Thanks.
Bottom line is that the site is on CloudFlare, and during heavy load (probably from Hacker News) the site did go down or slowed a lot. Unfortunately, it's the real web server that died or went very slow and not anything in CloudFlare.
The server appears to still be having problems because if I browse to other pages on the site (e.g. http://www.standalone-sysadmin.com/blog/sysadmin-calendar/) you'll see that CloudFlare's "Always Online" is enabled and showing a cached version of the page. Here's a picture of what that looks like: http://i.imgur.com/QIeQF.png
Anyway, it's not true. Air in the cabin is bled off the engines, from the early stage of the compressor, then pressurized and heated. It's not one cabinful of air that was in it from the ground endlessly recirculated.
QI also told the world that the Internet uses GPS to route packets (tho' some devices may use GPS for its clock signal, packets don't know geographically where they are).
a show with a team of good researchers, they can on occasion be wrong (and have corrected themselves for mistakes in previous shows in the past), but they won't put a fact into a show without getting good sources for it
So while they may be wrong in this instance, the fact that they are a comedy show isn't reason enough to think so.
You don't have to pay for air during flight - it comes from the outside air and is free, it's not canisters or something.
Yes, you can increase the pressure. But then your flying tube in a low pressure environment may explode
Or it'll suffer a bigger expansion/contraction with every cycle and hence less cycles or metal fatigue and failure at 37000feet (passenger won't ask for a refund as they will be unable to do)
So the "cabin altitude" is really a balance between mechanical resistance and people not passing out (though this may be a good idea with some passengers)
Result: Each air change costs around .62 of a gallon of gas (assuming perfect efficiency). Or around $2.50 - let's call it $10 to account for inefficiency. In contrast it costs around $10,000 per hour (not including salary) to fly a large plane.
Saying they don't circulate air to save money is ridiculous.
You can work this out my looking at an an airlines profits, and how many flights they did a year.
In this case, airlines are a business designed not to have runaway profit. The unions are very powerful. They know how much money the airline is making a demand large percentages of it. They leave a nominal profit for key investors but shareholders as a whole are regularly left out. In fact, if you look at the entire history of commercial flight, the industry is break-even.
That's not a fluke. If costs were higher, unions would get a smaller cut. If costs were lower, unions would take more.
Philip Greenspun has some great writing on this, as well as the old, shortlived but fantastic Enplaned blog.
By my calculations a smaller 70 passenger plane would use around 1/5 the energy per air change, and they typically fly for only an hour or two. So for an air change every half an hour it would cost them around $4 per flight (and that's assuming low efficiency). So $100 profit is still possible (although I have to say that that's amazing low, but I'll take your word for it).
I don't have a source and am too lazy to find one, but it was stated on QI which is a show with a team of good researchers, they can on occasion be wrong (and have corrected themselves for mistakes in previous shows in the past), but they won't put a fact into a show without getting good sources for it, so if they say that air gets recycled less now than when smoking was allowed, I believe them.
Sorry - it's my fault for not giving more background on Mr. Smith - Patrick Smith has been a Delta Air Lines pilot for about 10 years, written two books on airlines, before that flying cargo, and I've met him more than once, so I'll trust him and the other pilots I've met when they tell me how their airplanes work.
Here's more of his articles on the subject: http://www.salon.com/2009/09/25/askthepilot335/ http://www.askthepilot.com/questions-and-answers/#cX-q9
and another article here: http://airlinesafety.com/articles/FSFCabinAir.htm
I'll allow that it's certainly possible that manufacturers have tweaked the circulation post-smoking, but even if so, it wasn't done with some nefarious intent or to the detriment of passengers. The air we breathe (as I'm about to get on a flight) is incredibly clean, cleaner than in my office.
Your sources are all (I think?) about the fact that the way they deal with air is good, and you may well be right that it's cleaner than in your office. That doesn't mean that it's not less clean than when smoking was allowed - it may well be that in order to get rid of the smell of smoke they needed to clean the air way more than technically necessary, and that therefore after the smoking ban it could be lowered without being "some nefarious intent".
"Stephen Well, the question is . . . It was almost certainly a bad idea, erm . . . It was a lousy idea, in fact, 'cause when smoking was allowed, the cabin air was completely replaced with fresh air every three minutes, and now, the airlines save money . . . they save up to 6% of their fuel bills by using a mixture of fresh and recycled air--
Julia And SARS.
Peter Ohh.
Stephen --yeah . . . using under half the amount of fresh air needed for comfort; increasing the amount of carbon dioxide in the cabin; causing dizziness, and nausea, and allowing viruses to thrive. Passengers think that, because they can't smell smoke, the air is fresher. This is not so. Apart from anything else, it has dramatically increased the number of air rage incidents. One of the earliest reported incidents of air rage involved a passenger in first class, probably trying to take his mind, erm, off cigarettes, by drinking too much, and he was refused another drink, and so he decided to lodge his displeasure, and shat on top of the food trolley. "
While Patrick Smith may not be an air conditioning expert, as a pilot he's required to know how the AC systems work and how to operate them, and if there was a widespread modification to AC systems or pilot procedures after the smoking ban, I'd expect him to know about it and mention it in the article.
