On 12 August 1968, two Syrian air force lieutenants, Walid Adham and Radfan Rifai, took off in a pair of MiG-17Fs on a training mission. They lost their way and, believing they were over Lebanon, landed at the Betzet Landing Field in northern Israel. (One version has it that they were led astray by an Arabic-speaking Israeli). Prior to the end of 1968 these MiG-17s were transferred from Israeli stocks and added to the Area 51 test fleet. The aircraft were given USAF designations and fake serial numbers so that they could be identified in DOD standard flight logs. As in the earlier program, a small group of Air Force and Navy pilots conducted mock dogfights with the MiG-17s. Selected instructors from the Navy's Top Gun school at NAS Miramar, California, were chosen to fly against the MiGs for familiarization purposes. Very soon, the MiG-17's shortcomings became clear. It had an extremely simple, even crude, control system that lacked the power-boosted controls of American aircraft. The F-4's twin engines were so powerful it could accelerate out of range of the MiG-17's guns in thirty seconds. It was important for the F-4 to keep its distance from the MiG-17. As long as the F-4 was one and a half miles from the MiG-17, it was outside the reach of the Soviet fighter's guns, but the MiG was within reach of the F-4's missiles.
The data from the HAVE DOUGHNUT and HAVE DRILL tests were provided to the newly formed Top Gun school at NAS Miramar. By 1970, the HAVE DRILL program was expanded; a few selected fleet F-4 crews were given the chance to fight the MiGs. The most important result of Project HAVE DRILL is that no Navy pilot who flew in the project defeated the MiG-17 Fresco in the first engagement. The HAVE DRILL dogfights were by invitation only. The other pilots based at Nellis Air Force Base were not to know about the U.S.-operated MiGs. To prevent any sightings, the airspace above the Groom Lake range was closed. On aeronautical maps, the exercise area was marked in red ink. The forbidden zone became known as "Red Square".
During the remainder of the Vietnam War, the Navy kill ratio climbed to 8.33 to 1. In contrast, the Air Force rate improved only slightly to 2.83 to 1. The reason for this difference was Top Gun. The Navy had revitalized its air combat training, while the Air Force had stayed stagnant. Most of the Navy MiG kills were by Top Gun graduates.
In May 1973, Project HAVE IDEA was formed, which took over from the older HAVE DOUGHNUT, HAVE FERRY and HAVE DRILL projects, and the project was transferred to the Tonopah Test Range Airport. At Tonopah, testing of foreign technology aircraft continued and expanded throughout the 1970s and 1980s.
Area 51 also hosted another foreign materiel evaluation program called HAVE GLIB. This involved testing Soviet tracking and missile control radar systems. A complex of actual and replica Soviet-type threat systems began to grow around "Slater Lake", a mile northwest of the main base, along with an acquired Soviet "Barlock" search radar placed at Tonopah Air Force Station. They were arranged to simulate a Soviet-style air defense complex.
The Air Force began funding improvements to Area 51 in 1977 under project SCORE EVENT. In 1979, the CIA transferred jurisdiction of the Area 51 site to the Air Force Flight Test Center at Edwards AFB, California. Sam Mitchell, the last CIA commander of Area 51, relinquished command to USAF Lt. Col. Larry D. McClain.
In 2017, a USAF aircraft crashed at the site, killing the pilot, Lt. Colonel Eric "Doc" Schultz. The USAF refused to release further information regarding the crash. In 2022, unconfirmed reports emerged that the crash involved an SU-27 that was part of the classified Foreign Materials Exploitation program. The reports claimed that the aircraft suffered a technical issue that resulted in both crew members ejecting from the aircraft, resulting in the death of Schultz.
|
Area 51
|
Have Blue/F-117 program
|
Have Blue/F-117 program
The Lockheed Have Blue prototype stealth fighter (a smaller proof-of-concept model of the F-117 Nighthawk) first flew at Groom in December 1977.
thumb|left|Underside view of Have Blue
In 1978, the Air Force awarded a full-scale development contract for the F-117 to Lockheed Corporation's Advanced Development Projects. On 17 January 1981 the Lockheed test team at Area 51 accepted delivery of the first full-scale development (FSD) prototype 79–780, designated YF-117A. At 6:05 am on 18 June 1981 Lockheed Skunk Works test pilot Hal Farley lifted the nose of YF-117A 79–780 off the runway of Area 51.
Meanwhile, Tactical Air Command (TAC) decided to set up a group-level organization to guide the F-117A to an initial operating capability. That organization became the 4450th Tactical Group (Initially designated "A Unit"), which officially activated on 15 October 1979 at Nellis AFB, Nevada, although the group was physically located at Area 51. The 4450th TG also operated the A-7D Corsair II as a surrogate trainer for the F-117A, and these operations continued until 15 October 1982 under the guise of an avionics test mission.
Flying squadrons of the 4450th TG were the 4450th Tactical Squadron (Initially designated "I Unit") activated on 11 June 1981, and 4451st Tactical Squadron (Initially designated "P Unit") on 15 January 1983. The 4450th TS, stationed at Area 51, was the first F-117A squadron, while the 4451st TS was stationed at Nellis AFB and was equipped with A-7D Corsair IIs painted in a dark motif, tail coded "LV". Lockheed test pilots put the YF-117 through its early paces. A-7Ds were used for pilot training before any F-117As had been delivered by Lockheed to Area 51, later the A-7D's were used for F-117A chase testing and other weapon tests at the Nellis Range. On 15 October 1982, Major Alton C. Whitley Jr. became the first USAF 4450th TG pilot to fly the F-117A.
Although ideal for testing, Area 51 was not a suitable location for an operational group, so a new covert base had to be established for F-117 operations. Tonopah Test Range Airport was selected for operations of the first USAF F-117 unit, the 4450th Tactical Group (TG). From October 1979, the Tonopah Airport base was reconstructed and expanded. The 6,000-foot runway was lengthened to 10,000 feet. Taxiways, a concrete apron, a large maintenance hangar, and a propane storage tank were added.
By early 1982, four more YF-117As were operating at the base. After finding a large scorpion in their offices, the testing team (Designated "R Unit") adopted it as their mascot and dubbed themselves the "Baja Scorpions". Testing of a series of ultra-secret prototypes continued at Area 51 until mid-1981 when testing transitioned to the initial production of F-117 stealth fighters. The F-117s were moved to and from Area 51 by C-5 during darkness to maintain security. The aircraft were defueled, disassembled, cradled, and then loaded aboard the C-5 at night, flown to Lockheed, and unloaded at night before reassembly and flight testing. Groom performed radar profiling, F-117 weapons testing, and training of the first group of frontline USAF F-117 pilots.
While the "Baja Scorpions" were working on the F-117, there was also another group at work in secrecy, known as "the Whalers" working on Tacit Blue. A fly-by-wire technology demonstration aircraft with curved surfaces and composite material, to evade radar, was a prototype, and never went into production. Nevertheless, this strange-looking aircraft was responsible for many of the stealth technology advances that were used on several other aircraft designs, and had a direct influence on the B-2; with the first flight of Tacit Blue being performed on 5February 1982, by Northrop Grumman test pilot, Richard G. Thomas.
Production FSD airframes from Lockheed were shipped to Area 51 for acceptance testing. As the Baja Scorpions tested the aircraft with functional check flights and low observability (L.O.) verification, the operational airplanes were then transferred to the 4450th TG.
thumb|F-117 flying over mountains|alt=|left
On 17 May 1982, the move of the 4450th TG from Groom Lake to Tonopah was initiated, with the final components of the move completed in early 1983. Production FSD airframes from Lockheed were shipped to Area 51 for acceptance testing. As the Baja Scorpions tested the aircraft with functional check flights and L.O. verification, the operational airplanes were then transferred to the 4450th TG at Tonopah.
The R-Unit was inactivated on 30 May 1989. Upon inactivation, the unit was reformed as Detachment 1, 57th Fighter Weapons Wing (FWW). In 1990, the last F-117A (843) was delivered from Lockheed. After completion of acceptance flights at Area 51 of this last new F-117A aircraft, the flight test squadron continued flight test duties of refurbished aircraft after modifications by Lockheed. In February/March 1992 the test unit moved from Area 51 to the USAF Palmdale Plant 42 and was integrated with the Air Force Systems Command 6510th Test Squadron. Some testing, especially RCS verification and other classified activity was still conducted at Area 51 throughout the operational lifetime of the F-117. The recently inactivated (2008) 410th Flight Test Squadron traces its roots, if not its formal lineage to the 4450th TG R-unit.
|
Area 51
|
Later operations
|
Later operations
thumb|F-22 during a Red Flag exercise with Groom Lake in the background (March 2013)
Since the F-117 became operational in 1983, operations at Groom Lake have continued. The base and its associated runway system were expanded, including the expansion of housing and support facilities. In 1995, the federal government expanded the exclusionary area around the base to include nearby mountains that had hitherto afforded the only decent overlook of the base, prohibiting access to of land formerly administered by the Bureau of Land Management.
|
Area 51
|
Legal status
|
Legal status
|
Area 51
|
U.S. government's positions on Area 51
|
U.S. government's positions on Area 51
right|thumb|upright|A 1998 letter from the USAF replying to a query about Area 51
right|thumb|upright|CIA document from 1967 referring to Area 51
The United States government has provided minimal information regarding Area 51. The area surrounding the lake is permanently off-limits to both civilian and normal military air traffic. Security clearances are checked regularly; cameras and weaponry are not allowed. Even military pilots training in the NAFR risk disciplinary action if they stray into the exclusionary "box" surrounding Groom's airspace. Surveillance is supplemented using buried motion sensors. Area 51 is a common destination for Janet, a small fleet of passenger aircraft operated on behalf of the Air Force to transport military personnel, primarily from Harry Reid International Airport.
The United States Geological Survey (USGS) topographic map for the area only shows the long-disused Groom Mine, but USGS aerial photographs of the site in 1959 and 1968 were publicly available. A civil aviation chart published by the Nevada Department of Transportation shows a large restricted area, defined as part of the Nellis restricted airspace. The National Atlas shows the area as lying within the Nellis Air Force Base. There are higher resolution and newer images available from other satellite imagery providers, including Russian providers and the IKONOS. These show the runway markings, base facilities, aircraft, and vehicles.
In 1998 USAF officially acknowledged the site's existence. On 25 June 2013, the CIA released an official history of the U-2 and OXCART projects which acknowledged that the U-2 was tested at Area 51, in response to a Freedom of Information Act request submitted in 2005 by Jeffrey T. Richelson of George Washington University's National Security Archive. It contains numerous references to Area 51 and Groom Lake, along with a map of the area. Media reports stated that releasing the CIA history was the first governmental acknowledgement of Area 51's existence; rather, it was the first official acknowledgement of specific activity at the site.
|
Area 51
|
Environmental lawsuit
|
Environmental lawsuit
In 1994, five unnamed civilian contractors and the widows of contractors Walter Kasza and Robert Frost sued the Air Force and the United States Environmental Protection Agency. They alleged that they had been present when large quantities of unknown chemicals had been burned in open pits and trenches at Groom. Rutgers University biochemists analyzed biopsies from the complainants and found high levels of dioxin, dibenzofuran, and trichloroethylene in their body fat. The complainants alleged that they had sustained skin, liver, and respiratory injuries due to their work at Groom and that this had contributed to the deaths of Frost and Kasza.
The suit sought compensation for the injuries, claiming that the Air Force had illegally handled toxic materials and that the EPA had failed in its duty to enforce the Resource Conservation and Recovery Act which governs the handling of dangerous materials. They also sought detailed information about the chemicals, hoping that this would facilitate the medical treatment of survivors. Congressman Lee Hamilton, former chairman of the House Intelligence Committee, told 60 Minutes reporter Lesley Stahl, "The Air Force is classifying all information about Area 51 in order to protect themselves from a lawsuit."
thumb|The 1995 presidential determination by Bill Clinton preventing discovery from being able to continue in the lawsuit from former Area 51 employees.
