What are the benefits of capping frames per second? (If any)

Question: I am working on a simple game in OpenGL, using SDL for display initialization and input, and it appears in terms of timing I have two options available to me. Number one being just sleeping for the optimalTimePerFrame - theTimeTakenToRender, when the optimalTimePerFrame in seconds = 1/theFramerateCap. (I'm not entirely sure if this is necessary, as it is equivalent to using vsync, which may be more accurate. If my assumption is correct then please tell me wheter or not SDL + OpenGL has vsync by default, and if not how to enable it.) The other is to measure the time since the last frame was rendered, and merely adjust movement accordingly. (The shorter time taken to render a frame, the less far entities move in that frame). In terms of performance, and decreasing flicker etc, what are the advantages and disadvantages of these two methods?
Answer: If your frame time is unpredictable (whether or not this is your fault; the OS may be using resources occasionally, etc), capping to a predictable frame rate that is somewhat lower than your achievable framerate will do a lot for predictable latency, which can make the game feel a lot better.
Changing how long between when you process input and render changes related to that input can feel bad -- even if on average you're achieving less latency between the two, the "jitter" can be noticeable to humans (consciously or unconsciously).
See the Microsoft GameFest presentation What's In a Frame: Tearing, Latency, and Frame Rate for some insight here.  Carmack also has a series of blog posts that are useful in this.
Also be aware that some math can break down when you run frames using low deltaT values -- or even when you use variable deltaT at all (things can become harder or even intractable to do in a "stable" and predictable manner, which is important for things like replays and some forms of network synchronization).  See Fix Your Timestep for some insight here.
Comment: In SDL 2.0, you can enable vsync by passing the flag SDL_RENDERER_PRESENTVSYNC to SDL_CreateRenderer call, e.g. `SDL_CreateRenderer(window, -1, SDL_RENDERER_ACCELERATED | SDL_RENDERER_PRESENTVSYNC);`
Comment: (By the way, I'd highly recommend not capping by way of "sleep"; figure out what your vsync situation is on your platform and use vsync to drive you.  It's much more predictable and usually uses less resources.)
Comment: Thanks, I will definitely try to cap the framerate. Do you know how to enable vsync using SDL?
Answer: You will end up using a lot less CPU (multi taskers will thank you) and people on mobile devices will appreciate this, too.
Comment: Not to mention lower power usage (important for mobile devices/laptops), and less heat generation.
Comment: It reminds me of some games issue, when FPS in menus was unlimited and insanely high, alike 900fps, and that really stressed the CPU/GPU -> higher temp -> more noise.
Answer: You should never, ever, ever, ever, ever use Sleep to control framerate.
This has been gone over before and I'll refer you to the other question for discussion of the reasons why.  One thing not mentioned there is that at the typical modern refresh rate of 60Hz, and with the typical 1 millisecond granularity of Sleep calls, it's actually impossible to Sleep for the correct amount of time between frames.
I'm not saying that yielding CPU if you've nothing to do is a bad thing; far from it.  But it's not the same thing as controlling framerate and Sleep is a solution that's appropriate for the former but not the latter.
Instead check for time elapsed, and if it's time to run a frame, then do so, otherwise - and if you want to yield some CPU - Sleep for the bare minimum of time - 1 millisecond.  Also ensure that your sleep timer is set up appropriately for your platform so as to give you good resolution; i.e. that when you issue that "Sleep (1)" call you actually stand a chance of really Sleeping for 1 millisecond, rather than something like 15, 20 or 30 (which would be the case otherwise).  I believe that SDL will do this automatically for you.
You can also build some slack into it, so that if it's getting near time to run a frame, you stop Sleeping and start running flat-out until the frame runs, which can help you hit your desired frame interval more accurately.
What this ends up looking like is a whole bunch of Sleep (1) calls interspersed with the occasional frame, and that's OK.  You're still giving up CPU when you don't need it, but your frames will still be able to run on time.
Answer: Probably the most important benefit of capping frame rate is that it can help to prevent literal physical damage to the machine.  They forgot to do this on Starcraft II, which turned out to be very problematic (and expensive) for some users until they patched it.
Answer: As was mentioned earlier, it lowers CPU usage.  On the flipside, and increasingly important, that also drains battery life.  As a good example, FTL runs at nearly 100% CPU on my MBA.  As a result, it drains the battery in > 2 hours and runs very hot.  ( As a more direct result, I uninstalled and no longer play it... ).  A frame cap would have prevented this.
Another unmentioned advantage is, if its a multiplayer game, you also level the playing field by giving everyone the same experience.
Comment: Your framerate and game update loop don't have to be running at the same speed, so giving people the same experience doesn't rely on framerate alone.


Prayer direction inside kaabah

Question: If someone offer Salah prayer inside the Kaabah, in which direction do they face.
Comment: I hear they sometimes allow people, see video youtube https://www.youtube.com/watch?v=jXhNyq9dC5M
Answer: Basically you can pray inside the Ka'bah to what ever direction based on the hadith:

Pray in al-Hijr when you intend to enter the House (the Ka'bah), for it is a part of the House (the Ka'bah). Your people shortened it when they built the Ka'bah, and they took it out of the House. (Sunan abi Dawod)

For further references see also in Sahih al-Bukhari and Sahih Muslim (suggested by @Uma in a comment) and the post I'll refer to later.
Note that there are some narrations of ibn 'Abbas saying a prayer inside is invalid, the main opinion of the dhahiri and maliki school is that it is permissible to pray nafl (optional) prayers inside, but praying fard (obligatory) prayers is not valid and should be redone.
Imam a-Shafi'i has said that if some one prayed inside in the direction of the door of the Ka'bah with no part of the interior between him and the door his prayer is invalid. Else whatever direction he chose for the prayer inside the Ka'bah is a qiblah.

قال الشافعي : فيصلي في الكعبة النافلة والفريضة، وأيَّ الكعبة استقبل الذي يصلي في جوفها فهو قبلة... ولو استقبل بابها فلم يكن بين يديه شيء من بنيانها يستره لم يجزه.

See also Interior of Kaaba
Some references in Arabic:
islamweb #29271 and bin Baz #2482

Prayer direction inside kaabah


update SPList using csv via Powershell

Question: knowing that is possible in PS, exporting SPList items to PS objects(link1 link2) what is the best way, to go into the other way:
Create/Update an SPList from an exported csv or format-table.
Answer: After creating manually an list based on or csv template via UI...
<code>#get data
$csv = Import-Csv 'C:\MyData.csv'
#get list
$web = Get-SPWeb -identity "MyTargetListURL"

foreach ($row in $csv) {
    #Check for existing item
    $SPItem = $SPList.Items | Where { $_["ItemId"] -eq $row.ItemId }

    If ($SPItem -ne $null) {
        $SPItem["ColumnNumberType"] = [System.Convert]::ToInt32($row.ColumnNumberType)
        $SPItem["Column with special-chars"] = $row."Column with special-chars"
        #rest of fields

        $SPItem.Update()
    }
    Else {
        $SPNewItem = $SPList.Items.Add()
        $SPNewItem["ItemId"] = $row.ItemId
        #rest of fields

        $SPNewItem.Update()
    }
 }
</code>
Answer: There are 3rd party tools that can automate the update process (only changed items updated, so you can add workflows or attachments).
See here for step-by-step guide:
http://www.layer2.de/en/community/FAQs/BDLC/Pages/How-to-connect-text-file-to-sharepoint-list.aspx
Comment: Thanks a lot for the reply, but actually is not a complex PS script to do that. I just wanna know the best way to go.
Answer: I think fallout's answer partially answers the question. His 'if statement' checks if items exist, then updates items if they exist, otherwise it creates new items if they do not exist.
Depending on your columns, the trick is to update only those items that have changed in the CSV file (required for efficient version control in the sharepoint list).

update SPList using csv via Powershell


Why isn't there hot water coming from my faucet after stem replacement?

