P-value

In null hypothesis significance testing, the "p"-value is the probability of obtaining test results at least as extreme as the results actually observed, under the assumption that the null hypothesis is correct. A very small "p"-value means that such an extreme observed outcome would be very unlikely under the null hypothesis. Reporting "p"-values of statistical tests is common practice in academic publications of many quantitative fields. Since the precise meaning of "p"-value is hard to grasp, misuse is widespread and has been a major topic in metascience.
Basic concepts.
In statistics, every conjecture concerning the unknown probability distribution of a collection of random variables representing the observed data formula_1 in some study is called a "statistical hypothesis". If we state one hypothesis only and the aim of the statistical test is to see whether this hypothesis is tenable, but not, at the same time, to investigate other hypotheses, then such a test is called a "significance test". Note that the hypothesis might specify the probability distribution of formula_1 precisely, or it might only specify that it belongs to some class of distributions. Often, we reduce the data to a single numerical statistic formula_3 whose marginal probability distribution is closely connected to a main question of interest in the study.
The "p"-value is used in the context of null hypothesis testing in order to quantify the idea of statistical significance of evidence, the evidence being the observed value of the chosen statistic formula_3. Null hypothesis testing is a reductio ad absurdum argument adapted to statistics. In essence, a claim is assumed valid if its counterclaim is highly implausible.
Thus, the only hypothesis that needs to be specified in this test and which embodies the counterclaim is referred to as the null hypothesis; that is, the hypothesis to be nullified. A result is said to be "statistically significant" if it allows us to reject the null hypothesis. The result, being statistically significant, was highly improbable if the null hypothesis is assumed to be true. A rejection of the null hypothesis implies that the correct hypothesis lies in the logical complement of the null hypothesis. But no specific alternatives need to have been specified. The rejection of the null hypothesis does not tell us which of any possible alternatives might be better supported. However, the user of the test chose the test statistic formula_3 in the first place probably with particular alternatives in mind; such a test is often used precisely in order to convince people that those alternatives are viable because what was actually observed was extremely unlikely under the null hypothesis.
As a particular example, if a null hypothesis states that a certain summary statistic formula_3 follows the standard normal distribution N(0,1), then the rejection of this null hypothesis could mean that (i) the mean is not 0, or (ii) the variance is not 1, or (iii) the distribution is not normal. Different tests of the same null hypothesis would be more or less sensitive to different alternatives. Anyway, if we do manage to reject the null hypothesis, even if we know the distribution is normal and variance is 1, the null hypothesis test does not tell us which non-zero values of the mean are now most plausible. If one has a huge amount of independent observations from the same probability distribution, one will eventually be able to show that their mean value is not precisely equal to zero; but the deviation from zero could be so small as to have no practical or scientific interest. All other things being equal, smaller the p-values are taken as stronger evidence against the null hypothesis.
Definition and interpretation.
General.
Consider an observed test-statistic formula_7 from unknown distribution formula_3. Then the "p"-value formula_9 is what the prior probability would be of observing a test-statistic value at least as "extreme" as formula_7 if null hypothesis formula_11 were true. That is:
If the "p"-value is very small, then either the null hypothesis is false or something unlikely has occurred. In a formal "significance test", the null hypothesis formula_11 is rejected if the "p"-value is less than a pre-defined threshold value formula_18, which is referred to as the alpha level or significance level. The value of formula_18 is instead set by the researcher before examining the data. By convention, formula_18 is commonly set to 0.05, though lower alpha levels are sometimes used.
The "p"-value is a function of the chosen test statistic formula_3 and is therefore a random variable. If the null hypothesis fixes the probability distribution of formula_3 precisely, and if that distribution is continuous, then when the null-hypothesis is true, the p-value is uniformly distributed between 0 and 1. Thus, the "p"-value is not fixed. If the same test is repeated independently with fresh data (always with the same probability distribution), one will obtain a different "p"-value in each iteration. If the null-hypothesis is composite, or the distribution of the statistic is discrete, the probability of obtaining a "p"-value less than or equal to any number between 0 and 1 is less than or equal to that number, if the null-hypothesis is true. It remains the case that very small values are relatively unlikely if the null-hypothesis is true, and that a significance test at level formula_18 is obtained by rejecting the null-hypothesis if the significance level is less than or equal to formula_18.
Different "p"-values based on independent sets of data can be combined, for instance using Fisher's combined probability test.
Distribution.
When the null hypothesis is true, if it takes the form formula_25, and the underlying random variable is continuous, then the probability distribution of the "p"-value is uniform on the interval [0,1]. By contrast, if the alternative hypothesis is true, the distribution is dependent on sample size and the true value of the parameter being studied.
The distribution of "p"-values for a group of studies is sometimes called a "p"-curve. The curve is affected by four factors: the proportion of studies that examined false null hypotheses, the power of the studies that investigated false null hypotheses, the alpha levels, and publication bias. A "p"-curve can be used to assess the reliability of scientific literature, such as by detecting publication bias or "p"-hacking.
For composite hypothesis.
In parametric hypothesis testing problems, a "simple or point hypothesis" refers to a hypothesis where the parameter's value is assumed to be a single number. In contrast, in a "composite hypothesis" the parameter's value is given by a set of numbers. For example, when testing the null hypothesis that a distribution is normal with a mean less than or equal to zero against the alternative that the mean is greater than zero (variance known), the null hypothesis does not specify the probability distribution of the appropriate test statistic. In the just mentioned example that would be the "Z"-statistic belonging to the one-sided one-sample "Z"-test. For each possible value of the theoretical mean, the "Z"-test statistic has a different probability distribution. In these circumstances (the case of a so-called composite null hypothesis) the "p"-value is defined by taking the least favourable null-hypothesis case, which is typically on the border between null and alternative.
This definition ensures the complementarity of p-values and alpha-levels. If we set the significance level alpha to 0.05, and only reject the null hypothesis if the p-value is less than or equal to 0.05, then our hypothesis test will indeed have significance level (maximal type 1 error rate) 0.05. As Neyman wrote: “The error that a practising statistician would consider the more important to avoid (which is a subjective judgment) is called the error of the first kind. The first demand of the mathematical theory is to deduce such test criteria as would ensure that the probability of committing an error of the first kind would equal (or approximately equal, or not exceed) a preassigned number α, such as α = 0.05 or 0.01, etc. This number is called the level of significance”; Neyman 1976, p. 161 in "The Emergence of Mathematical Statistics: A Historical Sketch with Particular Reference to the United States","On the History of Statistics and Probability", ed. D.B. Owen, New York: Marcel Dekker, pp. 149-193. See also "Confusion Over Measures of Evidence (p's) Versus Errors (a's)in Classical Statistical Testing", Raymond Hubbard and M. J. Bayarri, The American Statistician, August 2003, Vol. 57, No 3, 171--182 (with discussion). For a concise modern statement see Chapter 10 of "All of Statistics: A Concise Course in Statistical Inference", Springer; 1st Corrected ed. 20 edition (September 17, 2004). Larry Wasserman.
Usage.
The "p"-value is widely used in statistical hypothesis testing, specifically in null hypothesis significance testing. In this method, as part of experimental design, before performing the experiment, one first chooses a model (the null hypothesis) and a threshold value for "p", called the significance level of the test, traditionally 5% or 1% and denoted as "α". If the "p"-value is less than the chosen significance level ("α"), that suggests that the observed data is sufficiently inconsistent with the null hypothesis and that the null hypothesis may be rejected. However, that does not prove that the tested hypothesis is false. When the "p"-value is calculated correctly, this test guarantees that the type I error rate is at most "α". For typical analysis, using the standard "α" = 0.05 cutoff, the null hypothesis is rejected when "p" < .05 and not rejected when "p" > .05. The "p"-value does not, in itself, support reasoning about the probabilities of hypotheses but is only a tool for deciding whether to reject the null hypothesis.
Misuse.
According to the ASA, there is widespread agreement that "p"-values are often misused and misinterpreted. One practice that has been particularly criticized is accepting the alternative hypothesis for any "p"-value nominally less than .05 without other supporting evidence. Although "p"-values are helpful in assessing how incompatible the data are with a specified statistical model, contextual factors must also be considered, such as "the design of a study, the quality of the measurements, the external evidence for the phenomenon under study, and the validity of assumptions that underlie the data analysis". Another concern is that the "p"-value is often misunderstood as being the probability that the null hypothesis is true.
Some statisticians have proposed replacing "p"-values with alternative measures of evidence, such as confidence intervals, likelihood ratios, or Bayes factors, but there is heated debate on the feasibility of these alternatives. Others have suggested to remove fixed significance thresholds and to interpret "p"-values as continuous indices of the strength of evidence against the null hypothesis. Yet others suggested to report alongside p-values the prior probability of a real effect that would be required to obtain a false positive risk (i.e. the probability that there is no real effect) below a pre-specified threshold (e.g. 5%).
Calculation.
Usually, formula_3 is a test statistic, rather than any of the actual observations. A test statistic is the output of a scalar function of all the observations. This statistic provides a single number, such as the average or the correlation coefficient, that summarizes the characteristics of the data, in a way relevant to a particular inquiry. As such, the test statistic follows a distribution determined by the function used to define that test statistic and the distribution of the input observational data.
For the important case in which the data are hypothesized to be a random sample from a normal distribution, depending on the nature of the test statistic and the hypotheses of interest about its distribution, different null hypothesis tests have been developed. Some such tests are the z-test for hypotheses concerning the mean of a normal distribution with known variance, the t-test based on Student's t-distribution of a suitable statistic for hypotheses concerning the mean of a normal distribution when the variance is unknown, the F-test based on the F-distribution of yet another statistic for hypotheses concerning the variance. For data of other nature, for instance categorical (discrete) data, test statistics might be constructed whose null hypothesis distribution is based on normal approximations to appropriate statistics obtained by invoking the central limit theorem for large samples, as in the case of Pearson's chi-squared test.
Thus computing a "p"-value requires a null hypothesis, a test statistic (together with deciding whether the researcher is performing a one-tailed test or a two-tailed test), and data. Even though computing the test statistic on given data may be easy, computing the sampling distribution under the null hypothesis, and then computing its cumulative distribution function (CDF) is often a difficult problem. Today, this computation is done using statistical software, often via numeric methods (rather than exact formulae), but, in the early and mid 20th century, this was instead done via tables of values, and one interpolated or extrapolated "p"-values from these discrete values. Rather than using a table of "p"-values, Fisher instead inverted the CDF, publishing a list of values of the test statistic for given fixed "p"-values; this corresponds to computing the quantile function (inverse CDF).
Example.
As an example of a statistical test, an experiment is performed to determine whether a coin flip is fair (equal chance of landing heads or tails) or unfairly biased (one outcome being more likely than the other).
Suppose that the experimental results show the coin turning up heads 14 times out of 20 total flips. The full data formula_1 would be a sequence of twenty times the symbol "H" or "T". The statistic on which one might focus, could be the total number formula_3 of heads. The null hypothesis is that the coin is fair, and coin tosses are independent of one another. If a right-tailed test is considered, which would be the case if one is actually interested in the possibility that the coin is biased towards falling heads, then the "p"-value of this result is the chance of a fair coin landing on heads "at least" 14 times out of 20 flips. That probability can be computed from binomial coefficients as
This probability is the "p"-value, considering only extreme results that favor heads. This is called a one-tailed test. However, one might be interested in deviations in either direction, favoring either heads or tails. The two-tailed "p"-value, which considers deviations favoring either heads or tails, may instead be calculated. As the binomial distribution is symmetrical for a fair coin, the two-sided "p"-value is simply twice the above calculated single-sided "p"-value: the two-sided "p"-value is 0.115.
In the above example:
Note that the Prob (no. of heads ≤ 14 heads) = 1 - Prob(no. of heads ≥ 14 heads) + Prob (no. of head = 14) = 1 - 0.058 + 0.036 = 0.978; however, symmetry of the binomial distribution makes it an unnecessary computation to find the smaller of the two probabilities. Here, the calculated "p"-value exceeds .05, meaning that the data falls within the range of what would happen 95% of the time were the coin in fact fair. Hence, the null hypothesis is not rejected at the .05 level.
However, had one more head been obtained, the resulting "p"-value (two-tailed) would have been 0.0414 (4.14%), in which case the null hypothesis would be rejected at the .05 level.
History.
Computations of "p"-values date back to the 1700s, where they were computed for the human sex ratio at birth, and used to compute statistical significance compared to the null hypothesis of equal probability of male and female births. John Arbuthnot studied this question in 1710, and examined birth records in London for each of the 82 years from 1629 to 1710. In every year, the number of males born in London exceeded the number of females. Considering more male or more female births as equally likely, the probability of the observed outcome is 1/282, or about 1 in 4,836,000,000,000,000,000,000,000; in modern terms, the "p"-value. This is vanishingly small, leading Arbuthnot that this was not due to chance, but to divine providence: "From whence it follows, that it is Art, not Chance, that governs." In modern terms, he rejected the null hypothesis of equally likely male and female births at the "p" = 1/282 significance level. This and other work by Arbuthnot is credited as "… the first use of significance tests …" the first example of reasoning about statistical significance, and "… perhaps the first published report of a nonparametric test …", specifically the sign test; see details at .
The same question was later addressed by Pierre-Simon Laplace, who instead used a "parametric" test, modeling the number of male births with a binomial distribution:
The "p"-value was first formally introduced by Karl Pearson, in his Pearson's chi-squared test, using the chi-squared distribution and notated as capital P. The "p"-values for the chi-squared distribution (for various values of "χ"2 and degrees of freedom), now notated as "P," were calculated in , collected in .
The use of the "p"-value in statistics was popularized by Ronald Fisher, and it plays a central role in his approach to the subject. In his influential book "Statistical Methods for Research Workers" (1925), Fisher proposed the level "p" = 0.05, or a 1 in 20 chance of being exceeded by chance, as a limit for statistical significance, and applied this to a normal distribution (as a two-tailed test), thus yielding the rule of two standard deviations (on a normal distribution) for statistical significance (see 68–95–99.7 rule).
He then computed a table of values, similar to Elderton but, importantly, reversed the roles of "χ"2 and "p." That is, rather than computing "p" for different values of "χ"2 (and degrees of freedom "n"), he computed values of "χ"2 that yield specified "p"-values, specifically 0.99, 0.98, 0.95, 0,90, 0.80, 0.70, 0.50, 0.30, 0.20, 0.10, 0.05, 0.02, and 0.01. That allowed computed values of "χ"2 to be compared against cutoffs and encouraged the use of "p"-values (especially 0.05, 0.02, and 0.01) as cutoffs, instead of computing and reporting "p"-values themselves. The same type of tables were then compiled in , which cemented the approach.
As an illustration of the application of "p"-values to the design and interpretation of experiments, in his following book "The Design of Experiments" (1935), Fisher presented the lady tasting tea experiment, which is the archetypal example of the "p"-value.
To evaluate a lady's claim that she (Muriel Bristol) could distinguish by taste how tea is prepared (first adding the milk to the cup, then the tea, or first tea, then milk), she was sequentially presented with 8 cups: 4 prepared one way, 4 prepared the other, and asked to determine the preparation of each cup (knowing that there were 4 of each). In that case, the null hypothesis was that she had no special ability, the test was Fisher's exact test, and the "p"-value was formula_30 so Fisher was willing to reject the null hypothesis (consider the outcome highly unlikely to be due to chance) if all were classified correctly. (In the actual experiment, Bristol correctly classified all 8 cups.)
Fisher reiterated the "p" = 0.05 threshold and explained its rationale, stating:
He also applies this threshold to the design of experiments, noting that had only 6 cups been presented (3 of each), a perfect classification would have only yielded a "p"-value of formula_31 which would not have met this level of significance. Fisher also underlined the interpretation of "p," as the long-run proportion of values at least as extreme as the data, assuming the null hypothesis is true.
In later editions, Fisher explicitly contrasted the use of the "p"-value for statistical inference in science with the Neyman–Pearson method, which he terms "Acceptance Procedures". Fisher emphasizes that while fixed levels such as 5%, 2%, and 1% are convenient, the exact "p"-value can be used, and the strength of evidence can and will be revised with further experimentation. In contrast, decision procedures require a clear-cut decision, yielding an irreversible action, and the procedure is based on costs of error, which, he argues, are inapplicable to scientific research.
Related quantities.
A closely related concept is the "E"-value, which is the expected number of times in multiple testing that one expects to obtain a test statistic at least as extreme as the one that was actually observed if one assumes that the null hypothesis is true. The "E"-value is the product of the number of tests and the "p"-value.
The "q"-value is the analog of the "p"-value with respect to the positive false discovery rate. It is used in multiple hypothesis testing to maintain statistical power while minimizing the false positive rate.


