Rocket Man

im not entirely sure how disk magnets will behave in this experiment but there are only two possibilities. 1: the magnets will not work in a line of more than 3 due to the problems faced with the original set up, 2: the magnets will offer no resistance in rotating pole over pole yet will remain coupled. any torque offered by the first is used to overcome the fricion in the second and third etc. may i recommend we ignore inertia for the moment untill we come to an agreement on how magnets behave. yes there will be a delay in the rotation of the second magnet due to interia but it will eventually rotate to mirror the exact angle the first has adopted. the torque is applied by the first, through the second and to the third untill the attractive forces between the folowing magnets becomes greater than the strength of applyable torque from the first.

unless there is torque applied by drag, where the center of drag will move to directly follow the centre of mass. key concept in model rocketry.

if you think about it, there is no dead point at 90 degrees, the magnets are attracting N-S and S-N, the magnets actually move most easily through this point. rotate the north of the first closer to the second, the south moves away reducing the attraction of the south and increasing the attraction of the north. so the force on the south of the second feels a stronger force than the north of the second so it moves to a new equilibrium with the same angle as the first.

so you have a 10 unit mass on one side and a 1 unit mass on the other.. basically, you have to find the balance point. suppose you put the thing on a fulcrum, where you balance the see-saw the thing will rotate freely in air. the point it rotates around is called the centre of mass with that, it's pretty self explanitory, the centre of mass is a fixed point within the object. you can make an equation for it, distance1 * mass1 = distance2 * mass2 so the distance from the 1 unit mass to the axis is 10 times the distance from the 10 unit mass to the axis. so you divide the length by 11, (10+1) and place the axis 1 unit distance from the 10 unit mass.

the next generation of peltier effect materials sounds promising, (unlikely to rival compression pumps on efficiency though) if you really wanted to save money on air cond, route the radiator of your fridge outside. with maxwells demon, he can probably work on a scale big enough to avoid the uncertaincy principal, the radium(?) atoms had to be cooled extremely close to 0 K for the effect to become apparant. im sure he could take an approximate enough estimate of speed to open a hole in the right spot, hell, give him a fudge factor, a band of momentum where nothing gets through either way.

i think the front page was also good for the general public, i know some people would wander in from google or somewhere and try to find a home page like the one we had before they look for what they want. i found it useful when i came here.

i feel almost offended here, i did say that you cannot actually get all the magents to spin, pitty about the torsion wires gcol, the main reason the magnets will not spin is that for any of them to spin, the distance between the poles of separate magnets will increase so the effect of further rotation reduces untill the back torque exerted by the rest of them "breaks the link" between the first and second. the second, third and so on will all snap back to their initial positions leaving the first to spin independantly. there may not be a reason for conservation of energy be we sure as hell wouldnt evolve without it. edit: (rewebster, try not to double post. edit instead.)

gcol, i will be amazed if you can get 3 identical bar magnets to turn about their centres on bearings with equal distances between, them let alone torsion guages. THAT would be a feat of precision motion. magnetism is an effect of moving charged particles. the orbitals of magnetic elements give a net polarity. it's electromagnetism on a picoscopic scale. the force of a magnet does not use any energy, the force is perpandicular to the particles motion. the scalar product of all vectors is equal to zero so no energy is lost or gained within the atom. this is all theory, but an experiment would only work if the magents are progressively further apart. my best guess is that the energy stored left of the second magnet is equal to the energy stored right. try it with 3 on bearings, it probably wont work.

hmm, perhaps mr north would like to visit egypt.. i really need to get my facts straight, i think this might clarify the subject. http://science.nasa.gov/headlines/y2003/29dec_magneticfield.htm it seems i was told siberia not sahara, still, its not there yet. tune in next week for more geographical blunders.

