CaptainPanic

Go for it! You're only 17! I'm not sure about the school systems in the USA (assuming you live there)... in the Netherlands it would be possible, although you'd have some delays. Plenty of people have a delay in their school-careers at some point. It's part of being young. It's good that you've learned from it already. (I would say you're an early learner... most start doing stupid stuff once they go to university here, out of their parents' protection). Two things you need to do: 1. Work hard 2. Show motivation and interest to those who need to help you (don't slime, don't show off, just show motivation and interest).

I have no clue what would currently need a usb that fast. But I can imagine a large hub with several "USB 2.0 like" connections saturating the line somehow? I'm positive that given the chance, someone will succeed to make a data storage that wants to push all that data through a cable. Btw, This HVD... That's a fancy disk. Any idea when it comes to the market? Wikipedia doesn't give any estimated time of arrival... although it does list some competition to the HVD. (Reading that makes you completely forget the blu-ray and hd dvd). One little problem: "However, holographic drives are projected to initially cost around US$15,000, and a single disc around US$120–180, although prices are expected to fall steadily(wikipedia)." But eeh... those larger flash drives contain 500 GB, don't they? Granted, they're still a little big, but they're rewritable by default, and getting smaller every day. I can see them catch up with those terabyte disks before those hit the market. Google search for terabyte flash actually already gets a hit. Seems all those disks are too little too late? Strange that most of my furniture is older than those ancient 1.44 floppies, yet those seem prehistoric now.

My tv is too old, and so is my monitor. Normal DVD's are finally becoming affordable. I see no reason to even consider buying the newest technology. I think hermanntrude made an excellent remark stating that the cd's and dvd's can get scratched, while a flash can't. I'll wait for the moment that movies are sold on huge flashdisks. The next generation USB can do 4800 Mbit/s (600 MB/s), and is planned to be available in 2009-2010 (see: wikipedia, "usb"). Although I cannot really grasp how fast that is, it means movies can be read directly from a usb at tremendous speeds. I don't see any point of having large cumbersome disks (cd's were once considered small, lol) of any type with this kind of technology available. I think the HD-dvd or blu-ray is like the last generation of steam engines. It's quite cool but not exactly "the new thing".

The reaction you wrote down is correct. The heptane reacted with air, not with moisture. Actually, it reacted only with the oxygen (O2) from air. The other compounds in air, such as nitrogen (N2), don't do much. Moisture is a product from the reaction. Moisture (water) is H2O that is formed. About the evaporation: when it burned it created heat. This heat made it evaporate faster. (It's like water: it evaporates a lot faster on a hot summer's day than in winter).

Viruses are obviously for free... And the fact that lots of computers are infected with rather smart viruses, the success of things like the stormbot and all kinds of scams must mean that quite a few people are working in the field of virus creation. I don't pay them in any way, and no money is transferred from my bank account to these people. So, then why is the anti-virus still so expensive? I get the feeling that anti-virus software companies are fighting each other rather than the viruses. It's like two surgeons fighting each other over who can operate the patient. Doesn't make any sense. As for routers, with the invention of wireless routers I think networks have become less safe rather than more safe. Do router-viruses exist already? Should exist, since routers contain software which can be updated.

Ska and oldskool funk! *bounces up and down, and attempts a moonwalk:cool: * p.s. BlackParade, what kind of person visits a scienceforum and then makes his first post in a thread like this one?

Although the additional information is interesting, it seems many people didn't answer the question: Smoke is aerosol particles floating in a gas (air). Gas is not smoke. Also, colored flames are not what's asked for in the question. The question was about colored smokes, while the majority of the answers seems to address colored gases (which indeed are in the "Kids, don't try this at home-category") or flames. I have no experience making colored smokes other than using regular smoke from a smoke machine (as found in clubs and discos) and shining a colored light on it. But wikipedia (again) provides info: http://en.wikipedia.org/wiki/Colored_smoke Think it's a matter of Google-ing to find a supplier of these smokes. But many may be used for military purposes, so I doubt it's easy to find. Please check the material safety data sheets (MSDS) of any of these chemicals before buying or using them!! finally, my smoke bomb recipe: take sugar and KNO3 (potassium nitrate), mix in roughly 1:1 ratio and try to ignite without burning yourself. The few times I played with this, it didn't ignite easily. I advise a fuse from fireworks (throw away the rest of the fireworks). Actually calculating the right stoichiometrics might also be helpful. I never bothered.

