CaptainPanic

yeps wasn't too hard - but I couldn't find any really tough one... probably because you're all better at chemistry than me hermanntrude is next!

5-aminotetrazole, [ce]CH3N5[/ce]? Seems to fit the description quite well... not sure how stable it is. Ok, I cheated a bit... I reverse engineered the solution using the percentage to find out how many C and H there were (using the assumption that C and H were the only other elements). I had never heard of the component until 2 minutes ago. Next one: I'm the glue of life, a heavily branched polymer, but not a sugar polymer. Without me, trees would fall.

Yup. If you want to leave it on the desk - get a desktop. If you want to use it in more than 1 place, get a laptop. In a comparison (taking a desktop and a laptop of the same price) desktops are more generally powerful than laptops... but laptops are more mobile.

Fact: Only 4 out of the first 100 posts in this thread contained a linked reference to some background article... A link like this. (I really hope I didn't make a mistake counting the references )

You're right - I should have said that the mean velocity of the molecules (plural) in a gas is related to the square root of the temperature.

Imagine an ideal gas that is cooling down by radiation (it's probably in space somewhere, and it's warmer than it's surroundings). The individual gas molecules have to emit a photon in order to cool down (probably, but not necessarily, in the infrared). What happens at the moment that a photon is emitted? It must mean that the molecule is colder now. Temperature and velocity of a gas molecule are related (velocity is a function of the square root of the velocity). So, does the molecule instantly slow down? And can this photon be emitted just in mid-flight of the molecule (without interaction with a second molecule), or only when it collides or interacts with another gas molecule? Does the emission of the photon have any influence on the trajectory of the molecule? Some Friday afternoon questions from a chemical engineer.

The sun's surface temperature is about 5800 K. The sun's atmosphere (the corona) however is over 1000000 K. How does the corona stay so hot? I read the wikipedia article that I linked to, and that suggests that magnetic field of the sun heats the corona. In addition, the sun spots seem to occur from the sun's interior. Finally, "coronal loops" are very common in the corona (they're the "basic structure" according to wikipedia). It also mentions that (part of) the corona is always moving away from the sun due to the magnetic fluxes generating the solar wind. In addition to the magnetic field that heats the corona, could it be that the corona is also heated by a constant flux of actual matter (atoms) that come from the interior of the sun to the corona. Gases cool down, and fall back into the sun where they can be heated again? Is there a link between the high temperature of the sun's corona and the high temperature of our own ionosphere, which is also warmer than the surface of the earth? Just some questions from a chemical engineer about stuff that we typically never have to think about. Friday afternoon brain fitness.

It's the gas inside the lungs that needs to push equally hard - not the lungs themselves. But you're basically correct. And the lungs, or the gas, don't have to do anything. It just happens. The gas simply gets compressed like the balloon example. In a theoretical case where you would be under 10 meters of water, and you would somehow happen to have air in your lungs at 1 bar (not 2 bar)... then the sea would simply crush you until the pressure inside your lungs is 2 bar (and the volume is only half of what it was before). Luckily, the breathing apparatus for scuba diving provides air at the right pressure... so thing is being compressed - you can just breathe normally - but you do breathe air at a higher pressure! The lungs are really very simple: they're just an open connection with the air around you. Whatever the pressure there, it's the same in your lungs. On a mountain, the air pressure is low, and the pressure in your lungs will also be low. Under water, the pressure is high, and in your lungs it will be high. It has to be like that, because if the pressure would not be the same the results would be painful. If you have more air in your lungs than outside (higher pressure inside than outside), then the air pushes so hard that you would just automatically breathe out. Your only alternative is to explode. If the pressure in your lungs is lower than outside, then your chest would be crushed... or, air would rush in through your mouth.

First of all: there are several systems for breathing under water. Let's only discuss the most simple one: just normal air from a gas tank. The pressure inside the air tanks is pressurized, typically over 100 bar (I'm guessing 200 bar(?) - I never went diving though). Then there is some gadget to regulate the pressure. And then the diver breathes the gas which is at the same pressure as the water. I could proceed to explain the whole breathing apparatus to you - but Wikipedia did that for me already. The important thing to remember is that the air in your lungs is at the same pressure as the ambient pressure (= pressure around you). At the surface, the air is 1 atm (atmospheric). Under 10 meters (33 ft) of water, the pressure is 2 bar - so, the air in your lungs will be 2 bar too. And that's why you get double the N2.