Question: I just completed the replacement of the hot and cold water stems form my bathtub faucets. The hot water was leaking so I went ahead and replaced both. They were probably original to the house circa late 50's. After finally getting them loose I inserted new correct replacements. The problem now is that when I run the hot water I only get cold water. I let it run for several minutes but still had no hot water coming out. There is hot water everywhere else in the house, even the sink near the tub. Has any else ever heard of this or encountered this problem.
Comment: I know this is going to sound dumb but did you turn the hot water feed back on under the sink?  if you had water before did you have to wait for it to warm up?
Comment: Can you post some pics of your faucet and the stems you used, a lot of them have options for reversing them.
Comment: Did you bleed out the lines before hooking them back up or installed a cartridge back wards? If its a single handle, remove the cartridges and clean/replace them.
Answer: This sounds like an older style (washer type) installation. Is it possible that part of an old washer is stuck in the seat, or was pushed back behind the seat into the pipe, preventing water flow? First, make sure you have hot water TO the tub area. Turn the water off and remove the hot side, stem and all. Inspect for obstructions. You may need to briefly turn the water back on with the stem OUT, to blow out any obstructions. Have a helper turn the water on and back off, as you watch for any debris coming out. Once you have established hot water to the valve, you can check for an obstruction AFTER the hot water valve where it feeds into the tub spout, either part of an old washer or other debris. With the valve stem out, and the cold water valve off, try blowing air back through the spout to clear this (it will go into the hot water valve area) and then clear the valve out again before replacing the stem and washer, handles, etc.
Nine times out of ten, some obstruction will be in the line either before the valve or after it, where it feeds into the common pipe to the spout.
Answer: If it is a single handle cartridge, remove and rotate it 180 degrees.  It worked for me.


Is there a way to transfer a Launchpad layout to another machine?

Question: If I spend time grouping apps in neat folders in Launchpad on one machine, is there a way to copy that mapping to another system without having to manually organize everything all over again ?
Answer: It does appear to work. Copy over the existing entry in the target ~/Library/Application\ Support/Dock folder with the source file. The first use of launchpad was missing the majority of the icons but logging out and back in again to the account resolved this.
Answer: I have not tested this yet, but I according to this TUAW article the .db files in <code>~/Library/Application\ Support/Dock</code> contain all the configuration information for Launchpad.
I presume copying this folder to another machine will duplicate the configuration. Let us know if it works.
There are three ways to get to your Library folder:
-You can use the terminal to copy the files manually
-You can enter this in the terminal to "unhide" your Library folder within Finder so that you are always able to see it.
    chflags nohidden ~/Library
-Or you can simply open Finder click Go, then press the Option key (alt) to temporarily show it in the list (this is the safest option).
Answer: What I ended up doing was copying the name of the original .db file that I wanted to remove, (let's say ABC123) then logged out of the user account. I logged in as an administrative user and deleted the original .db file then copied over my new one and gave it the ABC123 name I'd copied from the user's original. Convoluted, and maybe someone has a better way, but that's what worked for me. There was on icon out of place when I opened LaunchPad but it was easy enough to fix and all my folders were as I'd set them.
Answer: I haven't tried it, but there's lporg, a command-line utility that purports to do just this.


How can I create a fixed column header in Google Spreadsheet like the first sheet?

Question: How can I create a fixed column header in Google Spreadsheet like the first sheet?
Answer: Up to ten rows of each sheet can be designated as the column header. This is called freezing rows. Every sheet has a horizontal guideline which separates header rows from the rest of the sheet. This guideline has a gray handle. The gray handle initially appears above row "1" on the left hand side of the sheet. To set the number of rows in the column header, drag the handle up or down using the mouse.

Or you can set the number of rows using the menu option View → Freeze Rows.
There is also a vertical guideline which works in a very similar manner, and lets you freeze as many as five columns as row labels.
When you create a blank document, it comes with an initial sheet. This sheet does not have a column header.¹ Additional sheets, if you create them, are the same: they do not have column headers to begin with.
The Android app imposes a limitation on this feature. While it does show frozen row and column headers properly, it does not let you control which rows or columns are frozen. You need to use a PC based browser to change your row and column headers.
Notes

When the question was originally asked, the first sheet in a new untitled spreadsheet had one header row: row 1. This is no longer so. But it is why the question was asked the way it was.
Comment: Hover over the blue (dashed) line ....at the top left corner..wait for the hand shaped cursor ..then drag it down.
Comment: UPDATE: the dashed line may appear gray now, but turns blue when hovering.
Comment: When I create a new spreadsheet it doesn't default to one header row, so I'm assuming that's a change from before.  But, otherwise, this and the comments are still correct.  I.e. There's a horizontal/vertical dashed gray line at the top-left corner, and when you hover over one it turns blue and the cursor changes to a hand.  The other answer about "Freeze rows" is an alternative way to do this through the menu.
Comment: @MichaelKrebs Thanks for the update. I have changed the answer to reflect changes in the app, and added information about the Android app as well.
Answer:
Open Spreadsheet
Click on View from the menu
Click on Freeze rows from the dropdown menu
Choose how many rows you want to freeze.

Frozen row(s) will stay at the top of the sheet when viewing other portions of it.
Answer: In the new Google Sheets some elements related to freeze/unfreeze columns & rows were updated, while others remain the same. I.E.

The ten rows limit was removed.
The gray handle, mentioned in the accepted
answer is still there.

References
Freeze or unfreeze columns & rows - Docs Editors Help


PETG Sticking to Nozzle

Question: For a while now, my AmazonBasics PETG filament has been working like a charm. Now, it is balling up on my nozzle. I've tried slowing it down, re-leveling the bed, etc. I don't want to go through the hassle of replacing my nozzle with a Micro-Swiss all metal 0.4 mm nozzle. I've tried the other extruder which I know works with PLA, but same results. I'm using a Flashforge Creator Pro(2016).
Comment: Please add pictures and more information (by [edit]) when this happens, e.g. on the first layer or after a few layers. If it is a layer adhesion problem, maybe [this question](/q/727) may help you.
Answer: It could be that you're having issues now due to the filament absorbing moisture. I had a big problem with it doing that when I had waited for a few months after opening my filament. Dehydrated it using just my heated plate and a foil lined box over the top and it fixed it right up. If that's something you haven't tried yet perhaps that is what is causing you some grief.
Comment: Welcome at 3D Printing.SE Kaleb! You must have had a ventilation hole or something to get rid of the moist air?
Answer: PETG does this. PETG is like glue when soft this is why when you level the bed you have to add an additional 0.1 mm distance for PETG. PETG should not be as close as PLA, but futher away. It will stick to the hotend so preferably change the hotend from brass to a nickle plated nozzle (e.g. Micro Swiss, PETG does not stick to that nozzle at all).
Comment: I've printed kilometers of 2.85 mm PETG filament, but never needed an increased first layer height or an extra clearance between nozzle and bed. I guess it is depending on your setup. It may help, but it could be it also works without such measures.
Comment: Nice, I will change my nozzles I have a bunch of them since one year ago waiting to assembly my third printer and the new ones.
Comment: Its the makeup of PETG, it is a stickier thermal plastic and you get better results if you increase the distance, slightly, between the nozzle and bed. Maker Muse and Tom both suggest the same thing in their YouTube videos. When I print with PETG, I never get any stringing at all and it prints just like PLA. I get near perfect prints with zero cleanup or stringing at the end. When I do figures of any kind I use PETG instead of PLA.

PETG Sticking to Nozzle


Wifi Sniffing Prevention

Question: I share my wifi with my brother. Recently I came to know he is sniffing on my browsing. Is there a way I can prevent him from sniffing on my browsing?
PS: I can't afford VPN.
Comment: A very similar question has been asked before; see [this answer](http://security.stackexchange.com/a/56646/43847).
Comment: Time to beat your brother! :)
Answer: Encrypt. VPN, ssl, https, etc. That's what they are for, to create secure channels within insecure environments.
HTTPS is an option for 'browsing'. Always make sure you are using the https version of sites instead of the http version. There are browser plug-ins that can help with that, too.
Challenge your assumption that you cannot afford VPNs, With a little knowledge, you can create your own.
Another potential solution is to find a used wifi router for free and use that to connect to your home's Internet connection. Set it up for yourself and don't tell your brother the password ...
Answer: In addition to Schroeder's good answer, I'd like to say that you can use the Tor browser bundle. Once on your system, just click the onion and you're browsing privately. Tor won't work for watching videos, but it's great for browsing. I've used it for browsing Facebook (and other sites) which works fine. Even if your brother wouldn't be spying you, Tor is great to ensure your privacy.
Download the Tor browser bundle
I recommend reading the documentation before use. It's important to understand that browsing is anonymous, but if you enter a form (e.g. your name) on a web site, obviously the web site gets your info. It sounds like just want browsing privacy, so this should be acceptable for you.
Also, regarding the trust issue with your brother: Don't forget that your brother might try to boot your computer when you're absent. Make sure none of the passwords of your important accounts (email, Facebook, etc.) are easy to guess.

