CaptainPanic

Except that nobody is hurt if a pyramid has a little crack to the outside environment... but any storage for nuclear waste should be completely closed, or water will get in and start corrosion and leakages. Sure we can build something that is still there after 100000 years. But I doubt we can build something that is totally closed and remains totally closed for 100000 years (at a price that we can afford, because we have affordable alternatives that produce no nuclear waste at all).

In 2005, total worldwide energy consumption was 500 EJ/year (= 5 x 10^20 J/year)... The total energy from the sun that reaches earth is: 174 PW, or 5480000 EJ (which is about 11000 times as much as we consume). The earth actually absorbs a bit less: 3,850,000 EJ, but that is still 7700 times as much as our total energy consumption. Therefore, even if we double our energy consumption, you aren't very likely to see any change. Greenhouse gases on the other hand trap a percentage of this massive amount of solar energy. And that is actually significant.

That's quite tough... The initial acceleration comes from the force derived from the buoyancy. There is no drag (yet). Calculating the change of velocity is difficult. The formula for the drag is difficult. I'm not sure how deep into the matter you're going. The shape of the bubble itself changes as a function of velocity, size of the bubble and pressure.

The error was probably just typing it wrong on the calculator: To get the answer of [math]r = \frac{25}{2 \pi}[/math] you have to type on the calculator is 25, divide by 2, divide by pi. The result of 39.27 comes from 25, divide by 2, multiply by pi.

Engineering is pretty much hands-on, and practical. But perhaps not the "furry" kind of practical. But engineers do apply science, every day, again and again. Although your other interests don't seem to match pretty well (engineers don't release animals, although they might change (improve or destroy) an entire habitat). Hope this might still be a valuable answer for other people.

Thanks for correcting. My post is the result of a chemical engineer talking biochemical stuff. In my field, they're the same thing. In the book of the expert, they're not

You're planning on mixing two different gases, and then get a salt to form in mid-air... Hmm... Wouldn't that make everything a bit dirty? And in addition, you'll have to buy quite a lot of gas. Finally, DMSO boils at 189 deg C, which will make it a bit hard to vaporize it. You can't heat containers to >100 degrees. Some products inside might not like that I think a more conventional way to clean air would be to vent it into a scrubber, where you scrub the air from this methyliodine. This means you'll have to blow the MeI+air towards the scrubber. You'll therefore have to blow clean air into the container... this will dilute the MeI even more... but still better than reacting it all away to some salt. You might even be able to recover the MeI from the scrubbing liquid (in case you use a wet-scrubber). I don't know what would be a good liquid or a good design for this. I'd have to think a bit longer, and possible test the solubility of MeI in a couple of liquids. Before trying this out (I'm not sure if you're a Do-It-Yourself kinda person), please consider mass transfer - a badly designed scrubber does not work... but a good one can have many benefits

Hehe... indeed. And possibly tomorrow gravity reverses and we're all flung into outer space. This all doesn't make a lot of sense. Some things are just the way they are. The first law of thermodynamics is one of those things. You cannot make something out of nothing. Period. Accept it. We're done here.

Why would a Surface to Air Missile absorb latex? Three letter abbreviations are so nice, especially when you don't explain them. Google searches for the meaning of any 3 letter abbreviation always fail. Lesson #1 in scientific writing: assume that the reader is stupid, therefore: 1. Explain abbreviations 2. Explain symbols (including units!)

Thanks UC. Indeed, they are both called proteases, and proteinase. (I believe that it's the same group of enzymes, therefore the same thing).

The solvent is probably water. Milk is a stable emulsion of water and oil (water is the biggest fraction).

There are other areas where Muslims, Jews, Christians and whatever else live in peace together. Sarajevo was one of those places, then there came a war, and now it's peace again. Therefore, in theory it is possible... even after some pretty horrible things happened. (I'm not saying that people there have forgotten and forgiven, I am merely saying they stopped shooting each other, which is my definition of peace). Whether it is possible in "the Holy Land"... I don't know. I get the feeling that both Israelis and Palestinians are a lot more stubborn than people in other places... and that it has to do with the fact that some dudes built a bunch of temples on a couple of hills in that area a few thousand years ago. Please note that I lack some historical knowledge and that I am well aware that I am over-simplifying things.