The government invoked the state secrets privilege and petitioned U.S. District Judge Philip Pro to disallow disclosure of classified documents or examination of secret witnesses, claiming that it would threaten national security. Judge Pro rejected the government's argument. In response President Bill Clinton issued a presidential determination exempting what it called "the Air Force's operating location near Groom Lake, Nevada" from environmental disclosure laws.Presidential Determination No. 95–45, 60 F.R. 528823 (September 29, 1995). Archived from the original on September 23, 2020. Consequently, the judge dismissed the suit due to lack of evidence.
Jonathan Turley, the attorney for the plaintiffs, appealed to the U.S. Court of Appeals for the Ninth Circuit on the grounds that the government was abusing its power to classify material. Air Force Secretary Sheila E. Widnall filed a brief which stated that disclosures of the materials present in the air and water near Groom "can reveal military operational capabilities or the nature and scope of classified operations." The Ninth Circuit rejected the appealKasza v. Browner, 133 F.3d 1159 (1998). Archived from the original on March 14, 2012. and the U.S. Supreme Court refused to hear it, putting an end to the complainants' case.
The President annually issues a determination continuing the Groom exception which is the only formal recognition that the government has ever given that Groom Lake is more than simply another part of the Nellis complex. An unclassified memo on the safe handling of F-117 Nighthawk material was posted on an Air Force web site in 2005. This discussed the same materials for which the complainants had requested information, which the government had claimed was classified. The memo was removed shortly after journalists became aware of it.
|
Area 51
|
Civil aviation identification
|
Civil aviation identification
In December 2007, pilots noticed that the base had appeared in their aircraft navigation systems' latest Jeppesen database revision with the ICAO airport identifier code of KXTA and listed as "Homey Airport". The probably inadvertent release of the airport data led to advice by the Aircraft Owners and Pilots Association (AOPA) that student pilots should be explicitly warned about KXTA, not to consider it as a waypoint or destination for any flight even though it now appears in public navigation databases.
|
Area 51
|
Security
|
Security
thumb|The main gate to Area 51, on Groom Road
The perimeter of the base is marked out by orange posts and patrolled by guards in white pickup trucks and camouflage fatigues. The guards are popularly referred to as "camo dudes" by enthusiasts. The guards will not answer questions about their employers; however, according to the New York Daily News, there are indications they are employed through a contractor such as AECOM. Signage around the base perimeter advises that deadly force is authorized against trespassers.
Technology is also heavily used to maintain the border of the base; this includes surveillance cameras and motion detectors. Some of these motion detectors are placed some distance away from the base on public land to notify guards of people approaching.
thumb|left|Area 51 border and warning sign stating that "photography is prohibited" and that "use of deadly force is authorized"
|
Area 51
|
1974 Skylab photography
|
1974 Skylab photography
Dwayne A. Day published "Astronauts and Area 51: the Skylab Incident" in The Space Review in January 2006. It was based on a memo written in 1974 to CIA director William Colby by an unknown CIA official. The memo reported that astronauts on board Skylab had inadvertently photographed a certain location:
The name of the location was obscured, but the context led Day to believe that the subject was Groom Lake. Day wrote that "the CIA considered no other spot on Earth to be as sensitive as Groom Lake". Even within the agency's National Photographic Interpretation Center that handled classified reconnaissance satellite photographs, images of the site were removed from film rolls and stored separately as not all photo interpreters had security clearance for the information. The memo details debate between federal agencies regarding whether the images should be classified, with Department of Defense agencies arguing that it should and NASA and the State Department arguing that it should not be classified. The memo itself questions the legality of retroactively classifying unclassified images.
The memo includes handwritten remarks, apparently by Director of Central Intelligence Colby:
The declassified documents do not disclose the outcome of discussions regarding the Skylab imagery. The debate proved moot, as the photograph appeared in the Federal Government's Archive of Satellite Imagery along with the remaining Skylab photographs.
|
Area 51
|
2019 shooting incident
|
2019 shooting incident
On 28 January 2019, an unidentified man drove through a security checkpoint near Mercury, Nevada, in an apparent attempt to enter the base. After an vehicle pursuit by base security, the man exited his vehicle carrying a "cylindrical object" and was shot dead by NNSS security officers and sheriff's deputies after refusing to obey requests to halt. There were no other injuries reported.
|
Area 51
|
UFO and other conspiracy theories
|
UFO and other conspiracy theories
thumb|During the 2019 Raid of Area 51, protestors and UFO conspiracy theorists gathered at the back gate of Area 51.
Area 51 has become a focus of modern conspiracy theories due to its secretive nature and connection to classified aircraft research. Theories include:
The storage, examination, and reverse engineering of crashed alien spacecraft, including material supposedly recovered at Roswell, the study of their occupants, and the manufacture of aircraft based on alien technology.
Meetings or joint undertakings with extraterrestrials.
The development of exotic energy weapons for the Strategic Defense Initiative (SDI) or other weapons programs.
The development of weather control.
The development of time travel and teleportation technology.
The development of exotic propulsion systems related to the Aurora Program.
Activities related to the conspiracy theory of a one-world government.
thumb|left|A closed-circuit TV camera watches over the perimeter of Area 51.
Many of the hypotheses concern underground facilities at Groom or at Papoose Lake (also known as "S-4 location"), south, and include claims of a transcontinental underground railroad system, a disappearing airstrip nicknamed the "Cheshire Airstrip", after Lewis Carroll's Cheshire cat, which briefly appears when water is sprayed onto its camouflaged asphalt, and engineering based on alien technology.
In the mid-1950s, civilian aircraft flew under 20,000 feet while military aircraft flew up to 40,000 feet. The U-2 began flying above 60,000 feet and there was an increasing number of UFO sighting reports. Sightings occurred most often during early evening hours, when airline pilots flying west saw the U-2's silver wings reflect the setting sun, giving the aircraft a "fiery" appearance. Many sighting reports came to the Air Force's Project Blue Book, which investigated UFO sightings, through air-traffic controllers and letters to the government. The project checked U-2 and later OXCART flight records to eliminate the majority of UFO reports that it received during the late 1950s and 1960s, although it could not reveal to the letter writers the truth behind what they saw. Similarly, veterans of experimental projects such as OXCART at Area 51 agree that their work inadvertently prompted many of the UFO sightings and other rumors:
They believe that the rumors helped maintain secrecy over Area 51's actual operations. The veterans deny the existence of a vast underground railroad system.
thumb|Lincoln County deputies guard the back gate of Area 51 during the 2019 raid.
On October 14, 1988, the syndicated television broadcast UFO Coverup? Live introduced Americans to the Majestic 12 hoax. It featured the first public mention of Nevada's Area 51 as a site associated with aliens.
Bob Lazar claimed in 1989 that he had worked at Area 51's "Sector Four (S-4)", said to be located underground inside the Papoose Range near Papoose Lake. He claimed that he was contracted to work with alien spacecraft that the government had in its possession. Similarly, the 1996 documentary Dreamland directed by Bruce Burgess included an interview with a 71-year-old mechanical engineer who claimed to be a former employee at Area 51 during the 1950s. His claims included that he had worked on a "flying disc simulator" which had been based on a disc originating from a crashed extraterrestrial craft and was used to train pilots. He also claimed to have worked with an extraterrestrial being named "J-Rod" and described as a "telepathic translator".Dreamland, Transmedia and Dandelion Production for Sky Television (1996). In 2004, Dan Burisch (pseudonym of Dan Crain) claimed to have worked on cloning alien viruses at Area 51, also alongside the alien named "J-Rod". Burisch's scholarly credentials are the subject of much debate, as he was apparently working as a Las Vegas parole officer in 1989 while also earning a PhD at State University of New York (SUNY).
In July 2019, more than 2,000,000 people responded to a joke proposal to storm Area 51 which appeared in an anonymous Facebook post. The event, scheduled for 20 September 2019, was billed as "Storm Area 51, They Can't Stop All of Us", an attempt to "see them aliens". Air Force spokeswoman Laura McAndrews said the government "would discourage anyone from trying to come into the area where we train American armed forces". Two music festivals in rural Nevada, AlienStock and Storm Area 51 Basecamp, were subsequently organized to capitalize on the popularity of the original Facebook event. Between 1,500 and 3,000 people showed up at the festivals, while over 150 people made the journey over several miles of rough roads to get near the gates to Area 51. Seven people were reportedly arrested at the event.
|
Area 51
|
In popular culture
|
In popular culture
Because of Area 51's prominence in relation to aliens and conspiracy theories, it has often been used as a setting and theme in popular culture, especially in science fiction works involving aliens.
|
Area 51
|
See also
|
See also
Area 52
Black operation
Black project
Black site
List of United States Air Force installations
Special access program
|
Area 51
|
Footnotes
|
Footnotes
|
Area 51
|
Citations
|
Citations
|
Area 51
|
Sources
|
Sources
Darlington, David (1998). Area 51: The Dreamland Chronicles. New York: Henry Holt.
Patton, Phil (1998). Dreamland: Travels Inside the Secret World of Roswell and Area 51. New York: Villard/Random House
Stahl, Lesley "Area 51 / Catch 22" 60 Minutes CBS Television 17 March 1996, a US TV news magazine's segment about the environmental lawsuit.
|
Area 51
|
External links
|
External links
Las Vegas sectional aeronautical chart, centered on Groom Lake (Federal Aviation Administration – SkyVector.com)
Category:1942 establishments in Nevada
Category:Buildings and structures in Lincoln County, Nevada
Category:Installations of the Central Intelligence Agency
Category:Military installations in Nevada
Category:Military UFO conspiracy theories in the United States
Category:Research installations of the United States Air Force
Category:Secret places in the United States
|
Area 51
|
Table of Content
|
Short description, Geography, Area 51, Groom Lake, History, U-2 program, OXCART program, D-21 Tagboard, Foreign technology evaluation, Have Blue/F-117 program, Later operations, Legal status, U.S. government's positions on Area 51, Environmental lawsuit, Civil aviation identification, Security, 1974 Skylab photography, 2019 shooting incident, UFO and other conspiracy theories, In popular culture, See also, Footnotes, Citations, Sources, External links
|
Audio signal processing
|
short description
|
Audio signal processing is a subfield of signal processing that is concerned with the electronic manipulation of audio signals. Audio signals are electronic representations of sound waves—longitudinal waves which travel through air, consisting of compressions and rarefactions. The energy contained in audio signals or sound power level is typically measured in decibels. As audio signals may be represented in either digital or analog format, processing may occur in either domain. Analog processors operate directly on the electrical signal, while digital processors operate mathematically on its digital representation.
|
Audio signal processing
|
History
|
History
The motivation for audio signal processing began at the beginning of the 20th century with inventions like the telephone, phonograph, and radio that allowed for the transmission and storage of audio signals. Audio processing was necessary for early radio broadcasting, as there were many problems with studio-to-transmitter links. The theory of signal processing and its application to audio was largely developed at Bell Labs in the mid 20th century. Claude Shannon and Harry Nyquist's early work on communication theory, sampling theory and pulse-code modulation (PCM) laid the foundations for the field. In 1957, Max Mathews became the first person to synthesize audio from a computer, giving birth to computer music.