Wifi Sniffing Prevention


Shift+arrow to change window does not work in org-mode

Question: I installed a package that changes emacs windows using Shift+arrow, and it works in various modes I use but not in org-mode.  Is there a reason why org-mode shadows this command?
Comment: It would be helpful to know the package for window changing you are referring to (`windmove`?). Have a look at http://orgmode.org/manual/Conflicts.html.
Comment: The following link demonstrates how to disable a few `org-mode-map` key bindings:  http://stackoverflow.com/a/17540326/2112489  That approach will permit global key bindings to be used again.
Comment: Thanks for prompting me, I have now found it in my init file.  It is `framemove`.
Comment: @AlejandroErickson OK. The org-mode Conflicts section should help for that too. Check out the CUA and windmove sections over there.
Answer: Add the following to your config, like described in "Packages that conflict with Org mode":
(add-hook 'org-shiftup-final-hook 'windmove-up)
(add-hook 'org-shiftleft-final-hook 'windmove-left)
(add-hook 'org-shiftdown-final-hook 'windmove-down)
(add-hook 'org-shiftright-final-hook 'windmove-right)

Set org-support-shift-select customization variable to "Everywhere except timestamps" (setq org-support-shift-select 'always), otherwise shift+arrows will still have org-mode keybidnings on headings.
Answer: In Emacs 26.2 you only need to set the variable org-replace-disputed-keys to true while enabling windmove-default-keybindings to have the default windmove keybindings work normally. You don't need to configure the variable org-support-shift-select as said by the answer of kolen if you don't need the shift selection function because enabling default windmove keybindings will disable shift selection automatically (see C-h i g (emacs)Window Convenience). You only need to add
(add-hook 'org-shiftup-final-hook 'windmove-up)
(add-hook 'org-shiftleft-final-hook 'windmove-left)
(add-hook 'org-shiftdown-final-hook 'windmove-down)
(add-hook 'org-shiftright-final-hook 'windmove-right)

to init file if you want to keep the original org mode keybindings on regions where they take effect such as headings or list items and enable windmove on other regions (see C-h i g (org)conflicts). You may need to restart Emacs after making these changes to let them take effect.


Transplantation of stem cells

Question: During the autologous transplantation of stems cells from bone marrow to produce new blood cells why all the other stem cells other than the one obtained are destroyed?
Answer: Autologous stem cell transplants are used to treat individuals who have had their bone marrow destroyed or damaged by diseases such as lymphomas or by irradiation or cancer treatments. As they are damaged and potentially cancerous, they are removed. They are then replaced in the transplant. The whole idea is to destroy all the cells before transplanting the marrow back.
Comment: thank you
So the stem cell is obtained from another part of the body and transplanted into the bone marrow and not obtained from the bone marrow itself?
Comment: or to make it simple where is the stem cell obtained from ?
Comment: Although most of these stem cells are in the bone marrow, there are also some in the blood and these are collected in order to perform an autologous transplant.
Comment: What Alan said is not always true, they can be taken from the blood or bone. Certain chemicals can cause the cells to leave the bone marrow to collect them in the blood. They are collected when you are in remission or free of any disease and stored, frozen. Then if the disease comes back, every cell is destroyed (hopefully killing every cancer cell) then the frozen stem cells are transplanted back to reconstitute the immune system. This can be repeated but typically shouldn't need to be.

Transplantation of stem cells


Easy and good book on combinatorial problems

Question: I am searching for a book on combinatorics and/or mathematical puzzles for very beginners in easy English. The book should not contain detail mathematical expressions, will contain easy understanding logic behind the theory instead. I don't need problems/exercises and solutions as the book is not for mathematics student. I need the book for mathematics lovers who want to enjoy the theory maybe with some history and story. This should be a story book which one can read in leisure mood and can enjoy the thrill of mathematics.
Answer: This book is unfortunately out of print, but it is still accessible: The Penguin Book of Curious and Interesting Puzzles by David Wells. A majority of the problems are of a discrete or combinatorial flavor, and he avoids getting into mathematics in the form of mathematics in the answer. In addition, the book essential doubles as a history of recreational puzzles which is the original reason I came across it.
Comment: Does this explain the Science/Mathematics behind the puzzles?
Comment: Yes when applicable. For example, the Bridges of Konigsberg problem is included and the explanation is roughly equivalent to what you would see in an introductory discrete math book.


Triggers and order of execution on two different objects

Question: Hi I'm trying to totally wrap my head around how one trigger's execution could affect another. To make things clearer here's a scenario. Say I have 2 objects A and B. Both objects have a trigger each that fires after update. Object A makes an update on object B. By the order of execution as seen here, number 6 (Executes all after triggers) and number 17(Commits all DML operations to the database) at what point during Object A trigger execution does the Object B trigger fire? Is it at number 6 or after the commit of all DML operations to DB at number 17?
Answer: Triggers only fire on DML operations which you have already pointed out, does not occur until step 17 in the order of execution seen below and here.
So in your scenario, The trigger for Object B will not fire until step 17 (the DML operation is committed) in the trigger for Object A.
Comment: thanks for the quick answer and explanation. It does makes sense to me.


NSA Suite A Cryptography: Security through obscurity?

Question: What is the opinion of scholars, cryptographers on NSA Suite A? Containing unpublished algorithms. Could it really be that much better than the published algorithms besides being obscure and not documented publicly?
Comment: The decision may be related to economic attrition. The NSA spent a bunch of money on *mathematical research* to develop Suite A cryptosystems, why give that *research* to your adversaries for free by publishing? Make the adversary *pay* for it through reverse-engineering, espionage, diplomacy, etc.
Comment: I wouldn't be surprised if it used RC6 (or a minor tweak of RC6) instead of Rijndael/AES.
Comment: @CodesInChaos There was a report somewhere, a few years ago (around the time of the initial Snowden revelations) about some NSA exploit code containing RC6 constants. That doesn't have to mean anything at all, and of course even if it does, then using RC6 (which was already public) might simply have been a way to not risk any of their own crypto in case of a compromise.
Comment: It is entirely possible that China or Russia have have already obtained those algorithms through hacking cyber-attacks or espionage attacks. I mean we also lost a supposedly top secret drone over Iran, such should not come as a surprise. But that doesn't automatically means that US military comms have been compromised, as security lies in the key size and complexity, rather than alogrithms, as many users have noted. Until their cryptographers or cryptanalysis have found a way to break down every round, nothing has changed. But don't expect an equally culpable US govt to reveal this publicly.
Comment: @MichaelKjörling I was under the impression that they chose RC6 because the constants are less likely to set off IDS alarms for encryption signatures, while still being cryptographically secure.
Answer: My opinion (and I am a cryptographer -- I have a shiny diploma which says so) is that:

We cannot speculate on unknown algorithms, because they are, well, unknown.
NSA is like all secret services in the World, they really love secrecy and will practice it for the sake of it. So the fact that their algorithms are not published is in no way indicative of some particular strength or weakness of the said algorithms.
It is entirely plausible that the unpublished algorithms are indeed distinct from publicly known algorithms such as AES or RSA.
It is also entirely plausible that "Suite A" and "Suite B" are, in fact, identical. At some point, to use some algorithms, you must have implementations, and these things do not grow on trees. Having your own algorithms is thus expensive.
If I were a US taxpayer, I would be slightly dismayed at the misuse of my tax money, if it turned out that NSA spent it on developing and maintaining custom algorithms instead of reusing perfectly fine ones like the AES.
There most probably are some people with power to decide a lot of things in the NSA, who believe that not publishing algorithms increases their security. Such people exist everywhere. It does not make them right, though.
There is no better security than "cannot break it", which is what we already have with (properly used) AES, RSA, DH, ECC... The NSA could know of faster algorithms which are as secure as the public ones; however, it would be hard to beat the performance of hardware-accelerated AES, unless they have their own CPU foundry.