And after that, if there's still someone who dares to smuggle these terrorist cancer sticks onto a plane and lights one, he will bring the whole plane down because some FAA rule from 2020 requires immediate landing in that case to the nearest strip to ensure the safety of passengers.
All that, despite the fact that there's still that ashtray in the toilet, non-optionally.
Here's the text if it continues to not work:
I’ve been lucky enough to have the chance to fly a lot over the past year or so. Working with Stephen Foskett and the rest of the Tech Field Day crew means that I’ve been to California almost every month. That’s a lot of flying.
One of the things that I’ve noticed on my flights is that they don’t want you to smoke. You actually used to be able to smoke on planes, which seems weird now that you can’t even smoke outide.
I’m not a smoker, so it doesn’t bother me. (As an adorable aside, when I was five years old, I literally glued hand-made no-smoking signs to the walls of my grandparents’ house. They were less than amused.) But the occasional legacy arm-rest with an ashtray harkens back to days of yore when every Joe Cool enjoyed the wonders of aviation while kicking back with a flights as smooth as a Laramie cigarette. He probably got a full meal as part of his ticket, too, the jerk.
Then the bleeding-heart liberals attacked in 1988, complaining of their “filthy air” and their “lung cancer”. The FAA banned smoking on flights less than 2 hours, presumably because the pilots were getting nic-fits after longer than that.
This was, of course, the thin end of the wedge. In 2000, the FAA banned smoking on commercial planes altogether. Talk about a bunch of buzz-kills.
So now we’re flying without cigarettes, and they are not kidding around about this whole “no smoking” thing…all you have to do is open your eyes to see that they don’t want you smoking:
That light is never turned off. I have actually seen a few planes which were new enough that instead of a no-smoking sign say “Please turn off electronic devices”, under the assumption that everyone is already well-trained enough to not smoke, but those are comparatively rare. Nope, it’s mostly the “no smoking signs”. But in case you didn’t look up, here’s the safety information sheet on the airplane. See if you can count the number of “No Smoking” warnings:
And on top of this, there’s a smoke detector in the bathroom (along with a heavy fine for disabling the smoke detector, too!)
No, planes are pretty much set up for not-smoking. Heck, there’s even a “No Smoking” sign on the ashtray in the bathroom:
Wait, what? Yes, you read me right. You’ve probably even seen them yourself. In airplane bathrooms, there is an ashtray (complete with No Smoking sticker) for the people who smoke in the bathroom, even though they shouldn’t.
When I first started bringing this up to people, I encountered the same reaction again and again. People would say, “oh, it just costs too much to replace the door or take out the ashtray”. This is absolutely not the reason, though.
Allow me to quote from the Code of Federal Regulations for airworthiness:
Regardless of whether smoking is allowed in any other part of the airplane, lavatories must have self-contained, removable ashtrays located conspicuously on or near the entry side of each lavatory door, except that one ashtray may serve more than one lavatory door if the ashtray can be seen readily from the cabin side of each lavatory served.
The plane can not leave the terminal if the bathrooms don’t have ashtrays. They’re non-optional.
That’s an awfully strange stance to take for a vehicle with such a stringent “no smoking” policy, but it really does make a lot of sense. Back in 1973, a flight crashed and killed 123 people, and the reason for the crash was attributed to a cigarette that was improperly disposed of.
The FAA has decided that some people (despite the policies against smoking, the warning placards, the smoke detector, and the flight attendants) will smoke anyway, and when they do, there had better be a good place to put that cigarette butt.
There’s a lot of wisdom in a decision like that. I think that it’s a lesson that we can put to use in a lot of the things that we do. There’s a really interesting book on a similar topic, called Nudge.. The idea behind Nudge is that every design decision that you make, as an engineer, affects the way that people behave toward your creation, so you should tend toward design decisions that encourage positive behavior in users.
This is similar to the design consideration called affordance. If you’ve ever walked up to a door and pushed, then realized that the door was supposed to be pulled, even though it looked like it should have been pushed, then you’ve come up against someone who didn’t understand affordance.
Here’s a good image of handles which afford pushing or pulling by Yanko Design:
It’s a cross between form and function. We have “grippy” hands that open flat. We instinctively know how to use things like this because of how we are formed.
You don’t engineer your systems with the belief that none of your computers will ever break. That’s insane; you KNOW they’re going to break. So don’t assume that your users will never break the rules. Build in graceful failure as often as possible, whether you’re designing a user interface or a security policy.
Likewise, when you are designing your infrastructure (or security policies), keep in mind the idea of affordance, and nudge people into making the “right” decision each time. The cynical Hanlon’s Razor says
Never attribute to malice that which can adequately be ascribed to stupidity
Instead of stupidity, maybe people are trying to push on the door that’s supposed to be pulled.