Major developments in digital audio coding and audio data compression include differential pulse-code modulation (DPCM) by C. Chapin Cutler at Bell Labs in 1950, linear predictive coding (LPC) by Fumitada Itakura (Nagoya University) and Shuzo Saito (Nippon Telegraph and Telephone) in 1966, adaptive DPCM (ADPCM) by P. Cummiskey, Nikil S. Jayant and James L. Flanagan at Bell Labs in 1973,P. Cummiskey, Nikil S. Jayant, and J. L. Flanagan, "Adaptive quantization in differential PCM coding of speech", Bell Syst. Tech. J., vol. 52, pp. 1105—1118, Sept. 1973 discrete cosine transform (DCT) coding by Nasir Ahmed, T. Natarajan and K. R. Rao in 1974, and modified discrete cosine transform (MDCT) coding by J. P. Princen, A. W. Johnson and A. B. Bradley at the University of Surrey in 1987.J. P. Princen, A. W. Johnson und A. B. Bradley: Subband/transform coding using filter bank designs based on time domain aliasing cancellation, IEEE Proc. Intl. Conference on Acoustics, Speech, and Signal Processing (ICASSP), 2161–2164, 1987. LPC is the basis for perceptual coding and is widely used in speech coding, while MDCT coding is widely used in modern audio coding formats such as MP3 and Advanced Audio Coding (AAC).
|
Audio signal processing
|
Types
|
Types
|
Audio signal processing
|
Analog
|
Analog
An analog audio signal is a continuous signal represented by an electrical voltage or current that is analogous to the sound waves in the air. Analog signal processing then involves physically altering the continuous signal by changing the voltage or current or charge via electrical circuits.
Historically, before the advent of widespread digital technology, analog was the only method by which to manipulate a signal. Since that time, as computers and software have become more capable and affordable, digital signal processing has become the method of choice. However, in music applications, analog technology is often still desirable as it often produces nonlinear responses that are difficult to replicate with digital filters.
|
Audio signal processing
|
Digital
|
Digital
A digital representation expresses the audio waveform as a sequence of symbols, usually binary numbers. This permits signal processing using digital circuits such as digital signal processors, microprocessors and general-purpose computers. Most modern audio systems use a digital approach as the techniques of digital signal processing are much more powerful and efficient than analog domain signal processing.
|
Audio signal processing
|
Applications
|
Applications
Processing methods and application areas include storage, data compression, music information retrieval, speech processing, localization, acoustic detection, transmission, noise cancellation, acoustic fingerprinting, sound recognition, synthesis, and enhancement (e.g. equalization, filtering, level compression, echo and reverb removal or addition, etc.).
|
Audio signal processing
|
Audio broadcasting
|
Audio broadcasting
Audio signal processing is used when broadcasting audio signals in order to enhance their fidelity or optimize for bandwidth or latency. In this domain, the most important audio processing takes place just before the transmitter. The audio processor here must prevent or minimize overmodulation, compensate for non-linear transmitters (a potential issue with medium wave and shortwave broadcasting), and adjust overall loudness to the desired level.
|
Audio signal processing
|
Active noise control
|
Active noise control
Active noise control is a technique designed to reduce unwanted sound. By creating a signal that is identical to the unwanted noise but with the opposite polarity, the two signals cancel out due to destructive interference.
|
Audio signal processing
|
Audio synthesis
|
Audio synthesis
Audio synthesis is the electronic generation of audio signals. A musical instrument that accomplishes this is called a synthesizer. Synthesizers can either imitate sounds or generate new ones. Audio synthesis is also used to generate human speech using speech synthesis.
|
Audio signal processing
|
Audio effects
|
Audio effects
Audio effects alter the sound of a musical instrument or other audio source. Common effects include distortion, often used with electric guitar in electric blues and rock music; dynamic effects such as volume pedals and compressors, which affect loudness; filters such as wah-wah pedals and graphic equalizers, which modify frequency ranges; modulation effects, such as chorus, flangers and phasers; pitch effects such as pitch shifters; and time effects, such as reverb and delay, which create echoing sounds and emulate the sound of different spaces.
Musicians, audio engineers and record producers use effects units during live performances or in the studio, typically with electric guitar, bass guitar, electronic keyboard or electric piano. While effects are most frequently used with electric or electronic instruments, they can be used with any audio source, such as acoustic instruments, drums, and vocals.
|
Audio signal processing
|
Computer audition
|
Computer audition
Computer audition (CA) or machine listening is the general field of study of algorithms and systems for audio interpretation by machines. Since the notion of what it means for a machine to "hear" is very broad and somewhat vague, computer audition attempts to bring together several disciplines that originally dealt with specific problems or had a concrete application in mind. The engineer Paris Smaragdis, interviewed in Technology Review, talks about these systems "software that uses sound to locate people moving through rooms, monitor machinery for impending breakdowns, or activate traffic cameras to record accidents."Paris Smaragdis taught computers how to play more life-like music
Inspired by models of human audition, CA deals with questions of representation, transduction, grouping, use of musical knowledge and general sound semantics for the purpose of performing intelligent operations on audio and music signals by the computer. Technically this requires a combination of methods from the fields of signal processing, auditory modelling, music perception and cognition, pattern recognition, and machine learning, as well as more traditional methods of artificial intelligence for musical knowledge representation.
|
Audio signal processing
|
See also
|
See also
Sound card
Sound effect
|
Audio signal processing
|
References
|
References
|
Audio signal processing
|
Further reading
|
Further reading
Category:Audio electronics
Category:Signal processing
|
Audio signal processing
|
Table of Content
|
short description, History, Types, Analog, Digital, Applications, Audio broadcasting, Active noise control, Audio synthesis, Audio effects, Computer audition, See also, References, Further reading
|
Amdahl's law
|
short description
|
thumb|400px|Amdahl's Law demonstrates the theoretical maximum speedup of an overall system and the concept of diminishing returns. Plotted here is logarithmic parallelization vs linear speedup. If exactly 50% of the work can be parallelized, the best possible speedup is 2 times. If 95% of the work can be parallelized, the best possible speedup is 20 times. According to the law, even with an infinite number of processors, the speedup is constrained by the unparallelizable portion.
In computer architecture, Amdahl's law (or Amdahl's argument) is a formula that shows how much faster a task can be completed when more resources are added to the system.
The law can be stated as:
"the overall performance improvement gained by optimizing a single part of a system is limited by the fraction of time that the improved part is actually used".
It is named after computer scientist Gene Amdahl, and was presented at the American Federation of Information Processing Societies (AFIPS) Spring Joint Computer Conference in 1967.
Amdahl's law is often used in parallel computing to predict the theoretical speedup when using multiple processors.
|
Amdahl's law
|
Definition
|
Definition
In the context of Amdahl's law, speedup can be defined as:
or
Amdahl's law can be formulated in the following way:
where
represents the total speedup of a program
represents the proportion of time spent on the portion of the code where improvements are made
represents the extent of the improvement
The is frequently much lower than one might expect. For instance, if a programmer enhances a part of the code that represents 10% of the total execution time (i.e. of 0.10) and achieves a of 10,000, then becomes 1.11 which means only 11% improvement in total speedup of the program. So, despite a massive improvement in one section, the overall benefit is quite small. In another example, if the programmer optimizes a section that accounts for 99% of the execution time (i.e. of 0.99) with a speedup factor of 100 (i.e. of 100), the only reaches 50. This indicates that half of the potential performance gain ( will reach 100 if 100% of the execution time is covered) is lost due to the remaining 1% of execution time that was not improved.
|
Amdahl's law
|
Implications
|
Implications
Followings are implications of Amdahl's law:
Diminishing Returns: Adding more processors gives diminishing returns. Beyond a certain point, adding more processors doesn't significantly increase speedup.
Limited Speedup: Even with many processors, there's a limit to how much faster a task can be completed due to parts of the task that cannot be parallelized.
|
Amdahl's law
|
Limitations
|
Limitations
Followings are limitations of Amdahl's law:
Assumption of Fixed Workload: Amdahl's Law assumes that the workload remains constant. It doesn't account for dynamic or increasing workloads, which can impact the effectiveness of parallel processing.
Overhead Ignored: Amdahl's Law neglects overheads associated with concurrency, including coordination, synchronization, inter-process communication, and concurrency control. Notably, merging data from multiple threads or processes incurs significant overhead due to conflict resolution, data consistency, versioning, and synchronization.
Neglecting extrinsic factors: Amdahl's Law addresses computational parallelism, neglecting extrinsic factors such as data persistence, I/O operations, and memory access overheads, and assumes idealized conditions.
Scalability Issues: While it highlights the limits of parallel speedup, it doesn't address practical scalability issues, such as the cost and complexity of adding more processors.
Non-Parallelizable Work: Amdahl's Law emphasizes the non-parallelizable portion of the task as a bottleneck but doesn't provide solutions for reducing or optimizing this portion.
Assumes Homogeneous Processors: It assumes that all processors are identical and contribute equally to speedup, which may not be the case in heterogeneous computing environments.
Amdahl's law applies only to the cases where the problem size is fixed. In practice, as more computing resources become available, they tend to get used on larger problems (larger datasets), and the time spent in the parallelizable part often grows much faster than the inherently serial work. In this case, Gustafson's law gives a less pessimistic and more realistic assessment of the parallel performance.
Universal Scalability Law (USL), developed by Neil J. Gunther, extends the Amdahl's law and accounts for the additional overhead due to inter-process communication. USL quantifies scalability based on parameters such as contention and coherency.
|
Amdahl's law
|
Derivation
|
Derivation
A task executed by a system whose resources are improved compared to an initial similar system can be split up into two parts:
a part that does not benefit from the improvement of the resources of the system;
a part that benefits from the improvement of the resources of the system.
An example is a computer program that processes files. A part of that program may scan the directory of the disk and create a list of files internally in memory. After that, another part of the program passes each file to a separate thread for processing. The part that scans the directory and creates the file list cannot be sped up on a parallel computer, but the part that processes the files can.
The execution time of the whole task before the improvement of the resources of the system is denoted as . It includes the execution time of the part that would not benefit from the improvement of the resources and the execution time of the one that would benefit from it. The fraction of the execution time of the task that would benefit from the improvement of the resources is denoted by . The one concerning the part that would not benefit from it is therefore . Then:
It is the execution of the part that benefits from the improvement of the resources that is accelerated by the factor after the improvement of the resources. Consequently, the execution time of the part that does not benefit from it remains the same, while the part that benefits from it becomes:
The theoretical execution time of the whole task after the improvement of the resources is then:
Amdahl's law gives the theoretical speedup in latency of the execution of the whole task at fixed workload , which yields
|
Amdahl's law
|
Parallel programs
|
Parallel programs
If 30% of the execution time may be the subject of a speedup, p will be 0.3; if the improvement makes the affected part twice as fast, s will be 2. Amdahl's law states that the overall speedup of applying the improvement will be:
For example, assume that we are given a serial task which is split into four consecutive parts, whose percentages of execution time are , , , and respectively. Then we are told that the 1st part is not sped up, so , while the 2nd part is sped up 5 times, so , the 3rd part is sped up 20 times, so , and the 4th part is sped up 1.6 times, so . By using Amdahl's law, the overall speedup is
Notice how the 5 times and 20 times speedup on the 2nd and 3rd parts respectively don't have much effect on the overall speedup when the 4th part (48% of the execution time) is accelerated by only 1.6 times.
|
Amdahl's law
|
Serial programs
|
Serial programs
[[File:Optimizing-different-parts.svg|thumb|400px|Assume that a task has two independent parts, A and B. Part B takes roughly 25% of the time of the whole computation. By working very hard, one may be able to make this part 5 times faster, but this reduces the time of the whole computation only slightly. In contrast, one may need to perform less work to make part A perform twice as fast. This will make the computation much faster than by optimizing part B, even though part B'''s speedup is greater in terms of the ratio, (5 times versus 2 times).]]
For example, with a serial program in two parts A and B for which and ,
if part B is made to run 5 times faster, that is and , then
if part A is made to run 2 times faster, that is and , then
Therefore, making part A to run 2 times faster is better than making part B to run 5 times faster. The percentage improvement in speed can be calculated as
Improving part A by a factor of 2 will increase overall program speed by a factor of 1.60, which makes it 37.5% faster than the original computation.