All information has basically been given already. But I'll still add my reply. I use the following definition of a fire: A self-sustaining reaction of a fuel and oxygen (from air). As stated in many schoolbooks, fire needs 3 components: oxygen, fuel and the right temperature. Could we perhaps state that the coldest fire is the fire which has the lowest autoignition point? Wikipedia states for "autoignition temperature": "The autoignition temperature or kindling point of a substance is the lowest temperature at which it will spontaneously ignite in a normal atmosphere without an external source of ignition, such as a flame or spark." Wikipedia also lists a number of substances and their autoignition points. It seems that Triethylborane autoignites at -20 °C (-4 °F). Assuming you are able to remove all heat of reaction by any means, the reaction (fire) would keep going at -20 °C. (If you don't remove the heat with some cooling-device, it will rapidly get hotter and hotter...). Note that if you're able to keep the temperature low, this kind of fire probably doesn't have any light-effects. p.s. (1) A catalyst may lower the ignition temperature a LOT, and I didn't take this into account. I consider a catalyst "cheating" in this question. p.s. (2) This Triethylborane will probably autoignite at an even lower temperature in pure oxygen or at higher pressure... so changing the definition of "fire" also changes the answer. p.s. (3) There may be exotic chemicals with an even lower autoignition point. I didn't look further than wikipedia.

Interestingly, it has been said that the Dutch, and some other Europeans are now taller than Americans. However, it has also been said that the Dutch are no longer getting taller. The current generation might be the "tall generation". A trend has been observed which suggests that the maximum is reached. It is attributed to the food crops that are grown to have a high mass, but not necessarily contain a lot of healthy components (such as vitamins, or other essential chemicals). Many state that apples and tomatoes nowadays are looking better, more shiny, but are in fact more watery than ever. Source of the Dutch being the tallest http://www.timesonline.co.uk/article/0,,13509-2577471,00.html Source of the Dutch reaching the max. length. (unfortunately, it's in Dutch ) http://www.nu.nl/news/1380578/10/rss/Nederlander_groeit_nauwelijks_meer.html

Perhaps it was a ferret or a weasel? Not sure if they can walk/jump on their hind legs, but I don't see why not with some practice. They're very active and lively animals... Or it was an escaped miniature kangaroo?

If you have perfect (monochrome) yellow light, so 560 nm, and a filter for red light only (filtering only wavelengths from 600 nm to 700 nm), then the yellow light just passes through, as if there was no filter at all. Note: if you take a colored piece of glass as a filter, this might filter more than just 1 color. Also, the light from your lightbulb contains a lot of wavelengths.

There will merely be an overlap of the two types of light. With a filter that blocks red light you would see only the green light. The sunlight is a combination of light of a lot of different types of light with different wavelengths (the rainbow shows how many types ). Not sure where the idea of the "orange light" is starting... but it seems probable that this is only in our heads.

I always wonder whether the pointy nose of birds means that they plan to evolve into supersonic birds one day. (I'm very sorry... I'll keep the number of stupid posts limited).

I think you should try to read the "Handbook of chemistry and physics". http://www.hbcpnetbase.com/ It only has 20 sections, each with up to 500 pages. It will contain probably less than 1% of all the molecules with hydrogen in it. Why on earth do you want a list of molecules with hydrogen in it? I'm glad you realize that your question will not have a short answer. If you specify whether you're interested in either: 1. inorganic molecules 2. organic molecules 3. common molecules 4. something else, namely... Then someone might be able to refer to a book on a specific topic... Have you tried to do a google/amazon search on "hydrogen handbook"? I haven't, but it might help you. Good luck!

If you want to know the pressure at any altitude that is NOT in your table... the lazy and not-100%-correct-option is: Put all numbers in a spreadsheet (such as Excel), plot, add trendline, and click on the trendline to show the formula. Then use the formula to calculate the new numbers. It's not very scientific, but it's quick and dirty and will probably give you a better result than when you mess up some tricky math...

Sisyphus means that WW3 was prevented because of the nuclear (for illiterate Texans: nucular) deterrent. Our great leaders were so afraid to die, that they didn't start another world war. How that relates to biodiversity is... eeh... completely straightforward: nucular war, no more bio-anything. Of course, we have only prevented WW3 once we can guarantee that also in the future we're not going to blow each other up... something which I wouldn't bet on with the current instability and increasing number of countries with nukes.

Why would anyone want to put a pricetag on our biodiversity? I generally consider the price of something when I am thinking about the pros and cons of a purchase or action. Is anyone thinking about reducing (or increasing (GMO)) our biodiversity? I can't think of any group, organisation or company causing a reduction in biodiversity who would be interested in the actual monetary value of this biodiversity, or who would consider this price a real argument unless you are planning to put money on their bankaccount. Oh, wait. My local zoo is interested in biodiversity

It's priceless. An organism can evolve into something new in thousands/millions of years. If it's extinct, obviously this is no longer possible. Additionally, we can use any organism for our own benefit. We can develop medicine from it, and learn about the workings of nature. Humans are also nature. Additionally, a biodiverse environment is usually more balanced. If we're talking about growing crops, a diverse agriculture is less vulnerable to disease. Any disease breaking out may spread slower and will affect a smaller portion of the crops. And I'm sure more arguments can be found in favor of biodiversity. The one argument against it: One single crop means that agriculture can be industrialized easier. That means big money.

