CaptainPanic

Water has a lot of weight, and therefore the deeper you go in the ocean, the higher the pressure. For example, at 5 kilometers deep, the pressure is about 500 bar (or about 500 atmosphere). Every 10 meter is about 1 atmosphere of pressure extra. The boiling point of every liquid changes with the temperature. Here is a list of the boiling points of water at different pressures.You can see that at low pressure, the boiling point is lower. That means that for example in the high mountains, at 4 km altitude, water will boil already at 88°C! But under water, at 20 meters depth where the pressure is 3 bar (1 bar from our atmosphere + 2 bar from the water), the water boils at 130°C. And the deeper you go, the higher the boiling point becomes. Until... Until it gets so high that it enters the 'supercritical' state. Then water cannot evaporate because at the temperature and pressure at those vents, there is no distinction between gas and liquid water anymore. Sounds a bit mad, but it's true. There is a lot of information about supercritical water, so read up on it if you like. And by the way, all materials have a supercritical region, not only water.

You make it sound like there is a mistake in Psycho's post, but there isn't. He is not saying that the animals are not in those hydrothermal vents. He is saying that the water is not boiling. Boiling water forms steam. In the deep sea, the water is supercritical, and not boiling. The animals cannot survive boiling water, because there is no boiling water. It's like trying to survive a plane crash without a plane. It just doesn't work. The boiling point of water (100°C) as stated in many sources is the boiling point at 1 atmosphere of pressure (the pressure at sea level). At several thousand meters deep, the pressure is several hundreds of atmospheres, and that really changes the boiling point of water a lot. So much in fact that is simply refuses to boil, and instead becomes supercritical. I would definitely recommend the BBC documentaries for looking at animals... in my opinion a lot better than the Discovery channel.

They cannot survive boiling, because they would be ripped apart by the expanding steam. But they can survive >100°C easily. Here's an article (in Nature) about bacteria surviving >250°C in deep sea hydrothermal vents.

Excellent post. I just want to add that we must remember that acceleration and topspeed are a matter of convenience. People might want to make a small sacrifice to make it either cheaper or more ecological. Stopping a vehicle is a matter of safety, and different standards apply. All safety aspects just have to work, or it is not going to work. Ecology and economy always come second to safety. So, if you have a magnetically floating car which cannot safely stop when a child is crossing the road, this concept can go straight into the garbage bin. I am not saying this cannot work... I am only saying that we'd better solve this first before dreaming about a lower energy consumption.

Aluminium is used in places where power is very important, and convenience not so much. Wikipedia (of course) has an article on aluminium batteries. There are multiple reasons why diesel/gasoline is used more than aluminium... but I guess that the economics are the most important: liquid fuels give a good profit for companies, and they out-compete all other fuels on price per energy. It's easy to compete on a price per energy level if you only have to pump up the fuel from the ground. This may change in the future though (see also the quote under 'commercialization' inth3e wiki article). I am not sure how we can find out if anything real has a higher energy per volume (or weight). p.s. you link by clicking on the small 'insert link' button above the window where you write your text, and then copy-pasting the link into that. And if you select a piece of text before clicking onto that link, it becomes a hyperlink. [edit: forgot to add the wikipedia link]

Ok, a little more seriously, I'm sorry I hurt your feelings. When it comes to science, I am indeed quite direct. I find that the most functional way to communicate. It avoids confusion. Obviously, Fahrenheit is a very different story from Kelvin or Celsius. Fahrenheit, in this case, does make a difference, since 1 degree Fahrenheit is just 5/9th of a degree C or K.

Why do you sometimes shape your mouth so that it's actually a little harder to breathe out? You do this sometimes during (endurance) sports, or when you do a deep sigh. Here is an example (picture). Why do we do that? Is it to increase the pressure in the lungs, and therefore increase the oxygen intake? If so, does anyone know what the pressures in the lungs can be (the highest possible and the lowest possible during regular respiration)? If that's not it, then what is the reason?

Good point! Maybe that's why they don't want to have English as the official language. Americans stopped speaking English a long time ago, and replaced it with their own version of it, which they inconveniently still call English. We might be getting to the core of the problem here, which is an American minority complex about not having their own language. For those who have a very different sense of humor than me: I'm joking here.

Why? Redox reactions (for example fuel cells) are not limited by Carnot. I admit that putting the universe's highest energy chemical into a redox is a step we haven't made yet, but we're talking 'theoretically' here anyway. I think we might be able to find some maximum if we approach this from a molecular level: What's the highest energy bond between particles? And what's the lowest? The hydrogen-fluorine combination might be one of the most exothermic reactions, but it's possible to include some ring strain (i.e. get a ring structure with just 3-4 atoms). There might be some additional strain from steric hindrance, which can release even more energy when a structure is broken down. And I probably forget about a bunch of other options to pimp a molecule. Regarding petrol, I think it's not a fair comparison to look at such a fuel in terms of energy per volume, because the majority of the reaction product is in fact oxygen (which isn't in the fuel tank, but in the air). The OP does not seem to give us the option to import some extra reactants into our theoretical cubic meter. [edit] Shouldn't we approach this in terms of energy per mass, rather than energy per volume?

