insane_alien

why does it scare you?

foil won't do much. it can do stuff against thermal radiation but that is nowhere near your biggest heat loss vector. foil doesn't really help slowdown conduction and convection.

i think that would break the purpose of the challenge which is to provide the best insulation rather than who can stick a heater on it.

perhaps as an outer casing

it doesn't NEED a vacuum, yes it would be good but its not going to happen. the killer is going to be convection, do what you can to prevent air circulating inside the insulation. the second biggest factor is conduction. you'll want to have as little direct contact area with the inside chamber as possible(but without letting convection happen) and any contact should be done with low conductivity materials. radiative heat transfer will be negligible so you don't have to make any shiny parts. if you were dealing with liquid nitrogen or molten metal then yes, radiative heat transfer would be important.

yeah but you need the theory part to come up new and interesting experiments. i hated the theory part as well up until i discovered that if i done a bit of work on the theory side my experiments became much more interesting.

that was a very very rough estimate. to get a better one we will need to know the geometry of the rocket, the mass distribution, the type of fuel used, the nozzle design, the exhaust velocity, the orbit it is trying to achieve and where it is launched from and in what direction. all these and more will have an effect on the fuel required.

won't make it. too small. iirc for every kilogram of mass you want to put up there you need about 10kg of fuel. so, a 25lbs rocket(assuming single stage) would need about 250lbs of fuel. although that is a rule of thumb and generally applies to larger rockets, i'm not sure how well it scales.

If my higher exam results came out different i would have been there studying chemistry, actually, i probably would have graduated by now. anyway, i'm over at strathclyde. and we need more scots on here.

depends on the mass of the object. the more mass the more thrust needed.

next time you copy paste out of a website post the link to the website. otherwise it is plagiarism and is against the forum rules.

invisible and yellow are mutually exclusive. also, post a source for that.

There is a video of it although there are debates as to whether it was faked or not. i can't actually find anything beyond all the tosh that people have posted about it on the net(various crap from Bryukhonenko decapitating himself and his head being kept alive in a jar a la futurama to him working on aliens that crash landed in siberia) Here is the wikipedia article.

hey and welcome to the forums. werple, i noticed you came on the IRC chat but only stuck around for less than a minute. if you stay on it a bit longer you'll probably see someone active.

Don't worry about your grammer it is better than some of the native english speakers we have had here. If we don't understand you we will ask for clarification and if you don't understand us just tell us and we will try to explain it better.

Sam, things in science have to be well defined and limited to one definition. if they are not things get needlessly complicated extremely fast as it can be difficult to distinguish which meaning is intended.

what me? i've never touched a drop of alcohol in my life! its always been bucket loads.

labs are being refitted just now at uni. i'll get some pictures january or so when everything is still nice and shiny. by march it'll be back to its grubby old self

yes and it is also how the cannibals like their fortune tellers.

i numbered the uestions to make it easier to follow. 1/ not very. most of the speed is gained where the air density is so low frictional heating is minimal. 2-300*C would be tops even on the most extreme launch trajectory. 2/ about 120*C on the sun facing side and about -200*C on the space facing side. rotation will minimise thermal expansion/contraction and temperature difference. 3/read up on orbital mechanics. you'll be wanting to do a hohmann transfer from LEO(Low earth orbit). 4/depends, what is the fuel limitations and equipment limitations. the apollo missions took a couple of days. some probes can do it faster, others slower. 5/ depends on the size of the craft. 6/ gravity cannot be tapped into. but you wouldn't need a constant level of thrust.

uhh, how did you get that i was eight years old from my reply? i didn'tmention anything about my age. anyway, i'm 19. you might want to not just jump to conclusions, thats not a good practise to get into in science.

Hey all new people. The unknown, you are one of the youngest. we don't make such a big deal of age here. it's more defined by how you think(or don't if that is the case). If you are unsure of something, just ask. someone will help you no matter what the subject.

i think the fact is assuming the 'proper' typing method and a en_US or en_UK qwerty keyboard(not sure about other localisations). can't do it on my keyboard, i switched to dvorak. keys are all over the place now.

well there are 6.6 billion molecules of DNA each of which would take a good chunk of a library to write out. then theres the rest of the organic molecules. proteins have really long chemical formulae and viruses. it will be possible when we have denser digital data storage and 1 exabyte is relatively cheap.

there are other representations of the table to focus on specific properties but the standard table is IMHO the best at describing lots of trends, arrangements and properties all at once. sticking with the standard table would definitely be best for general high school level chemistry.