I think this thread already proves that a religious forum would not work here. The two camps base their entire argumentation on a completely different set of assumptions, and neither group is willing to discuss their most fundamental beliefs. However, both groups will happily discuss all the observations they make. Obviously, having two different sets of assumptions, they will always arrive at two different conclusions. And this is then discussed in forums that probably make up 50% of the internet by volume (the other 50% being mostly porn).

Personally, I think that the rep system is fine as it is right now. No negative rep. The positive rep is easy to understand. And mine is going up all the time.

Even without a cup of coffee, the answer is: [hide]4100[/hide] But more important is the question, what color is it?

I think solar sails lose efficiency the further away from the sun you go. Also, I think that space dust eventually will destroy them? but you're right that they require zero fuel, yet still provide some acceleration. It's hard to beat that in terms of efficiency. However: The following part of my response is totally subjective (meaning that it's my opinion, and it's not based on any science or valid reasoning): Personally I hope we won't be sailing through space. I'd rather have us get a cheap way to get lots of fuel into space. Big engines. Lots of steel. And a jacuzzi on board. I also find formula 1 more attractive to watch than the world solar challenge. It's more fun to see a sprint than a marathon. And I rather have a steak than a carrot. I hope we'll go into space in big, bulky, steel machines. I'd rather waste some fuel in space (no greenhouse problems there anyway) than save on weight if I have to spend an eternity up there. In other words: I'd rather have this one than this one. This one is good, and this one I don't like. The ships with huge glowing exhausts look fine to me. Why save on weight if you can also blast another ton of fuel into orbit cheaply (or better: when you can create it in orbit)? Bigger is better anyway. If one engine isn't enough, add another one. If one fuel tank isn't enough, add another one. With a staged design, there is no limit. A sail is just annoying. It's very slow, will easily break, doesn't attract girls, doesn't work far away from a star and you can't see a damned thing of where you're going half the time because your sail is blocking your view...

I can see two reasons why a rocket was used for the first space flight: If you attempt to put a 10 kg satellite in orbit, a rocket is simple. The cannon is a lot bigger than the rocket. I think a 5-10 km barrel is realistic. The rockets were only 50 meters tall. However, if you attempt to put a thousand 10 kg satellites in orbit, a cannon is might be simpler. In the 1950's and 1060's, the goal was to put a single satellite in orbit. Nowadays we want as many as possible. Also, in the 1950's and 1060's, the technology wasn't so robust that a radio transmitter could survive 1000 G acceleration. Nowadays this is entirely possible. [edit] And as SH3RLOCK correctly points out, a satellite would still require an engine (though a lot smaller (?)) to correct its trajectory and to get into a proper orbit that does not intersect with the earth itself... unless the escape velocity is achieved.

We're all volunteers here - helping people out. The reason people just kept repeating the same thing over and over again was that you did not tell us that you read anything about non-newtonian liquids. Also, you told us "to tell you how it works". It's not how things work here. You either ask a specific question, or you make a statement. Example for a specific question: What's the relation between temperature and viscosity, and how does that count for non-Newtonian liquids as well? Example for a statement (I'm not saying whether this is right or wrong!): Newtonian liquids have a lower viscosity at higher temperatures. It's usually best to add a question to that statement ("is this true?", or "what do you think?"). I don't understand what "collidal sollution" (colloidal solution) you're talking about? You said you tested 2 temperatures. So, I assume you prepared 2 times 500 g conrnstarch + 200 ml of water? One at room temperature, one at "high" temperature? (What temperature? Boiling point of water?) What were your observations in the 1st experiment, and what were your observations in the 2nd experiment? What were the differences? Please answer all these questions - then we can help you from there. And make sure to ask the right questions. p.s. I also did not know the answer to your questions, but I found it in 2 minutes in google. Just use the right keywords (which were very logical, really - no rocketscience needed), and it will be the 1st hit in the list.

I didn't click the link - but I also fail to see the point you're trying to make. Are we discussing the differences between Lebanon and the USA? Or are we discussing medical care and debts resulting from lack of insurance? Or are we discussing the success of the Darwin Awards?