The danger in security by obscurity is in believing that it works well. It may induce people to feel safe with homemade algorithms, because they would assume that the obscurity will hide the weaknesses of their algorithms. However, if you use good algorithms with published and well-studied protocols (i.e. AES, SSL...) then there is no harm done in not saying that you do.
Comment: Re 5th point: I don't mind if NSA develops algorithms.  Even if other algo's work, I have no problem if a trivial slice of tax money goes to the NSA to do crypto algorithm research some of which results in new secret algos.   You pay someone to research stuff in the number theory, cryptography, etc and they may just come up with a new algorithm even if that wasn't the original goal.  Re: 6th, their boss may want to keep it secret not to increase security, but to make it so rivals don't have the algorithm/math to use themselves or are a few years behind (and not let flaws be publicly revealed).
Comment: "It would be hard to beat the performance of hardware-accelerated AES, unless they have their own CPU foundry" - they do, of course. Or rather, they have military contractors who produce their hardware designs, for DOD secure communication sets and the like.
Comment: Suite A and B are not identical. The public information we _do_ have shows that some of the ciphers have properties that do not match any public cipher (whether due to a strange key size or a non-flat keyspace where control bits determine things like the number of rounds). It's possible that it is _based_ off of public primitives, but I don't think it's possible that they are identical.
Comment: Finally it's entirely plausible that they just happen to be implantations of well known algorithms too, ultimately we don't know.
Answer: An interesting data point here is the DES s-box constants.
Wikipedia NSA
Wikipedia DES
NSA recommended changes in the S-box constants to make DES resistant to differential analysis, which was unknown in the academic and commercial cryptography world at the time.
In that case, they were able to make that improvement in a way that was opaque to the users of the algorithm. It's possible that publishing the algorithms for secret crypto systems would reveal some other technique used to counter another attack that's not well-known outside their community yet.
Comment: I was thinking about the same thing! The tl;dr version is that the NSA was about 20 years ahead of academia (and possibly still is) WRT cryptoanalysis. They secretly showed IBM in 1975 how to modify DES to resist differential cryptanalysis, which wasn't *officially* discovered until around 1990.
Comment: Great point! Very salient here.
Comment: @tylerl `and possibly still is` They haven't been for decades. Universities have not only caught up, but greatly exceeded the amount of mathematicians being used for things like cryptography. It has been a long time since the NSA could boast that they hired the most cryptographers in the world. Now granted, many universities work on classified stuff, but so much of it is public that the secret work is dwarfed in comparison. They were certainly ahead of us in '75, but now?
Answer: I don't believe in security by obscurity in general, but in case of crypto it's actually worse, because it violates Kerckhoffs Principle
So is it better?  Maybe.  Is it different?  Sure.  Is it necessary to hide the algos?  If your crypto was good to begin with, you would not need to hide the algorithms, just the keys.
On the other hand, you have the 'many eyeballs make all bugs shallow' idea.  However, in case of crypto, there are not too many (well educated) eyeballs to actually point out bugs in crypto algos.  So one possible explanation for the hiding would be that the NSA makes the bet that there is a higher chance of another (not friendly) nation state having more and/or better eyeballs, as opposed to the benefits of potential improvement coming from opening algos to the community.  Or maybe it's not the probabilities of bug-finding, but the impact that finding a vulnerability would have on the information they use their Suite A to protect.  Either way, we will not know, because they will Never Say Anything ;)
Comment: I think you're misunderstanding, or maybe misapplying Kerchoffs's Principle. "A cryptosystem should be secure even if everything about the system, except the key, is public knowledge." just means that you shouldn't be relying on the secrecy of the algorithm for security. Keeping the algorithm a secret may (or may not) increase security, but it can't be *required* for a particular level of security. NSA designs their algorithms under the assumption that opponents know how they work. They don't publish them so as to not make it any easier on the bad guys than they have to.
Comment: Also, the NSA probably has the capability to hire many cryptographers for review work, and also has the power to forbid them to publish the details. Most other people do not; thus, obscure algorithms are likely to be very weak.
Comment: Also, if the NSA has developed a new and more secure system, they may not want to release details so no one else can use it. Releasing the details of a system doesn't just let others analyze it, it lets others _use_ it, which is generally a bad thing if you want to read their mail.
Comment: @MarkBessey That is correct (in that is the NSA's thinking) but it is also a fallacy.  Is Suite A secure?  Maybe.  There is no provable security so the best defense against compromise is to put it out there and let millions of people TRY to break it.  In the case of Suite A that won't happen until the obscurity is broken at which point either it is still secure or it will break horribly.  If it is the former nothing is lost by making it public now, if it is the later then it really is only secure through obscurity.
Answer: On the other hand, it could well be that such agencies have certain knowledges far ahead of the public. One example, if I don't err, would be the case of public key crypto, where the British agency kept their knowledge from the public for quite a time.
Answer: I'm not a professional cryptographer, however I can think of several reasons why the NSA would want to keep their algorithms secret.

If an attacker has to guess how the algorithm works, that puts an enormous obstacle in their way.

If the NSA published their algorithms, that would enable attackers to discover the bugs; one would assume that they have large teams of cryptographers that work hard to eliminate bugs. Public domain cryptgraphy has to rely on the publishing an algorithm so that the wider community can discover the bugs.

The NSA may have discovered weaknesses in the some of the publicly available algorithms which they want to exploit. If they reveal their algorithms (which will not have such weaknesses), they might give clues about those weaknesses, or would allow attackers to avoid those weaknesses.

The advice against "security through obscurity", I think is misunderstood. Security through obscurity is only problem when it is used on its own, or with an underlying algorithm that is weak.
All cryptography is based on some degree of security through obscurity; the actual key used is obscured within a keyspace that is so large that it cannot be discovered by brute-force search within a resonable time-scale; the key cannot be calculated from the encrypted data because the algorithm makes the relationship too obscure. In a good algorithm, the obscurity is mathematically calculated and can be precisely defined.


Sewer and Water GIS Data

Question: Is there such thing as a national or statewide GIS data set for existing sewer and water lines?
Comment: I asked a Florida water GIS expert, the reply wasn't so promising: "Miami Dade still has all their data in paper form. They are in the process of trying to digitize it. Just trying to get _one city's_ stormwater system in GIS was a full time job."
Answer: There is a program designed to prevent accidental destruction of buried utilities, which has made the effort to provide data about underground utilities to the public. This is the "Call before you dig" (http://call811.com/) program. Each state has it's own version of the "call before you dig" program. This free program will send a person out to a planned dig site to mark the ground with spray paint where there are buried utilities. The user experience is pretty low-tech, but there does appear to be geospatial source data. I wasn't able to figure out how to get access to that source data. I haven't fully investigated, but I suspect it's proprietary.
Here's the information I was able to glean from my recent experience with this program.
I made a "design request" for a single parcel with the Ohio program (http://www.oups.org) and they emailed me diagrams of the property with its nearby buried utilities. The information about each utility (gas, water, sewer, electrical, etc) came separately, and the quality varied from utility to utility. For example, here's what they sent me about sewers:

Several planning diagrams, apparently scanned from paper copies of 100-year old diagrams. Some of the streets in these diagrams don't exist today, and it's not clear if those streets were ever actually built. Given that, I'm not sure how accurate the sewer locations themselves would be.
A pdf of a map that was clearly produced in a GIS software, with line and point data overlaid on a basemap with streets names and aerial imagery. The source data must have been a vector layer, presumably digitized from those original diagrams.

The data was sent to me by a private company, One Call Concepts Locating Services (occls.com). That company obviously has geospatial data of the buried utilities. This quote from their website leads me to believe that they will not provide that data to you.

Our proprietary records management software, PlatView, allows us to search and review customers' records upon arrival at a locate request site. PlatView can use the actual GPS location of the vehicle to search for the correct utility records, providing the most efficient use of the technician's time on site.

If their business revolves around locating buried utilities (for a price), providing the source data would make them obsolete.
The free "call before you dig" service only provides information about public utilities. The only way to know where private utilities (pipes, wires, etc) are buried on private property is if all the previous property owners kept good records and passed them on to the current property owner. Obviously that information is not publicly available. You can hire a service to do a site visit and locate forgotten buried utilities. After making my "call before you dig" request, I received several emails advertising various private utility locating services (eg Blood Hound, https://www.bhug.com/). I believe these companies use a device to locate forgotten buried utilities, like this:

TL;DR: Geospatial data about water and sewer pipes exists, but it seems to be proprietary.

