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October 14[edit]

Sharing Wikipedia articles on Facebook[edit]

i just wanna ask a simple question:will you in the future have a button some where to share what you put here with places like facebook cause i would totally like to put some things i read here that where really cool out there for the world to see more,but the no facebook status has it a bit on the why side.amanda titus. my email is [redacted].thank you. — Precedingunsigned comment added by 24.255.132.24 (talk) 01:20, 14 October 2012 (UTC)[reply]

I added a title. StuRat (talk) 01:22, 14 October 2012 (UTC) [reply]

Are you saying that Facebook blocks Wikipedia pages ? If you put a link to this Q there:

http://en.wikipedia.org/wiki/Wikipedia:Reference_desk/Miscellaneous#Sharing_Wikipedia_articles_on_Facebook

What happens ? StuRat (talk) 01:25, 14 October 2012 (UTC)[reply]

The question is about a Facebook feature to "share" a website by posting a link to it in a certain way. Answered at Wikipedia:Help desk#Button for Facebook share. Please only post a question in one place. PrimeHunter (talk) 01:49, 14 October 2012 (UTC)[reply]

As long as we are exporting Wikipedia and not importing Facebook lol. Marketdiamond (talk) 03:05, 14 October 2012 (UTC)[reply]

How to do fish processors remove mercury from them?[edit]

Or do they not? Hasn't there been a process invented to remove all toxins from fish?

Or is there a government conspiracy that prevents such an invention from occurring? --70.179.167.78 (talk) 01:34, 14 October 2012 (UTC)[reply]

There could be a government conspiracy, but if it was any good, I guess we wouldn't know. HiLo48 (talk) 02:03, 14 October 2012 (UTC)[reply]

Mercury removal would likely make the result into fish slurry, so not very appetizing. It would also make the result quite expensive. It's more sensible just to limit your consumption of fish so as to keep mercury to a safe level. StuRat (talk) 02:06, 14 October 2012 (UTC)[reply]

The idea of removing all toxins is nonsense. The idea of a government conspiracy is also nonsense. There have been several studies that looked at the possibility of reducing mercury levels in fish fillets or fish slices using chelating agents or other treatments, with moderately positive results, but as far as I can see there has been no uptake by industry. Looie496 (talk) 02:23, 14 October 2012 (UTC)[reply]

Or you could just go mercury free with the healthy, omega loaded and now so plentiful they are giving it away in some parts of the U.S. . . Asian carp. ;-) Marketdiamond (talk) 02:51, 14 October 2012 (UTC)[reply]

Why would they be mercury free ? StuRat (talk) 02:58, 14 October 2012 (UTC)[reply]

Well, they aren't actually mercury-free -- they aren't all that low really. But in general fresh-water fish such as catfish and trout have relatively low mercury levels. See our article on mercury in fish for more information. Looie496 (talk) 15:06, 14 October 2012 (UTC)[reply]

Ears popping on flight[edit]

Do my ears pop while ascending/descending on a pressurized commercial airliner because the cabin is not perfectly pressurized? Would my ears still pop if the cabin was perfectly pressurized? Does this happen to military pilots in modern fighter jets like the F-22? Acceptable(talk) 17:22, 14 October 2012 (UTC)[reply]

As Cabin pressurization#Cabin altitude notes, they allow the cabin pressure to fall a bit as the plane ascends. If they kept cabin pressure at the 1 bar (or so) it was at ground level (as one business jet, mentioned in that article, does) then your ears wouldn't pop at all. -- Finlay McWalterჷTalk 17:29, 14 October 2012 (UTC)[reply]

Wouldn't that business jet that remains fully pressurized cause a problem when the door is opened at the destination, and the pressure suddenly equalizes, popping everyone's ears at once (unless the destination just happens to have identical air pressure) ? StuRat (talk) 18:25, 14 October 2012 (UTC)[reply]

They will have to take steps to gradually equalise as they approach the destination. A pressurised aircraft, unlike a spacecraft, is not a closed system, so varying the pressure is a matter of altering the settings of the cabin/bleed-air pressurisation system. A space capsule, which is a closed system during most of its flight, has to have valves which are opened in the lower stages of its descent to equalise the capsule pressure with the environment. As reentry capsule notes, the malfunction of this system caused the death of the crew of the Soyuz 11 reentry vehicle. --Finlay McWalterჷTalk 18:35, 14 October 2012 (UTC)[reply]

It's my understanding that military aircraft operate in much the same way (at lower altitudes; as they fly much higher, the pressure is allowed to fall at higher altitudes). Dressing for Altitude: U. S. Aviation Pressure Suits: Wiley Post to Space Shuttle p176 by Dennis R. Jenkins says the F-15 had a cabin pressure of 6.7 psi (15 psi is around 1 bar). Fighter pilots receive additional oxygen from a face mask and wear pressure suits. --Finlay McWalterჷTalk 17:46, 14 October 2012 (UTC)[reply]

I'm surprised they let it get that low. Wouldn't they black out if their oxygen mask fails ? Seems too risky. StuRat (talk) 18:26, 14 October 2012 (UTC)[reply]

Pressurising the cabin places a mechanical pressure on the airframe. Fighter aircraft are, naturally, robustly constructed, but they fly so high (an F22 tops out at about 65,000 ft, more than double the ceiling of a 737) that 1 bar is a high additional load to bear. And the pilot has to be able to survive (and hopefully continue to operate) with the cabin depressurised due to damage or failure anyway, so the mask and suit has to be able to take the strain. The complexities of this system seem to be responsible for the problems F22 pilots have been reporting. SR71 pilots (who flew up to 85,000 ft) wore what amounted to space suits (see Lockheed SR-71_Blackbird#Life support) because of the risk of depressurisation (the cabin could be pressurised up to 10,000 ft) and to allow them to survive ejection (in theory). -- Finlay McWalterჷTalk 18:45, 14 October 2012 (UTC)[reply]

Time of useful consciousness at 6.7 psi (if I've done the conversions correctly) is about 10 minutes. That's plenty of time to put the plane into a steep descent as long as you notice the problem quickly enough (which can be difficult with a gradual failure - one of the symptoms ofhypoxia is not realising that you are hypoxic!). --Tango (talk) 19:54, 14 October 2012 (UTC)[reply]

Eaaaars poppin' on flight.. afternoon delight! 203.112.82.1 (talk) 16:59, 16 October 2012 (UTC)[reply]