However, improving part B by a factor of 5, which presumably requires more effort, will achieve an overall speedup factor of 1.25 only, which makes it 20% faster.
Optimizing the sequential part of parallel programs
If the non-parallelizable part is optimized by a factor of , then
It follows from Amdahl's law that the speedup due to parallelism is given by
When , we have , meaning that the speedup is
measured with respect to the execution time after the non-parallelizable part is optimized.
When ,
If , and , then:
Transforming sequential parts of parallel programs into parallelizable
Next, we consider the case wherein the non-parallelizable part is reduced by a factor of , and the parallelizable part is correspondingly increased. Then
It follows from Amdahl's law that the speedup due to parallelism is given by
Relation to the law of diminishing returns
Amdahl's law is often conflated with the law of diminishing returns, whereas only a special case of applying Amdahl's law demonstrates law of diminishing returns. If one picks optimally (in terms of the achieved speedup) what is to be improved, then one will see monotonically decreasing improvements as one improves. If, however, one picks non-optimally, after improving a sub-optimal component and moving on to improve a more optimal component, one can see an increase in the return. Note that it is often rational to improve a system in an order that is "non-optimal" in this sense, given that some improvements are more difficult or require larger development time than others.
Amdahl's law does represent the law of diminishing returns if one is considering what sort of return one gets by adding more processors to a machine, if one is running a fixed-size computation that will use all available processors to their capacity. Each new processor added to the system will add less usable power than the previous one. Each time one doubles the number of processors the speedup ratio will diminish, as the total throughput heads toward the limit of 1/(1 − p'').
This analysis neglects other potential bottlenecks such as memory bandwidth and I/O bandwidth. If these resources do not scale with the number of processors, then merely adding processors provides even lower returns.
An implication of Amdahl's law is that to speed up real applications which have both serial and parallel portions, heterogeneous computing techniques are required. There are novel speedup and energy consumption models based on a more general representation of heterogeneity, referred to as the normal form heterogeneity, that support a wide range of heterogeneous many-core architectures. These modelling methods aim to predict system power efficiency and performance ranges, and facilitates research and development at the hardware and system software levels.
|
Amdahl's law
|
See also
|
See also
Gustafson's law
Universal Law of Computational Scalability
Analysis of parallel algorithms
Critical path method
Moore's law
List of eponymous laws
|
Amdahl's law
|
References
|
References
|
Amdahl's law
|
Further reading
|
Further reading
|
Amdahl's law
|
External links
|
External links
. Amdahl discusses his graduate work at the University of Wisconsin and his design of WISC. Discusses his role in the design of several computers for IBM including the STRETCH, IBM 701, and IBM 704. He discusses his work with Nathaniel Rochester and IBM's management of the design process. Mentions work with Ramo-Wooldridge, Aeronutronic, and Computer Sciences Corporation
"Amdahl's Law" by Joel F. Klein, Wolfram Demonstrations Project (2007)
Amdahl's Law in the Multicore Era (July 2008)
Category:Analysis of parallel algorithms
Category:Computer architecture statements
|
Amdahl's law
|
Table of Content
|
short description, Definition, Implications, Limitations, Derivation, Parallel programs, Serial programs, See also, References, Further reading, External links
|
April 27
|
pp-move
| |
April 27
|
Events
|
Events
|
April 27
|
Pre-1600
|
Pre-1600
247 – Philip the Arab marks the millennium of Rome with a celebration of the ludi saeculares.
395 – Emperor Arcadius marries Aelia Eudoxia, daughter of the Frankish general Flavius Bauto. She becomes one of the more powerful Roman empresses of Late Antiquity.
711 – Islamic conquest of Hispania: Moorish troops led by Tariq ibn Ziyad land at Gibraltar to begin their invasion of the Iberian Peninsula (Al-Andalus).
1296 – First War of Scottish Independence: John Balliol's Scottish army is defeated by an English army commanded by John de Warenne, 6th Earl of Surrey at the Battle of Dunbar.
1509 – Pope Julius II places the Italian state of Venice under interdict.
1521 – Battle of Mactan: Explorer Ferdinand Magellan is killed by natives in the Philippines led by chief Lapulapu.
1539 – Official founding of the city of Bogotá, New Granada (nowadays Colombia), by Nikolaus Federmann and Sebastián de Belalcázar.
1565 – Cebu is established becoming the first Spanish settlement in the Philippines.
1595 – The relics of Saint Sava are incinerated in Belgrade on the Vračar plateau by Ottoman Grand Vizier Sinan Pasha; the site of the incineration is now the location of the Church of Saint Sava, one of the largest Orthodox churches in the world
|
April 27
|
1601–1900
|
1601–1900
1650 – The Battle of Carbisdale: A Royalist army from Orkney invades mainland Scotland but is defeated by a Covenanter army.
1667 – Blind and impoverished, John Milton sells Paradise Lost to a printer for £10, so that it could be entered into the Stationers' Register.
1805 – First Barbary War: United States Marines and Berbers attack the Tripolitan city of Derna (The "shores of Tripoli" in the Marines' Hymn).
1813 – War of 1812: American troops capture York, the capital of Upper Canada, in the Battle of York.
1861 – American President Abraham Lincoln suspends the writ of habeas corpus.
|
April 27
|
1901–present
|
1901–present
1906 – The State Duma of the Russian Empire meets for the first time.
1909 – Sultan of Ottoman Empire Abdul Hamid II is overthrown, and is succeeded by his brother, Mehmed V.
1911 – The Second Canton Uprising took place in Guangzhou, Qing China but was suppressed.
1927 – Carabineros de Chile (Chilean national police force and gendarmerie) are created.
1936 – The United Auto Workers (UAW) gains autonomy from the American Federation of Labor.
1941 – World War II: German troops enter Athens.
1945 – World War II: The last German formations withdraw from Finland to Norway. The Lapland War and thus, World War II in Finland, comes to an end and the Raising the Flag on the Three-Country Cairn photograph is taken.
1945 – World War II: Benito Mussolini is arrested by Italian partisans in Dongo, while attempting escape disguised as a German soldier.
1953 – Operation Moolah offers $50,000 to any pilot who defects with a fully mission-capable Mikoyan-Gurevich MiG-15 to South Korea. The first pilot was to receive $100,000.
1967 – Expo 67 officially opens in Montreal, Quebec, Canada with a large opening ceremony broadcast around the world. It opens to the public the next day.
1974 – 109 people are killed in a plane crash near Pulkovo Airport.
1976 – Thirty-seven people are killed when American Airlines Flight 625 crashes at Cyril E. King Airport in Saint Thomas, U.S. Virgin Islands.
1978 – John Ehrlichman, a former aide to U.S. President Richard Nixon, is released from the Federal Correctional Institution, Safford, Arizona, after serving 18 months for Watergate-related crimes.
1978 – The Saur Revolution begins in Afghanistan, ending the following morning with the murder of Afghan President Mohammed Daoud Khan and the establishment of the Democratic Republic of Afghanistan.
1978 – Willow Island disaster: In the deadliest construction accident in United States history, 51 construction workers are killed when a cooling tower under construction collapses at the Pleasants Power Station in Willow Island, West Virginia.
1986 – The city of Pripyat and surrounding areas are evacuated due to the Chernobyl disaster.
1987 – The U.S. Department of Justice bars Austrian President Kurt Waldheim (and his wife, Elisabeth, who had also been a Nazi) from entering the US, charging that he had aided in the deportations and executions of thousands of Jews and others as a German Army officer during World War II.
1989 – The April 27 demonstrations, student-led protests responding to the April 26 Editorial, during the Tiananmen Square protests of 1989.
1992 – The Federal Republic of Yugoslavia, comprising Serbia and Montenegro, is proclaimed.
1992 – Betty Boothroyd becomes the first woman to be elected Speaker of the British House of Commons in its 700-year history.
1992 – The Russian Federation and 12 other former Soviet republics become members of the International Monetary Fund and the World Bank.
1993 – Most of the Zambia national football team lose their lives in a plane crash off Libreville, Gabon en route to Dakar, Senegal to play a 1994 FIFA World Cup qualifying match against Senegal.
1994 – South African general election: The first democratic general election in South Africa, in which black citizens could vote. The Interim Constitution comes into force.
2005 – Airbus A380 aircraft has its maiden test flight.
2006 – Construction begins on the Freedom Tower (later renamed One World Trade Center) in New York City.
2007 – Estonian authorities remove the Bronze Soldier, a Soviet Red Army war memorial in Tallinn, amid political controversy with Russia.
2007 – Israeli archaeologists discover the tomb of Herod the Great south of Jerusalem.
2011 – The 2011 Super Outbreak devastates parts of the Southeastern United States, especially the states of Alabama, Mississippi, Georgia, and Tennessee. Two hundred five tornadoes touched down on April 27 alone, killing more than 300 and injuring hundreds more.
2012 – At least four explosions hit the Ukrainian city of Dnipropetrovsk with at least 27 people injured.
2018 – The Panmunjom Declaration is signed between North and South Korea, officially declaring their intentions to end the Korean conflict.
2024 – The worst day of the tornado outbreak sequence of April 25–28, 2024, with 42 tornadoes, including one confirmed EF4 tornado, and two confirmed EF3 tornadoes, which killed 4 people in total.