Sewer and Water GIS Data


agglutination test using blood of the donor and the recipient

Question: we were told that agglutination occurs when the matching antibody react with its antigen on the RBC surface (as antibody B with antigen B)....
Also when blood transfusion, Donors plasma with antibodies is diluted , so when o-donor gives blood to  B-recipient , B antibodies ( of the donor) is diluted
........
My question is in lab cross-matching test  when we put recipient's plasma(o with b antibodies for example) on the donor's RBCs (B with b antigens)..... is there agglutination, If so, how would we know the right group then?....if not ,Why not?
if the whole thing is misunderstood ,i wish to be told how it's done.
Answer: Disregarding Rh factor for a moment: when you add A-antibodies to a blood sample and agglutination occurs, this means the blood contained A-antigens (A-type). The same can be said for a sample of blood to which B-antibodies are added (B-type). If agglutination for both antibodies occurs in separate assays on the same sample of blood, it means the sample contains both A and B antigens (AB-type). If the sample is said to be O-type, this means neither A or B antigen would be present in these cells. It's safe to transfuse O-type blood into any recipient due to this fact. What you also want to watch out for, is attack on the recipients RBC's by antibodies in the donor's plasma. This can result in a hemolytic transfusion reaction (HTR), but it's noted in the following text:

Red blood cell incompatibility may also occur when the patient's RBC antigens are attacked by antibodies from the donor's plasma. This tends to be a minor problem because of the small amount of antibody present in the donated plasma, which is further diluted on transfusion into the recipient's circulation.

If you're in the lab doing a Coombs test, for example, you're checking to see if there are any extraneous antigens present that might results in a HTR. In a normal result, ergo there aren't any antibodies to RBC's in the sample mixture, you wont see any agglutination. This is for considerations outside of ABO antibodies, generally. If you're adding to B-type RBC's a plasma with known antibodies to B antigen, like O-type plasma, you can probably expect an event. To my knowledge, O-type plasma wouldn't be safe to give to anyone but an O-type recipient.
additional source
Comment: what i know is that o is the universal donor what i don't get is how do we know it's compatible when its plasma has the antibodies or is it not done this way at all(mixing donor's RBCs and recipient's plasma)?
Comment: O group RBC's lack antigens to either A or B antibodies, making them suitable for donation to any blood type. The recipients body wont attack the donor RBC's. The donor plasma contains antibodies to both A and B antigens, however. The assumption we're making is that out of total blood volume, donor + recipient, the amount of A/B antibody in the O group plasma will be dilute enough that there's a deleterious effect on hemolytic events involving donor anitbodies. What you *wouldn't* do, is give O group plasma to anyone other than an O group recipient during a plasma transfusion.
Comment: The way we find out if it's compatible, is we add A and B antibodies to separate samples of blood to determine if agglutination occurs. For O group blood, you wont see any of this. To confirm, you can back type the blood. Take the O group serum, and add either A blood cells or B blood cells to separate samples. You should see clumping in both cases (you're type AB if no clumping occurs in back typing).
Comment: is cross matching done with the blood of the donor and recipient or not ?
Comment: It's done with the serum of the recipient, and the donor's packed red blood cells.


What is the difference between Serial.write and Serial.print? And when are they used?

Question: What is the difference between Serial.write and Serial.print? And when are they used?
Both have been used to print on serial monitor, what are their actual differences?
Answer: Serial.write is more down to earth , it is simple and fast, it is made to talk binary, one byte at a time.
example:
Serial.write(0x45);   // will write 0100 0101 to the cable

Serial.print in the other hand is more versatile , it will do the conversion for you from ASCII to binary it also can convert to BIN/ HEX/OCT/DEC but you need to specify a second argument like so
Serial.print(76, BIN) gives "0100 1100"
Serial.print(76, OCT) gives "114"
Serial.print("L", DEC) gives "76"
Serial.print(76, HEX) gives "4C"

more examples with visual serial output :
Code:
  Serial.write(0x48);   // H
  Serial.write(0x45);   // E
  Serial.write(0x4C);   // L
  Serial.write(0x4C);   // L
  Serial.write(0x4F);   // O

SERIAL OUTPUT :

Code:
  Serial.print("HELLO");

SERIAL OUTPUT :

Serial.println() in the other hand will add end of line 2 bytes 0x0D and 0x0A as you can see in the frame
Code:
  Serial.println("HELLO");

SERIAL OUTPUT :
Answer: From the Arduino site for Serial.write and Serial.print:
Serial.write()

Writes binary data to the serial port.
This data is sent as a byte or series of bytes; to send the characters representing the digits of a number use the print() function instead.

Serial.print()

Prints data to the serial port as human-readable ASCII text.
This command can take many forms. Numbers are printed using an ASCII character for each digit. Floats are similarly printed as ASCII digits, defaulting to two decimal places. Bytes are sent as a single character. Characters and strings are sent as is
Answer: Serial.write sends bytes to the serial port while Serial.print sends ASCII characters so people can read easily.
Some devices work using bytes to set configurations, commonly use packets of data and you need to use write function to communicate with them. Eventually they will send bytes through serial interface and then you can interpret by going each byte.
Answer: All of the examples above are correct, but maybe more clearly.... All data sent through the serial port is sent as 1's and 0's. (obvious.... I hope)... The difference in the two commands is how whatever is being sent is actually translated/interpreted to/from these 1's and 0's. The clearest example involves transmitting numbers.
Let's say you need to send the number 217. The binary (1's and 0's) representation of this number is 11011001. Using the command Serial.write(217) will literally just send 11011001 across the line. The Hex representation of the same number is 0xD9, and the command Serial.write(0xD9) will send the same thing ... 11011001.
Here is where it gets interesting... If you were to use the command Serial.write("217") you would instead get this: 00110010 00110001 00110111... WHAT?!?!?
When a string is passed as the argument it is broken down into individual characters, converted to ASCII, and then sent as a byte for each character. You would get the exact same output if you were to use the following:
Serial.write(50);
Serial.write(51);
Serial.write(55);

(00110010 00110001 00110111)
Now let's look at Serial.print(). The commands Serial.print(217) or Serial.print("217") will both print the same thing: 00110010 00110001 00110111. This is because the print command first converts any number to a string representation and then uses the command Serial.write() to send each character as individual ASCII bits.
Though this is not a COMPLETE description, I hope it helps to get you thinking in the right direction...
Answer: Yet another way to answer this is to state the Serial.write accepts single characters where Serial.print accepts strings. There may be some differences but this is the main one.
Comment: What about `Serial.write(stringData.c_str());`? if stringData is defined as String.
Comment: Please show how stringData is defined as String.


Diesel engine on LPG

Question: I have seen LPG powered petrol cars which can run on both the fuels. But I have not seen any Diesel engine car running on LPG. Is it possible to run a diesel engine on LPG?
Answer: Yes, but not very easily or effectively. To convert to 100% lpg means reducing the compression ratio and providing a spark. The lower compression ratio takes away diesel as a fuel and providing a spark means introducing a spark plug into the head - with machining issues : space, depth etc.
Using lpg with diesel - called fumigation can improve deisel economy but the cost of the lpg equipment is also a factor.
As the diesel engines are designed with a lower rev range compared to petrol engines, it seems obvious why it is not popular....
More info here : http://www.go-lpg.co.uk/diesel.html
Comment: But what could this experiment accomplish in terms of MPG economy? The high compression ratio of diesel itself is very efficient. But your suggestion of fumigation sounds promising. Do you believe this method could benefit transportation trucks in achieving higher MPG?

Diesel engine on LPG


screensaver lock won't release

Question: I have my Ubuntu 12 desktop set to lock after a time period-- this works fine, but when I go to unlock it sometimes (usually only after leaving it locked overnight) won't come out of the locked state-- the lock dialog goes away but it still shows the image from the locked screen (usually a picture from variety, which I use as a background switcher).
I can Ctrl-Alt-F1 into a command prompt, and the processes seem to be fine, so I think the system is fine, it's just the lock app (or whatever it is) that might be screwed up.
How can I diagnose this? Is there a kill command I can issue from the command prompt to disable the lock view?
Answer: In 12.04, you could try gnome-screensaver-commands -d, to deactivate it.
(This is outdated as of 14.04)

screensaver lock won't release


Microphone for six year old

Question: My 6 year old son wants a 'real' microphone and stand just to sing with and pretend he's on stage like Billie Jo!! I'm confused with mixers and amps and microphone systems. I just want a cheap way of powering a microphone.  Can anyone help?
Answer: The cheapest you can go while still using "real" equipment that works is probably going to be over $200, plus tax.
You will need a mic (Nady SP9), a mic stand, a mic cable (NO LESS than 25 ft; buy one longer than you think you need), and an amp.
The amp is the "big ticket" item in this setup; everything else is bottom of the barrel or the only appropriate option. This "Fender Mini" linked above is really a bunch of normally separate components in one kid-sized package -- a mic preamp, a mixer, an effects box, and an amp. It's even got a separate input for an instrument like electric guitar or bass. Basically it's a garage band starter kit.