I gave you an objective remark about your post. Use it to learn if you like. You do not post on this forum to please me, I hope. I hope you're here to learn and share insights. You made an error in your post, and then you reply in a way that suggests you're annoyed that someone corrected you. I do not understand why, but maybe I misunderstood the tone of your post. Anyway, one of my points was: 4 trillion is 4 times bigger than 1 trillion. The difference is 400%. That is a significant difference. But 273 degrees of 4 trillion is 0.000000006% of 4 trillion, which is utterly insignificant. So, you don't really have to correct for it, and at such temperatures and such uncertainties you might as well say that celsius and kelvin are the same.

Does that mean that congress can dream up some new laws, and decide to put them into the book of laws in Spanish or French, if they like?

umm... The million, billion, trillion set goes with multiples of 1000. So, a trillion is 1000 billion, not 100. It is explained here on wikipedia. And at the temperatures you're talking about, you might as well say that Kelvin is the same as Celsius (in other words: the difference of 273 degrees is completely insignificant). Nope. The temperature is actually still the same... but the number that we use to express it is higher. What you say is that 298.15 K is hotter than 25 deg C. It's not. It is the same.

Good point. So, the answer to the question is: No, nothing can directly or indirectly make English the official language of the USA, other than a law that specifically states that English is the official language. It's a pretty boring answer, actually.

There's a fundamental difference between the example that JohnB gives and the issue that JustinW explains. JAL airline pilots are on a closed communications network, and English is the chosen language. But the HAZ-COM labeling is a regulation which is meant to be a communication between a producer of chemicals, and the general public (anyone who buys it). Since an official language of a country is obviously meant for communication with the general public, the example is not valid. From JohnB's example, we may only conclude that the official language of international air traffic control is English. But we cannot conclude anything about Japan's national language. I think that if a government creates some regulations which state that English is the only language necessary on any hazard labels, then the answer to the OP's questions is "Yes, in practice it is the official language.".

Nope Sorry Cap that wasnt what I meant. By posting two messages I will show you. I have quoted your message above in my message. This (above) then? You can click on the quote in my post (which will get you a quote, with name, and tag), and select all, copy. Then go back, and reply to the other post, which will get you the other quote tags, with name, time, etc. And then paste the other one into that quote. It's the only way I know of.

And this is the quote. will get you: And this is the quote. Was that the question?

ROFL! This is a fantastic thread. First of all, it certainly showed that the OP was right. All the mods that replied here show that they can't control their vicious instincts, and should they seek psychiatrict help. Secondly, it also shows we absolutely adore trolls. Can we keep this one, please, please, please, please, please ??

+1 for the smartest question in this thread so far. There are a million ways to adjust the density of a liquid... and it all depends on what you need it for.

As imatfaal says: it's not so new. But it is quite nice that you found out yourself.

Pfft... You all sound like a commercial for a body lotion. You all sound like you go through the following phases in life: Child (happy, life is simple) Youngster (you're strong now) Senile old fart (you're useless and broken) [queue the slogan: use our product, and postpone aging by a few years] I'm quite looking forward to all the wisdom that will come with more life experience. When I was 20, I really knew nothing. I have learned so much every single year after that...

Aging and immortality are mutually exclusive. It's either one or the other, not both. That, or your view of immortality is really sick. Take a normal person, and see how this normal person ages. Then extrapolate that line for another 1,000,000 years. Ugh. I see only dust with a consciousness.

What did you expect from us? Of course we will try to find problems with your suggestion. That's what we do on this forum! And unfortunately for this thread, finding the practical problems regarding the change in time is a lot easier than identifying the biological effects of working in the evening and relaxing in the morning/afternoon.

google.com (google scholar) sciencedirect.com When I dump your thread title into science direct, it gives 34 hits. No clue if any of them are useful for you. You'll have to see for yourself. (And no, in the big science-world, we often do not find exactly what we want... you'll have to go with something that is remotely related, and learn from that).

My advice: Don't be creative. Just steal someone else's idea. And with "someone else", I mean a professional.

You could say that the maintenance costs of the ship is tax. It can be paid with money or community service. Compared to smaller ships, this ship has so much indoors, that the maintenance will not be affected much by the salt water. Sure, a 1 mile ship has a lot of hull to paint, but the outside area is a square function of the length of the ship, but volume is a third power... and the amount of people you can fit in a ship is related to the volume. But there are a lot of other shared cost factors: waste disposal (which is the topic of the thread, may I remind you all), heating and/or cooling (i.e. fuel costs). And it might or might not include things like education and healthcare. Good point. I wonder whether they will make the ship able to withstand all kinds of climates. To be able to go around the globe, they need to be able to go round the south points of Africa and South-America. It's quite something to be able to withstand cold winter storms (in the middle of the ocean!) and tropical heat as well. Insulation is a big factor for the investment costs, and airco and heating are a massive cost for the everyday running costs. I don't understand why these guys don't just buy 10 old cruise ships, and go around the world with 10 villages instead of 1 town. Then they can try out the whole community thing without first also having to try to build this huge ship with untested technology.