i think the easiest way to go about this one is to assume no energy comes from no where and go from there. i think i get your system, the magnets are allowed to hinge at their centres while facing pole to pole all in a line. as you turn the first magnet, the pole of the first magnet pulls the pole of the second to the side, slowly but surely the attraction of the far poles becomes apparrant the result is a locking effect. when you turn the first magnet, the second turns to keep it's pole as close to the first pole as possible. when you introduce a third, there is back torque on the second, it is trying have it's north close to the first's south while having it's south close to the thirds north. the second magnet is experiencing forces in two different (rotational) directions, so the force required (exerted by the first) to turn it is greater. e=fs, energy applied increases. at 90 degrees, there is a lot of stored energy all added to the system by the first magnet, further rotation releases this energy. i think the main point of confusion comes from having very little or no velocity and almost no friction component. the force applied by the first magnet will cause energy to be stored in the second, but add a third, it will be difficult to get the second and third to rotate, they will have an attraction force between them that may not be possible to overcome simply by rotating the first. (at a stretch it is possible to do with 3 magnets, the first will apply exactly as much force as the third as long as it remains perfectly parrallel with the first) a fourth, fifth and hundredth simply compounds this problem.

what speed does matter have to exit as the exhaust of a rocket for it to produce the same thrust of the mass energy as light? if we could turn matter into energy we could have a fairly simple propulsion method (antimatter?)

this device runs on induced current from the coil above the plasma, the whole system works on a high frequency AC current in the top coil inducing a current in the bottom one. if you've ever seen those ring lifter things you'll know what im talking about, a coil wrapped around a copper stalk, a conductive ring floats above the coil around the copper. in this case, the ring is a toroidal section of plasma and its contained between the ground, the board and held central to the coil because the coil is wider than the cushion of plasma so the plasma is generally repelled to the centre. the magnetic feild simply acts to magnetise and contain an ionised gas, much like the skirt of a hovercraft. theres been ideas thrown about to use a UV lamp to ionise the air.

mine is a section of the mandelbrot set, i wrote a program to generate and navigate it as an assignment last year, i had a bit of fun and framed a section for my avatar. i used this mainly because i love the sheer complexity and beauty of fractals.

i've always been confused over this topic, is the increase of intertia due to time dailation? and what is the speed relative to?

when i was reading about the LHC, i found that there is a team of scientists devoted to doomsaying for just such a scenario or the possibility of something going terribly wrong and punching a hole in our side of the galaxy... again, it doesnt answer the question but there are a number of people making a profit from the notion.

i would roughly double/triple the force to reach equilibrium, most model rocket engines have a thrust curve made to get the rocket up to enough speed to have the drag stabilise the flight, not enough and the rocket could fall off the launch rod before it hits a stable speed... not pretty... "pages and pages of info" sounds like you'd have the center of drag-center of gravity right, (i did a course on rocketry and an unstable rocket is plain scary) but make sure you balance it, i've forgotten more than once. just out of interest, what brand of engine are you using?

a really effective one is the monkey and hunter ballistics demo, theres heaps of info about it strewn all over the net, so how it works is easy enough to find out, i did this one in year 10, it used an electro magnet to hold the monkey and an electrically released projectile. the demo was flawless (thank god!) and theres a lot of balaistics topics you can relate it to. as for a lazer, you can get lazer diodes if that will help, but depending on your budget and access to the right glass ware, you might be able to make a carbon dioxide lazer. with this you can go onto excitation energies, refractive indexes, and all manner of electric and optic topics. these sorts of lazers usually draw a lot of power at high voltage, theyre a bugger to cool too. good for burning stuff at distance though. google "power labs" and look for his lazer.

[ATTACH]1397[/ATTACH] sorry about the image quality, but you get the idea, the cap is inside a pipe in a fitting. the other, larger object is the assembled inlet valve piece, the valve itself is shown as well. (note the circle of rubber still attached, this allows it to hold pressure without blowing off) everything is set up with screw connections for easy modification, this is the most versatile thing i've ever made, i can get gasses to super saturate water, turn it into a water rocket, water gun, gas gun for cleaning dust, and of course demonstrate balistics. a word of caution... this sort of thing is VERY dangerous, im assuming you're using a 2L bottle, 2L @ 80 psi gives an explosive decompression, venting this amount of gas quickly applies huge forces. shrapnel from shattered pvc can be lethal, you should wrap the whole thing in a teatowel (or other strong fabric) as well as stand back. 80psi in a bottle will allow it to resonate when it's struck.