Voluntary disclosure: I don't work for zZounds, I just really like their website.
Comment: Brilliant thankyou very helpful :)
Comment: I think this covers it well enough to not need another answer by me, but I'd comment that it would be possible to save a bit by using a cheap ASIO interface for a computer and using the computer's speakers as the amp.  It would also allow for recording your kid's sessions.
Comment: An ASIO interface?
Comment: AKA an Audio Interface -- basically something that lets you plug a microphone into a computer. The fender amp technically _is that_, since it has a USB port, but you can go cheaper and cheaper until you hit something like [this](http://www.zzounds.com/item--IONMICLINK). But then you have two issues: dealing with computer software, and the fact that there is now a chain of cables connecting your rock and roll six year old to a _computer_; likely a much more expensive piece of equipment (and less tolerant of abuse) than the fender amp.
Comment: Ha ha true! But I have recently got a new laptop and still got my old one so its a possibility. Cheers
Answer: You need a Shure SM58.  They cost 100$ always, and they are the staple microphone of the live sound world.  The SM58's cousin, the SM57 is the Presidential microphone of choice for the lectern.  Someone buried a SM58 and it worked just like normal after 1 year.  Some people I know have 20 year old SM58s that are still in service.
So anyways, I don't think a 6 year old could damage it.
Plus it sounds great.
Comment: You can find them a bit cheaper used, and while I'm not generally a fan of used gear, SM58s are pretty safe.  I do a demonstration with one of my SM58s where I throw it (literally underhand lob it) across the room and let it slam in to the ground, pick it up, plug it in and it simply doesn't care.  I've seen the things get swung on a cable and smashed in to corners of road cases and outside of some superficial dents on the wire mesh, the thing is undamaged and works as good as new.  Certainly 6 year old proof unless they drop it in water, though it might be a bit big for their hands.

Microphone for six year old


Are there any known botnets targetting smartphones?

Question: Are there any known botnets that specifically target smartphones? What is their topology and how are they controlled?
What are they used for?
Answer: Generally speaking, we haven't seen large, long-lived botnets formed by compromising smartphones, in the same way as we've seen for desktops.  (There are small-scale exceptions, but this is is a good first approximation.)  There certainly has been no shortage of malware targeting smartphones, but what it does once it compromises your machine looks a bit different from what tends to happen on desktops.
It's instructive to look at why.  Why do bad guys want to compromise your desktop or your smartphone?  Because they want to make money.  Therefore, they are going to be driven and motivated by what they can do with your compromised machine -- in particular, how they can make money from it.
Right now, the main ways of making money off a compromised desktop are things like sending spam, hosting bad web sites (phishing sites, pharmaceutical storefronts, etc.), launching DDoS attacks, stealing users' credentials, and so on.
Most of those attacks are not possible or less attractive on smartphones.  Smartphones tend to have lower network bandwidth than desktops, so they're not as useful for sending spam, hosting bad sites, or launching DDoS attacks.  Also, due to sandboxing and other security protections, it is not as easy to steal users' credentials (it is possible, but not as trivial).
For these reasons, we shouldn't expect to see bad guys leverage compromised smartphones in the same way that they leverage compromised desktop machines.
For more detail, see the following research paper, which surveys smartphone malware seen in the wild (up to 2011) and speculates on incentives that might drive malicious behavior in the future:

A Survey of Mobile Malware in the Wild.  Adrienne Porter Felt, Matthew Finifter, Erika Chin, Steven Hanna, and David Wagner.  ACM SPSM 2011.

For more research, see the following:

Dissecting Android malware: Characterization and evolution.  Yajin Zhou, Xuxian Jiang.  IEEE S&P 2012.
Answer: There is at least one botnet I know of, it was malware cloaked as a regular app. While the app was running it logged into Yahoo email addresses and started sending spam. This particular botnet was discovered by Terry Zink, a security researcher at Microsoft.
The malware was spread by using   independent application stores. Almost all of the phones resided in Argentina, Ukraine, Pakistan, Jordan and Ryssua, where independent appstores are popular but often contain more malware.
SMS controlled botnet
Georgia Weidman, a famous security researcher currently focusing on Android, made a proof of concept for a botnet to be used on smartphones. It used SMS to communicate to the different bots by using an encrypted payload that only the bot application would be able to decrypt and recognize.
The bot would position itself between the modem and the userspace. If the bot receives a messages destined for him he will keep it (signature), otherwise it will be sent to userspace.
The topology is 1 master -> multiple sentinels (long infected bots) -> other bots
Her example  included a PoC for Android (Root exploit) and for iPhone (Jailbroken and iKbee worm for non-rooted phones).
Complete presentation here.
If you wonder why sms, it's because it uses less batteries than a constant probe using the internet connection.
Ikee.b worm
The Ikee.b worm resulted from Ashley Towns Ikee.a worm. Where Ikee.a was relatively benign (Rick Rolling users). However Ikee.b was used to extort users. It also listened to a C&C server in Lithuania. Periodically all bots would probe the server to check if there were any instructions.
More info on this worm can be found here.
Answer: Spam Soldier (see here, here, and here) targets android devices with text messages that lead you to download malware. The malware is then used to make your device part of a spamming botnet. This is a 'in the wild' attack, not just a theoretical exercise. The 'business model' behind the attack is the standard standard spam business model.


Rendered on selectlist not unrendering when a value is selected

Question: I have a problem that I really can't seem to understand.
I have a custom Page that has 2 sections. In the first section I select the type of information wanted, and on the second section I display a list of that kind of information.
For one specific kind of information, I want to put a select list in order to filter the information on the year it was created.
So basically, on that second section I have a select list rendered only if the type of information is the one that this select list was created for, and a list of information.
Before I put my selectlist, everything was working fine. But somehow, after adding it, once I display the select list once, this section of the page stays the same. If I go back and move to another type of information, the old information and the select list will still be displayed.
Even more confusing, if in my select list I have the selectOption('','') and this one is selected, then it works correctly... I can move to a new information and the new information will be displayed, and not the selectlist.
I was wondering if anyone had encounter this kind of problem before, and how he solved it.
Here is the problematic part of my code :

      <apex:outputPanel id="pnlRankingDetail">

      <apex:selectList value="{!rankingYear}" style="width: 100%;}" size="1" rendered="{!isViewType}">
          <apex:selectOptions value="{!rankingYears}"></apex:selectOptions>
      </apex:selectList>

          <apex:repeat value="{!lsRankingResults}" var="res">

                            {!res.resCategory}

                            {!res.resName}

I also tried using :
<apex:outputPanel style="{!IF(isViewType,'','display:none;')}">
    <apex:selectList value="{!rankingYear}" style="width: 100%;" size="1" >
        <apex:selectOptions value="{!rankingYears}"> </apex:selectOptions>
    </apex:selectList>
</apex:outputPanel>


Bought a used ledger nano s from Amazon / Ebay. How do you factory reset the Ledger Nano S?

Question: I just bought a used ledger nano s from amazon and ebay. What is the best method of wiping this device and factory reset it? What are some other precautions before using this used device?
Answer: From the Nano S Configuration Guide:

How to erase or reset your Ledger Nano S?
If you acquired a second-hand Ledger Nano S, or if you want to create
a second wallet, follow this tutorial to learn how to reset your
device first.

Connect your Ledger Nano S
Enter a wrong PIN code and validate by
pressing both buttons
Repeat the 2nd step two more times
Once your Nano S displays the message "Your device has been reset", press both buttons until the "Welcome" message is displayed, or disconnect and reconnect your device.

Then you will be able to restore a wallet or create a new one.

Also keep in mind that your device may have been tampered with and does not contain genuine hardware. You will want to read this guide to ensure that your hardware is genuine.
Answer: CryptoSec.info has a complete and updated guide for this specific problem.
To summarize the article, here are the two methods to restore your Ledger Nano S/X:

Open your device and Navigate to Settings > Device > Reset all
Enter the wrong PIN three times

For the full detailed guide, check out: How To Reset Your Ledger Nano S/Nano X
Comment: Welcome to Bitcoin.SE. While this link may answer the question, it would be [preferable](https://bitcoin.stackexchange.com/help/how-to-answer) to include quotes from the linked site that explain what to do. Links can disappear and their contents change.


