Rocket Man

do you have a salvage yard or anything near by? all you really need is the tubes, valve and compressor from an old fridge. if you can get the tubes out of a fridge without releasing the freon you're set. just place the cold tubes in the greenhouse/tank and the hot tubes on the outside. another type of heat pump is a peltier plate. you can buy them for computers, some of them can extract about 70 watts of heat. (damn inefficient though)

the way they expect to run the thing on NiCad batteries, high energy lazers drain a lot of juice, then they expect to hold an induced current in the plasma and repel it with an electromagnet. i would only expect a few minuites riding time. perhaps with a scaled up power supply, but then it becomes ridiculous before it becomes practical. im not going to attack the physics behind it, but the gear they're using ought to drain more power than they account for.

the effect the lifters run on is disputed, most research says that the ion wind alone couldn't manage that force. it's probably just measurement errors though. the voltage used is capable of a lot of force. (i think that one in a vacuum wont do very much.) i was actually referring to something else entirely. the physics seems right at first glance, though it doesnt look too promising: http://www.hovertech.com/home/index.html ion wind is VERY different to and ion rocket, an ion rocket pushes plasma at velocities comparable to C, ion wind applies an electrostatic force in air to attract air from one electrode to another, neutralise it, then leave it to continue on its merry way thus producing thrust. i think that an ion rocket uses magnetics as well. a solar sail is less powerful than an array and rocket. radiation pressure provides less force than can be acheived by the same energy powering an engine. i thought that this was for getting around in atmosphere, otherwise i would have suggested a magnetic sail to catch solar wind. (15km artificial magnetosphere catches moving ions kindly provided by the sun. much more effective than trying to catch light)

there are many ways to generate lift. a jet engine is actually less efficient than a prop because it is moving less mass of air (E=1/2 MV^2) a jet aircraft uses the wings to create downwash and applies newtons laws to give lift. so it expends minimal energy keeping it off the ground and puts it's main efforts into keeping speed. one way of producing lift is by ion wind. high voltage ionises air, then repels it at some velocity. VERY innefficient there are designs for a magnetic hover craft, it uses ionised gas trapped under the base held under pressure with a magnetic feild. it's not really good for height though. creative, reliable, cheap... look up the "gossamer albatross" on google (just hope your legs hold up) "Is a mass driver a practical way for a plane to take off?" actually yes... especially if its kerosene powered and drives a mass of hot gas

look, smallispower, the bush administration has a LOT going against it, but that doesnt mean you can blame them for everything... they're not that clever. the taliban enthusiastically claimed responsibility for the attack. do you think that they would have agreed to ANYTHING America, "the head of the serpent" suggested? the dust leaving the building DID leave more violently as it collapsed, to a point. generally known as a cruise speed. the resistance provided by the floors slowly increased as the top half accelerated. so the dust left faster as the building went down then leveled off before it hit the ground. the resistance increases because it needs to accelerate a mass of floor to an ever increasing velocity(requiring more energy each time) and the pressure of trapped gas under the falling half. who was it who said that the building fell symetrically? take a look at the videos, the top half leaned at least five degrees as it fell. in a controlled demolition, there is usually an explosion just before the building falls. in all the videos i saw, the plane hit, big fireball, lots of smoke, then the building starts to collapse with a plume of smoke ejected from the holes the plane made. when the sound reaches the camera, there is a rumble that gets louder, not the sudden sound of an explosive. just a point, wasn't this five years ago? and yet we're still bickering over whos fault it was.

ah, right, so a red-shift could apply more force than a blue-shift depending on the atom because it has a sort of response curve (forgive the acoustic terminology) so basically, there is no way you can acheive equilibrium because the velocity will determine it's response to certain wavelengths, when it changes velocity it responds much differently to the same light. interesting... thanks for clarifying.

i had a thought about this, its true that magnets induce an electric current on moving conductors. if the fluid in the pipe is conductive, the magnet will cause drag and probably turn the turbulance into heat. but thats about the extent of what a magnet can do on liquids.

surely you could do much the same thing with blue light, i think they only chose red because rubidum doesnt interact well with wavelengths around a small band of red light. the system would be very ineffective with randomly chosen wavelengths. radiation pressure would be a net force. it would have an equilibrium at some velocity. howeverthe background radiation would give a very random input to the equation

i read up on the design of the twin towers, they were NOT designed for a plane to hit them. they were designed to sheild each other from the wind, buildings designed to do that probaly wont survive a jet or they wouldnt need the wind sheilding. thermite is a combination of aluminium and iron-oxide, so there is actually no chance of there being thermite anywhere near there, the aluminium would take the oxygen before the iron could get to it. jet fuel can burn at any temperature, give it the right conditions, you can potentially burn it well beyond the capacities of thermite. on the point of burning substances, the floors were built from thin trusses, these would break away quickly allowing an up-draft to occur through the shattered windows below to power a raging firestorm above. as for structural damage, remove two or three floors, heat the iron supports till they're about as sound as lead, then try to hold up thirty floors of office... not going to happen. the buildings were designed with a central pillar for suppport, the plane buried itself most of the way through that, didnt you see debris coming out the sides almost all the way through it? then didnt you see debris ejected out the other side? "what central pillar?" you might say. the way those buildings fell was one story after another, drop thity office floors about 2.5 metres, the next set of floors arent going to hold. it might stall the progression, but it will drop a further 2.5 metres to the next. and so on... the top portion had enough vertical length to not tilt far due to inretia. the whole thing did tilt slowly on the way down though, a minor tilt at the top would crumple the remaining supports enough to put breaking strain on the remaining ones. it only needs to tilt a few fractions of a degree to buckle verticle steel supports. after a little thought, it seems likely that the buildings wouldnt cope. oh, smallispower, i would try bush for the same charges.