|
April 27
|
Births
|
Births
|
April 27
|
Pre-1600
|
Pre-1600
85 BC – Decimus Junius Brutus Albinus, Roman politician and general (d. 43 BC)
1468 – Frederick Jagiellon, Primate of Poland (d. 1503)
1564 – Henry Percy, 9th Earl of Northumberland (d. 1632)
1556 – François Béroalde de Verville, French writer (d. 1626)
1593 – Mumtaz Mahal, Mughal empress buried at the Taj Mahal (d. 1631)
|
April 27
|
1601–1900
|
1601–1900
1650 – Charlotte Amalie of Hesse-Kassel, Queen Consort of Denmark (1670–1699) (d. 1714)
1654 – Charles Blount, English deist and philosopher (d. 1693)
1701 – Charles Emmanuel III of Sardinia (d. 1773)
1718 – Thomas Lewis, Irish-born American surveyor and lawyer (d. 1790)
1748 – Adamantios Korais, Greek-French philosopher and scholar (d. 1833)
1755 – Marc-Antoine Parseval, French mathematician and theorist (d. 1836)
1759 – Mary Wollstonecraft, English philosopher, historian, and novelist (d. 1797)
1788 – Charles Robert Cockerell, English architect, archaeologist, and writer (d. 1863)
1791 – Samuel Morse, American painter and inventor, co-invented the Morse code (d. 1872)
1812 – William W. Snow, American lawyer and politician (d. 1886)
1812 – Friedrich von Flotow, German composer (d. 1883)
1820 – Herbert Spencer, English biologist, anthropologist, sociologist, and philosopher (d. 1903)
1822 – Ulysses S. Grant, American general and politician, 18th President of the United States (d. 1885)
1840 – Edward Whymper, English-French mountaineer, explorer, author, and illustrator (d. 1911)
1848 – Otto, King of Bavaria (d. 1916)
1850 – Hans Hartwig von Beseler, German general and politician (d. 1921)
1853 – Jules Lemaître, French playwright and critic (d. 1914)
1857 – Theodor Kittelsen, Norwegian painter and illustrator (d. 1914)
1861 – William Arms Fisher, American composer and music historian (d. 1948)
1866 – Maurice Raoul-Duval, French polo player (d. 1916)
1875 – Frederick Fane, Irish-born, English cricketer (d. 1960)
1880 – Mihkel Lüdig, Estonian organist, composer, and conductor (d. 1958)
1882 – Jessie Redmon Fauset, American author and poet (d. 1961)
1887 – Warren Wood, American golfer (d. 1926)
1888 – Florence La Badie, Canadian actress (d. 1917)
1891 – Sergei Prokofiev, Russian pianist, composer, and conductor (d. 1953)
1893 – Draža Mihailović, Serbian general (d. 1946)
1893 – Allen Sothoron, American baseball player, coach, and manager (d. 1939)
1894 – George Petty, American painter and illustrator (d. 1975)
1894 – Nicolas Slonimsky, Russian pianist, composer, and conductor (d. 1995)
1896 – Rogers Hornsby, American baseball player, coach, and manager (d. 1963)
1896 – William Hudson, New Zealand-Australian engineer (d. 1978)
1896 – Wallace Carothers, American chemist and inventor of nylon (d. 1937)
1898 – Ludwig Bemelmans, Italian-American author and illustrator (d. 1962)
1899 – Walter Lantz, American animator, producer, screenwriter, and actor (d. 1994)
1900 – August Koern, Estonian politician and diplomat, Estonian Minister of Foreign Affairs in exile (d. 1989)
|
April 27
|
1901–present
|
1901–present
1902 – Tiemoko Garan Kouyaté, Malian educator and activist (d. 1942)
1904 – Cecil Day-Lewis, Anglo-Irish poet and author (d. 1972)
1904 – Nikos Zachariadis, Greek politician (d. 1973)
1905 – John Kuck, American javelin thrower and shot putter (d. 1986)
1906 – Yiorgos Theotokas, Greek author and playwright (d. 1966)
1909 – Lim Bo Seng, Chinese businessman, resistance fighter of Force 136 and war hero of Singapore (d. 1944)
1910 – Chiang Ching-kuo, Chinese politician, 3rd President of the Republic of China (d. 1988)
1911 – Bruno Beger, German anthropologist and ethnologist (d. 2009)
1911 – Chris Berger, Dutch sprinter and footballer (d. 1965)
1912 – Jacques de Bourbon-Busset, French author and politician (d. 2001)
1912 – Zohra Sehgal, Indian actress, dancer, and choreographer (d. 2014)
1913 – Philip Abelson, American physicist and author (d. 2004)
1913 – Irving Adler, American mathematician, author, and academic (d. 2012)
1913 – Luz Long, German long jumper and soldier (d. 1943)
1916 – Robert Hugh McWilliams, Jr., American sergeant, lawyer, and judge (d. 2013)
1916 – Enos Slaughter, American baseball player and manager (d. 2002)
1917 – Roman Matsov, Estonian violinist, pianist, and conductor (d. 2001)
1918 – Sten Rudholm, Swedish lawyer and jurist (d. 2008)
1920 – Guido Cantelli, Italian conductor (d. 1956)
1920 – Mark Krasnosel'skii, Ukrainian mathematician and academic (d. 1997)
1920 – James Robert Mann, American colonel, lawyer, and politician (d. 2010)
1920 – Edwin Morgan, Scottish poet and translator (d. 2010)
1921 – Robert Dhéry, French actor, director, and screenwriter (d. 2004)
1922 – Jack Klugman, American actor (d. 2012)
1922 – Sheila Scott, English nurse and pilot (d. 1988)
1923 – Betty Mae Tiger Jumper, Seminole chief (d. 2011)
1924 – Vernon B. Romney, American lawyer and politician, 14th Attorney General of Utah (d. 2013)
1925 – Derek Chinnery, English broadcaster (d. 2015)
1926 – Tim LaHaye, American minister, activist, and author (d. 2016)
1926 – Basil A. Paterson, American lawyer and politician, 59th Secretary of State of New York (d. 2014)
1926 – Alan Reynolds, English painter and educator (d. 2014)
1927 – Coretta Scott King, African-American activist and author (d. 2006)
1927 – Joe Moakley, American soldier, lawyer, and politician (d. 2001)
1929 – Nina Ponomaryova, Russian discus thrower and coach (d. 2016)
1931 – Igor Oistrakh, Ukrainian violinist and educator (d. 2021)
1932 – Anouk Aimée, French actress (d. 2024)
1932 – Pik Botha, South African lawyer, politician, and diplomat, 8th South African Ambassador to the United States (d. 2018)
1932 – Casey Kasem, American disc jockey, radio celebrity, and voice actor; co-created American Top 40 (d. 2014)
1932 – Chuck Knox, American football coach (d. 2018)
1932 – Derek Minter, English motorcycle racer (d. 2015)
1932 – Gian-Carlo Rota, Italian-American mathematician and philosopher (d. 1999)
1933 – Peter Imbert, Baron Imbert, English police officer and politician, Lord Lieutenant for Greater London (d. 2017)
1935 – Theodoros Angelopoulos, Greek director, producer, and screenwriter (d. 2012)
1935 – Ron Morris, American pole vaulter and coach (d. 2024)
1936 – Geoffrey Shovelton, English singer and illustrator (d. 2016)
1937 – Sandy Dennis, American actress (d. 1992)
1937 – Robin Eames, Irish Anglican archbishop
1937 – Richard Perham, English biologist and academic (d. 2015)
1938 – Earl Anthony, American bowler and sportscaster (d. 2001)
1938 – Alain Caron, Canadian ice hockey player (d. 1986)
1939 – Judy Carne, English actress and comedian (d. 2015)
1939 – Stanisław Dziwisz, Polish cardinal
1941 – Fethullah Gülen, Turkish preacher and theologian (d. 2024)
1941 – Dilip Kumar Chakrabarti, Indian archaeologist
1941 – Lee Roy Jordan, American football player
1942 – Ruth Glick, American author
1942 – Jim Keltner, American drummer
1943 – Helmut Marko, Austrian race car driver and manager
1944 – Michael Fish, English meteorologist and journalist
1944 – Cuba Gooding Sr., American singer (d. 2017)
1944 – Herb Pedersen, American singer-songwriter and guitarist
1945 – Martin Chivers, English footballer and manager
1945 – Terry Willesee, Australian journalist and television host
1945 – August Wilson, American author and playwright (d. 2005)
1946 – Franz Roth, German footballer
1947 – G. K. Butterfield, African-American soldier, lawyer, and politician
1947 – Nick Greiner, Hungarian-Australian politician, 37th Premier of New South Wales
1947 – Pete Ham, Welsh singer-songwriter and guitarist (d. 1975)
1947 – Keith Magnuson, Canadian ice hockey player and coach (d. 2003)
1947 – Ann Peebles, American soul singer-songwriter
1948 – Frank Abagnale Jr., American security consultant and criminal
1948 – Josef Hickersberger, Austrian footballer, coach, and manager
1948 – Kate Pierson, American singer-songwriter and bass player
1950 – Jaime Fresnedi, Filipino politician
1950 – David W. Duclon, American television writer and producer (d. 2025)David W. Duclon Dies: ‘Punky Brewster’ Creator Was 74David W. Duclon, ‘Punky Brewster’ Creator, Dies at 74
1951 – Ace Frehley, American guitarist and songwriter
1952 – Larry Elder, American lawyer and talk show host
1952 – George Gervin, American basketball player
1952 – Ari Vatanen, Finnish race car driver and politician
1953 – Arielle Dombasle, French-American actress and model
1954 – Frank Bainimarama, Fijian commander and politician, 8th Prime Minister of Fiji
1954 – Herman Edwards, American football player, coach, and sportscaster
1954 – Mark Holden, Australian singer, actor, and lawyer
1955 – Eric Schmidt, American engineer and businessman
1956 – Bryan Harvey, American singer-songwriter and guitarist (d. 2006)
1957 – Dietmar Keck, Austrian politician
1957 – Willie Upshaw, American baseball player and manager
1959 – Sheena Easton, Scottish-American singer-songwriter, actress, and producer
1959 – Marco Pirroni, English singer-songwriter, guitarist, and producer
1960 – Mike Krushelnyski, Canadian ice hockey player and coach
1961 – Andrew Schlafly, American lawyer and activist, founded Conservapedia
1962 – Ángel Comizzo, Argentinian footballer and manager
1962 – Seppo Räty, Finnish javelin thrower and coach
1962 – Im Sang-soo, South Korean director and screenwriter
1962 – Andrew Selous, English soldier and politician
1963 – Russell T Davies, Welsh screenwriter and producer
1965 – Anna Chancellor, English actress
1966 – Peter McIntyre, Australian cricketer
1966 – Yoshihiro Togashi, Japanese illustrator
1967 – Willem-Alexander, King of the Netherlands
1967 – Tommy Smith, Scottish saxophonist, composer, and educator
1967 – Erik Thomson, Scottish-New Zealand actor
1967 – Jason Whitlock, American football player and journalist
1968 – Dana Milbank, American journalist and author
1969 – Cory Booker, African-American lawyer and politician
1969 – Darcey Bussell, English ballerina
1972 – Nigel Barker, English photographer and author
1973 – Sharlee D'Angelo, Swedish bass player and songwriter
1973 – Sébastien Lareau, Canadian tennis player
1974 – Frank Catalanotto, American baseball player
1975 – Chris Carpenter, American baseball player
1975 – Pedro Feliz, Dominican baseball player
1975 – Kazuyoshi Funaki, Japanese ski jumper
1976 – Isobel Campbell, Scottish singer-songwriter and cellist
1976 – Sally Hawkins, English actress
1976 – Walter Pandiani, Uruguayan footballer
1979 – Vladimir Kozlov, Ukrainian actor and wrestler
1980 – Sybille Bammer, Austrian tennis player
1980 – Christian Lara, Ecuadorian footballer
1983 – Ari Graynor, American actress and producer
1984 – Pierre-Marc Bouchard, Canadian ice hockey player
1984 – Daniel Holdsworth, Australian rugby league player
1984 – Patrick Stump, American musician, singer, and songwriter
1985 – Meselech Melkamu, Ethiopian runner
1986 – Jenna Coleman, English actress
1986 – Dinara Safina, Russian tennis player
1987 – Taylor Chorney, American ice hockey player
1987 – William Moseley, English actor
1987 – Wang Feifei, Chinese singer and actress
1988 – Lizzo, American singer and rapper
1988 – Semyon Varlamov, Russian ice hockey player
1989 – Lars Bender, German footballer
1989 – Sven Bender, German footballer
1990 – Austin Dillon, American race car driver
1991 – Lara Gut, Swiss skier
1992 – Keenan Allen, American football player
1994 – Corey Seager, American baseball player
1995 – Nick Kyrgios, Australian tennis player
1997 – Jesse Ramien, Australian rugby league player
1998 – Cristian Romero, Argentine footballer
1999 – Peter Hola, Australian rugby league player
2002 – Anthony Elanga, Swedish footballer
2003 – Xavier Worthy, American football player
2004 – Arch Manning, American football player
2005 – Mathys Tel, French footballer
|
April 27
|
Deaths
|
Deaths
|
April 27
|
Pre-1600
|
Pre-1600
