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I'm so excited to see this diary and hear the positive supportive comments.
The only time I ever mentioned maglev trains in an comment on DKos, I was shot down with the bullet about cost of installation as compared to using tracks already in existence with energy efficient trains.
Maglev excites me, not b/c it is sci-fi, but b/c it's FREE energy! (In a time we need to take serious consideration of oil depletion and the fact that oil must be used in the production of alternative energies.) I think we're going to have to use all possibilities of energy production just to keep up a fraction of our current energy use as our future plays out.
Not so sure I want to see all those rails blocking the sky, tho...
Finding your own Voice -- The personal is political!
by In her own Voice on Wed Jan 16, 2008 at 06:21:17 AM PDT
But you seriously need to take a real physics course.
Maglev might reduce friction a bit, but it does not produce "free" energy. I don't know who has been filling your head with such ideas, but it just doesn't work that way.
To move a train requires energy. Once it is moving, then less energy is required (for example, the existing high-speed trains require little energy to keep going once they have accelerated to their normal speed). The momentum of the train carries it along, but it still has to overcome friction -- air friction, at the very least.
If you keep on about the "free energy" of maglev trains, then I'm going to start demanding my own flying car, as promised 50 years ago in Popular Mechanics.
Blessed is the man who, having nothing to say, abstains from giving wordy evidence of the fact. -- George Eliot
by bryfry on Wed Jan 16, 2008 at 06:39:20 AM PDT
[ Parent ]
but the limitations of "physics" has a lot to do with the limitations of the human imagination and willingness to think beyond the box...
Tweak it a bit, bryfry, and you may have your flying car...
by In her own Voice on Wed Jan 16, 2008 at 06:51:08 AM PDT
development of classical chemistry and physics, and to thermodynamics. And thermodynamics sez TANSTAAFL. The three basic laws of thermondynamics, and other conservation laws, have been pretty well prodded without any sigh they'll get up and walk away. Oh, and trust me, there's plenty of imagination and out-of-box thinking going on, even within mainstream physicals research.
The real world keeps tripping us up. The loses in a maglev system include those from turbulence - even the best manmade vacuums are fairly thick, and the cost of making and maintaining that type of vacuum on a large scale would be enormous. Other losses include those in eddy currents and reactive losses in the linear motors.
Maglev can save a lot of energy, but it is still an energy sink.
by wondering if on Wed Jan 16, 2008 at 10:02:03 PM PDT
Please explain or post a link on the energy sink involved with maglev technology.
Also, can you compare the energy cost ratio of maglev tech as compared to other alternative energy sources/channels?
I realize the cost of funding most any new energy system is going to be phenomenal, but it is going to be required to shift from fossil fuels. And it's best to think ahead to determine which ones we should invest in, considering many require fossil fuels to procure and provide.
I am thinking not only of what energy source will cause less pollution of the environment, and which are most efficient, but which will not run into "the wall" of limits -- those which are non-renewable sources such as oil, coal, uranium -- etc.
While scanning through internet articles on maglev tech, I discovered some wind turbines run by maglev tech. They are being produced for sale at this time, though their claims of energy efficiency and production are still unproven...
by In her own Voice on Fri Jan 18, 2008 at 08:01:01 AM PDT
think beyond the the box all you like, but if the walls are made of concrete no amount of willingness is going to get you out...
by sila332 on Thu Jan 17, 2008 at 01:42:27 AM PDT
I couldn't include enough of the physics in the excerpts, but the paper has a lot of sound energy physics in it.
CAMs in particular recover most of their acceleration energy on deceleration, given an appropriate in-ground-storage-coil system along the track for storing and reusing that electrical energy. Like a Prius but without on-board batteries. The paper admits such coil storage systems need a lot of research before we will have workable ones; current maglev trains do not do this.
Much also depends on the proposed constant acceleration aspect. The paper's "nearly free ride" claim is limited to constant-acceleration-maglevs (CAMs) in partially evacuated straight tunnels, with an energy recovery storage system in the track. That's a big set of qualifiers. But the paper's horizon is a century hence, so the authors felt confident these are problems with solutions in known physics -- as opposed to scientific speculation.
I refer you to the original paper, which is quite responsible technically, and full of "real physics". Indeed, that was what impressed me about it. I agree with you that a great deal of "future tech" is pie-in-the-sky whimsy by people short on physics training. A lot of the excitement over solar and wind power falls into that category, because when you do the math, current technologies, at least, come up way short as a replacement for fossil energy. Not that we shouldn't be pushing that envelope as hard as we can too, but solar could really use a major scientific breakthrough that made it an order of magnitude more productive.
CAMs actually work though, and this paper describes them (and their limitations) accurately. The main reason they stress CAMs is that alone among impending solutions, they do reduce energy and increase speed at the same time. That's a first.
The paper really is a a good read for a physics wonk, check it out, you'll enjoy it.
"The universe is a sphere whose center is wherever there is intelligence." -Thoreau
by samizdat on Wed Jan 16, 2008 at 11:35:06 AM PDT
wide narrow
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