Rocket Man

the early worm is for the birds. i'm not sure it's exactly fuzzy processing, rather, eight hours straight reasoning thoroughly filtered to give you the interesting parts. i know i'd start abstracting information after 8 hrs solid.

iirc, you can use NO2 or other liquid oxidiser. nasa is using liquid oxygen, they get a very impressive thrust (enough to consider retiring the old shuttle boosters) i've seen a film of a no2 / parafin rocket fly. it had a fairly hard wax to begin with, plus powdered carbon. they set that into a tube and pumped NO2 through it. they just straight lit it. i think they had a steel pipe as the fuselage (plumbing grade) and a tank of NO2 inverted to give a liquid flow. one way of making parafin combust quickly is to heat it up till it burns like butane. if any water gets into that, you get a lot of combusting surface area plus the intense expansion of water. how you'll contain the combustion while allowing air to the flame is beyond me.

i can't think of any way gravity could have any lateral effects, it's pretty much a direct attracitve force between particles. all mass has a gravitational feild, otherwise it wouldn't be a mass. iirc, the only properties of mass are inertia and gravity. some have even speculated that they are the same thing. if you look at the universe as though mass were gobbling up space-time, it would be inertia that applies the force. so if an object has inertia, it has gravity. a black hole is a large amount of matter in a very small area. it can be moved by a speck of dust in much the same manner as you can move a large star with a speck of dust. the only thing a black hole can be said to orbit would be something heftier, like a bigger star or a bigger black hole.

how accurate does your five seconds need to be? i built the circuit yt suggested a while back with a trimpot as a time delay for a speaker, the pcb would have fit snugly between the pins of a relay. if you need a really accurate 5s, you'd probably be best off with the 555.

in a stagnant room, you're pumping heat out. that heat provides a small amount of convection. the air is normally cooler than you are so it absorbs heat as it passes (even when you ignore perspiration) a fan will move the air faster so it's like turning on the pump to a radiator. you can safely ignore the pressure cooling effect as the room is supposedly a closed system of roughly uniform pressure. boyles law cannot apply to this scenario nor will the fan remove any energy from the system.

if you have a death wish, it is possible to distill h2o2 into jet pack quality stuff. if you toss silver oxide gauze in that, you'll get a very large steam explosion. however, you get much the same effect if you hold a match to it (decomposition chain reaction)

thermonic emmission (the Edison effect) is as efficient as you can supply the heat. any waste energy is likely to turn into heat and get converted back into electricity. it's not the most practical though, as it only works in the thousands of degrees celcius.

isn't this the one where you need a big ol power plant pumping gigawatts of energy into the sky before you can tap into it's vast, inefficient resrevoir? edit: sorry, my mistake, just did a google search. i can't see any way for this to work unless the "elevated plate" were in the middle of the aurora borealis/australis. there isn't really enough positive charge carrying radiadion to do squat down this low.

both turbo and supercharge? uh, yeah, good luck with that.. both have exactly the same function, compress the air before it enters the engine. that way you get more bang per cylinder. i think if you had a supercharger running and the engine idling, the exhaust gas would be insufficient to spin the turbo against the inlet pressure. if they were in series, you might be onto something. but if you squeeze too much air in then inject fuel to match, most cars would start spitting crank arms. even the bigger, gruntier cars. basically the only reason you don't see both on a car is because you can alter one to match the power of both unmodified. a supercharger draws energy from the axle, a turbo applies back pressure on the exhaust. both, i think would the essence of redundacy.

the minto wheel runs on the carnot cycle. it's probably down there with the worst offenders in terms of efficiency.

i read that from a handout at a gym. it's actually pretty accurate. when i go on a hard start on a bike, the first 30-40 seconds are just flat out, i don't start really breathing until 1min30 to 2 mins later. that's the point where lactic acid builds up and your joints ache. after that, the pain goes away without reducing your load. it said the first 20 mins run on blood sugar. when you run low on blood sugar, you start attacking fat.

