sanjay0828 0 Report post Posted November 26, 2007 i know perpetual motion is not possible........ YET..... but let's just look at the various factors hindering this possibilty assume, we are trying to trap the kinetic energy of a body that is moving forever now, the most powerful opposing force is friction if the body is rotating on an axle or something, there is sliding friction (or rotating friction) also, there is friction from contact with air (or any medium) but... what if... the object was falling in vacuum - pure vacuum - touching nothing????? the object i m referring to is a spacecraft - high above the earth's atmosphere - falling without any opposing force so how do you get energy from this???? any object moving in a magnetic field (the earth's magnetic field in this case) generates an electric current the current thus generated could be converted into radio waves or something and send back to earth or it could be used to power equipments on board the craft i like this idea... but i have this nagging feeling - i missed some point here can you spot it???? Share this post Link to post Share on other sites
Galahad 0 Report post Posted November 27, 2007 Well, sounds nice in theory, but I think that would be impossible to make... And here's why...Say you make something that will "fall", or better yet, move in Earths' magnetic field... Perhaps I'm wrong, I'm not particularly versed in this subject, but I believe that magnetic field would also produce some sort of a friction effect on the object in question.. Why? Well, if you want to create energy, you need an object that will interact with some soert of magnetic field... For example, some sort of a metal object, in order to "capture" the energy of a magnetic field... As a result of that interaction between the object and the magnetic field, some sort of a "braking" effect would occur... I suppose... Strength of the magnetic field also is of importance... And I don't know how far out goes Earths' atmosphere, and how far Earths' magnetic field streches... I guess it's a nice theory... But I bet there are much smarter people than me that can point out other flaws in this idea... I was never good in physics... Share this post Link to post Share on other sites
rvalkass 5 Report post Posted November 27, 2007 i know perpetual motion is not possible........ YET.....According to the First Law of Thermodynamics (the total energy of the Universe remains constant), energy cannot be created or destroyed. So, the only way perpetual motion could be possible is if a device was 100% efficient. Friction and other forces, no matter how minute, stop this from ever being achieved. Still, laws have been proved wrong, so lets press on. what if... the object was falling in vacuum - pure vacuum - touching nothing????? the object i m referring to is a spacecraft - high above the earth's atmosphere - falling without any opposing force In space there are, on average, 2 molecules per cubic metre. That is an absolutely tiny amount of matter, but it is there and it exists. The spacecraft will hit those molecules and that will cause friction. OK, a microscopic amount of friction, but it is there and will affect the spacecraft. It will eventually (millions of years) slow it down. any object moving in a magnetic field (the earth's magnetic field in this case) generates an electric currentNo, any metal object can have an emf induced in it. This, if connected in a circuit, can lead to a current. This means you need your spacecraft to be made of metal. It must also have some method of transferring and storing the power, which needs to be 100% efficient. Also, the magnetic flux of Earth is so low, the electricity is pretty much useless, and becomes less dense the further you go from the surface. So, out in space it is minimal. the current thus generated could be converted into radio waves or something and send back to earth [...]The method of storing, transferring and receiving the power would need to be 100% efficient. Also, its path through the atmosphere would need to be completely unobstructed. I think there is research at the moment into transmitting power via 'beams' of some sort or another but it is still in its infancy and we don't really know if it will work yet. or it could be used to power equipments on board the craftSolar energy is the best we have at the moment, The effect of Earth's magnetic flux would be so small that it wouldn't be useful to power anything. You can get a couple of volts of potential difference in a plane at full altitude, and that decreases the higher you get. You might just be able to light an LED on your spacecraft. Share this post Link to post Share on other sites
Angelo 0 Report post Posted December 8, 2007 I won't call your "experiment" Perpetual Motion it should rather be energy transformation/exchange and Nasa proved your theory many years ago. The astronuats pulled a few miles long cable and measured the voltage generated by cutting the earht magnetic field. It was hundreds of volts and if you google the experiment, willlbe able to get alot more info like "NASA shuttle mission will duplicate Ben Franklin's experiment".keep up the good thinking, it will take you far, far away! Share this post Link to post Share on other sites
shadowx 0 Report post Posted December 8, 2007 As pointed out in theory, and apparently in practice, it will generate electrical energy, but when you think abut the money and energy spent on the design and build and of course testing of the craft it would be easier to make a few square miles of solar panels, the only way for perpetual motion would be a perfect, gravity free vacuum with a wheel spinning in the middle, it would, in theory, spin forever once started by being spun by hand or something. Of course it would be useless because to get electricity we would have to use either a dynamo or magnets on this wheel and that would make it stop and therefore be useless. In theory perpetual motion is totally possible but as a means of generating electricity its impossible, lets take my wheel as an example, for the wheel to spin it needs the first burst of energy, now as i understand it, that energy is now "stored" in the wheel because energy cant just disappear, now if we attach a dynamo electricity is made, and energy from the wheel goes into the dynamo as kinetic energy and comes out as electrical, so in effect the dynamo is "draining" energy from the wheel so the wheel runs out of energy and stops. Bad times. Share this post Link to post Share on other sites
darthvaron 0 Report post Posted December 10, 2007 In any case.Even if somehow you can get profit of that. You're taking energy from the earths magnetic field so it isn't a perpetual motion. You may tray to get energy from sources unexploded, instead of creating it from nothing. And try to "get it all" for use. That's how the alternative energy works. Share this post Link to post Share on other sites
Elessar 0 Report post Posted February 5, 2008 Perpetual motion DOES create electricity, but its just not feasible. In physics, there is a concept saying that energy cannot be created or destroyed. The same principle works in generators and governs the Faraday's Law and Lenz Law: Lenz Law states that the production of electricity through means of cutting a magnetic flux with a conductor will produce a magnetic field opposing the force producing it. Which means, suppose we do have a conductor of some sort cutting Earth's magnetic field to generate electricity, the space generator itself will produce opposing magnetic flux which will make it spin out of control, unless you have some sort of device to counter the magnetic effect.Secondly, space is not totally empty. It is vacuum but there are tiny microscopic energy particles that can collide with the generator and thus slow it down, damage the equipment etc. Satellites have special coating to protect the innards so they're not really damaged, but in the case of our 'generator' here, exposure to space is needed so theoretically its impossible to protect the equipments.Its a good idea in itself, but there are major hurdles to overcome. Share this post Link to post Share on other sites
tricky77puzzle 0 Report post Posted February 5, 2008 Well, one relief from work is superconductors - the resistance is zero. This reduces the work needed to try to transfer the object.The density of space is 2 hydrogen particles per cubic metre? That could create friction, but we can find a way to lower that density down to maybe about 0.02 particles per cubic metre, at least in a laboratory. Let's just hope that it doesn't spontaneously implode. Share this post Link to post Share on other sites