Regular temperament

Regular temperament is any tempered system of musical tuning such that each frequency ratio is obtainable as a product of powers of a finite number of generators, or generating frequency ratios. For instance, in 12-TET, the system of music most commonly used in the Western world, the generator is a tempered fifth (700 cents), which is the basis behind the circle of fifths.
When only two generators are needed, with one of them the octave, this is called "linear temperament". The best-known example of a linear temperaments is meantone temperament, where the generating intervals are usually given in terms of a slightly flattened fifth and the octave. Other linear temperaments include the schismatic temperament of Hermann von Helmholtz and miracle temperament.
Mathematical description.
If the generators are all of the prime numbers up to a given prime "p", we have what is called "p"-limit just intonation. Sometimes some irrational number close to one of these primes is substituted (an example of tempering) to favour other primes, as in twelve tone equal temperament where 3 is tempered to 2 to favour 2, or in quarter-comma meantone where 3 is tempered to 2 to favor 2 and 5.
In mathematical terminology, the products of these generators define a free abelian group. The number of independent generators is the rank of an abelian group. The rank-one tuning systems are equal temperaments, all of which can be spanned with only a single generator. A rank-two temperament has two generators. Hence, meantone is a rank-2 temperament.
In studying regular temperaments, it can be useful to regard the temperament as having a map from "p"-limit just intonation (for some prime "p") to the set of tempered intervals. To properly classify a temperament's dimensionality one must determine how many of the given generators are independent, because its description may contain redundancies. Another way of considering this problem is that the rank of a temperament should be the rank of its image under this map.
For instance, a harpsichord tuner it might think of quarter-comma meantone tuning as having three generators—the octave, the just major third (5:4) and the quarter-comma tempered fifth—but because four consecutive tempered fifths produces a just major third, the major third is redundant, reducing it to a rank-two temperament.
Other methods of linear and multilinear algebra can be applied to the map. For instance, a map's kernel (otherwise known as "nullspace") consists of "p"-limit intervals called commas, which are a property useful in describing temperaments.


Review Board

Review Board is a web-based collaborative code review tool, available as free software under the MIT License.
An alternative to Rietveld and Gerrit, Review Board integrates with Bazaar, ClearCase, CVS, Git, Mercurial, Perforce, and Subversion.
Review Board can be installed on any server running Apache or lighttpd and is free for both personal and commercial use.
There is also an official commercial Review Board hosting service, RBCommons.
Review requests can be posted manually or automatically using either a REST Web API, or a Python script.
Users.
Some of the notable users of Review Board are:


Shoalwater Bay

Shoalwater Bay is a large bay on the Capricorn Coast of Central Queensland, Australia 100 km north of the coastal town of Yeppoon and 628 km north-north-west of the state capital, Brisbane. Since 1966, the land surrounding Shoalwater Bay has been under the ownership of the Australian Defence Force, for the purpose of military training exercises. Shoalwater Bay is also a noted dugong habitat and is part of the Great Barrier Reef Marine Park. The bay is bounded by the Torilla Peninsula to the west and the Warginburra Peninsula and Leicester and Townshend islands to the east.
History.
Pre-colonial.
The traditional inhabitants of Shoalwater Bay are the Darumbal people.The Darumbal (Tarumbul, Tharoombool) language region includes the city of Rockhampton extending south towards Raglan Creek and north towards the Styx River and inland along the Broad Sound Ranges. Specific tribes that lived and in some cases continue to live in the area include the Cookeeburra (green-headed ant people of the Warginburra Peninsula), the Risteburra (the sandfly people of Raspberry Creek), the Cooinmurburra (the plains people of Torilla) and the Woppaburra (the people of the islands in the region).
Colonial.
The first recorded European to sight Shoalwater Bay was British navigator James Cook on 28 May 1770. Cook referred to the entire region, from Cape Palmerston (south of Mackay) to Cape Townshend, including Shoalwater Bay, as the "Bay of Inlets", a name which is no longer in use. Cook bestowed the name "Shoalwater Bay" on the southeasternmost of these bays, a reference to the number of sandbars in the bay. Following Cook, Matthew Flinders conducted further exploration of Shoalwater Bay in 1802, landing on Akens Island (a small island on the western side of Shoalwater Bay) and exploring the head of the bay. Flinders described the land as such:
The hills are stony, but some of them are clothed with grass and wood, and the pine grows in the gullies between them. The low land is sandy or stony, but covered with wood & herbage. Fresh water stands in ponds at the foot of the hills.
European colonisation of the land in Shoalwater Bay region commenced in 1858. By the early 1860s, it had been divided into four pastoral stations: Tilpal, Raspberry Creek, The Peninsula and Torilla. The process of colonisation was violent with the killings of settlers and the massacres of local Aboriginal people being recorded frequently until the mid 1870s.
Tilpal.
Tilpal was formed as a sheep station in the late 1850s by "Hobby" Elliott. Not long after establishing Tilpal, Elliott and his shearers had a skirmish with the local Aboriginal people which resulted in the death or severe wounding of two of his workers and seven Aboriginal men being shot. The Native Police were called in and they tracked down "the blacks" to Torilla Hill where some more were shot. Elliott later sold Tilpal to James Black and a minor gold rush occurred on the property in the late 1860s.
Raspberry Creek.
Raspberry Creek was initially taken up by James Ross and James Hutton. Hutton commenced building the Raspberry Creek Homestead and brought his family to the station in 1861. The resident Risteburra people speared Hutton's cattle and the Native Police were called in to "disperse" the tribe. Many were shot or fell from cliffs after being pursued by the troopers into the Polygon Range. Raspberry Creek remained under the ownership of the Hutton family until 1917.
The Peninsula.
The Peninsula Station was taken up by Edward Hampton Baker (also known as "Cranky" Baker), which encompassed the entirety of the area today known as the Warginburra Peninsula. Baker was consistently at war with the local Cookeeburra people who took his rations and speared his cattle. Baker booby-trapped his house with self-firing rifles and poisoned the Cookeeburra with arsenic-laced flour. Native Police operations occurred frequently in the 1860s on The Peninsula with Baker being pleased with the efforts of Inspectors Aubin and Compigne "to inspire the natives with a wholesome respect for their Majesty's colors." Baker offered money to Rockhampton residents to shoot Aboriginal people on his property, and threatened to place an advertisement in the local newspaper offering "a premium for scalps" if the government did not provide him with even more assistance against "the blacks." In 1873 Inspector Alexander Douglas of Native Police led a large patrol through The Peninsula and around the adjacent islands. A local colonist later described the operation:
"the blacks were robbing huts and doing other damage on The Peninsula, when the owner asked for police protection. The authorities gathered several detachments, and by marching in open order from one end to the other of the Peninsula, actually drove them, like a RABBIT OR KANGAROO DRIVE into the sea, shooting any that broke back. The rest took to the sea to swim to an island, but a boat was handy, and the police got in and shot all they could when swimming. When the Inspector wired to his chief to inform him he had "dispersed" seventy blacks, a reply was received in writing as follows: — A native police officer is supposed to do his duty without making it public."
In 1876, Baker sold The Peninsula to James Hutton owner of the neighbouring Raspberry Creek property, and became a travelling photographer.
Torilla.
Torilla was formed by British colonist Frank Newbold in 1858. Newbold did not allow the local Cooinmurburra people to be present upon what was now viewed as his property and conflict ensued. In 1868, around forty Cooinmurburra attacked the Newbold's homestead, fatally wounding his son William Newbold. Around twenty Aboriginal people were shot dead. The Newbold family and their relatives, the Rogers family, retained the Torilla run for many decades afterwards. The town of Stanage on the Torilla property was established by the Rogers family in the early 1870s and was named after their hometown in the United Kingdom.
Shoalwater Bay Military Training Area.
The Shoalwater Bay Military Training Area encompasses 4,545 km2, which includes the Warginburra Peninsula, the Torilla Peninsula east of the Stanage Bay Road, Townshend and Leicester Islands, and a sizable chunk of the Shoalwater Bay hinterland north of the village of Byfield. Suggestions that the Shoalwater Bay region be acquired for the purpose of a training ground first appeared in 1960. The army formally took control of the land on 1 July 1965; by the following year, the last landholder had vacated his property. The training area was used by troops who were deployed to the Vietnam War.
In 2005 the federal government entered into a long-term agreement with the US over the use of Shoalwater Bay for military training purposes. Similar agreements over a shorter time span have been agreed to with the Singapore Ministry of Defence.
Military exercises with the United States have aroused considerable controversy in the Rockhampton-Yeppoon area, due to the threat of environmental damage to the Shoalwater Bay region. In recent years, concern has been raised, although unfounded about the possibility of depleted uranium weaponry been used during training exercises at Shoalwater Bay. Peace activists protesting Exercise Talisman Saber were arrested in 2009.
Support for a permanent US presence has been expressed by the former Rockhampton mayor, Brad Carter in 2011, and by current mayor, Margaret Strelow.
7 August 2017: "The Australian Navy has located a missing US military aircraft that crashed off Australia's east coast on Saturday, Defense Minister Marise Payne said in a statement Monday. Three US Marines have been missing since what the Marine Corps calls a "mishap" with an MV-22 aircraft. Twenty-three of the 26 personnel on board the aircraft were rescued, the Corps said."
Environment.
The bay contains one of the most important seagrass habitats in the Great Barrier Reef Marine Park. A plan of management for the bay's dugong population was released in 1997 to protect the dugong population and reduce impacts on the seagrass meadows.
Important Bird Area.
A 483 km2 area of the bay and its surrounds, covering all the habitat types suitable for migratory waders, or shorebirds, has been identified by BirdLife International as an Important Bird Area (IBA) because it supports over 1% of the world populations of pied oystercatchers, Far Eastern curlews and grey-tailed tattlers, and over 1% of the East Asian – Australasian Flyway populations of bar-tailed godwits, Eurasian whimbrels and Terek sandpipers. It also contains populations of beach stone-curlews and mangrove honeyeaters.


Maroc Soir (newspaper)

Maroc Soir is an evening Moroccan newspaper that is published in French-language.
History and profile.
"Maroc Soir" was launched on 10 November 2005 by the publishing group of the same name, Maroc Soir Group, headed by Othman Al Omeir. The paper is the successor of the newspaper with the same name which was started in 1902. The headquarters of the paper is in Casablanca. The paper is published five times per week. The editor is Mahdi Harizi, a famous Moroccan writer and journalist.
The paper is published in tabloid format and consists of 24 full color pages. The newspaper has a pro-government stance.