630 – Ardashir III of Persia (b. 621)
1160 – Rudolf I, Count of Bregenz (b. 1081)
1272 – Zita, Italian saint (b. 1212)
1321 – Nicolò Albertini, Italian cardinal statesman (b. c. 1250)
1353 – Simeon of Moscow, Grand Prince of Moscow and Vladimir
1403 – Maria of Bosnia, Countess of Helfenstein (b. 1335)
1404 – Philip II, Duke of Burgundy (b. 1342)
1463 – Isidore of Kiev (b. 1385)
1521 – Ferdinand Magellan, Portuguese sailor and explorer (b. 1480)
1599 – Maeda Toshiie, Japanese general (b. 1538)
|
April 27
|
1601–1900
|
1601–1900
1605 – Pope Leo XI (b. 1535)
1607 – Edward Cromwell, 3rd Baron Cromwell, Governor of Lecale (b. 1560)
1613 – Robert Abercromby, Scottish priest and missionary (b. 1532)
1656 – Jan van Goyen, Dutch painter and illustrator (b. 1596)
1694 – John George IV, Elector of Saxony (b. 1668)
1695 – John Trenchard, English politician, Secretary of State for the Northern Department (b. 1640)
1702 – Jean Bart, French admiral (b. 1651)
1782 – William Talbot, 1st Earl Talbot, English politician, Lord Steward of the Household (b. 1710)
1813 – Zebulon Pike, American general and explorer (b. 1779)
1873 – William Macready, English actor and manager (b. 1793)
1882 – Ralph Waldo Emerson, American poet and philosopher (b. 1803)
1893 – John Ballance, Irish-born New Zealand journalist and politician, 14th Prime Minister of New Zealand (b. 1839)
1896 – Henry Parkes, English-Australian businessman and politician, 7th Premier of New South Wales (b. 1815)
|
April 27
|
1901–present
|
1901–present
1915 – John Labatt, Canadian businessman (b. 1838)
1915 – Alexander Scriabin, Russian pianist and composer (b. 1872)
1932 – Hart Crane, American poet (b. 1899)
1936 – Karl Pearson, English mathematician and academic (b. 1857)
1937 – Antonio Gramsci, Italian sociologist, linguist, and politician (b. 1891)
1938 – Edmund Husserl, Czech mathematician and philosopher (b. 1859)
1949 – Benjamin Faunce, American druggist and businessman (b. 1873)
1952 – Guido Castelnuovo, Italian mathematician and statistician (b. 1865)
1961 – Roy Del Ruth, American director, producer, and screenwriter (b. 1893)
1962 – A. K. Fazlul Huq, Bangladeshi-Pakistani lawyer and politician, Pakistani Minister of the Interior (b. 1873)
1965 – Edward R. Murrow, American journalist (b. 1908)
1967 – William Douglas Cook, New Zealand farmer, founded the Eastwoodhill Arboretum (b. 1884)
1969 – René Barrientos, Bolivian soldier, pilot, and politician, 55th President of Bolivia (b. 1919)
1970 – Arthur Shields, Irish rebel and actor (b. 1896)
1972 – Kwame Nkrumah, Ghanaian politician, 1st President of Ghana (b. 1909)
1973 – Carlos Menditeguy, Argentinian race car driver and polo player (b. 1914)
1977 – Stanley Adams, American actor and screenwriter (b. 1915)
1988 – Fred Bear, American hunter and author (b. 1902)
1989 – Konosuke Matsushita, Japanese businessman, founded Panasonic (b. 1894)
1992 – Olivier Messiaen, French organist and composer (b. 1908)
1992 – Gerard K. O'Neill, American physicist and astronomer (b. 1927)
1995 – Katherine DeMille, Canadian-American actress (b. 1911)
1995 – Willem Frederik Hermans, Dutch author, poet, and playwright (b. 1921)
1996 – William Colby, American diplomat, 10th Director of Central Intelligence (b. 1920)
1996 – Gilles Grangier, French director and screenwriter (b. 1911)
1998 – John W. H. Bassett, Canadian journalist and politician (b. 1915)
1998 – Carlos Castaneda, Peruvian-American anthropologist and author (b. 1925)
1998 – Anne Desclos, French journalist and author (b. 1907)
1998 – Browning Ross, American runner and soldier (b. 1924)
1999 – Al Hirt, American trumpet player and bandleader (b. 1922)
1999 – Dale C. Thomson, Canadian historian, author, and academic (b. 1923)
1999 – Cyril Washbrook, English cricketer (b. 1914)
2002 – George Alec Effinger, American author (b. 1947)
2002 – Ruth Handler, American inventor and businesswoman, created the Barbie doll (b. 1916)
2005 – Red Horner, Canadian ice hockey player (b. 1909)
2006 – Julia Thorne, American author (b. 1944)
2007 – Mstislav Rostropovich, Russian cellist and conductor (b. 1927)
2009 – Frankie Manning, American dancer and choreographer (b. 1914)
2009 – Woo Seung-yeon, South Korean model and actress (b. 1983)
2009 – Feroz Khan (actor), Indian Actor, Film Director & Producer (b. 1939)
2011 – Marian Mercer, American actress and singer (b. 1935)
2012 – Daniel E. Boatwright, American soldier and politician (b. 1930)
2012 – Bill Skowron, American baseball player (b. 1930)
2013 – Aída Bortnik, Argentinian screenwriter (b. 1938)
2013 – Lorraine Copeland, Scottish archaeologist (b. 1921)
2013 – Antonio Díaz Jurado, Spanish footballer (b. 1969)
2013 – Jérôme Louis Heldring, Dutch journalist and author (b. 1917)
2013 – Aloysius Jin Luxian, Chinese bishop (b. 1916)
2013 – Mutula Kilonzo, Kenyan lawyer and politician, Kenyan Minister of Justice (b. 1948)
2014 – Yigal Arnon, Israeli lawyer (b. 1929)
2014 – Vujadin Boškov, Serbian footballer, coach, and manager (b. 1931)
2014 – Daniel Colchico, American football player and coach (b. 1935)
2014 – Harry Firth, Australian race car driver and manager (b. 1918)
2015 – Gene Fullmer, American boxer (b. 1931)
2015 – Verne Gagne, American football player, wrestler, and trainer (b. 1926)
2015 – Alexander Rich, American biologist, biophysicist, and academic (b. 1924)
2017 – Vinod Khanna, Indian actor, producer and politician (b. 1946)
2017 – Sadanoyama Shinmatsu, Japanese sumo wrestler (b. 1938)
2021 – Manoj Das, Indian writer (b. 1934)
2022 – Liao Guoxun, Chinese politician (b. 1963)
2023 – Jerry Springer, American politician and actor (b. 1944)
2024 – C. J. Sansom, British author (b. 1952)
2025 – Jiggly Caliente, Filipino-American drag performer, singer and actress (b. 1980)
|
April 27
|
Holidays and observances
|
Holidays and observances
Christian feast days:
Anthimus of Nicomedia
Assicus
Floribert of Liège
John of Constantinople
Liberalis of Treviso
Pollio
Virgin of Montserrat, co-patroness of Catalonia
Zita
Origen Adamantius
April 27 (Eastern Orthodox liturgics)
Day of Russian Parliamentarism (Russia)
Day of the Uprising Against the Occupying Forces (Slovenia)
Flag Day (Moldova)
Freedom Day (South Africa)
Independence Day, celebrates the independence of Sierra Leone from United Kingdom in 1961.
Independence Day, celebrates the independence of Togo from France in 1960.
King's Day (Netherlands, Aruba, Curaçao, Sint Maarten) (celebrated on April 26 if April 27 falls on a Sunday)
National Veterans' Day (Finland)
|
April 27
|
References
|
References
|
April 27
|
External links
|
External links
BBC: On This Day
Historical Events on April 27
Category:Days of April
|
April 27
|
Table of Content
|
pp-move, Events, Pre-1600, 1601–1900, 1901–present, Births, Pre-1600, 1601–1900, 1901–present, Deaths, Pre-1600, 1601–1900, 1901–present, Holidays and observances, References, External links
|
Ayahuasca
|
Short description
|
AyahuascaPronounced as in the UK and in the US. Also occasionally known in English as ayaguasca (Spanish-derived), aioasca (Brazilian Portuguese-derived), or as yagé, pronounced or . Etymologically, all forms but yagé descend from the compound Quechua word ayawaska, from aya () and waska (). For more names for ayahuasca, see § Etymology. is a South American psychoactive decoction prepared from Banisteriopsis caapi vine and a dimethyltryptamine (DMT)-containing plant, used by Indigenous cultures in the Amazon and Orinoco basins as part of traditional medicine and shamanism. The word ayahuasca, originating from Quechuan languages spoken in the Andes, refers both to the Banisteriopsis caapi vine and the psychoactive brew made from it, with its name meaning “spirit rope” or “liana of the soul.”
The specific ritual use of ayahuasca was widespread among Indigenous groups by the 19th century, though its precise origin is uncertain. Ayahuasca is traditionally prepared by macerating and boiling Banisteriopsis caapi with other plants like Psychotria viridis, through a ritualistic, multi-day process. Ayahuasca has been used in diverse South American cultures for spiritual, social, and medicinal purposes, often guided by shamans in ceremonial contexts involving specific dietary and ritual practices, with the Shipibo-Konibo people playing a significant historical and cultural role in its use. It spread widely by the mid-20th century through syncretic religions in Brazil. In the late 20th century, ayahuasca use expanded beyond South America to Europe, North America, and elsewhere, leading to legal cases, non-religious adaptations, and the development of ayahuasca analogs using local or synthetic ingredients.
While DMT is internationally classified as a controlled substance, the plants containing it—including those used to make ayahuasca—are not regulated under international law, leading to varied national policies that range from permitting religious use to imposing bans or decriminalization. The United States patent office controversially granted, challenged, revoked, reinstated, and ultimately allowed to expire a patent on the ayahuasca vine, sparking disputes over intellectual property rights and the cultural and religious significance of traditional Indigenous knowledge.
Ayahuasca produces intense psychological and spiritual experiences with potential therapeutic effects. A systematic review found that ayahuasca and its alkaloids show promising anxiolytic and antidepressant effects in both animal and human studies, suggesting the potential for new treatments with fewer side effects. A 2024 systematic review found that traditional ayahuasca use is generally safe, though higher doses of ayahuasca or higher doses of isolated harmala alkaloids like harmaline may pose risks.
|
Ayahuasca
|
Etymology
|
Etymology
Ayahuasca is the hispanicized spelling (i.e., spelled according to Spanish orthography) of a word that originates from the Quechuan languages, which are spoken in the Andean states of Ecuador, Bolivia, Peru, and Colombia. Speakers of Quechuan languages who use modern Quechuan orthography spell it ayawaska. The word refers both to the liana Banisteriopsis caapi, and to the brew prepared from it. In the Quechua languages, aya means "spirit, soul", or "corpse, dead body", and waska means "rope" or "woody vine", "liana".Teofilo Laime Ajacopa, Diccionario Bilingüe Iskay simipi yuyayk'ancha, La Paz, 2007 (Quechua-Spanish dictionary) The word ayahuasca has been variously translated as "liana of the soul", "liana of the dead", and "spirit liana". In the cosmovision of its users, the ayahuasca is the vine that allows the spirit to wander detached from the body, entering the spiritual world, otherwise forbidden for the alive.
|
Ayahuasca
|
Common names
|
Common names
Although ayahuasca is the most widely used term in Peru, Bolivia, Ecuador and Brazil, the brew is known by many names throughout northern South America:
hoasca or oasca in Brazil
(or , from the Cofán language or iagê in Portuguese). Relatively widespread use in Andean and Amazonian regions throughout the border areas of Colombia, Peru, Ecuador and Brazil. The Cofán people also use the word .
(or / in Tupi–Guarani language or in proto-Arawak language), used to address both the brew and the B. caapi itself. Meaning "weed" or "thin leaf", it was the word utilized by Spruce for naming the liana.
(or /), used by the Colorado people
(or ), from the Chicham languages
, (or ) and , from the Yaminawa language
, from the Shipibo language
, , , and , from the Kashinawa language
, and , used by the Tucano people
(or ) and , from the Arawakan languagesDE MORI, Brabec (2011): Tracing Hallucinations – Contributing to a Critical Ethnohistory of Ayahuasca Usage in the Peruvian Amazon
, from Bora-Muinane languagesSeifart, Frank, & Echeverri, Juan Alvaro (2015). Proto Bora-Muinane. LIAMES: Línguas Indígenas Americanas, 15(2), 279 - 311.
