CaptainPanic

You can test the effect of salt to the plants' growth? Take 5 (or any number of) plants, and give one normal tap water, one water with a little salt, and build it up until the last plant gets normal seawater. This is something you can do for sure... no difficult equipment needed, and only water and salt (and an idea of the composition of seawater) needed. If you have actual seawater available, you can just blend it with normal water. If you do a little research, you might also find some plants that are more resistant to salt. Do this test with two types of plants to show the difference. Also, you can test how much energy it takes to desalinate water. And how much it takes to only desalinate it for 50%. I admit that this is a lot more difficult than the 1st experiment. It's a tough problem, but it is important to determine how much energy it takes to grow the plants: you need to desalinate your water, and you have artificial lights. It's quite likely that this greenhouse consumes lots of energy!

You do this in a continuous reactor - so you create and also get rid of the gas at the same rate. Therefore, in time there is no accumulation of gas. Also, the hydrogen appears on one electrode, oxygen on the other. If designed correctly, the two resulting gases are nearly pure and kept completely separate, so no flammability problems occur:

I think that the climate scientists should be objective about it. But in the scientific world, there are plenty of people who have both authority (perhaps not on climate change though), and a strong opinion about climate change. For a journalist, or for any layman it is very hard to distinguish between a real climate scientist, and somebody who is a scientist that works in a field related to the climate (like environmental research, sustainable energy - or oil and petrochemical industry). Look for example at this forum. How many of us are really involved in the climate research? And how many of us have joined in a discussion about climate change? Most of us are scientists, and most of us can claim to have some authority in some field - quite possibly related to the climate research. And finally, many people might have two functions: one related to climate, one related to another topic. These two jobs might conflict.

ROFL. That trick would work here every day... especially in autumn. Let's see for today: I'll write with the blue pen for a change - and voila, it's going to rain in the next 5 minutes. The long term predictions are a little harder, but I think that if I take double sugar in my coffee, I can create lots of wind tomorrow! Most (if not all) styrofoam (polystyrene foam) however is made from petroleum. Note that I am not saying that Phi is wrong, but he could have phrased it a little better - starch is used in addition to the polystyrene, creating a composite material. I'm risking hijacking this thread, I'm sorry. But Phi started. *points at the other guy*

You, sir, earned my respect. You made an account with the only purpose of giving the wrong answer when the right answer was already given twice in previous posts. He shoots, he scores, the crowd cheers!

I didn't read it all (too long). But I'll still post something, hoping it's on topic: Just split up the republican and democrat parties into smaller parties. Within those two parties there are enough people who disagree on many topics, so writing the party programs shouldn't even be too hard. Then you nearly automatically get a multi-party system, and your problem is solved. (Perhaps the voting system also needs to be reviewed though - not sure if the US systems would function with multi-party politics at all).

If the punctuation and spelling wouldn't be all messed up, I would have thought we're communicating with a poorly written bot here. My humble apologies for making a joke about somebody... But I really don't understand this last post.

Ah, yes - That too. At low pressure, the liquid will boil at lower temperature. On top of a high mountain, water might boil already at 70 deg C... but in a pressure cooker it won't boil even at 140 deg C.

I have a feeling you can see the difference between nitrocellulose and cellulose. First of all, the NO2 groups add a significant amount of weight (it nearly doubles the molecular weight of a monomer). Also, the production (soaking in acid) will change the structure, and color. No way that you can actually pull this one off without anyone noticing any changes in a banknote.

I think it's just dependent on that kind of elements are present on your planet? There are theories about the formation of our solar system, and about the formation of solar systems in general.

No. The time it takes to heat the water depends on the heat capacity (or specific heat). Also, the amount of energy you need to put into the water depends on the heat capacity. The heat capacity is dependent on the salt concentration though. The boiling point is independent of this, and depends on molecular properties (like for example how polar the molecules are). Finding the boiling point: I advise to look up in handbooks (big books with almost only numbers in tables, and perhaps graphs).