Arago spot

In optics, the Arago spot, Poisson spot, or Fresnel spot is a bright point that appears at the center of a circular object's shadow due to Fresnel diffraction. This spot played an important role in the discovery of the wave nature of light and is a common way to demonstrate that light behaves as a wave (for example, in undergraduate physics laboratory exercises).
The basic experimental setup requires a point source, such as an illuminated pinhole or a diverging laser beam. The dimensions of the setup must comply with the requirements for Fresnel diffraction. Namely, the Fresnel number must satisfy
where
Finally, the edge of the circular object must be sufficiently smooth.
These conditions together explain why the bright spot is not encountered in everyday life. However, with the laser sources available today, it is undemanding to perform an Arago-spot experiment.
In astronomy, the Arago spot can also be observed in the strongly defocussed image of a star in a Newtonian telescope. There, the star provides an almost ideal point source at infinity, and the secondary mirror of the telescope constitutes the circular obstacle.
When light shines on the circular obstacle, Huygens' principle says that every point in the plane of the obstacle acts as a new point source of light. The light coming from points on the circumference of the obstacle and going to the center of the shadow travels exactly the same distance, so all the light passing close by the object arrives at the screen in phase and constructively interferes. This results in a bright spot at the shadow's center, where geometrical optics and particle theories of light predict that there should be no light at all.
History.
At the beginning of the 19th century, the idea that light does not simply propagate along straight lines gained traction. Thomas Young published his double-slit experiment in 1807. The original Arago spot experiment was carried out a decade later and was the deciding experiment on the question of whether light is a particle or a wave. It is thus an example of an "experimentum crucis".
At that time, many favored Isaac Newton's corpuscular theory of light, among them the theoretician Siméon Denis Poisson. In 1818 the French Academy of Sciences launched a competition to explain the properties of light, where Poisson was one of the members of the judging committee. The civil engineer Augustin-Jean Fresnel entered this competition by submitting a new wave theory of light.
Poisson studied Fresnel's theory in detail and, being a supporter of the particle theory of light, looked for a way to prove it wrong. Poisson thought that he had found a flaw when he argued that a consequence of Fresnel's theory was that there would exist an on-axis bright spot in the shadow of a circular obstacle, where there should be complete darkness according to the particle theory of light. Since the Arago spot is not easily observed in everyday situations, Poisson interpreted it as an absurd result and that it should disprove Fresnel's theory.
However, the head of the committee, Dominique-François-Jean Arago (who incidentally later became Prime Minister of France), decided to perform the experiment in more detail. He molded a 2 mm metallic disk to a glass plate with wax. He succeeded in observing the predicted spot, which convinced most scientists of the wave nature of light and gave Fresnel the win.
Arago later noted that the phenomenon (later known as "Poisson's spot" or the "spot of Arago") had already been observed by Delisle and Maraldi a century earlier.
It only turned out much later (in one of Albert Einstein's "Annus Mirabilis" papers) that light can be equally described as a particle (wave–particle duality of light).
Theory.
At the heart of Fresnel's wave theory is the Huygens–Fresnel principle, which states that every unobstructed point of a wavefront becomes the source of a secondary spherical wavelet and that the amplitude of the optical field "E" at a point on the screen is given by the superposition of all those secondary wavelets taking into account their relative phases. This means that the field at a point P1 on the screen is given by a surface integral:
where the inclination factor formula_3 which ensures that the secondary wavelets do not propagate backwards is given by
and
The first term outside of the integral represents the oscillations from the source wave at a distance "r"0. Similarly, the term inside the integral represents the oscillations from the secondary wavelets at distances "r"1.
In order to derive the intensity behind the circular obstacle using this integral one assumes that the experimental parameters fulfill the requirements of the near-field diffraction regime (the size of the circular obstacle is large compared to the wavelength and small compared to the distances "g" = P0C and "b" = CP1). Going to polar coordinates then yields the integral for a circular object of radius "a" (see for example Born and Wolf):
This integral can be solved numerically (see below). If "g" is large and "b" is small so that the angle formula_7 is not negligible one can write the integral for the on-axis case (P1 is at the center of the shadow) as (see ):
The source intensity, which is the square of the field amplitude, is formula_9 and the intensity at the screen formula_10. The on-axis intensity as a function of the distance "b" is hence given by:
This shows that the on-axis intensity at the center of the shadow tends to the source intensity, as if the circular object was not present at all. Furthermore, this means that the Arago spot is present even just a few obstacle diameters behind the disc.
Calculation of diffraction images.
To calculate the full diffraction image that is visible on the screen one has to consider the surface integral of the previous section. One cannot exploit circular symmetry anymore, since the line between the source and an arbitrary point on the screen does not pass through the center of the circular object. With the aperture function formula_12 which is 1 for transparent parts of the object plane and 0 otherwise (i.e. It is 0 if the direct line between source and the point on the screen passes through the blocking circular object.) the integral that needs to be solved is given by:
Numerical calculation of the integral using the trapezoidal rule or Simpson's rule is not efficient and becomes numerically unstable especially for configurations with large Fresnel number. However, it is possible to solve the radial part of the integral so that only the integration over the azimuth angle remains to be done numerically. For a particular angle one must solve the line integral for the ray with origin at the intersection point of the line P0P1 with the circular object plane. The contribution for a particular ray with azimuth angle formula_14 and passing a transparent part of the object plane from formula_15 to formula_16 is:
So for each angle one has to compute the intersection point("s") of the ray with the circular object and then sum the contributions formula_18 for a certain number of angles between 0 and formula_19. Results of such a calculation are shown in the following images.
The images show simulated Arago spots in the shadow of a disc of varying diameter (4 mm, 2 mm, 1 mm – left to right) at a distance of 1 m from the disc. The point source has a wavelength of 633 nm (e.g. He-Ne Laser) and is located 1 m from the disc. The image width corresponds to 16 mm.
Experimental aspects.
Intensity and size.
For an ideal point source, the intensity of the Arago spot equals that of the undisturbed wave front. Only the width of the Arago spot intensity peak depends on the distances between source, circular object and screen, as well as the source's wavelength and the diameter of the circular object. This means that one can compensate for a reduction in the source's wavelength by increasing the distance l between circular object and screen or reducing the circular object's diameter.
The lateral intensity distribution on the screen has in fact the shape of a squared zeroth Bessel function of the first kind when close to the optical axis and using a plane wave source (point source at infinity):
where
The following images show the radial intensity distribution of the simulated Arago spot images above:
The red lines in these three graphs correspond to the simulated images above, and the green lines were computed by applying the corresponding parameters to the squared Bessel function given above.
Finite source size and spatial coherence.
The main reason why the Arago spot is hard to observe in circular shadows from conventional light sources is that such light sources are bad approximations of point sources. If the wave source has a finite size "S" then the Arago spot will have an extent that is given by "Sb"/"g", as if the circular object acted like a lens. At the same time the intensity of the Arago spot is reduced with respect to the intensity of the undisturbed wave front. Defining the relative intensity formula_21as the intensity divided by the intensity of the undisturbed wavefront, the relative intensity for an extended circular source of diameter w can be expressed exactly using the following equation:
where formula_23and formula_24are the Bessel functions of the first kind. R is the radius of the disc casting the shadow, formula_25the wavelength and "g" the distance between source and disc. For large sources the following asymptotic approximation applies:
Deviation from circularity.
If the cross-section of the circular object deviates slightly from its circular shape (but it still has a sharp edge on a smaller scale) the shape of the point-source Arago spot changes. In particular, if the object has an ellipsoidal cross-section the Arago spot has the shape of an evolute. Note that this is only the case if the source is close to an ideal point source. From an extended source the Arago spot is only affected marginally, since one can interpret the Arago spot as a point-spread function. Therefore, the image of the extended source only becomes washed out due to the convolution with the point-spread function, but it does not decrease in over all intensity.
The circular object's surface roughness.
The Arago spot is very sensitive to small-scale deviations from the ideal circular cross-section. This means that a small amount of surface roughness of the circular object can completely cancel out the bright spot. This is shown in the following three diagrams which are simulations of the Arago spot from a 4 mm diameter disc ("g" = "b" = 1 m):
The simulation includes a regular sinusoidal corrugation of the circular shape of amplitude 10 μm, 50 μm and 100 μm, respectively. Note, that the 100 μm edge corrugation almost completely removes the central bright spot.
This effect can be best understood using the Fresnel zone concept. The field transmitted by a radial segment that stems from a point on the obstacle edge provides a contribution whose phase is tight to the position of the edge point relative to Fresnel zones. If the variance in the radius of the obstacle are much smaller than the width of Fresnel zone near the edge, the contributions form radial segments are approximately in phase and interfere constructively. However, if random edge corrugation have amplitude comparable to or greater than the width of that adjacent Fresnel zone, the contributions from radial segments are no longer in phase and cancel each other reducing the Arago spot intensity.
The adjacent Fresnel zone is approximately given by:
The edge corrugation should not be much more than 10% of this width to see a close to ideal Arago spot. In the above simulations with the 4 mm diameter disc the adjacent Fresnel zone has a width of about 77 μm.
Arago spot with matter waves.
In 2009, the Arago spot experiment was demonstrated with a supersonic expansion beam of deuterium molecules (an example of neutral matter waves). Material particles behaving like waves is known from quantum mechanics. The wave-nature of particles actually dates back to de Broglie's hypothesis as well as Davisson and Germer's experiments. An Arago spot of electrons, which also constitute matter waves, can be observed in transmission electron microscopes when examining circular structures of a certain size.
The observation of an Arago spot with large molecules, thus proving their wave-nature, is a topic of current research.
Other applications.
Beside the demonstration of wave-behavior, the Arago spot also has a few other applications. One of the ideas is to use the Arago spot as a straight line reference in alignment systems. Another is to probe aberrations in laser beams by using the spot's sensitivity to beam aberrations. Finally, the aragoscope has been proposed as a method for dramatically improving the diffraction-limited resolution of space-based telescopes.


334 Chicago

Chicago (minor planet designation: 334 Chicago) is a very large main-belt asteroid. It is classified as a C-type asteroid and is probably composed of carbonaceous material.
It was discovered by Max Wolf on August 23, 1892, in Heidelberg.


Daylight saving time in Oceania

Parts of Australia, New Zealand, Fiji and Samoa are areas of Oceania that currently observe daylight saving time (DST).
By country and region.
Australia.
Currently, New South Wales, Victoria, Tasmania, Australian Capital Territory, Jervis Bay Territory and South Australia apply DST each year, from the first Sunday in October to the first Sunday in April.
The Northern Territory, Queensland, Western Australia and the external territories do not observe DST.
Daylight saving was first used in Australia during World War I, and was applied in all states. It was used again during the Second World War. A drought in Tasmania in 1967 led to the reintroduction during the summer, and this was repeated every summer since. In 1971, New South Wales, Victoria, Queensland, South Australia, and the Australian Capital Territory followed Tasmania in observing daylight saving, Western Australia and the Northern Territory did not. Queensland abandoned daylight saving time in 1972. Originally Tasmania alone commenced daylight saving on the first Sunday in October, while the other states began on the last Sunday in October and finished on the last Sunday in March, until 2008 excepting in 2000 when all the states observing DST moved forward the commencement date to Sunday, 27 August 2000 because of the Sydney Olympic Games which commenced in mid-September. From 2008/09 daylight saving has been extended another four weeks in NSW, Victoria, SA and the ACT, in addition to Tasmania, from the first Sunday in October to the first Sunday in April.
Queensland again trialled daylight saving, for three years between 1989 and 1992, with a referendum on daylight saving held on 22 February 1992, which was defeated with a 54.5% ‘no’ vote - with regional and rural areas strongly opposed, while those in the metropolitan South East Queensland were in favour.
In December 2008, the Daylight Saving for South East Queensland (DS4SEQ) political party was officially registered, advocating the implementation of a dual-time zone arrangement for Daylight Saving in South East Queensland while the rest of the state maintains standard time. The party contested the March 2009 Queensland State election with 32 candidates and received around one percent of the state-wide primary vote, equating to around 2.5% across the 32 electorates contested.
On 14 April 2010, and after being approached by the Daylight Saving for South East Queensland (DS4SEQ) political party, Queensland Independent member Peter Wellington, introduced the Daylight Saving for South East Queensland Referendum Bill 2010 into Queensland Parliament, calling for a referendum to be held at the next State election on the introduction of daylight saving into South East Queensland under a dual-time zone arrangement. The Bill was defeated in Queensland Parliament on 15 June 2011.
In Western Australia, four referendums in 1975, 1984, 1992 and 2009 have rejected DST.
In 2006, the Parliament of Western Australia approved a three-year daylight saving trial to be followed by a referendum to decide whether DST should be put in place permanently. However, public opposition mounted during the first year of the trial, and the WA Nationals announced a public campaign to bring the referendum forward to 2007. The trial continued until the referendum, held on 16 May 2009. The result was another rejection of DST, by a larger margin compared to the three previous referendums. Although as previously the suburbs of the state capital, Perth, supported the proposal, it was by a much narrower margin than before with significant swings against it in several areas, most notably in the East Metropolitan region. As a result, the Premier of Western Australia has said that the DST issue should not be considered for at least another 20 years.
The Northern Territory experimented with daylight saving in the early part of the 20th century. It was last used in 1944.
Fiji.
Despite its proximity to the equator and therefore a relatively small variation of daylight length, Fiji implemented daylight saving time in 1998-99 but it ended after that. Fiji restarted DST in 2009 starting on November 29 and ending on April 26, 2010. The decision was based on a report by the Attorney-General, Mr Aiyaz Sayed-Khaiyum. "Mr Sayed-Khaiyum said that from the information available, the implementation of daylight saving in 1998 and 1999 received very encouraging response from the people and the business community. Apart from availability of more daylight time for sport, leisure and shopping, the working people are able to spend quality daylight time in the afternoons and evenings with their family and loved ones, including engaging in healthy activities such as gardening or going for a walk. In 1999, the Ministry of Labour reported that there was an overall increase in economic activity and productive work as a result of daylight saving." For the 2010-2011 summer, DST started on fourth Sunday in October and ended on last Sunday in March. Fiji changed the ending of DST to the last Sunday in January in 2011.
Hawaii.
Although Hawaii is further away from equator than Fiji, and therefore there is a slightly greater variation in the daylight length, Hawaii does not observe DST. Most of the inhabited islands are located close to the west end of the Hawaii-Aleutian time zone, and Oahu, Kauai and Niihau are located more than 7 degrees west of the Hawaii-Aleutian time zone's meridian and should, theoretically, be located in the next time zone to the west. Therefore advancing the clock in Hawaii would make sunrise times close to 7:00 a.m. even in June.
Hawaii did experiment with DST for three weeks between April 30, 1933 and May 21, 1933; there are no known official records as to why it was implemented or discontinued. Hawaii has never observed daylight saving time under the Uniform Time Act, having opted out of the Act's provisions in 1967.
New Zealand.
From 30 April 2007, DST begins at 02:00 NZST on the last Sunday in September each year, and ends at 03:00 NZDT (or 02:00 NZST as defined in the Time Act 1974) on the first Sunday in April.
New Zealand time, including DST, is used by several Antarctic bases that are supplied from New Zealand. This results in the oddity that the Amundsen-Scott South Pole Station sets its clocks an hour further ahead during the southern summer, when the sun is constantly above the horizon, than in the southern winter, when the sun is constantly below the horizon. The extreme geographic position of the base means that no possible adjustment of the daily activity cycle can have any effect on the amount of sunlight received during those activities. However, the arrangement presumably makes real time communications with New Zealand more practical, particularly in dealing with offices.
The New Zealand dependencies of Tokelau, Cook Islands and Niue do not maintain DST. The latter two are on the other side of the International Date Line and differ between 22 and 24 hours from New Zealand proper.
Samoa.
Samoa started with DST in 2010, starting on the last Sunday in September and ending on first Sunday in April.
U.S. territories.
All U.S. insular territories with civilian government in Oceania, American Samoa, Guam, and the Northern Mariana Islands lie in the tropics and do not observe DST.