, used by Ese'Ejja people
, from Guahibo language
(or /), used by Tsáchila people
, from Kamëntšá languageHuber, Randall Q. and Robert B. Reed. 1992. Vocabulario comparativo: Palabras selectas de lenguas indígenas de Colombia (Comparative vocabulary: Selected words in indigenous languages of Colombia). Bogota, Colombia: Summer Institute of Linguistics.
("") or , in Portuguese language, used by União do Vegetal church members
Daime or Santo Daime, meaning "give me" in Portuguese, the term was coined by Santo Daime's founder Mestre Irineu in the 1940s, from a prayer dai-me alegria, dai-me resistência ("give me happiness, give me strength"). Daime members also uses the words Luz ("light") or Santa Luz ("holy light")
Some nomenclature are created by the cultural and symbolic signification of ayahuasca, with names like planta professora ("plant teacher"), professor dos professores ("teacher of the teachers"), sagrada medicina ("holy medicine") or la purga ("the purge").
|
Ayahuasca
|
Other names in the Western world
|
Other names in the Western world
In the last decades, two new important terminologies emerged. Both are commonly used in the Western world in neoshamanic, recreative or pharmaceutical contexts to address ayahuasca-like substances created without the traditional botanical species, due to it being expensive and/or hard to find in these countries. These concepts are surrounded by some controversies involving ethnobotany, patents, commodification and biopiracy:
Anahuasca (ayahuasca analogues). A term usually used to refer to the ayahuasca produced with other plant species as sources of DMT (e.g., Mimosa hostilis) or β-carbolines (e.g., Peganum harmala).
Pharmahuasca (pharmaceutical ayahuasca). This indicates the pills produced from freebase DMT, synthetic harmaline, MAOI medications (such as moclobemide) and other isolated or purified compounds or extracts.
|
Ayahuasca
|
History
|
History
|
Ayahuasca
|
Origins
|
Origins
Archaeological evidence of the use of psychoactive plants in northeastern Amazon dates back to 1500–2000 BCE. Anthropomorphic figurines, snuffing trays and pottery vessels, often adorned with mythological figures and sacred animals, offer a glimpse of the pre-Columbian culture regarding use of the sacred plants, their preparation and ritual consumption [citar naranjo 86]. Although several botanical specimens (like tobacco, coca and Anadenanthera spp.) were identified among these objects, there is no unequivocal evidence of this date referring directly to ayahuasca. Banisteriopsis caapi use is suggested from a pouch containing carved snuffing trays, bone spatulas and other paraphernalia with traces of harmine and DMT, discovered in a cave in southwestern Bolivia in 2008, and chemical traces of harmine in the hair of two mummies found in northern Chile. Both cases are linked to Tiwanaku people, circa 900 CE. There are several reports of oral and nasal use of Anadenanthera spp. (rich in bufotenin) ritualistically and therapeutically during labor and infancy, and researchers suggest that addition of Banisteriopsis spp. to catalyze its psychoactivity emerged later, due to contact between different groups of Amazon and Altiplano.
Despite claims by numerous anthropologists and ethnologists, such as Plutarco Naranjo, regarding the millennial usage of ayahuasca, compelling evidence substantiating its pre-Columbian consumption is yet to be firmly established. As articulated by Dennis McKenna: "No one can say for certain where the practice may have originated, and about all that can be stated with certainty is that is already spread among numerous indigenous tribes throughout Amazon basin by the time ayahuasca came to the attention of Western ethnographers in the mid-nineteenth century" The first western references of the ayahuasca beverage dates back to seventeenth century, during the European colonization of the Americas. The earlier report is a letter from Vincente de Valverde to the Holy Office of the Inquisition. Jose Chantre y Herrera still in the seventeenth century, provided the first detailed description of a "devilish potion" cooked from bitter herbs and lianas (called ayaguasca) and its rituals: "[...] In other nations, they set aside an entire night for divination. For this purpose, they select the most capable house in the vicinity because many people are expected to attend the event. The diviner hangs his bed in the middle and places an infernal potion, known as ayahuasca, by his side, which is particularly effective at altering one's senses. They prepare a brew from bitter vines or herbs, which, when boiled sufficiently, must become quite potent. Since it's so strong at altering one's judgment in small quantities, the precaution is not excessive, and it fits into two small pots. The witch doctor drinks a very small amount each time and knows well how many times he can sample the brew without losing his senses to properly conduct the ritual and lead the choir". Another report produced in 1737 by the missionary Pablo Maroni, describes the use of a psychoactive liana called ayahuasca for divination in the Napo River, Ecuador: thumb|right|Ayahuasca cooking"For divination, they use a beverage, some of white datura flowers, which they also call Campana due to its shape, and others from a vine commonly known as Ayahuasca, both highly effective at numbing the senses and even at taking one's life if taken in excess. They also occasionally use these substances for the treatment of common illnesses, especially headaches. So, the person who wants to divine drinks the chosen substance with certain rituals, and while deprived of their senses from the mouth downwards, to prevent the strength of the plant from harming them, they remain in this state for many hours and sometimes even two or three days until the effects run their course, and the intoxication subsides. After this, they reflect on what their imagination revealed, which occasionally remains with them for delirium. This is what they consider accomplished and propagate as an oracle." Latter reports were produced by Juan Magnin in 1740, describing ayahuasca use as a medicinal plant by the Jivaroan peoples (called ayahuessa) and by Franz Xaver Veigl in 1768, that reports about several "dangerous plants", including a bitter liana used for precognition and sorcery. All these reports were written in context of Jesuit missions in South America, specially the Mainas missions, in Latin and sent only to Rome, so their audience wasn't very large and they were promptly lost in the archives. For this reason, ayahuasca didn't receive interest for the entire subsequent century.
|
Ayahuasca
|
Early academic research
|
Early academic research
In academic discourse, the initial mention of ayahuasca dates back to Manuel Villavicencio's 1858 book, "Geografía de la República del Ecuador." This work vividly delineates the employment and rituals involving ayahuasca by the Jivaro people. Concurrently, Richard Spruce embarked on an Amazonian expedition in 1852 to collect and classify previously unidentified botanical specimens. During this journey, Spruce encountered and documented Banisteriopsis caapi (at time named Banisteria caapi) and observed an ayahuasca ceremony among the Tucano community situated along the Vaupés River. Subsequently, Spruce uncovered the usage and cultivation of B. caapi among various indigenous groups dispersed across the Amazon and Orinoco basins, like the Guahibo and Sápara. These multifarious encounters, together with Spruce's personal accounts of subjective ayahuasca experiences, were collated in his work, "Notes of a Botanist On The Amazon and Andes.". By the end of the century, other explorers and anthropologists contributed more extensive documentation concerning ayahuasca, notably the Theodor Koch-Grünberg's documents about Tucano and Arecuna's rituals and ceremonies, Stradelli's first-hand reports of ayahuasca rituals and mythology along the Jurupari and Vaupés and Alfred Simson's first description of admixture of several ingredients in the making of ayahuasca in Putumayo region, published in 1886.
In 1905, Rafael Zerda Bayón named the active extract of ayahuasca as telepathine, a name latter used by the Colombian chemist Guillermo Fischer Cárdenas when he isolated the substance in 1932. Contemporaneously, Lewin and Gunn were independently studying the properties of the banisterine, extracted of the B. caapi, and its effects on animal models. Further clinical trials were being conducted, exploring the effects of banisterine on Parkinson's disease. Later it was found that both telepathine and banisterine are the same substance, identical to a chemical already isolated from Peganum harmala and given the name Harmine.
|
Ayahuasca
|
Shamanism, ''mestizos'' and ''vegetalistas''
|
Shamanism, mestizos and vegetalistas
Researchers like Peter Gow and Brabec de Mori argue that ayahuasca use indeed developed alongside the Jesuit missions after the 17th century. By examining the ícaros (ayahuasca-related healing chants), they found that the chants are always sung in Quechua (a lingua franca along the Jesuit and Franciscan missions in the region), no matter the linguistic background of the group, with similar language structures between different ícaros that are markedly different from other indigenous songs. Moreover, often the cosmology of ayahuasca often mirrors the Catholicism, with particular similarities in the belief that ayahuasca is thought to be the body of ayahuascamama that is imbibed as part of the ritual, like wine and bread are taken as being the body and blood of Jesus Christ during Christian Eucharist. Brabec de Mori called this “Christian camouflage” and suggested that rather than being a way for disguising the ayahuasca ritual, it suggests that practice evolved entirely within these contexts.
Indeed, the colonial processes in Western Amazon are intrinsically related with the development of ayahuasca use in the last three centuries, as it promoted a deep reshape in traditional ways of life in the region. Many indigenous groups moved into the Missions, seeking protection from death and slavery promoted by the Bandeiras, inter-tribal violence, starvation and disease (smallpox). This movement resulted in an intense cultural exchange and resulted in the formation of mestizos (in Spanish) or caboclos (in Portuguese), a social category formed by people with mixture of European and native ancestry, who were an important part of the economy and culture of the region. According to Peter Gow, the ayahuasca shamanism (the use of ayahuasca by a trained shaman to diagnose and cure illnesses) was developed by these mestizos in the processes of colonial transformation. The Amazon rubber cycles (1879–1912 and 1945–1945) sped up these transformations, due to slavery, genocide and brutality against indigenous populations and large migratory movements, specially from the Brazilian Northeast Region as a workforce for the rubber plantations. The mestizo practices became deeply intertwined with the culture of rubber workers, called caucheros (in Spanish) or seringueiros (in Portuguese). Ayahuasca use with therapeutic goals is the main result of this Trans-cultural diffusion, with some practitioners pointing the caucheros as the main responsible for using ayahuasca to cure all sort of ailments of the body, mind and soul, with even some regions using the term Yerba de Cauchero ("rubber-worker herb"). As a result, the ayahuasca shamans in urban areas and mestizo settlements, specially in the regions of Iquitos and Pucallpa (in Peru), became the vegetalistas, folk healers who are said to gain all their knowledge from the plants and the spirits bound to it.
So the vegetalist movement was a heterogeneous mixture of Western Amazon (mestizo shamanic practices and cauchero culture) and Andean elements (shaped by other migratory movements, like those originated from Cuzco through Urubamba Valley and from western Ecuador), influenced by Christian aspects derived from the Jesuit missions, as reflected by the mythology, rituals and moral codes related to vegetalista ayahuasca use.
|
Ayahuasca
|
Ayahuasca religions
|
Ayahuasca religions
Although mestizo, vegetalista and indigenous ayahuasca use was part of a longer tradition, these several configurations of mestizo vegetalismo were not isolated phenomena. In the end of the nineteenth century, several messianic/millennialist cults sparkled across semi-urban areas across the entire Amazon region, merging different elements of indigenous and mestizo folk culture with Catholicism, Spiritism and Protestantism. In this context, the use of ayahuasca will take form of urban, organized non-indigenous religions in outskirts of main cities of northwest of Brazil, (along the basins of Madeira, Juruá and Purus River) within the cauchero/seringueiro cultural complex, resignifying and adapting both the vegetalista and mestizo shamanism to new urban formations, unifying essential elements to building a cosmology for the new emerging cult/faith, merging with elements of folk Catholicism, African-Brazilian religions and Kardecist spiritism. These new cults arise from charismatic leaderships, often messianic and prophetic, who came from rural areas after migration movements, sometimes called ayahuasqueiros, in semi-urban communities across the borders of Brazil, Bolívia and Peru (a region that will later form the state of Acre). This new configuration of these belief systems is referred by Goulart as tradição religiosa ayahuasqueira urbana amazônica ("urban-amazonian ayahuasqueiro religious tradition") or campo ayahuasqueiro brasileiro ("brazilian ayahuasqueiro field") by Labate, emerging as three main structured religions, the Santo Daime and Barquinha, in Rio Branco and the União do Vegetal (UDV) in Porto Velho, three denominations that, notwithstanding shared characteristics besides ayahuasca utilization, have several particularities regarding its practices, conceptions and processes building social legitimacy and relationships with Brazilian government, media, science and other society stances. Since the latter half of twentieth century, the ayahuasca religious expanded to other parts of Brazil and several countries in the world, notably in the West.
|
Ayahuasca
|
Modern use
|
Modern use
Beat writer William S. Burroughs read a paper by Richard Evans Schultes on the subject and while traveling through South America in the early 1950s sought out ayahuasca in the hopes that it could relieve or cure opiate addiction (see The Yage Letters). Ayahuasca became more widely known when the McKenna brothers published their experience in the Amazon in True Hallucinations. Dennis McKenna later studied pharmacology, botany, and chemistry of ayahuasca and oo-koo-he, which became the subject of his master's thesis.
