insane_alien

air alone would work, just not effectively as it is so light. one way to increase the thrust is a higher pressure inside, this would also increase momentum. i'll do some math later and i'll see how the increased mass affects it. i'll also see if an optimum can be worked out. actually, found this site it'll calculate it for you http://polyplex.org/rockets/simulation/

just because you can't imagine itdoesn't mean nobody else can. there are many many people who work with vast scales(or the opposite, tiny ones) that necessarily have a very good sense of proportion outside that of a normal person. i for instance deal with very tiny things(atoms and such) but i deal with them in vast vast quantites. when i started i couldn't get my head round the scales and my estimates were often off by several orders of magnitude, but by working with them regularly i now have a good sense of proportion on it and can make quite accurate estimates. similarly, cosmologists and the like are used to dealing with the vastness of the universe. it will be equally easy for them to comprehend the distances in the universe as it is for me to comprehend a couple of molecules in relation to a swimming pool

i is not a variable, it is the base unit for imaginary numbers (the 1 of imaginary numbers). i is the square root of negative 1. this has no normal number counterpart. so, the mathematicians decided to say, well, what if we let this equal some imaginary number i, and see if we can do anything with it, as it turns out you can, you can do a lot with it. though the term now is complex numbers, not imaginary numbers. it can be difficult to get your head round at first but basically you are turning the numberline you learned in your first years of school into a number plane with two axes(like an x-y plot where x is a normal number and y is the imaginary number)

umm, no. the colour of light is dependant on its wavelength, if you use a wavelength that the human eye can't detect the beam will be invisible but it will not appear as if a shadow is coming out of it. a shadow is the absence of light.

newscience, nothing dug out the earth is in isolation. iron is stable yet is often found with a mix of other elements particularly oxygen. it must be refined from iron ore(iron oxide). it is rare that any particular element will be found in a pure state in nature never mind a particular isotope.

distilling sodium chloride will not result in sodium and chlorine. they cannot be separated that way. you would need electrolysis. electrolysis is where you apply a DC current to a solution or condunctive substance and collect the constituent chemicals. with a sodium chloride solution, you could gather some chlorine gas but the sodium will react with the water and make sodium hydroxide, this could be shown by measuring the pH of the solution before and after electrolysis. you could also do it with plain water(perhaps some sodium hydroxide thrown in to aid conductivity) and collect the hydrogen and oxygen given off at each electrode. you can even show which gas is which with a flame test for hydrogen and a smoldering bit of wood relit for oxygen.

do you know what sucks, i get to vegas on the 23rd oh well, sure there plenty of otherstuff to do in vegas even though i'm still too young to drink and gamble there

i think its good that he his showing up bad fathers for what they are but i think theres too much emphasis on the race, maybe it is only the way that article is worded but it sounds as if it is ONLY black people who run out on being fathers. Now, i am unaware of the statistics for the US so, maybe there are a disproportionate number of missing black fathers but it will be true that there are lot of missing fathers in all ethnicities. IMO this is a problem that trancends the colour of the skin and is a deeper societal problem.

no, the pressure will still be atmospheric, you'll just have a friction term in bernoullis equation.

it is easier to use linux when you only rarely used windows, my dad is an example of that, he made the switch without noticing and still doesn't know. then again, the most difficult to pick up thing he does on the computer is check his bank balance online. and even then i have to help him.

partition coefficients only come into play when there is a two phase situation, ie. at least two components are imiscible in each other. what we are talking about here is a homogenous mixture. ie, methanol and ethanol, water and ethanol, liquid N2 and liquid O2.

i'd be wary about informing XP or vista that there is a linux partition there. mainly because XP and vista can get viruses, if they get one, not only can they screw up your windows installation, but using that driver they can also screw up your linux installation which would be otherwise safe.

please, do not just give out answers to something that is obviously homework. point them in the right direction, maybe use a similar example but don't just tell them the answe flat out as they won't learn anything.

the pressure at the exit of the siphon will be atmospheric assuming it has not been submerged. the pressure head is converted to a velocity head, this is the basic principle of siphon operation.

yes, i thought that was what the OP was talking about, a temporary change. especially as the OP mentioned an enzyme, presumably the effect would disappear along with the enzyme.

speaking as something of an adrenaline junkie, adrenaline alone is enough to make you lose rational thought and/or coherency which may be perceived as a drop in IQ

well, until experimental observations are carried out (due to temporal constraints this will need to wait till 2012) it is entirely possible that the world COULD end in 2012

klaynos is right, the joule is a derived unit, it is better expressed in terms of the base units

interesting that the peak for CMBR lambda is 1.9mm

myocardial infarction. IIRC. its not a disease though.

no, it reads like 'extraordinary claims require extraordinary evidence' there are only a very few other theories that have a catalogue of observational and experimental evidence as biga as or larger than relativity. we know that relativity is wrong and we are open to alternatives but it must be able to explain everything relativity explains AND at least one of the bits that relativity cannot explain.

it has to be distillation as you will get some of the substance you want carried off with the boiling. although single stage distillation will work to a degree (which is pretty much just boiling it and collecting the vapour, although collecting the vapour is not necessary if you only want the less volatile substance.) multi stage distillation will give you a much better separation. if the substances form an azeotrope then you cannot distill or boil through that temperature and there will not be separation. further separation would need to be achieved through other means.

use proper accepted notation. ^ means to the power of. 1x10^5 and 1^6 are not the same, the former is 100000 and the latter is 1. the point is that it never does.

or you could push the definition to its limits like this guy does with 'wrist watch' http://leapsecond.com/pages/atomic-bill/

if they were atomic stopwatches you could do it...