727 Nipponia

727 Nipponia is a minor planet orbiting the Sun. It is a member of the Maria family of asteroids.
"Nipponia" was originally discovered by Shin Hirayama in Tokyo on March 6, 1900. However, he was not able to determine its orbit. After it was rediscovered by Adam Massinger on February 11, 1912, Massinger gave the honor of naming it to Hirayama, who chose to name it from a latinization of "Nippon" (Japan in Japanese). Massinger, however, remains the officially credited discoverer of "Nipponia".


4486 Mithra

4486 Mithra ("prov. designation:" ), is an eccentric asteroid and suspected contact-binary, classified as near-Earth object and potentially hazardous asteroid, approximately 2 kilometers in diameter. It belongs to the Apollo group of asteroids and is a relatively slow rotator.
The asteroid was discovered on 22 September 1987, by Belgian astronomer Eric Elst and Bulgarian astronomer Vladimir Shkodrov at Rozhen Observatory, in the Smolyan Province of Bulgaria. It was named after the Indo-Iranian divinity Mithra.
Orbit and classification.
"Mithra" orbits the Sun at a distance of 0.7–3.7 AU once every 3 years and 3 months (1,192 days). Its orbit has an eccentricity of 0.66 and an inclination of 3° with respect to the ecliptic. In 1974, "Mithra" was first identified as at Crimea–Nauchnij. The body's observation arc begins 8 months prior to its official discovery observation, with a precovery taken at the Japanese Kiso Observatory in January 1987.
Close approaches.
As a potentially hazardous asteroid, it has a low minimum orbit intersection distance with Earth of or 18 lunar distances. On 14 August 2000, it passed from Earth.
Physical characteristics.
Rotation period and shape.
Radar imaging using a delay-Doppler technique at the Arecibo and Goldstone observatories rendered a rotation period of hours. Based on the radar analysis, "Mithra" is also a strong candidate for a contact binary, which is composed of two distinct lobes in mutual contact, held together by their weak gravitational attraction. They typically show a , dumbbell-like shape "(also see 4769 Castalia)". A large number of near-Earth objects are believed to be contact-binaries.
Diameter and albedo.
According to the survey carried out by the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, "Mithra" measures 1.85 kilometers in diameter and its surface has a high albedo of 0.297, while the "Collaborative Asteroid Lightcurve Link" assumes a standard albedo for stony asteroids of 0.20 and calculates a diameter of 2.25 kilometer with an absolute magnitude of 15.6.
Naming.
This minor planet was named after Mithra "(also see Mitra)", deity in the proto-Indo-Iranian religion. The mystery religion of Mithraism was practiced in the Roman Empire between the 1st and 4th century. Considered to be a rival of early Christianity, both religions shared similar characteristics such as elevation and the ritual of baptism. In the Hellenistic world, Mithra was conflated with Apollo. The asteroid 1862 Apollo is the namesake of this asteroid's orbital group. The approved naming citation was published by the Minor Planet Center on 5 September 1990 ().


Kibble balance

A Kibble balance is an electromechanical measuring instrument that measures the weight of a test object very precisely by the electric current and voltage needed to produce a compensating force. It is a metrological instrument that can realize the definition of the kilogram unit of mass based on fundamental constants.
It was originally called the watt balance because the weight of the test mass is proportional to the product of current and voltage, which is measured in watts. In June 2016, two months after the death of its inventor, Bryan Kibble, metrologists of the Consultative Committee for Units of the International Committee for Weights and Measures agreed to rename the device in his honor.
Prior to 2019, the definition of the kilogram was based on a physical object known as the International Prototype of the Kilogram (IPK).
After considering alternatives, in 2013 the General Conference on Weights and Measures (CGPM) agreed on accuracy criteria for replacing this definition with one based on the use of a Kibble balance. After these criteria had been achieved, the CGPM voted unanimously on November 16, 2018 to change the definition of the kilogram and several other units, effective May 20, 2019, to coincide with World Metrology Day.
Design.
The Kibble balance is a more accurate version of the ampere balance, an early current measuring instrument in which the force between two current-carrying coils of wire is measured and then used to calculate the magnitude of the current. The Kibble balance operates in the opposite sense; the current in the coils is measured using the definition of the Planck constant to "measure mass without recourse to the IPK or any physical object." The balance determines the weight of the object; then the mass is calculated by accurately measuring the local Earth's gravity (the net acceleration combining gravitational and centrifugal effects) with a gravimeter. Thus the mass of the object is defined in terms of a current and a voltage—an "electronic kilogram."
Origin.
The principle that is used in the Kibble balance was proposed by Bryan Kibble of the UK National Physical Laboratory (NPL) in 1975 for measurement of the gyromagnetic ratio.
The main weakness of the ampere balance method is that the result depends on the accuracy with which the dimensions of the coils are measured. The Kibble balance uses an extra calibration step to cancel the effect of the geometry of the coils, removing the main source of uncertainty. This extra step involves moving the force coil through a known magnetic flux at a known speed. This step was first performed in 1990.
The Kibble balance originating from the National Physical Laboratory was transferred to the National Research Council of Canada (NRC) in 2009, where scientists from the two labs continued to refine the instrument.
In 2014, NRC researchers published the most accurate measurement of the Planck constant at that time, with a relative uncertainty of 1.8. A final paper by NRC researchers was published in May 2017, presenting a measurement of Planck's constant with an uncertainty of only 9.1 parts per billion, the measurement with the least uncertainty to that date. Other Kibble balance experiments are conducted in the US National Institute of Standards and Technology (NIST), the Swiss Federal Office of Metrology (METAS) in Berne, the International Bureau of Weights and Measures (BIPM) near Paris and Laboratoire national de métrologie et d’essais (LNE) in Trappes, France.
Principle.
A conducting wire of length "L" that carries an electric current "I" perpendicular to a magnetic field of strength "B" experiences a Lorentz force equal to the product of these variables. In the Kibble balance, the current is varied so that this force counteracts the weight "w" of a mass "m" to be measured. This principle is derived from the ampere balance. "w" is given by the mass "m" multiplied by the local gravitational acceleration "g". Thus,
The Kibble balance avoids the problems of measuring "B" and "L" in a second calibration step. The same wire (in practice, a coil) is moved through the same magnetic field at a known speed "v". By Faraday's law of induction, a potential difference "U" is generated across the ends of the wire, which equals "BLv". Thus
The unknown product "BL" can be eliminated from the equations to give
With "U", "I", "g", and "v" accurately measured, this gives an accurate value for "m".
Both sides of the equation have the dimensions of power, measured in watts in the International System of Units; hence the original name "watt balance".
Implementation.
The Kibble balance is constructed so that the mass to be measured and the wire coil are suspended from one side of a balance scale, with a counterbalance mass on the other side. The system operates by alternating between two modes: "weighing" and "moving". The entire mechanical subsystem operates in a vacuum chamber to remove the effects of air buoyancy.
While "weighing", the system measures the "I" component and the "v" component. The system controls the current in the coil to pull the coil through a magnetic field at a constant velocity "v". Coil position and velocity measurement circuitry uses an interferometer together with a precision clock input to determine the velocity and control the current needed to maintain it. The required current is measured, using an ammeter comprising a Josephson junction voltage standard and an integrating voltmeter.
While "moving", the system measures the "U" component. The system ceases to provide current to the coil. This allows the counterbalance to pull the coil (and mass) upward through the magnetic field, which causes a voltage difference across the coil. The velocity measurement circuitry measures the speed of movement of the coil. This voltage is measured, using the same voltage standard and integrating voltmeter.
A typical Kibble balance measures U, I, and v, but does not measure the local gravitational acceleration "g", because "g" does not vary rapidly with time. Instead, "g" is measured in the same laboratory using a highly accurate and precise gravimeter. In addition, the balance depends on a highly accurate and precise frequency reference such as an atomic clock to compute voltage and amperage. Thus, the precision and accuracy of the mass measurement depends on the Kibble balance, the gravimeter, and the clock.
Like the early atomic clocks, the early Kibble balances were one-of-a-kind experimental devices and were large, expensive, and delicate. As of 2019, work is underway to produce standardized devices at prices that permit use in any metrology laboratory that requires high-precision measurement of mass.
As well as large Kibble balances, microfabricated or MEMS watt balances (now called Kibble balances) have been demonstrated since around 2003. These are fabricated on single silicon dies similar to those used in microelectronics and accelerometers, and are capable of measuring small forces in the nanonewton to micronewton range traceably to the SI-defined physical constants via electrical and optical measurements. Due to their small scale, MEMS Kibble balances typically use electrostatic rather than the inductive forces used in larger instruments. Lateral and torsional variants have also been demonstrated, with the main application (as of 2019) being in the calibration of the Atomic Force Microscope.
Measurements.
Accurate measurements of electric current and potential difference are made in conventional electrical units (rather than SI units), which are based on fixed "conventional values" of the Josephson constant and the von Klitzing constant, formula_5 and formula_6 respectively. The current Kibble balance experiments are equivalent to measuring the value of the conventional watt in SI units. From the definition of the conventional watt, this is equivalent to measuring the value of the product "K"J2"R"K in SI units instead of its fixed value in conventional electrical units:
The importance of such measurements is that they are also a direct measurement of the Planck constant "h":
The principle of the electronic kilogram relies on the value of the Planck constant, which is as of 2019 an exact value. This is similar to the metre being defined by the speed of light. With the constant defined exactly, the Kibble balance is not an instrument to measure the Planck constant, but is instead an instrument to measure mass:


Square degree

A square degree (deg2) is a non-SI unit measure of solid angle. Other denotations include "sq. deg." and (°)2. Just as degrees are used to measure parts of a circle, square degrees are used to measure parts of a sphere. Analogous to one degree being equal to  radians, a square degree is equal to ()2 steradians (sr), or about  sr or .
The whole sphere has a solid angle of which is approximately :


3542 Tanjiazhen


Concordia Laptop Orchestra


Tumult Records

Tumult Records (stylized tUMULt) is an independent record label in San Francisco run by Andee Connors (also of Aquarius Records). It has released music by Acid Mothers Temple, Avarus, Brainbombs, Circle, Eikenskaden, Guapo, Harvey Milk, Leviathan, The Margins, The Ohsees, Skullflower, and Souled American.
In 2007, plans were made for a sublabel of tUMULt named Heavy Rescue, aiming to rerelease "lost eighties metal classics." That project seems to still be unrealized.


Super PI

Super PI is a computer program that calculates pi to a specified number of digits after the decimal point—up to a maximum of 32 million. It uses Gauss–Legendre algorithm and is a Windows port of the program used by Yasumasa Kanada in 1995 to compute pi to 232 digits.
Significance.
Super PI is popular in the overclocking community, both as a benchmark to test the performance of these systems and as a stress test to check that they are still functioning correctly.
Credibility concerns.
The competitive nature of achieving the best Super PI calculation times led to fraudulent Super PI results, reporting calculation times faster than normal. Attempts to counter the fraudulent results resulted in a modified version of Super PI, with a checksum to validate the results. However, other methods exist of producing inaccurate or fake time results, raising questions about the program's future as an overclocking benchmark.
Super PI utilizes x87 floating point instructions which are supported on all x86 and x86-64 processors, current versions which also support the lower precision Streaming SIMD Extensions vector instructions.
The future.
Super PI is single threaded, so its relevance as a measure of performance in the current era of multi-core processors is diminishing quickly. Therefore, wPrime has been developed to support multiple threaded calculations to be run at the same time so one can test stability on multi-core machines. Other multithreaded programs include: Hyper PI, IntelBurnTest, Prime95, Montecarlo superPI, OCCT or y-cruncher. Last but not least, while SuperPi is unable to calculate more than 32 million digits, and Alexander J. Yee & Shigeru Kondo were able to set a record of 10 Trillion 50 Digits of Pi using y-cruncher under a 2 x Intel Xeon X5680 @ 3.33 GHz - (12 physical cores, 24 hyperthreaded) computer on October 16, 2011 Super PI is much slower than these other programs, and utilizes inferior algorithms to them.


3865 Lindbloom


4342 Freud


Hypophrygian mode

The Hypophrygian (deuterus plagalis) mode, literally meaning "below Phrygian (plagal second)", is a musical mode or diatonic scale in medieval chant theory, the fourth mode of church music. This mode is the plagal counterpart of the authentic third mode, which was called "Phrygian". In the Middle Ages and Renaissance this mode was described in two ways: the diatonic scale from B to B an octave above, divided at the mode final E (B–C–D–E + E–F–G–A–B); and as a mode with final E and ambitus from the A below to the C above. The note A above the final (the tenor of the corresponding fourth psalm tone) had an important melodic function. The melodic range of the ecclesiastical Hypophrygian mode therefore goes from the perfect fourth or fifth below the tonic to the perfect fifth or minor sixth above.
The name Hypophrygian originates in an octave species of ancient Greek music theory. According to Aristoxenus, this octave species was originally described around the year 400 BC by the Harmonicist school of Eratocles in terms of the enharmonic genus of the tetrachord: a series of rising intervals of two quarter tones followed by a ditone, together spanning a perfect fourth. The Dorian octave species begins with this tetrachord, which is followed by a whole tone and another tetrachord to complete the octave with a pattern of ¼, ¼, 2, 1, ¼, ¼, and 2 tones. This pattern is rotated downward one degree for the Hypolydian, and one more for the Hypophrygian, for an octave species of 2, 1, ¼, ¼, 2, ¼, and ¼ tones.
The name was appropriated by Ptolemy of Alexandria for one of his seven "tonoi", or transposition keys. Ptolemy's system differed from the earlier Aristoxenian model, which had thirteen transpositional levels each a semitone from its neighbours. Ptolemy substituted a diatonic sequence of seven transpositions pitched either a whole tone or a semitone apart. The entire double-octave scale system was then transposed onto each of these relative pitch levels, requiring (in modern terms) a different key signature in each case, and therefore a different sequence of whole and half steps in the fixed central octave span. The Hypophrygian transposition was the second-lowest of these, a whole tone above the Hypodorian. A whole tone higher was the Hypolydian, followed a semitone higher still by the Dorian, then after another whole tone by the Phrygian, and so on. Four centuries later, the term was taken from Ptolemy in exactly the same sense by Boethius, who described these seven names as "toni, tropi, vel modi" (tones, tropes or modes) in the fourth book of his "De institutione musica". In the late 9th century, in the Carolingian treatises "Alia musica" and in a commentary on it called the "Nova expositio", this set of seven terms, supplemented by an eighth name, "Hypermixolydian", was given a new sense, designating a set of diatonic octave species, described as the tonal embodiments of the eight modes of Gregorian chant.
"Missa Mi-mi" ("Missa quarti toni") by Johannes Ockeghem is a well-known example of a work written in the Hypophrygian mode.


C tuning (guitar)

C tuning is a type of guitar tuning. The strings of the guitar are tuned two whole steps lower than standard tuning. The resulting notes can be described most commonly as C-F-A♯-D♯-G-C or C-F-B♭-E♭-G-C. This is not to be confused with C tuning, which is one and one half steps lower than standard tuning.
The tuning is commonly used by metal and hard rock artists to achieve a heavier, deeper sound. Slackening regular strings on a regular guitar to a lower pitch makes bending easier. Depending on personal playing style, some guitarists find this desirable, while others switch to heavier-gauge strings to avoid unintentional bending and to play chords in tune more easily. Another option is the use of a baritone guitar, which is built slightly longer and stronger than a regular guitar to achieve the desired pitch with heavy strings at average tensions.