Richard Evans Schultes allowed Claudio Naranjo to make a special journey by canoe up the Amazon River to study ayahuasca with the South American Indigenous peoples. He brought back samples of the beverage and published the first scientific description of the effects of its active alkaloids.
In recent years, the brew has been popularized by Wade Davis (One River), English novelist Martin Goodman in I Was Carlos Castaneda, Chilean novelist Isabel Allende, writer Kira Salak, author Jeremy Narby (The Cosmic Serpent), author Jay Griffiths (Wild: An Elemental Journey), American novelist Steven Peck, radio personality Robin Quivers,, writer Paul Theroux (Figures in a Landscape: People and Places), and NFL quarterback Aaron Rodgers.
|
Ayahuasca
|
Preparation
|
Preparation
thumb|Ayahuasca being prepared in the Napo region of Ecuador
Sections of Banisteriopsis caapi vine are macerated and boiled alone or with leaves from any of a number of other plants, including Psychotria viridis (chacruna), Diplopterys cabrerana (also known as chaliponga and chacropanga), and Mimosa tenuiflora, among other ingredients which can vary greatly from one shaman to the next. The resulting brew may contain the powerful psychedelic drug dimethyltryptamine and monoamine oxidase inhibiting harmala alkaloids, which are necessary to make the DMT orally active by allowing it (DMT) to be processed by the liver. The traditional making of ayahuasca follows a ritual process that requires the user to pick the lower Chacruna leaf at sunrise, then say a prayer. The vine must be "cleaned meticulously with wooden spoons" and pounded "with wooden mallets until it's fibre."
Brews can also be made with plants that do not contain DMT, Psychotria viridis being replaced by plants such as Justicia pectoralis, Brugmansia, or sacred tobacco, also known as mapacho (Nicotiana rustica), or sometimes left out with no replacement. This brew varies radically from one batch to the next, both in potency and psychoactive effect, based mainly on the skill of the shaman or brewer, as well as other admixtures sometimes added and the intent of the ceremony. Natural variations in plant alkaloid content and profiles also affect the final concentration of alkaloids in the brew, and the physical act of cooking may also serve to modify the alkaloid profile of harmala alkaloids.
The actual preparation of the brew takes several hours, often taking place over the course of more than one day. After adding the plant material, each separately at this stage, to a large pot of water, it is boiled until the water is reduced by half in volume. The individual brews are then added together and brewed until reduced significantly. This combined brew is what is taken by participants in ayahuasca ceremonies.
|
Ayahuasca
|
Traditional use
|
Traditional use
thumb|right|Ayahuasca cooking in the Loreto region of Peru
thumb|right|Ayahuasca being prepared in Ecuador
The uses of ayahuasca in traditional societies in South America vary greatly. Some cultures do use it for shamanic purposes, but in other cases, it is consumed socially among friends, in order to learn more about the natural environment, and even in order to visit friends and family who are far away.
Nonetheless, people who work with ayahuasca in non-traditional contexts often align themselves with the philosophies and cosmologies associated with ayahuasca shamanism, as practiced among Indigenous peoples like the Urarina of the Peruvian Amazon. Dietary taboos are often associated with the use of ayahuasca, although these seem to be specific to the culture around Iquitos, Peru, a major center of ayahuasca tourism. Ayahuasca retreats or healing centers can also be found in the Sacred Valley of Peru, in areas such as Cusco and Urubamba, where similar dietary preparations can be observed. These retreats often employ members of the Shipibo-Konibo tribe, an indigenous community native to the Peruvian Amazon.
In the rainforest, these taboos tend towards the purification of one's self—abstaining from spicy and heavily seasoned foods, excess fat, salt, caffeine, acidic foods (such as citrus) and sex before, after, or during a ceremony. A diet low in foods containing tyramine has been recommended, as the speculative interaction of tyramine and MAOIs could lead to a hypertensive crisis; however, evidence indicates that harmala alkaloids act only on MAO-A, in a reversible way similar to moclobemide (an antidepressant that does not require dietary restrictions). Dietary restrictions are not used by the highly urban Brazilian ayahuasca church União do Vegetal, suggesting the risk is much lower than perceived and probably non-existent.
The ritual use of ayahuasca by the Achuar people is featured in the Bruce Parry 2008 documentary series Amazon, in which Parry forces himself to participate in the rite.
|
Ayahuasca
|
Ceremony and the role of shamans
|
Ceremony and the role of shamans
Shamans, curanderos and experienced users of ayahuasca advise against consuming ayahuasca when not in the presence of one or several well-trained shamans.
In some areas, there are purported brujos (Spanish for "witches") who masquerade as real shamans and who entice tourists to drink ayahuasca in their presence. Shamans believe one of the purposes for this is to steal one's energy and/or power, of which they believe every person has a limited stockpile.
The shamans lead the ceremonial consumption of the ayahuasca beverage, in a rite that typically takes place over the entire night. During the ceremony, the effect of the drink lasts for hours. Prior to the ceremony, participants are instructed to abstain from spicy foods, red meat and sex. The ceremony is usually accompanied with purging which include vomiting and diarrhea, which is believed to release built-up emotions and negative energy.
|
Ayahuasca
|
Shipibo-Konibo and their relation to Ayahuasca
|
Shipibo-Konibo and their relation to Ayahuasca
It is believed that the Shipibo-Konibo are among the earliest practitioners of Ayahuasca ceremonies, with their connection to the brew and ceremonies surrounding it dating back centuries, perhaps a millennium.
Some members of the Shipibo community have taken to the media to express their views on Ayahuasca entering the mainstream, with some calling it "the commercialization of ayahuasca." Some of them have even expressed their worry regarding the increased popularity, saying "the contemporary 'ayahuasca ceremony' may be understood as a substitute for former cosmogonical rituals that are nowadays not performed anymore."
|
Ayahuasca
|
Icaros
|
Icaros
The Shipibo have their own language, called Shipibo, a Panoan language spoken by approximately 26,000 people in Peru and Brazil. This language is commonly sung by the shaman in the form of a chant, called an Icaro, during the Ayahuasca ritual as a way to establish a "balance of energy" during the ritual to help protect and guide the user during their experience.
|
Ayahuasca
|
Traditional brew
|
Traditional brew
thumb | right | B. caapi inflorescence
Traditional ayahuasca brews are usually made with Banisteriopsis caapi as an MAOI, while dimethyltryptamine sources and other admixtures vary from region to region. There are several varieties of caapi, often known as different "colors", with varying effects, potencies, and uses.
DMT admixtures:
Psychotria viridis (Chacruna)Rätsch, Christian (2005), pp. 704-708. The Encyclopedia of Psychoactive Plants: Ethnopharmacology and Its Applications. Rochester, Vermont: Park Street Press, 1998. – leaves
Psychotria carthagenensis (Amyruca) – leaves
Diplopterys cabrerana (Chaliponga, Chagropanga, Banisteriopsis rusbyana) – leaves
Mimosa tenuiflora (M. hostilis) - root bark
Other common admixtures:
Justicia pectoralis
Brugmansia sp. (Toé)
Opuntia sp.
Epiphyllum sp.
Cyperus sp.
Nicotiana rustica (Mapacho, variety of tobacco)
Ilex guayusa, a relative of yerba mate
Lygodium venustum, (Tchai del monte)
Phrygilanthus eugenioides and Clusia sp (both called Miya)
Lomariopsis japurensis (Shoka)
Common admixtures with their associated ceremonial values and spirits:
Ayahuma bark: Cannon Ball tree. Provides protection and is used in healing susto (soul loss from spiritual fright or trauma).
Capirona bark: Provides cleansing, balance and protection. It is noted for its smooth bark, white flowers, and hard wood.
Chullachaki caspi bark (Byrsonima christianeae): Provides cleansing to the physical body. Used to transcend physical body ailments.
Lopuna blanca bark: Provides protection.
Punga amarilla bark: Yellow Punga. Provides protection. Used to pull or draw out negative spirits or energies.
Remo caspi bark: Oar Tree. Used to move dense or dark energies.
Wyra (huaira) caspi bark (Cedrelinga catanaeformis): Air Tree. Used to create purging, transcend gastro/intestinal ailments, calm the mind, and bring tranquility.
Shiwawaku bark: Brings purple medicine to the ceremony.
Uchu sanango: Head of the sanango plants.
Huacapurana: Giant tree of the Amazon with very hard bark.
Bobinsana (Calliandra angustifolia): Mermaid Spirit. Provides major heart chakra opening, healing of emotions and relationships.
|
Ayahuasca
|
Non-traditional use
|
Non-traditional use
In the late 20th century, the practice of ayahuasca drinking began spreading to Europe, North America and elsewhere. The first ayahuasca churches, affiliated with the Brazilian Santo Daime, were established in the Netherlands. A legal case was filed against two of the Church's leaders, Hans Bogers (one of the original founders of the Dutch Santo Daime community) and Geraldine Fijneman (the head of the Amsterdam Santo Daime community). Bogers and Fijneman were charged with distributing a controlled substance (DMT); however, the prosecution was unable to prove that the use of ayahuasca by members of the Santo Daime constituted a sufficient threat to public health and order such that it warranted denying their rights to religious freedom under ECHR Article 9. The 2001 verdict of the Amsterdam district court is an important precedent. Since then groups that are not affiliated to the Santo Daime have used ayahuasca, and a number of different "styles" have been developed, including non-religious approaches.
|
Ayahuasca
|
Ayahuasca analogs
|
Ayahuasca analogs
thumb|right|Syrian rue seeds can be used to provide an MAOI.
In modern Europe and North America, ayahuasca analogs are often prepared using non-traditional plants which contain the same alkaloids. For example, seeds of the Syrian rue plant can be used as a substitute for the ayahuasca vine, and the DMT-rich Mimosa hostilis is used in place of chacruna. Australia has several indigenous plants which are popular among modern ayahuasqueros there, such as various DMT-rich species of Acacia.
The name "ayahuasca" specifically refers to a botanical decoction that contains Banisteriopsis caapi.
Brews similar to ayahuasca may be prepared using several plants not traditionally used in South America:
DMT admixtures:
Acacia maidenii (Maiden's wattle) – bark *not all plants are "active strains", meaning some plants will have very little DMT and others larger amounts
Acacia phlebophylla, and other Acacias, most commonly employed in Australia – bark
Anadenanthera peregrina, A. colubrina, A. excelsa, A. macrocarpa
Desmanthus illinoensis (Illinois bundleflower) – root bark is mixed with a native source of beta-Carbolines (e.g., passion flower in North America) to produce a hallucinogenic drink called prairiehuasca.
MAOI admixtures:
Harmal (Peganum harmala, Syrian rue) – seeds
Passion flower
synthetic MAOIs, especially RIMAs (due to the dangers presented by irreversible MAOIs)
|
Ayahuasca
|
Effects
|
Effects
|
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.