First give the actual problem, then ask for help. Yes, I think I can help.

In the Netherlands, many old houses are build on wooden poles, drilled into the soil (for the foundation). Also, the roofs are usually suppored by wooden beams. Some, like in Amsterdam, are 400 years old. I'd say this shows it is at least durable. And you can go up 5 stories. I agree that skyscrapers will not be made of wood. I also agree it's not the strongest, but I disagree with the words "it is far from the best.". It really depends on the criteria you use. I think "the best" can mean the best price/quality ratio (economics), or the best material properties. These are obviously not the same. Can I say that this thread is very ugly because of all the different fonts and fontsizes? It isn't inviting me to read.

Since nobody seems to know what gravity exactly is (has anyone ever measured a "graviton" or something like that?), and why it's there... It might be a safe conclusion to say that gravity is merely a model that seems to fit our observations very well. I cannot think of a reason why there shouldn't be another model, without gravity included, that can describe the reality that we measure and see with our eyes. However, such model has not been developed yet, so we assume gravity to be real. It also feels very real when you go head first to the pavement. There are some people who have interesting arguments that say the gravity model is incomplete (they don't seem to disagree with the concept of gravity). They have grouped themselves in a movement (if you can call it that) called "the electric universe". I have read some electric universe webpages (just google it)... and hardcore models seem hard to find on websites. However, in more conventional websites, I also have never seen a good explanation why Saturn's rings don't condense into some spheres (moons). A ring seems to defy gravity. Electric forces can explain rings quite well, since it includes both attraction and repulsion. Gravity, to my knowledge, only includes attraction. If anyone has a good explanation about Saturn's rings, I'm interested. Disclaimer: I have not studied the subject to a great detail. Before stating things I wrote here as a fact, please study the subject, and doublecheck everything. (Ha, quite proud of myself for adding a disclaimer here ).

I'll still reply, because a similar problem can be found where I live (Netherlands, Europe). Our teachers at grammar school (kids of ages 5-12 yrs) are very poor at math. Result is that we start secondary school having only basic calculating skills. Secondary school should be devided into two parts: that part where all courses are compulsory: the general level of math is low, and adapted to the slowest student. The second part is where those slowest students will have dropped the subject, and a little more advanced math is given. The same goes for physics and chemistry. Those who have some interest find it really easy, because they pay attention and study it a bit. The lessons are adapted to those who have no interest and motivation. These pupils still need to pass the exams. I believe I was prepared for university, but more because university has adapted to the level of the average student. We were taught a lot of basic math at uni, while I believe I have seriously underachieved during the first 18 years of my life. I never had to study really hard at secondary school... University in the Netherlands is supposed to be a 5 year study. The curriculum is 5 years. For engineering studies and studies like physics and chemistry, the average student needs 7 years. That's because the university has adapted the level at which we start, but not the level of the students that graduate. We just have to learn a lot, and that means we all fail exams (I see no problem with that, because it's not too expensive to be at university...) This is my view now, as a working engineer... looking back. (While I was in school, I enjoyed having little homework and still getting high grades).

Make sure to include a pan with water of 100 degrees Celcius. Hard boiled eggs tend to be stronger. (Sorry). I think the trick here is to apply the force that accelerates the egg to the whole shell (or at least to as much surface as possible). The larger the area, the more power you can apply, and therefore the further you can shoot your egg without breaking it. If you're really into some engineering, you can make a egg-gun. Same idea as with the potato guns (http://en.wikipedia.org/wiki/Spud_gun). Make sure to use a sabot to protect the egg while launching it (http://en.wikipedia.org/wiki/Sabot). Polystyrene foam is probably a good material to make a sabot. To get the shape of the egg into the foam, it might be as easy as boiling an egg, and pressing it into the foam (its glass temperature is 95 deg C, just below the boiling point of water... but I never tried this myself as I never thought of launching eggs).

Martin, thanks for pointing out that I should have written the phrase "I believe" 2 lines earlier, so that it included my entire post. Apologies for letting a simplified metaphor and an opinion seem like a fact. At least I think I expressed a common misconception so that others knew better what to explain. I think this thread has some good explanations now (although I am certain that they would have been given also without my post).

last things first: yes, rubidium dihydrogenphosphate = RbH2PO4 In the reaction: KOH + RBH2PO4, 2 things will happen: 1. it will dissolve, you can call that a reaction if you like: KOH -> K+ + OH- RbH2PO4 -> Rb+ + H2PO4- 2. OH- and H2PO4- will find a new equilibrium with H2O and HPO4(2-) reaction: OH- + H2PO4- <--> H2O + HPO4(2-) I'm glad you did not ask where the equilibrium is, because I'm lazy to calculate it. Check the acid/base theory for that. p.s. next time, don't use abbreviations in your question. "eq" can be (reaction)equation, equilibrium.