Wolf interval

In music theory, the wolf fifth (sometimes also called Procrustean fifth,
or imperfect fifth)
is a particularly dissonant musical interval spanning seven semitones. Strictly, the term refers to an interval produced by a specific tuning system, widely used in the sixteenth and seventeenth centuries: the quarter-comma meantone temperament. More broadly, it is also used to refer to similar intervals produced by other tuning systems, including most meantone temperaments.
When the twelve notes within the octave of a chromatic scale are tuned using the quarter-comma mean-tone systems of temperament, one of the twelve intervals spanning seven semitones (classified as a diminished sixth) turns out to be much wider than the others (classified as perfect fifths). In mean-tone systems, this interval is usually from C to A or from G to E but can be moved in either direction to favor certain groups of keys. The eleven perfect fifths sound almost perfectly consonant. Conversely, the diminished sixth is severely dissonant and seems to howl like a wolf, because of a phenomenon called beating. Since the diminished sixth is meant to be enharmonically equivalent to a perfect fifth, this anomalous interval has come to be called the wolf fifth.
Besides the above-mentioned quarter comma meantone, other tuning systems may produce severely dissonant diminished sixths. Conversely, in 12-tone equal temperament, which is currently the most commonly used tuning system, the diminished sixth is not a wolf fifth, as it has exactly the same size as a perfect fifth.
By extension, any interval which is perceived as severely dissonant and may be regarded as howling like a wolf may be called a wolf interval. For instance, in quarter comma meantone, the augmented second, augmented third, augmented fifth, diminished fourth and diminished seventh may be considered wolf intervals, as their size significantly deviates from the size of the corresponding justly tuned interval (see Size of quarter-comma meantone intervals).
Temperament and the wolf.
In 12-tone scales, the average value of the twelve fifths must equal the 700 cents of equal temperament. If eleven of them have a value of 700 − "ε" cents, as in quarter-comma meantone and most other meantone temperament tuning systems, the other fifth (more properly called a diminished sixth) will equal 700 + 11"ε" cents. The value of "ε" changes depending on the tuning system. In other tuning systems (such as Pythagorean tuning and twelfth-comma meantone), eleven fifths may have a size of 700 + "ε" cents, thus the diminished sixth is 700 − 11"ε" cents. If 11"ε" is very large, as in the quarter-comma meantone tuning system, the diminished sixth is regarded as a wolf fifth.
In terms of frequency ratios, the product of the fifths must be 128, and if "f" is the size of a fifth, 128:"f"11, or "f"11:128, will be the size of the wolf.
We likewise find varied tunings for the thirds. Major thirds must average 400 cents, and to each pair of thirds of size 400 ∓ 4"ε" cents we have a third (or diminished fourth) of 400 ± 8"ε" cents, leading to eight thirds 4"ε" cents narrower or wider, and four diminished fourths 8"ε" cents wider or narrower than average. Three of these diminished fourths form major triads with perfect fifths, but one of them forms a major triad with the diminished sixth. If the diminished sixth is a wolf interval, this triad is called the wolf major triad.
Similarly, we obtain nine minor thirds of 300 ± 3"ε" cents and three minor thirds (or augmented seconds) of 300 ∓ 9"ε" cents.
Quarter comma meantone.
In quarter-comma meantone, the fifth is of size , about 3.42157 cents (or exactly one twelfth of a diesis) flatter than 700 cents, and so the wolf is about 737.637 cents, or 35.682 cents sharper than a perfect fifth of size exactly 3:2, and this is the original howling wolf fifth.
The flat minor thirds are only about 2.335 cents sharper than a subminor third of size 7:6, and the sharp major thirds, of size exactly 32:25, are about 7.712 cents flatter than the supermajor third of 9:7. Meantone tunings with slightly flatter fifths produce even closer approximations to the subminor and supermajor thirds and corresponding triads. These thirds therefore hardly deserve the appellation of wolf, and in fact historically have not been given that name.
The wolf fifth of quarter-comma meantone can be approximated by the 7-limit just interval 49:32, which has a size of 737.652 cents.
Pythagorean tuning.
In Pythagorean tuning, there are eleven justly tuned fifths sharper than 700 cents by about 1.955 cents (or exactly one twelfth of a Pythagorean comma), and hence one fifth will be flatter by twelve times that, which is 23.460 cents (one Pythagorean comma) flatter than a just fifth. A fifth this flat can also be regarded as howling like a wolf. There are also now eight sharp and four flat major thirds.
Five-limit tuning.
Five-limit tuning was designed to maximize the number of pure intervals, but even in this system several intervals are markedly impure. 5-limit tuning yields a much larger number of wolf intervals with respect to Pythagorean tuning, which can be considered a 3-limit just intonation tuning. Namely, while Pythagorean tuning determines only 2 wolf intervals (a fifth and a fourth), the 5-limit symmetric scales produce 12 of them, and the asymmetric scale 14. It is also important to note that the two fifths, three minor thirds, and three major sixths marked in orange in the tables (ratio 40/27, 32/27, and 27/16 (or G−, E♭−, and A+), even though they do not completely meet the conditions to be wolf intervals, deviate from the corresponding pure ratio by an amount (1 syntonic comma, i.e., 81/80, or about 21.5 cents) large enough to be clearly perceived as dissonant.
Five-limit tuning determines one diminished sixth of size 1024:675 (about 722 cents, i.e. 20 cents sharper than the 3:2 Pythagorean perfect fifth). Whether this interval should be considered dissonant enough to be called a wolf fifth is a controversial matter.
Five-limit tuning also creates two "impure" perfect fifths of size 40:27 (about 680 cents; less "pure" than the 3:2 Pythagorean perfect fifth). These are not diminished sixths, but relative to the Pythagorean perfect fifth they are less consonant (about 20 cents flatter) and hence, they might be considered to be wolf fifths. The corresponding inversion is an "impure" perfect fourth of size 27:20 (about 520 cents). For instance, in the C major diatonic scale, an impure perfect fifth arises between D and A, and its inversion arises between A and D.
Since the term "perfect" means, in this context, perfectly consonant, the impure perfect fourth and perfect fifth are sometimes simply called "imperfect" fourth and fifth. However, the widely adopted standard naming convention for musical intervals classifies them as "perfect" intervals, together with the octave and unison. This is also true for any perfect fourth or perfect fifth which slightly deviates from the perfectly consonant 4:3 or 3:2 ratios (for instance, those tuned using 12-tone equal or quarter-comma meantone temperament). Conversely, the expressions "imperfect fourth" and "imperfect fifth" do not conflict with the standard naming convention when they refer to a dissonant augmented third or diminished sixth (e.g. the wolf fourth and fifth in Pythagorean tuning).
"Taming the wolf".
Wolf intervals are a consequence of mapping a two-dimensional temperament to a one-dimensional keyboard. The only solution is to make the number of dimensions match. That is, either:
Keep the piano keyboard.
When the perfect fifth is tempered to be exactly 700 cents wide (that is, tempered by approximately of a syntonic comma, or exactly of a Pythagorean comma) then the tuning is identical to the familiar 12-tone equal temperament.
Because of the compromises (and wolf intervals) forced on meantone tunings by the one-dimensional piano-style keyboard, well temperaments and eventually equal temperament became more popular.
A fifth of the size Mozart favored, at or near the 55-equal fifth of 698.182 cents, will have a wolf of 720 cents, 18.045 cents sharper than a justly tuned fifth. This howls far less acutely, but still very noticeably.
The wolf can be tamed by adopting equal temperament or a well temperament. The very intrepid may simply want to treat it as a xenharmonic music interval; depending on the size of the meantone fifth it can be made to be exactly 20:13 or 17:11, or less commonly to 32:21 or 49:32.
With a more extreme meantone temperament, like 19 equal temperament, the wolf is large enough that it is closer in size to a sixth than a fifth, and sounds like a different interval altogether rather than a mistuned fifth.
Keep the two-dimensional tuning system.
To use a two-dimensional temperament without wolf intervals, one needs a two-dimensional keyboard that is "isomorphic" with that temperament. A keyboard and temperament are isomorphic if they are generated by the same intervals. For example, the Wicki keyboard shown in Figure 1 is generated by the same musical intervals as the syntonic temperament — that is, by the octave and tempered perfect fifth — so they are isomorphic.
On an isomorphic keyboard, any given musical interval has the same shape wherever it appears — in any octave, key, and tuning — except at the edges. For example, on Wicki's keyboard, from any given note, the note that is a tempered perfect fifth higher is always up-and-rightwardly adjacent to the given note. There are no wolf intervals within the note-span of this keyboard. The only problem is at the edge, on the note E. The note that is a tempered perfect fifth higher than E is B, which is not included on the keyboard shown (although it could be included in a larger keyboard, placed just to the right of A, hence maintaining the keyboard's consistent note-pattern). Because there is no B button, when playing an E power chord, one must choose some other note that is close in pitch to B, such as C, to play instead of the missing B. That is, the interval from E to C would be a "wolf interval" on this keyboard. In 19-TET, the interval from E to C would be (enharmonic to) a perfect fifth.
However, such edge conditions produce wolf intervals only if the isomorphic keyboard has fewer buttons per octave than the tuning has enharmonically distinct notes. For example, the isomorphic keyboard in Figure 2 has 19 buttons per octave, so the above-cited edge condition, from E to C, is "not" a wolf interval in 12-TET, 17-TET, or 19-TET; however, it "is" a wolf interval in 26-TET, 31-TET, and 53-TET. In these latter tunings, using electronic transposition could keep the current key's notes centered on the isomorphic keyboard, in which case these wolf intervals would very rarely be encountered in tonal music, despite modulation to exotic keys.
A keyboard that is isomorphic with the syntonic temperament, such as Wicki's keyboard above, retains its isomorphism in any tuning within the tuning continuum of the syntonic temperament, even when changing tuning dynamically among such tunings. Figure 2 shows the valid tuning range of the syntonic temperament.
Listen to it.
Listen to the two fifths here:


Tom Hall (electronic musician)

Tom Hall is an Australian audio/visual artist, residing in Los Angeles.
Hall's work characterized by field recordings, synthesizer, computer software processing and improvisation, which generates a large range of possible sounds including; melodic rhythms, grainy textures, and drone.
Hall's eclectic works flourish by utilizing a variety of mediums, each that reflect on his varied background and interests. With a strong focus on elements of the 'everyday' Hall's practice involves considered explorations into place, space and time. Drawing inspiration from countless 'peripheral' spaces, Hall focuses on using multiple approaches to engage and recontextualise them to the public.
Hall focuses and uses sound as a means to translate feeling, create hybrid environments and notions of journey. Stylistically these outcomes vary from noise orientated improvisation, to structured drone and melody.
Biography.
Tom Hall is a graduate of The Australian National University with Honours where he majored in Photomedia, studying under the guidance of Dr. Martyn Jolly. During Hall's time at university he spent 1 year abroad (2004) on a scholarship studying sound and moving image at Kyoto Seika University under the guidance of Saburo Hirano and Shinsuke Ina where Hall was introduced Max/MSP.
Hall utilises custom designed software and a variety of unorthodox approaches to combining imagery and sound, producing an array outcomes that have seem him exhibit and perform globally in the past decade. During his career he has completed consecutive residencies at The Perth International Arts Festival, residencies in San Francisco, Netherlands and Japan. Hall has developed a reputation for touring tirelessly having completed multiple tours throughout Australia, Japan, Europe, UK and America. In addition to this Hall has also completed a number of sound based installations and exhibited works globally.
Hall is also the recipient of the 2009 Brisbane Lord Mayors Fellowship that allowed him to complete a four-month residency in San Francisco, USA.
During his career Hall has worked with and played alongside artists such as Steinbruchel, Sawako, Tim Hecker, Jason Khan, Lawrence English, Takashi Kojima, Haco, Birchville Cat Motel, Isis, Health (band), Lichens and Max Cooper.
Hall is also a member of AXXONN. A stream-line electronic music project that transcends pop/electro/doom and noise.