12.04 install partition tool doesnt have ntfs available

Question: I want to manually partition my disk for install. Installing 12.04 only on this laptop, so I create a /, swap, /boot and /home (all ext4) and then I want to create a ntfs for sharing data between Ubu and my windows VM. But the manual partition tool in the install doesnt have NTFS as a filesystem type in the drop down, only Fat or Fat32.. How come?
Comment: A Windows VM? What virtualization software are you using? Wouldn't it be better to use shared folders like Virtualbox does or using common file sharing services like samba/smb?
Answer: I figured this out... The install partition tool doesn't let you create a NTFS logical part. However if you simply leave it as 'free space' after install you can use disk utility to format that free space as NTFS. Job done.
Not sure why the partition tool during install doesnt let you create an NTFS partition though!
Answer: If the builtin partitioner doesn't meet your needs, then download gparted.  It is available as a live CD so you can boot from it and work on your system disk while it isn't mounted at all.  It will not delete/reuse any existing partitions on your disk (e.g.Windows) unless you explicitly tell it to.  Of course, you'll have to first shrink an existing partition to free up space for the new partitions you want to create.
http://gparted.sourceforge.net/livecd.php/
When I do a new install, I always start with this and get everything just the way I want it before the actual install.  Later, during the install, select manual partitioning and it will let you tell it what goes where.  gparted is easy to use (once you get used to it) and lets you preview and edit what it will do before it does it.  It handles ntfs easily.
Since moving/resizing existing partitions can take a lot of time (hours), keep editing your gparted tasks until they do exactly what you want the first time, hopefully, resizing/moving each partition just once.
gparted also allows you to change the labels on your partitions.  It's a good idea to edit these to make them meaningful like "Windows", "root", "home" so when you need to work on them in the future, you know exactly what's what without a lot of head scratching.
If you like things to look tidy, then, before you start, pull out your calculator app.  If you want a partition that's 30 GiB, then enter it's size as 30720 (1024*30 Mib).


What is the global warming potential (GWP) of any gas over a 1 day time frame?

Question: Since in 100 years, the global warming potential (GWP) of methane is 28-36, what will be the GWP in 1 day time frame?
Can it be calculated that way?
Answer: It can, but it's not very helpful. A large number of gasses (methane being one) decompose relatively quickly in the atmosphere to form other compounds. A longer time horizon means you capture all of that change in the metric (as compared to CO2), while if you did it for a day you'd end up with a figure that only really made sense for that day. The details of how it's calculated and why the time horizons are where they are is in the IPCC AR5 WG1 CH8 technical supplement (8.SM.11.1 Equations for the Global Warming Potential)
Comment: thanks for fixing the link @klanomath


Automation Stops reading properly in Pro Tools LE.

Question: I'm working on a feature film in Pro Tools 8 LE on my Macbook. There's a scene in where I'm automating a reverb plug-in on my dialog aux, due to the characters going in different rooms down a long hallway, in one single take. About halfway, my automation stops reading correctly and when I go back earlier in the scene after it stops reading, all of the parameters for the plug are all wonky. It's only until I go to a different point in the timeline or just relaunch the session, where everything is okay until it gets to the same point. What is causing this and what should I do?
Comment: have you actually looked at the automation lanes for your reverb plug-in at that point? if you haven't, it would be worth checking them to make sure the automation wasn't recorded that way.
Comment: The automation is supposed to read as a small room and it turns into a large one, even though the automation paths only go from small to medium. Once this change happens in the scene, all of the automation from before gets set to the large echo, that only goes back to my original automation once I either quit the session or dramatically go back and forth in the timeline.
Answer: Shot in the dark, are you using D-Verb? I've ran into this many times and eventually just stopped using the plug because of it. It's a known bug that sadly seems to have been around a long time. I'm pretty sure it's switching either the algorithm or the size that screws things up.
Find another reverb you love and don't look back IMO.
http://duc.avid.com/showthread.php?t=306998
http://duc.avid.com/showthread.php?t=200883
Comment: Thanks Luca! I'm looking into Valhalla Room from Valhalla DSP. It's pretty cheap and will be better suited for the time being.


What grains (and in what ratios) go into a nine-grain flour?

Question: Many recipes are available for making nine-grain bread, but they presuppose that you have nine-grain flour. We have a wheat grinder so we would like to use it to make our flour to make the bread.
Answer: There is no fixed set of grains or ratios that define nine-grain flour. It is just meant to generically suggest "uber-healthy". Some things you may want to use include: whole wheat, rye, triticale, barley, oats, buckwheat, spelt, emmer, millet, flax, etc. Most so-called 9-grains or 12-grain etc will "cheat" and include wheat in multiple forms, like wheat flour, cracked wheat, vital wheat gluten and so forth. In any case, if you are going to use it for bread, you'll probably want at least 50-75% wheat flour so that there is enough gluten to successfully rise. The rest can be in any proportion that pleases you for taste or nutritional purposes.
Answer: We ended up buying a nine grain mix from a Mennonite bulk store. It doesn't tell exact ratios, but by law it has to list the ingredients in order of abundance:

Red wheat
White wheat
Rye
Barley
Corn
Millet
Oats
Flax
Buckwheat
Comment: and how was the bread?
Comment: @Doug Excellent. My favorite bread ever.


Does the concept of Gentile exist in Christianity?

Question: Judaism and Bani Israel have concept of Gentile to represent the pagans and Idolaters with a corpus of rules dealing with them, So does Christianity inherit this concept? If yes where ? and Are Jews considered to Be gentiles by Christians as its known that Jews consider the Christians to be Gentiles and Avodah Zarah?
Comment: Well, I know that Latter-Day Saints call themselves Latter-Day Saints. They call non-Latter-Day Saints "Gentiles".
Comment: Related: [Are other religions treated differently by any major branch of Christianity?](http://christianity.stackexchange.com/q/9899)
Comment: That Mormons use the term is an interestesting annecdote, but you asked about the concept in Christianity, of which they are not broadly representative. You're acceptance of that as an answer has turned this into something much less than useful. It also suggests that you are not looking for the truth of the matter.
Comment: @Anonymous thats an interesting answer , please do post it as an your own answer. Most of the other answers try to explain the concept of gentile which was not even asked.
Comment: @Caleb I suggest editing the question a bit: "In modern times, how do Mormons view themselves and non-Mormons?"
Comment: I noticed that Mawia already summarized and included my answer in his/her answer. So, I started to delete my own answer, but I can't, because it's already accepted. :(
Comment: @Anonymous Don't worry, at least you get some points. 25-6=19. Be happy :-)
Comment: possible duplicate of [Are there Old Testament Scriptures that mention salvation for the Gentiles?](http://christianity.stackexchange.com/questions/11288/are-there-old-testament-scriptures-that-mention-salvation-for-the-gentiles)
Comment: I think you should reword the question "Do Christians consider Jews to be Pagans?" since Gentile very specifically means a non-Jew. And you might also ask if Christians consider Jews to be idolators (the equivalent to Avodah Zarah) and some undoubtedly do since the god of the Talmud IS NOT the God of the Bible just as the god of the Koran is not the God of the Bible.
Answer: The term Gentile in the Bible simply means non-Jew or non-Hebrew. In Old Testament times, the Hebrews called the other non-Hebrews as Gentiles and in the New Testament, non-Jews are Gentiles.
In the New Testament, Paul was famous for preaching to the Gentiles. Because Paul was a Jew, he was zealous for his own people and preached the gospel mostly to the Jews first. But later, as his own people rejected him, his focus shifted towards the Gentiles.

Romans 10:1 (NIV) Brothers and sisters, my heart's desire and prayer
  to God for the Israelites is that they may be saved.
Acts 18:5-6 (NIV) When Silas and Timothy came from Macedonia, Paul devoted himself exclusively to preaching, testifying to the Jews that
  Jesus was the Messiah. But when they opposed Paul and became abusive,
  he shook out his clothes in protest and said to them, "Your blood be
  on your own heads! I am innocent of it. From now on I will go to the
  Gentiles."
Romans 11:11 (NIV) Again I ask: Did they stumble so as to fall beyond recovery? Not at all! Rather, because of their transgression,
  salvation has come to the Gentiles to make Israel envious.

