> An alternate operating mode, once the magnet has been energized, is to short-circuit the windings with a piece of superconductor. The windings become a closed superconducting loop, the power supply can be turned off, and persistent currents will flow for months, preserving the magnetic field.
Re:Physicists discover flaws in superconductor theory
by ape4 on Saturday April 09, 2016 @05:29AM
(#11460621)
It would be interesting to imagine a society without magnets. We could use steam engines to pump water. Fiber optic light pipes for some home lighting. Gas stoves for cooking.
Re:Physicists discover flaws in superconductor theory
by Retric on Saturday April 09, 2016 @07:35AM
(#11460857)
I always thought that was the steam punk idea. No magnets = no radio or other long distance communication. Other than possibly a fiber optic telegraph with limited range.
Re:Physicists discover flaws in superconductor theory
by Retric on Saturday April 09, 2016 @10:39AM
(#11461405)
You can get into arguments about specifics by saying they still have light so they still have say EM radiation. But, what is and is not magnetism get's a little wonky when you get into the specifics. Strong, weak, electromagnetic force, and gravity. That's it. Without magnetism you don't get atoms.
However, if you hand wave that the induction coil is a transformer used to step up voltage and transformers work fairly directly though magnetism.
Re:Physicists discover flaws in superconductor theory
by donquichotte on Saturday April 09, 2016 @09:20AM
(#11461104)
Agreed, it's probably MRI. There's more strange things going on in this article. While "In a way, they [superconductors] are the opposite of toasters" made me giggle a little, "Without magnets, we'd lack generators [electric lights and toasters], motors [municipal water supplies, ship engines], magnetrons [microwave ovens], and much more" made me cringe. Electric lights and toasters are pretty much unrelated to generators and I've yet to see an electric engine on a commercial ship. I wonder whether the author of the article put the examples there, I doubt that Prof. Weinstein did.
Re:Physicists discover flaws in superconductor theory
by maho on Saturday April 09, 2016 @09:47AM
(#11461200)
Electric light and toasters run on electricity "generated" by the generator.
A lot of ships have electric engines. On cruise ships, diesel electric propulsion offers quieter and smoother rides. Some air-craft carriers and submarines have nuclear-electric propulsion systems.
The article made me cringe, too, but mainly because it created a false impression on how big magnets are really energized. I've done it a few times (always with the same magnet, which keeps quenching...), and described the process here:
Re:Physicists discover flaws in superconductor theory
by extrapickles on Saturday April 09, 2016 @11:48AM
(#11461749)
Diesel electric propulsion is quietly taking over most large mobile applications. Even cars are slowly going gasoline-electric. Better magnetics would only speed up the switch.
Of ships it has what you stated, and you no longer have to build the engine on a incline to drive the propeller or have complex transmissions. Other benefits are you can have 2 engines and only run 1 during calm weather cruse. Also electric motors are able to be mounted in stearable pods, greatly increasing maneuverability of a ship (need fewer tugs to go into port). Some ships have nothing but the pods for good station keeping.
Multiple locomotive trains only need 1 engine, but run power to several for extra traction, and it enables things like traction control that can't be cheaply done mechanically.
Re:Physicists discover flaws in superconductor theory
by Sniffnoy on Saturday April 09, 2016 @10:32AM
(#11461374)
No, why would it be? Previously, pulse strengths 2-3.2 times as strong as the TFM were required, and they're trying to bring it down, so this is a good result. It's a weird way of phrasing it, but I assume that's for emphasis.
Looks like this will lead to new physics discoveries? And better electric engines?
Does anybody think this could extend to antennas too?
> An alternate operating mode, once the magnet has been energized, is to short-circuit the windings with a piece of superconductor. The windings become a closed superconducting loop, the power supply can be turned off, and persistent currents will flow for months, preserving the magnetic field.
Batteries was (iirc) the typical way it was done before Faraday.
However, if you hand wave that the induction coil is a transformer used to step up voltage and transformers work fairly directly though magnetism.
(And I'm guessing they meant MRI instead of X-ray in that last paragraph)
A lot of ships have electric engines. On cruise ships, diesel electric propulsion offers quieter and smoother rides. Some air-craft carriers and submarines have nuclear-electric propulsion systems.
The article made me cringe, too, but mainly because it created a false impression on how big magnets are really energized. I've done it a few times (always with the same magnet, which keeps quenching...), and described the process here:
http://physics.stackexchange.com/questions/69222/
Of ships it has what you stated, and you no longer have to build the engine on a incline to drive the propeller or have complex transmissions. Other benefits are you can have 2 engines and only run 1 during calm weather cruse. Also electric motors are able to be mounted in stearable pods, greatly increasing maneuverability of a ship (need fewer tugs to go into port). Some ships have nothing but the pods for good station keeping.
Multiple locomotive trains only need 1 engine, but run power to several for extra traction, and it enables things like traction control that can't be cheaply done mechanically.
I have to assume that's a typo, right?