Why are the topics arranged by company / news agency or publisher and not by topic? It all seems a bit random to me.

Yes. The smaller the ecosystem, the easier it is to unbalance it (what if all 100 people start doing serious exercise? Do you run out of oxygen faster? What if you have 1 bad harvest?) Earth has some pretty serious buffers of almost everything (oxygen, food, water), and even here we run into problems. There have been experiments with this on earth. It was called "biosphere 2" (there probably also was a biosphere 1). Read more: http://en.wikipedia.org/wiki/Biosphere_2 I think this is an engineering issue, perhaps also biochemical and biological. Not physics. But that's not important.

Yes, peptide bonds (as I prefer to call amides) can be hydrolysed. This can be done chemically (either at low or high pH and about 100 deg C, and in water (of course, since I mentioned pH)) or enzymatically (in that case you need to get the right enzyme for the right type of peptide bond): The peptide bonds are for example found in proteins (the amino acids are bonded like that). For hydrolysis of those, you can use "proteinase". There exist many different types of proteinase... but a cheap one is found in laundry detergent (if I'm not mistaken).

Your question is so enormously broad that people can write several books about it. That's also why you didn't get an answer... it's a long answer, and I wouldn't know where to start. So... Metal has metallic bonds. They're in a lattice. <-- read on wikipedia what all that means. An elastic (please specify what type, probably rubber) consists of polymers. These are branched and therefore can change shape better. The structure in the elastic is not rigid. That makes it elastic. I hope that is the answer you need. At least you got some new keywords. A thousand apologies that the volunteers on this forum didn't meet your deadline for answering the question. In stead of asking for help using CAPS, next time spend a bit of time to write down a better question... it really helps to get an answer.

If aliens would visit earth, they'd get a tourist book, visit the Eiffel Tower in Paris, and go "Mouhahahha" because it doesn't even have propulsion.

hehe... no more anonymous people. Great stuff. They should put name tags on those faces for everybody. Actually, I'm kidding, I don't like the loss of privacy because of all the new technical possibilities... although I am also impressed with these new technologies.

My opinion: No need to start focussing yet. If your son, at the age of 16, is already "focussing" on the science (physics, math, and hopefully chemistry too), then that is a good start. I'm not sure even on which continent you are, so I might give irrelevant info. In the Netherlands, the choice for a university comes at the age of 18-19. This gives the kid 2 more years. Then it comes to a point where he must choose between physics, chemistry, applied physics, aerospace engineering... that sort of broad fields. Those are all faculties at a university. Really specializing into a field will come during the studies at university, or when doing a PhD, or even after that. At 16, nobody is going to be advanced. You might be talented, or really smart... but there is plenty of time. Of course, a hobby can be fun. That would channelize something perhaps. But I would advise against pushing too hard. But that's just my idea of teaching kids. (It should be voluntarily, and fun).

Well... 10% (guessing) efficiency for earth-based lasers is pretty good. You should realize that the spacecraft that is propelled by these 10% efficient lasers is also a lot smaller: it has no engine, no reactor for energy (or solar panels if you want). It can be as simple as a tin can with a payload. I wouldn't be surprised if an engine on a spacecraft is more than 90% of the weigth (especially with conventional rockets - it's guessing for out fusion-laser-spacecraft of course). You cannot dismiss one idea because one part of the idea is less efficient. You have to look at the whole picture. Still, losses in the atmosphere can be a problem... I agree with that. And I think that the efficiency problem is not so much in the atmosphere as in the concept in itself. 3.33 N thrust from a Gigawatt... well... that's not much. I've seen that. It seems quite cool, and has the potential to be very efficient... again because you have a smaller spacecraft. Funfact: the Saturn V rocket produced 190 GW, which produced 34.02 MN (MegaNewton) of thrust in the 1st stage... In other words, the thrust to power ratio of the old saturn V rocket was 0.18E-3 N/W, while the laser concept gets 3.3E-9 N/W. The Saturn V rocket gets 54000 times as much thrust per Watt. In other words (coming back to buttacup's guessed efficiency): I wouldn't worry too much about the 90% efficiency losses of the lasers in the atmosphere (if that number you guessed is correct). There are other losses to worry about. And even then, this idea can still be more efficient than a conventional rocket. It just depends how much you want to accelerate. For nuclear powered rockets (one made it as far as the test-phase in the 50's and 60's) - I linked to Project Pluto earlier this month in the engineering forum. This thread is about a nuclear cruise missile (that did not have any combustion - it just superheated normal air with a nuclear engine. Good thing they never tested it in the air, only on the ground somewhere in the desert).