If urea and cellulose would react to form an explosive, then peeing against a tree would be lethal. Trees contain up to 30% cellulose. And pee contains urea. Urea itself can not explode either. Urea needs water to decompose. [ce]Urea + H2O --> CO2 + 2 NH3[/ce] First of all, the decomposition isn't very energetic. Secondly, you turn two molecules into 3 molecules, two of which are soluble in water (and water is present). That means you'll make a liquid, not a gas. That means you make no explosion. It's completely understandable that the movie makers do NOT show how to make an explosive in a blockbuster movie which will be seen by a billion people.

Ah, you, and all your country are still in the phase where you think that a bicycle is a status symbol (it's not much of a status symbol, I admit). Over here, it's simply the fastest way to get from A to B (old town centers, many one-way streets, never any traffic jam for bikers). Hmm - running inside can be quite dangerous. I was thinking of outside - plenty of space, good view and cool air. Anyway, you can still run. Just wait until it starts to rain. Sometimes I am even happy when it's raining. Gives me an excuse to run. Depending on the quality of your roof, this one probably won't work inside either.

If we would run, it is likely that: 1. We'd be in a better shape, so we'd be less tired upon arrival. Marathon runners also don't get tired from a 2 km run. 2. We would probably have less body fat, and have a lower weight. This means we would actually have to use less energy / kilometer 3. We'd actually sweat a lot less per km than we do now, because of (2.) 4. If it is normal to run everywhere - we would wear different clothing and we'd adapt our deodorants and such... again resulting in less sweat. My reason for not running is that I have a bicycle which gets me there faster than I could ever run at half the energy.

In the unlikely event that you manage to attach urea to cellulose, the amount of urea will no be enough to create anything interesting. I'm saying that you won't manage to even react sufficient urea with cellulose to make anything interesting. If you do this in water, upon heating, urea will react with the water and will decompose. It forms CO2 and 2 NH3. Ammonia and cellulose don't form anything explosive. CO2 and cellulose don't form anything explosive either.

The problem is actually simple. The solution is not. Objects in low earth orbit (200 km altitude) have a velocity of about 7800 m/s. The total energy they have (kinetic and potential) is therefore: [math]E=m\cdot{g\cdot{}h}+0.5\cdot{m\cdot{v^2}}=m\cdot({g\cdot{h}}+0.5\cdot{v^2})=1\cdot({9.81\cdot{200000}}+0.5\cdot{7800^2})=32 MJ[/math] (per kg) Now, that's a lot of energy. This number clearly shows that you have to dump the heat (absorbing all the heat will cause you to evaporate). And whether you like it or not, you have to get rid of it - and, unless you use thrusters (rockets) to slow down, the only place you can dump it is in the atmosphere, through heat transfer and/or radiation. You have to heat the air by friction. p.s. cool thread to necro

You're a bit sceptical only about that part of the bond movies? How about the Moonraker movie with space multiple shuttle launches from underground secret bases on pacific islands? Or the satellite with mirrors that can burn the earth? Did you ever do the maths for that one? Or the Quantum of Solace eco-hotel with hydrogen storage in every single hotel room? How did that make sense? Ok, sorry, I am only joking. You're right to be skeptical. Urea and cellulose (base material for paper) don't react to form an explosive... although googling for [urea cellulose reaction] does give some hints that something happens.

The two objects have the same potential energy: [math] E=m\cdot{g\cdot{h}}[/math] [math] E=m\cdot{g\cdot{h}}=1\cdot{9.81\cdot{4}}=39.24J[/math] [math] E=m\cdot{g\cdot{h}}=4\cdot{9.81\cdot{1}}=39.24J[/math] Therefore, they will have the same kinetic energy after they fall down. But: the 1 kg object falls much longer (4 meters instead of 1)... so it will have more velocity. In fact, it's velocity will be exactly twice that if the 4 kg object. After falling: [math]E=0.5\cdot{m\cdot{v^2}}=0.5\cdot{1\cdot{8.86^2}}=39.24J[/math] [math]E=0.5\cdot{m\cdot{v^2}}=0.5\cdot{4\cdot{4.43^2}}=39.24J[/math] You can check the velocity of the object yourself with the formulas found here: http://en.wikipedia.org/wiki/Acceleration