iirc, silver mesh is a particularly good catalyst. the bell jet pack ran on 99% H2O2, pumped it through a catalyst then through the nossles. common commercial concentrations are about 3% or 9%. nothing quite so volatile as to be called explosive. at best, you're going to get a little fizzle of steam and oxygen.

cycling is a good one, zero impact (normally) and you can go as long and hard as you like. IIRC, the first 40 seconds burns your phosphates (a good hard start), the first 2 mins is anaerobic, the next 20 mins won't touch your fat stores. but after that, just go. i never used to excercise, but i started cycling to commute and i clock up 70km every week on average.

a latch circuit controlled by two buttons? it's a 2 transistor thing. one is held on by the other being off until one of the buttons applies a bigger bias to force the circuit into the other state. i'll try to dig it up from my pile-o-junk and post a schematic

clay + cement + steel = house i don't think the construction is the issue. standard materials are pretty cheap. the main problem is the demand for houses as investment opportunities.

a current shunt can be activated by anything. the simplest description is just giving the current a less resistive path. a wet suit wouldn't save you in water. theres all sorts of gaps where you can conduct electricity. it's the same problem with chain mail protection. if you leave absolutely no path for the electricty to hit you, you'll be right as long as the voltage is lower than the break down of your insulator.

hmm, theres a difference between a farrady cage and a current shunt. plate armour/chain mail can be used to reduce the amount of energy passing through your body by "shunting" the current, giving it a different, easier path to go through. a faraday cage is designed to stop radio noise with minimal materails. this question could be answered in terms of lightning striking water you're swiming in. if it's fresh water, you're screwed. the current will pass through you becasue you have less resistance than the surrounding water. if it's sea water. you'll feel a hell of a kick and probably die but you're safer because the water will carry more current than your body.

if it's navigaion all you need to do is get a compass to deflect 90 degrees or so in a roughly uniform fashion. did you think of magnetising long strips of ferrous metal to place underneath the arena? it would be easier to bury steel rods at the beach than to construct a Helmholtz coil.

theres no hard evidence for a specific speed for gravity, some measurements of binary neutron stars suggest that energy is being lost to the propogation of gravity as though it were moving at c, but some sources will say it's instant

i can't think of any reason a semiconductor would have greater hall effect properties than any other conductor. it's just that you can costruct a hall effect device using the same equipment in the same layer as the operating circuitry. pure convenience that's all.

i read some where that a flame has a prefered direction of current. it's like a diode but behaves quite a lot differently. leaking under reverse bias minimum voltages etc. i wouldn't recomend turning a candle into a crystal radio but you can partially rectify under certain conditions

what factors gave you 7 degrees? what value did you use for resistance per metre? the uniform area is a cylinder 1/5 the coil diameter. 2m gives a 40cm test area. double the coil cross section area, halve the power. if the coil gets too big, you'll loose uniformity in the feild. length of wire itself will do nothing for the power if you go down in diameter. the current density for the coil will remain constant unless you increase the area of the cross section

that's the seebeck effect. put power back into it and one side gets cold, one side gets hot. that's the peltier effect. you draw energy from the temp differental. the edison effect actually converts heat energy directly into electricity (it takes about 5000 degrees celcius to get anything measurable though).

10 amps is a lot. i'm not surprised at 7 degrees per second. copper has a fairly standard resistance, ratings don't take heat dissapation into account. the magnetic intensity determined by current * length yes? if you take a cable twice as long, you can halve the current. if you use a cable such that the entire loop occupies the same area, resistance must go up by 4. (double the length, halve the cross section area.) so the power demand remains constant (the same current density). if you use a coil cross section with double the area, power will drop proportionaly. are you using dc? if you are, you can pass copper plates through the coil to act as heatsinking fins. enameled copper wire doesn't mind fluids either. you could potentially mount the coil inside a pipe and pump chilled freon.

a flame has diode like properties. it's used as an active test to keep a pilot light going. you could probably get a candle to produce electricity, certain chemicals in the wick etc, it wouldn't look like a candle though. and like swansont said, it would be related to the seebeck effect, or the Edison effect (that would be a pretty hot candle).