i once built an "anti simian cannon" to demonstrate the monkey and hunter principle (my physics teacher asked for a replica) anyway, it used soda bottles, the 600ml ones can stand around 250psi, (dont quote me) i used 25mm retic pipe with a lid titan bonded: http://www.bostik.com.au/pdf/datasheet/bostik_titan_bond.pdf#search=%22titan%20bond%20plus%22 it in place. the lids you get with the bottle should fit rather snugly in the pipe. i drilled out the centre of the lid and glued it in the pipe. this config was tested several times to 90psi with a 2L bottle without fail. (the gun was built modular so it's grown to ridiculous proportions) i'll put up a pic of the lid in the fitting. the type of lid is also important, i found ones with a good seal design and complete threads on a water bottle, they also fit perfectly in 25mm pipe. the inlet valve was cut from a bike tube and glued into a pvc end cap. again, i'll put some pics up.

they use false colour in electron microscopy, you cant get much colour from the original image but the texture detail is the important part, the false colouring is used to clearly show different materials/sections of a specimin. normally it's just an overlay of colour on the image determined by a series of algorythms, for example i've seen pictures of hot pink and green beetles (black beetles as seen without false colour) but the false colour is often used to mimic what would normally be seen.

my opinion, we so rarely use our muscles to their full extent that a chimp seems stronger. theres two things that contribute to strength, muscle mass and tone. use it at max load, it gets bigger, use it a lot at less load, it gets stronger. we have more manual dexterity because of our opposable digit, but we lack strength because we use technology to compensate. we dont spend all our time swinging from tree to tree. if you go to an indoor rock climbing centre, look for the finger board. people climb using only their fingers and upper body strength. more use makes more strength it's also a matter of practice, most people have never used their full strength, they just havent learned how, spend your time writing, you get good at writing, spend your time tree hopping, you get good at tree hopping. some people cant use their full strength because of a weakness in other areas. top cyclists have huge leg strength but scrawny arms, useless at tug-o-war. if you spent a month running from predators, you'd soon get a little stronger. we might be specialised for precision but adrenalin strips precision and gives us greater strength, thats why you shake when you get an adrenalin rush. i think adrenalin helps activate the whole muscle all at once. like turning up the gain on your nerves. we can actually use a very small portion of muscle rather than the whole lot to get better fine control.

bbc does a really good one, "focus" it's more laid back than new scientist, the articles are well written and always explore all sides to a debate. it's all science oriented and it has so much variety. (normally 100+ pages) definately worth the cost, pitty its monthly though.

magnetic? i can see why you put it in italics. alternative engine... well theres the 'quasiturbine' it's a rotary engine, and its expected to do what the wankel does but better. apparantly it can be used with almost any fuel if its built right. (pneumatic inclusive) jtm, look up "plasmagnetic levitation" on wikipedia or else where, sure its omnidirectional but you dont need tyres. as for alternate energy sources im all for solar. also, hydrogen peroxide should be easier to get. commuting on a bell jetpack would be awesome, however impractical.

when i try to learn anything at all, i try to apply the formulae to mental pictures/diagrams ect, for the equations, sketch a mental graph. for everything else, try to look at the really small scale, particle interactions ect. if you do that, you can recreate the equations on demand, its what i do, i come very close to the top of my classes and get hated for the low effort i put in. invariably theres a small key missing, you'll need to work it out, if something describes a small difference, envisage a huge one or one that should exaggerate the results. by far, the most important thing is sleep and breaks. you can get seriously bogged on a simple misconception, take a step back, consider different approaches or leave it to settle out of your immediate thoughts. when you get back you'll probably see it in a different light and realise what the book is on about. other than that, just try to apply it. i've practically developed that into a habit, think of a scenario, no matter how small, and reproduce the effect. thought experiments.