Indeed. Except that it is not a flaw. It actually works: I live in a socialist country (the Netherlands). Our government currently consists of 3 parties. Labour (the socialists), the Christian democrats and another small Christian party. We have strong worker's unions almost everywhere, and a social backup if you get fired. Employers must have a good reason to lay down someone. Lots of qualifications to fit in the "socialism" category... although socialism isn't the only category that European countries fit in. "Democracy" is another one... and strangely, "capitalism" also fits. So, The "person who determines my abilities" is my boss. He evaluated me before hiring me. And our government has established a number of minimum "needs" (a house, food, some energy and water, education, and a little extra for the kids). If you're unemployed, all those who do have work will pay for it through social taxes. That's socialism. The system works, and has worked for several decades. I really don't see what the fuss is all about. Eh? People just search for a job. You're free to search, you're free to apply, you're free to send your CV and to write a letter. But socialism does not suggest that you can just pick any job you like. Nor does it suggest that the dictator or central party must decide. The standard methods like we are all used to will do fine... As I wrote before - socialism does not mean that the government decides where you work, or what you are. There is no conflict between socialism and freedom. The main idea of socialism is that the working class, mostly employed, but possibly also unemployed, get a proper share of the wealth that is generated by themselves.

I agree with UC that "chemical engineering" doesn't include much chemistry. I have a MSc in it, and I never do any labwork. I design factories for a living... and we don't get started until somebody in the lab has worked out something new - or unless the market demands an improvement of a process. Typically, the oil and energy (increasingly also sustainable energy) markets are the biggest. Petrochemistry, plastics, steel and other metals, food and pharma are pretty big too. The cool thing is that there is hardly a material around you that doesn't come from a factory that was designed by a chemical engineer. The plastics, paints, paper, coatings, metals, foams, glass - all the materials come from big factories. They're all expected to be high quality and low price goods... and chemical engineers do the optimization of the factories to achieve and improve that. It's the coolest job in the world

Because M is mass, and Mo is molybdenum? Actually I don't know... Google however seems to suggest there is an answer: http://answers.yahoo.com/question/index?qid=20071203033226AASQ8Hl ...but I cannot judge if it is valid.

I think you did threaten, and I have asked the moderators to remove only the part of the posts which is completely irrelevant to the scientific discussion. I'm no expert myself, so I cannot judge the science. But I would like to read the objective, and emotionless scientific discussion about this.

Hmm... Global warming isn't proven. The amount of data is insufficient. However, contrary to (rather) popular belief, this does not mean that the opposite is automatically true. Global cooling is even less likely. From the measurements, most (not all) signs seem to point at the scenario of increasing CO2 from us (people in Western countries) and global warming as a result.

So, it's just allowed to ignore the chairman? Did the republicans get away with this? This is really amazing. It's an act of sabotage against democracy. Sabotage against the Freedom that the Americans (both parties) like to preach. I was already convinced that the USA isn't a democracy anymore - but it's worse than I thought. I think the only thing worse than this would be a complete Coup d'Etat!

Is the carbonate in solution in water? Heating will remove CO2 from the water (gas solubility decreases at higher temperatures). This should influence the equilibrium between CO2 and bicarbonate, and in turn the equilibrium between carbonate and bicarbonate. Monohydrate means that per mol Na2CO3, there is 1 mol water present in the crystal. It's written: [ce]Na2CO3.H2O[/ce] Decahydrate: [ce]Na2CO3.10H2O[/ce] The presence of water means that a different decomposition reaction is possible. Answer to your last question: I think so (not sure). It will form CO2 and NaOH (please doublecheck)