You can cool with air in stead of cooling towers. But that would only be bigger. If you want to transfer a few megawatts to normal air at a max. temperature difference of 50 degrees, then you will require an enormous heat exchanger. The cooling towers are actually one of the more efficient and certainly more cost-efficient ways to do it. Dumping the waste heat into the sea / river / lake is even cheaper, which is why so many power plants are built near water. Those often don't have a cooling tower, unless there is a limitation to the heat they can dump in the surface water. That actually makes sense. But I have never heard any nuclear engineer/scientist/journalist or whoever involved in the nuclear business propose that we just blow up (dilute in a controlled way) the nuclear waste in such a way that we evenly distribute it over the entire earth as fast as possible. This idea will probably have a serious marketing problem But since it is done in the Soviet Union, I guess the concept is known to those involved in the business. In stead, every proposal is about building some enormous cave system where we can store the stuff. I don't like that idea, simply because humans have only produced a couple of (monumental) buildings that have lasted 5000 years (the pyramids). Everything else we've built is much younger and is already falling apart. Nuclear waste needs to be safely stored for much longer. I just don't believe anyone who claims it's possible to build something that lasts 100000 years. I agree with SkepticLance's idea to temporarily store it for the fast decaying isotopes. Then dump it. Or even better: no nuclear energy at all. I don't see why we'd invest in anything other than sustainable energy. But that's off topic.

Well... the answer you will arrive at is that a perpetual motion is not possible. So, the fact that it all doesn't work will be a perfect result for your science project. In fact, I am sure you'll fail the class if you really build something that seems to have perpetual motion (because it means you're cheating somehow).

If something has a molecular weigth of 121.1 g/mol, and you need 0.1 M (0.1 M means 0.1 mol/liter)... The info is right in front of you. You should realize that a mol is just a "number of molecules" (but a very large number). It's the same as a dozen or any number. Dozen = 12 Gross = 144 (12*12) Mol = 6.022*10^23 How do you make 200 liter of a 10 eggs/liter mix when the eggs are have a weight of 121.1g/dozen (they're tiny eggs)? I.e. how many grams of egg do you have to add? I'm sure you can answer that question. Just do the same for the molecules. They're a bit smaller, but in the end, the question is the same (note, I changed the numbers a bit, so the answer is, obviously, not the same for both questions). Good luck... and sorry for not giving the answer - we don't answer homework questions here. We want you to learn.

A mixture of 2 chemicals (for example: a salt and water) will have only 1 eutectic point. Therefore, it would be possible to list it. But, there are lots and lots of chemicals, and since eutectic points always require 2 chemicals, the list can be enormous. Therefore, I am not sure that the data you need is in the following source: DECHEMA is a source for phase diagrams (mostly liquid-liquid equilibria, vapor-liquid equilibria)... Click here and look under point #4 for the source: Eutectic Data (and the price, which is not cheap). Your best option may be to find a university library, and borrow it from there, or go there and make a copy. Alternatively, search for the sales office of Dechema, and buy it. I seriously doubt that you can find the info online. It would help if you give us a few examples of eutectic mixtures that you are interested in.

Forget about dissolving it. Although I am sure it is possible, I am also fairly sure that anything that can do it will kill all life forms within sight for the next century or two. Just dig it up and, if possible, have it recycled.