6249 Jennifer


Preparation (music)

In tonal music, a preparation is the consonant pitch or chord which precedes a dissonant nonharmonic tone. The move from a dissonance to a consonance constitutes a resolution.
In the following example, the C major chord on the left is a preparation which precedes a nonharmonic tone that serves as an anticipation (center, marked in red) to the G major harmony on the right. This harmony resolves the preceding dissonance:


National Standard Examination in Biology

The National Standard Examination in Biology or NSEB is an examination for biology for higher secondary school students in India, usually conducted in the end of November. The examination is organized by the Association of Teachers in Biological Sciences in association with Indian Association of Physics Teachers and Homi Bhabha Centre for Science Education (HBCSE). Each year over 30,000 students of 12th Standard or below , sit for this examination.
Eligibility.
The examination is intended for students in 12th standard, though 11th standard students are also allowed to give the examination. Usually, the qualifying students are from 12th standard.
Qualification.
There is a designated statewise quota according to which the students are selected for the next stage i.e. INBO. Further all students scoring greater than 80% of the average of the top ten scores at national level(called as Merit Index Score) get automatically selected irrespective of the statewise quota.
Usually the top 1% students from this examination are selected to sit for the Indian National Biology Olympiad.
Format.
The NSEB comprises only multiple choice questions. The questions include plant physiology, genetics and human physiology. The stress on biochemistry is more in the NSEB than in the typical school syllabi.
Fee.
As per new revised norms the fee for the NSEB is about Rs. 150. Application for this examination is typically handled through the school/college to which the student is affiliated.
Indian National Biology Olympiad.
It's held in January, and consists of objective as well as subjective questions. The top 35 performers here, are selected for the Orientation-Cum-Selection-Camp (OCSC), Biology , where they're trained and tested in theory and experiment. The top 4 performers from OCSC Biology are selected to represent India in the International Biology Olympiad.
Before IBO, the selected team undergoes rigorous training in theory and experiment, in a Pre-Departure Training Camp (PDC).


Diffuse reflectance infrared Fourier transform spectroscopy

Diffuse reflectance infrared fourier transform spectroscopy (DRIFTS) is an infrared spectroscopy sampling technique used on powder samples without prior preparation. The sample is added to a sample cup and the data is collected on the bulk sample. The infrared light on a sample is reflected and transmitted at different amounts depending on the bulk properties of the material. Diffuse reflection of the incident light produced by the sample's rough surface reflection in all directions is collected by use of an ellipsoid or paraboloid mirror. Shape, compactness, refractive index, reflectivity and absorption of the particles are all characteristic of the material being analyzed. If the sample is too absorbent, then it can be diluted with a nonabsorbent material such as potassium bromide, potassium chloride, etc. The particle size should be smaller than the wavelength of the incident light in order to minimize Mie scattering, so this would infer that it should be less than 5 µm for mid-infrared spectroscopy. The spectra are plotted in units of log inverse reflectance (log 1/R) versus wavenumber. Alternative plots of Kubelka-Munk units can be used, which relate reflectance to concentration using a scaling factor. A reflectance standard is needed in order to quantify the reflectance of the sample because it cannot be determined directly.


3S (music)


4686 Maisica


Glimpse of the Garden

Glimpse of the Garden is a 1957 five-minute short experimental film made by Marie Menken, showing film clips of a garden, with birds chirping for the soundtrack.
In 1958, the film won an award at the Exposition Universelle et Internationale at Brussels. In 2007, the film was included in the annual selection of 25 motion pictures added to the National Film Registry of the Library of Congress being deemed "culturally, historically, or aesthetically significant" and recommended for preservation.


Sensistor

Sensistor is a resistor whose resistance changes with temperature.
The resistance increases exponentially with temperature, that is the temperature coefficient is positive (e.g. 0.7% per degree Celsius).
Sensistors are used in electronic circuits for compensation of temperature influence or as sensors of temperature for other circuits.
Sensistors are made by using very heavily doped semiconductors so that their operation is similar to PTC-type thermistors. However, very heavily doped semiconductor behaves more like a metal and the resistance change is more gradual than it is the case for other PTC thermistors.


Yangcheng Evening News

Yangcheng Evening News or "Ram City Evening News" (), also known as "Yangcheng Evening Post" or "Ram City Evening Post", is a Chinese newspaper in the Standard Chinese language, national unified publication number CN44-0006 in Guangzhou, Guangdong, China.
History.
The publication of "Yangcheng Evening Post" was started on October 1, 1957, in Guangzhou, China. The newspaper was forced to stop publication during the Cultural Revolution and resumed publication on February 15, 1980. Started from May 18, 1998, the paper became among several newspapers published by the Yangcheng Evening News Group.
"Yangcheng Evening Post" is one of the world's largest circulated newspapers: in 2008, its daily circulation was estimated to be 1,170,000, distributed mainly in the Pearl River Delta area in southern China.


2040 Chalonge


National Large Solar Telescope

The National Large Solar Telescope (NLST) is a Gregorian multi-purpose open telescope proposed to be built in Merak village in Ladakh in India and aims to study the sun's microscopic structure.
The Indian Institute of Astrophysics is the nodal agency charged with various scientific bodies like the Indian Space Research Organisation (ISRO), Aryabhatta Research Institute of Observational-Sciences, Tata Institute of Fundamental Research (TIFR) and Inter-University Centre for Astronomy and Astrophysics (IUCAA) also participating.
Location.
The proposed site for the location of the telescope is Merak Village in Ladakh, India. The village is near Pangong Lake.
Telescope.
NLST is proposed to be on-axis alt-azimuth Gregorian multi-purpose open telescope with the provision of carrying out night time stellar observations using a spectrograph. It hopes to resolve features on the Sun of the size of about 0.1 arcsec. The focal plane instruments are to include a high resolution polarimeteric package to measure polarization with an accuracy of 0.01 per cent; a high spectral resolution spectrograph to obtain spectra in 5 widely separated absorption lines simultaneously and high spatial resolution narrow band imagers in various lines.


Soundtrack from the Film Mabuta no Ura

Soundtrack from the Film Mabuta no Ura is the ninth studio album by Japanese experimental band Boris, released on June 29, 2005 through Catune and Inoxia and on November 12 of the same year through Essence Music. The album includes the song "A Bao A Qu" which shares the same name as the version included on the album "The Thing Which Solomon Overlooked". However, both versions are quite different from one another. The band used this version of the song "A Bao A Qu" and created a 7" single with an extended version of the track. A music video was also released for this song but it is based on the 7" single. There is yet another version of the song which was included on the 2010 compilation, "Boris / Variations + Live in Japan", and a live recording is included in "Archive II". The 2016 re-release of "Pink" includes a bonus disc with the track "Your Name Part 2," apparently a sequel to the track of that name from this album.
Album title.
Though the title describes the album as a soundtrack for the film "Mabuta no Ura" (lit. "Under the Eyelids"), no such film exists. The album is rather the result of the band imagining a film in their heads and writing a soundtrack for it. Because of this, the band has classified this as a concept album. The album's concept is also driven by photography and art-styling which is included on a version of the album.
Release.
Two versions of this album exist. The first one is the version of the album was released on CD by the label Catune. This version was housed on brown packaging which included story cards with photos and the stories and lyrics in Japanese. Inoxia released this version of the album on an LP limited to 600 copies with a different cover and photo book. The second version was released by the Brazilian label Essence Music, limited to 2000 copies, this version has a different arrangement and song list to the other versions mentioned above. This version shows the same cover as the LP version and includes numerous photos, story card materials, and lyrics in English. They also made a special box-set edition limited to 199 hand-numbered copies that contained art prints, flyers, and a bunch of dead flowers.


2956 Yeomans

2956 Yeomans, provisional designation , is a stony asteroid from the central regions of the asteroid belt, approximately 10 kilometers in diameter. It was discovered on 28 April 1982, by astronomer Edward Bowell at the Anderson Mesa Station of the Lowell Observatory in near Flagstaff, Arizona. It was named after American astronomer Donald Keith Yeomans.
Orbit and classification.
"Yeomans" is a non-family asteroid from the asteroid belt's background population. It orbits the Sun in the central main-belt at a distance of 2.5–3.0 AU once every 4 years and 7 months (1,679 days). Its orbit has an eccentricity of 0.09 and an inclination of 3° with respect to the ecliptic.
The asteroid was first identified as at the Johannesburg Observatory in May 1950. The body's observation arc begins with its identification as at Crimea–Nauchnij in September 1974, almost 8 years prior to its official discovery observation at Anderson Mesa.
Physical characteristics.
In the SMASS classification, "Yeomans" is an Sr-subtype that transitions from the stony S-types to the uncommon R-type asteroids.
Rotation period.
In April 2014, a rotational lightcurve of "Yeomans" was obtained from photometric observations made at the Isaac Aznar Observatory in Spain. Lightcurve analysis gave a rotation period of 3.4 hours with a brightness variation of 0.28 magnitude (). A similar period of 3.509 hours with an amplitude of 0.24 magnitude was found by astronomers at the Palomar Transient Factory in October 2011 ().
Diameter and albedo.
According to the survey carried out by the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, "Yeomans" measures 9.350 kilometers in diameter and its surface has an albedo of 0.292. The "Collaborative Asteroid Lightcurve Link" assumes a standard albedo for stony asteroids of 0.20 and derives a diameter of 11.30 kilometers based on an absolute magnitude of 12.1.
Naming.
This minor planet was named after American astronomer Donald Keith Yeomans, a celestial mechanician at JPL and astrometry-expert of the International Halley Watch. The official naming citation was published by the Minor Planet Center on 18 September 1986 ().


Malvidin glucoside-ethyl-catechin

Malvidin glucoside-ethyl-catechin is a flavanol-anthocyanin adduct. Flavanol-anthocyanin adducts are formed during wine ageing through reactions between anthocyanins and tannins present in grape, with yeast metabolites such as acetaldehyde. Acetaldehyde-induced reactions yield ethyl-linked species such as malvidin glucoside-ethyl-catechin.
This compound has a better color stability at pH 5.5 than malvidin-3O-glucoside. When the pH was increased from 2.2 to 5.5, the solution of the pigment became progressively more violet (λmax = 560 nm at pH 5.5), whereas similar solutions of the anthocyanin were almost colorless at pH 4.0.
Other types of aldehyde, such as isovaleraldehyde, benzaldehyde, propionaldehyde, isobutyraldehyde, formaldehyde or 2-methylbutyraldehyde, show the same reactivity in model solutions.


The Text of Light

The Text of Light is a 1974 American experimental film directed by Stan Brakhage.
Synopsis.
Time-lapse photography of books, paintings, reflections, and light falling on textures, shot entirely through a glass ashtray.
Reception.
The film received a positive reception, rating 6,4 out of 10 on IMDb.