Karzai had full support of most Western countries even when the election committee said that the elections were a big fraud. Only after extensive media coverage worldwide did the Afghans get a second election. And the only serious candidate suddenly withdrew... and all Western countries are happy. The same Western countries usually claim that they value democracy and freedom. I think that Karzai is: A puppet of a (bunch of) warlord(s) in Afghanistan who themselves are listening to someone from Washington/London (probably both). I think that the Western allies chose to have the same guy in office there so they won't get any surprises. Any new president was a risk, although there was obviously the possibility of improvement. Even more instability is just around the corner in that country. I think they argued that it's too early for completely fair elections. Better to have fake elections that might fool some people than to have real ones that might ruin the few meager results that were achieved so far in 8 years of war. (Before you scream that Afghans have the right for fair elections - Remember that there's a war going on there! Security comes before fair elections in importance).

Society would pretty much grind to a complete halt I think because we would get blackouts everywhere. And I've been told that it will take months or even years to replace the transformers... so that's a pretty long blackout. Please note: I'm no expert, and I just wrote down info from "hearsay"... so please doublecheck it if it's important to you. Do satellites (GPS and communication satellites) have any protection against a big solar storm? Or will they just get fried and become a lump of metal and silicon in orbit? If such satellites go down, the world might change for decades. We wouldn't know what's happening everywhere anymore.

Just give random positive rep to any red dot you see.

I think I'll skip this one because I have little problems with my current system. I'm just too lazy to update. I still run on Ubuntu 8.10. The next one (10.04) is a Long Term Support version, so that is probably more interesting for a lazy Ubuntu user like me. (I'm the kind of guy they want to convince to use Ubuntu: knows little of computers, and just find it at least equally attractive as Windows).

The thing with the negative rep is that it will not scare away any professional trolls and spammers... They usually know from the start that their stay here on the forum lasts only as long as the mods don't find out about them. It will however discourage newbies if they start off with negative rep. I remember my first few posts. The scientific ones we alright, but on the "other topics" boards I got quite some negative responses to my posts. Had that resulted in a bunch of negative reps, I am not sure I would have stayed around... There are also other science forums online. Being new on a forum is a weird thing. Regardless of your age, it does feel a bit like being the new kid at school. Little things can mean a lot. A little friendliness is like a big welcome, and a little negative rep can mean you feel like an outcast. Generally speaking, the older members have plenty of positive rep to deal with a few negative clicks... But if your icon jumps to red just because of a single person disliking one of your first posts, then that can mean a lot for the newbie...

Same goes for opera music. I hate it, and so do many people. So, let's make that illegal too. Shall we just outlaw everything that a majority of society dislikes? I know we don't want that. Repression, control and a police state cause: 1) Paranoia 2) Inefficiency 3) A large workload which contributes nothing to society 4) Money spent on police that should be used to feed your children 5) A very significant portion of the population in prison 6) A dislike of one's government I am sure I can go on. All very unhealthy things for society don't you think? Just look at the countries that have the strictest police. How successful are they compared to countries with freedom? Here's a link to Dutch data regarding healthcare for addicted people. People registered for: Alcohol addiction: about 539.200 For opiate abuse: about 25.000 to 29.000 For cannabis: "much less" This is a state sponsored institute. And the numbers honestly strengthen my belief that cannabis is harmless to our society - especially when we note that the number of users exceeds one million. The costs for "verslavingszorg" (that's the care for addicts) equals 12-20 million euro/year... or about 0.75 - 1.25 Euro per person per year. Sure we have problems with drugs. We however do better than other countries on the point of cannabis (note: I'm only addressing that particular drug). I don't need to look harder - I have lived here for quite a while. But those problems affect a small portion of the users... mostly people who came into contact with the heavier types of drugs. Note: the heavier drugs are illegal, and are sold on the streets. People who only use cannabis cannot buy these in the regular shops. As far as I'm concerned, cannabis is a category on its own.

Taking your post as the start of a thread,

The government would most definitely spend billions if it generates votes! People have been screaming for "security" and "safety" for years now. Ever since people got unrealistically scared of terrorism it has been the average citizen of Western countries (not the governments) that was asking for security. So, in order to gain votes, the governments gave people what they want. Only recently the debate about privacy started, because it happens to be that the best way to fight terrorism is by monitoring all the people. (That's actually true - it works, though I think it's just not worth it).

Except for the case of cannabis, which is already widely used in all the Western world. Please elaborate on this, because I believe I disagree. I'd like to have a little more explanation though. What "social and economical loss due to cannabis" are you talking about? I live in the Netherlands, where we tolerate cannabis use. The Netherlands is right there in the top-10 of the wealthy nations, it's a functioning democracy and has, on average, quite happy people (#4 in the world on some (probably subjective) list). Explain to me how this country would be better if we'd change the law and made cannabis illegal again... if that is what you claim.