hmm... a generally defined speed in any given direction... could the velocity of the objects creating the background radiation give a "relative" to have veloticty to? i would otherwise have difficulty defining the velocity, even if it's a probability. this comes to mind after doing some research on the bose condensate, it was acheived using minute doppler shifitng on lazer light, any velocity the particles had would shift the light infront to a higher energy relative to it, so the radiation pressure applies a net hindering force no matter which direction it travels at. so if the radiation is coming in from all directions with an even spread (ideal situation) the doppler effect would slow the particle to an almost complete stop. im guessing that a real scenario would have the particle move away from the most intense light source to hit an equilibrium with the wavelengths and intensities. (likely to be quite fast within the galaxy)

what determines how fast the pain comes? the chemical stimulates the heat nerves directly but why are some slower than others? could it be the temperature it's served at? i heard of someone who had a hobby of concentrating chillis, he eventually came out with a sauce so hot, the unfortunate (willing) victim had half his face paralysed. (might be just another urban myth) edit: i found it! http://www.chilefarm.co.uk/daves_insanity_hot_sauce.html

they dissect the eye, they determine how light behaves as it travels through the lenses, and they look at the projection pattern on the retina. i had another thought about this one, it's not about how big the object is, but how much of your vision it occupys. so we dont acually see sizes, we see angles. then we use the second eye to check distances and make an estimate as to the actual size. this is also why most people have one eye stronger than the other. my right eye is stronger than my left. if i close my left i can almost cope, if i close my right, i have difficulty making out shapes, its not blurry, but i normally depend on my right for textures, shapes etc and use my left for depth.

a bunch of japanese scientist made proto-type a pneumatic exoskeleton, it had an external power source/compressor and used pressure sensors that activate the cyliders to take the load, so all the user needs to do is gesture and the exo will do the heavy lifting, they're going to clean it up and put it into use in hospitals etc the power source is too big and clunky to pack mount though.

if you have an atom sitting in space, you will know its velocity to be 0... if you know it's velocity, then the uncertainty principle will say that you can't know its position. the background radiation keeps space at 2-3 degrees kelvin. so it would heat multiple particles to 2-3 K, but how does this effect single particle systems? if it moves, you could take a different reference frame and remove all heat from it. or does the uncertainty principle help in this matter.

i heard that tea has about as much caffeine as coffee but it also has a chemical that cancels some of the effects, jitters being one of them it also relaxes you without making you drowsy, useful for keeping your wits. aside from all of that, it tastes good.

doesnt aluminium burn like magnesium when it gets hot enough? who needs the thermite reaction when you can go straight there? the jet fuel could probably ignite the aluminium in the jet and keep the surroundings hot enough to keep the jet burning.

huntsman spiders! they are freaky! theyre so fragile but so big and hairy, occasionally they crawl out from behind the steering wheel when you turn the car on. the best part is, theyre not venomous, however, i would watch out for septic bites. i mostly commute by bike, i have had a bee land in my eye once, i swear it had evil intents! no matter which way i duck, it just keeps coming straight for my face. and of course glasses would help, but i cant get a pair which won't distort the image. three days later, i was fine. i cant say the same for the bee though...

i built a miniature once, it was a suped-up computer fan. it didnt have enough power to hold batteries though, but it did remove most of the friction over smooth surfaces if given external power. i was thinking about building a ride on hover craft built over two half-inflated tyres, i would have used the fans from old vacuum cleaners, they can apply quite a bit of pressure, they're also difficult to stall, a blockage will result in higher fan speeds and a higher pressure. probably the optimum fan design will be an inertia based system instead of a conventional fan... a standard fan will labour over a blockage, while a fan with a central intake will spin faster. control systems, if you have a really powerful pump for the skirt, you can vector some of the gas out and control it with a servo. otherwise, you can have a propellor on a servo mount. hovercrafts sit very low off the ground, the largest in the world only rises 30cm, my model could'nt get any noticable distance.

right, i forgot that the temperature drops during expansion. i was thinking about the mechanical work that could be done by a volume of gas under pressure, so assuming the pressure is relative to STP, and and the temperature is initialy at 0 celcius (to match ambient conditions)

i cant see an equation in there that describes energy pressure and volume, that site mostly deals with heat

a great way to understand how dimensions work is by programming 4, 5 and 6 dimensional matrices.... you can get lost in there, i have a "cube" of numbers, 3 values on each side, it has 243 values in it. five dimensions. the descriptions of folding dimensions, i dont like that idea, for multiple dimensions to exist, they must be perpandicular to each other. so you fold x over z to have y meet at a different x position, you have just made x and z no longer perpandicular to eachother. vectors only work if all dimensions are at right angles and dont curve. how would you make the x axis fluctuate up and down the y? everything falls apart or at best follows proportionately so no effect occurs. the flatlanders concept works, trig works on 2 dimensions so they can have "depth" perception, so flatlanders see the 2 dimensional boundarys of themselves just as we see the 3 dimensional boundarys of eachother consider their world as consisting of height and depth.

$50m, it sounds like the x-prize all over again.

that makes NO sense, iii has more height, "mm h20" IS a recognised pressure value. "how much pressure is exterted on the bottom of the container" it might mean force instead... actually, no, that would give ii as the greatest followed by i=iii perhaps it's a mistake.

how would i go about determining the energy stored in a volume of gas under pressure?