According to New Testament, anyone who is not a Jew is a Gentile, whether he is a Christian or not. And believe it or not, most of the users in this site are Gentile Christians.
Some recent new Christian sects call all non-Christians including Jews as Gentiles but it's not biblical. All non-Jews are Gentiles but non-Jews who are non-Christians are more appropriate to be referred to as Pagans, Heathens, Infidels or simply non-believers, depending on the target.
Comment: +1 I agree. Gentile always refers to people who are non Jews, regardless if they are Christians or not. Non-christians are either non-christians or pagans.
Answer: Most branches of Christianity see Jesus, the Son of God, as the Jewish Messiah in fulfillment of Jewish prophecies and foreshadowing in the Jewish Scriptures.
God foretold, though, that the Seed of Abraham would be a blessing to all people--every tribe, tongue and nation.  The apostle Paul specifies that the gospel is to the Jew first and also to the Gentile.

For I am not ashamed of the gospel, for it is the power of God for salvation to everyone who believes, to the Jew first and also to the Greek *[Gentile]*.  Romans 1:16 ESV

Jesus was born to a Jewish mother in a Jewish city in the land of the Jews.  His first followers were Jews and the earliest growth of the church was among Jews (Acts 1-7).
So, non-Jewish believers in Jesus identify themselves as the Gentiles--the ones who were once "outside" but who are now "included".  We see ourselves as the "other sheep" of which Jesus spoke when He was addressing a Jewish audience.

And I have other sheep that are not of this fold. I must bring them also, and they will listen to my voice. So there will be one flock, one shepherd.  John 10:16 ESV

Messianic Jews--Jews who recognize Jesus as their Messiah--oftentimes consider themselves "completed Jews", or Jews that recognize the Messiah that God foretold and sent into the world.
So, in conclusion, non-Jewish Christians see themselves as the Gentiles that God blessed through Jesus, who is both the God of Abraham and the descendant of Abraham in the flesh.
Answer: No.
In Christianity, there are two sets of people, but one group is not excluded or held to different standards than the other. There are:

God's chosen covenant people.
Everybody else.

God's people are identified solely by their faith in Jesus Christ as savior/redeemer. By faith we become part of the same family. With those who have faith in His Son, God had made an everlasting covenant to bring them into His kingdom as join heirs with Christ himself.
Everybody else can be labeled however you like (e.g. pagans, non-Christians) but it all boils down to the same thing. The "rules" that apply to them are simple:

Acts 16:31 (ESV)
31  […] "Believe in the Lord Jesus, and you will be saved, you and your household."
Comment: This is incomplete.  Romans 11 tells us that the Jews having been "cut off" from the root (i.e. the source of both the Old and New Covenant) through their rejection of the Messiah, will be re-grafted (en-mass) when their eyes are opened to His glory (in the eschaton).  Because of this, the Jew/Gentile distinction remains, is meaningful and of current relevance to orthodox Christian theology.
Answer: In the Teachings of Jesus and the writings of the Apostles, there is a common theme of the world that represents an established system that is separate from and foreign to Messiah.

John 14:16-18
And I will ask the Father, and he will give you another co-minister, that he should abide with you into the ages: the Spirit of Truth, whom the world is not able to receive, because the world does not contemplate the Spirit or know the Spirit. But you know the Spirit, for the Spirit abides in you, and in you the Spirit will be. I will not leave you orphans, I am coming to you. Just a little while longer, and the world will not see me, but you will see me.
John 17:14
I have given your word to [the men you have given me], and the world detested them, because they are not of the world as I am not of the world.
John 14:27
I leave you with peace. I give you my own peace. I do not give to you like the world gives. Do not let your hearts be troubled.
John 14:30
No longer will I speak many things with you, for the one of the world is coming- the chief, and he does not have one thing in me.

This chief (αρχε "principle" or "foremost") of the world is also mentioned by Paul,

Ephesians 2:1-3
And you were dead in your trespasses and sins, in which at one time you walked according to the age of this world, according to the chief of the power of the air of the spirit of the one now working in the sons of disobedience.

John clarifies the spirit to which Paul refers in his own teaching on the world.

1 John 4:2-6
And every spirit that does not acknowledge Jesus Christ has come in the flesh is not of God, this is that of the antichrist, of which you have heard, 'it is coming', and now it is already in the world. You are from God, little children, and have overcome them; because greater is He who is in you than he who is in the world. They are from the world; therefore they speak as from the world, and the world listens to them. We are from God; he who knows God listens to us; he who is not from God does not listen to us. By this we know the spirit of truth and the spirit of error.

The world is a system which in the mind of the Christian is similar to the notion of Avoda Zarah among Jews. Avoda Zarah translates to "foreign worship" or "idolatry." In Romans, Paul equates men operating according to the spirit of error with idolaters,

Romans 1:18-23
For the wrath of God is revealed from heaven against all ungodliness and unrighteousness of men who suppress the truth in unrighteousness, because that which is known about God is evident within them; for God made it evident to them. For since the creation of the world His invisible attributes, His eternal power and divine nature, have been clearly seen, being understood through what has been made, so that they are without excuse. For even though they knew God, they did not honor Him as God or give thanks, but they became futile in their speculations, and their foolish heart was darkened. Professing to be wise, they became fools, and exchanged the glory of the incorruptible God for an image in the form of corruptible man and of birds and four-footed animals and crawling creatures.

"An image in the form of corruptible man and of birds and four-footed animals and crawling creatures" is an idol. Paul continues speaking of those who suppress the truth,

Romans 1:24-25
Therefore God gave them over in the lusts of their hearts to impurity, so that their bodies would be dishonored among them. For they exchanged the truth of God for a lie, and worshiped and served the creature rather than the Creator, who is blessed forever. Amen.

These men who operate according to the spirit of the world, the spirit of error, are then by definition idolaters, which is Avoda Zarah. Those who teach lies according to the spirit that is in the world are antichrists, which translates literally from the Greek to the counter-anointed.

1 John 2:18-19
Children, it is the last hour. You heard that the antichrist is coming, even now many antichrists exist. This is how we know that it is the last hour. They went out from us, but they were not of us; for if they had been of us, they would have abided with us; but this happened so that it would be apparent that not all are of us.

The world has no part in Messiah or in the Kingdom of God, because the world rejects and hates the things of God. This is how Christians are taught to see the world in practice:

1 John 2:15
Do not love the world, or the things of the world! If anyone loves the world, the love of the Father is not in him, because every thing in the world- the desire of the flesh, the desire of the eyes, and the vanity of living- is not of the Father, but is of the world.


In "The Lobster" how much of original human mind is left after transformation?

Question: In The Lobster (Yorgos Lanthimos, 2015) people who can't find a romantic pair in 45 days are transformed into animals. There is a transformation room where supposedly people are transformed..  But the details mentioned are only rumours and the actual procedure is kept secret. Is there any clue in the movie indicating whether any of the original human characteristics are transferred to the animal? For instance, the Colin Farrell's dog shows any sign of being his brother? I wonder how much of human could be transfered into a lobster.. none of it I suppose.
Answer:
Is there any clue in the movie indicating whether any of the original human characteristics are transferred to the animal?

The only characteristic that's hinted at in the film is compassion/love.
At one point, The Limping Man comments about how his parents were turned into wolves and then later placed in captivity. He eventually goes to visit them and tries to determine which of the wolves are his parents by jumping in the cage with all the other wolves, with the idea that his parents wouldn't attack him. There were in fact two wolves that didn't attack him, which he then believed to be his parents.
Of course, this is a [relatively] completely arbitrary and non-reliable way of trying to determine if any of those wolves were really his parents. However, again, this is the only time that a characteristic of a person with respect to after they've been transformed into an animal is mentioned.
In my opinion though, after giving the film much thought and consideration since I've seen it, I don't believe the people are actually turned into animals.
Comment: Isn't the dog the main character's brother?
Comment: @ChronoTrigger Yes... not seeing what your point is though. The OP asked in general if the film depicts any transferred characteristics, and then suggested the possibility of the David's brother as a dog showing any signs. The question though wasn't specifically asking about David's dog, though, I did still indirectly address this by stating that the only possible indication of transferred characteristics was with The Limping Man's parents as wolves.
Comment: I overlooked OP's comment about the main character's dog and focused on you don't believing people are actually turned into animals. To me, that observation was clearly false because of the dog, but now I understand that's the point of the discussion.
Comment: @Charles: I am afraid your recollection of the movie is a bit sketchy. There were indeed two wolves, who refrained from attacking the limping man, but only one of them was (believed) to be his parent (mother). There is no information given about his father, but since his mother went to the hotel, he was most likely out of the picture. "My mother entered the hotel, but didn't make it and was turned into a wolf. I really missed her.". My interpretation would rather be that random facts get overexaggerated into an emotion. Maybe none of the wolves was his mother and they simply were not hungry.