If Light Could Be Converted Into Magnetism

[Spacescifi]

 

We already know light can be converted into electricity easily. 

Since light is electromagnetic, there is reason to believe it can be converted into magnetism as well.

In fact, according to the following site, if you presume they are telling the truth (I don't think this is beyond belief), it has already been done experimentally with some losses probably due to heat absortion of the light.

https://kaw.wallenberg.org/en/research/coupling-light-magnetism-nanoscale

https://www.google.com/amp/s/phys.org/news/2019-09-laser-metal-magnet.amp

They use a kind of receiver that converts EM into magnetism.

Main Question: If mankind ever becomes really proficient at converting light into magnetism, what are the tech implications? Like what if we could convert 99% of light received by a receiver into magnetism?

For communications tech?

Computing?

Space travel tech?

My guess: Magnets are known to both attract and repel each other. We know light offers at best, super weak thrust. Perhaps if the light was converted into magnetism the thrust could be increased significantly?

Or even if this works it won't matter because the magnetism must be super strong? Magnet breaking strong? I doubt that.

Applications: Scifi tractor beams, just take an ordinary laser and shoot it at a magnetic impulse converter, and suddenly the pulled in object is attracted with far greater force than the laser beam's actual thrust from light itself. You could more or less sit still and attract ANY vessel with an impulse receiver to you all day long.

Propulsion: Lots of ways. With big enough station lasers, it would be possible to magnetically push spacecraft across space and use moon station lasers to slow it for landing.

Since magnets and by extension impulse receivers can be polarized.

 

What do you think?

 

Edited October 24, 2020 by Spacescifi

[magnemoe]

How can light be converted to electricity except with solar cells? Lower frequencies interact easier, microwaves and higher just require an antenna. 
Electricity and magnetism is much easier to convert between as one create the other 

[JoeSchmuckatelli]

I think it's an interesting question.  As pointed out, we regularly convert what we think of as electricity in a wire to an EM wave and then back again to use the electricity to drive speakers (radio). 

Is there a definable difference between EM as a signal traveling through space or air and the electricity in the wire?  

Is magnetism distinct from EM? 

 

Or are these questions merely exposing how the general public does not understand how these are all expressions of the same thing? 

[Snark]

3 hours ago, Spacescifi said:

Since light is electromagnetic, there is reason to believe it can be converted into magnetism as well.

I have no idea what you mean by "convert to magnetism".

Light is magnetism, in a sense-- that's why it's called an "electromagnetic wave".  A propagating beam of light (or radio, or microwaver, or any electromagnetic wave) consists of an oscillating electric field at right angles to an oscillating magnetic field.

What exactly do you mean by "convert to magnetism"?

[Shpaget]

How (and why) would this conversion offer superior performance and different capabilities than regular permanent or electromagnets?

[NFUN]

(to SpaceScifi and Joe): I think you're conflating "electricity" and "electric fields", or at least not really understanding the distinction between them. Electricity is the movement of electrons, or generally charged particles. Without magnetic monopoles, magnetism doesn't have a direct analogue, so in that sense, you can't convert light into "magnetism" the way you can convert it into "electricity". It doesn't really make sense as a question in this context. If you mean converting light to magnetic fields, sure, that's possible. You can use light to jiggle electrons, which you implicitly noted in your radio example, which necessarily creates magnetic fields as well. If you mean using light to magnetize a material, that's been done.

[JoeSchmuckatelli]

On 10/24/2020 at 1:25 PM, NFUN said:

(to SpaceScifi and Joe): I think you're conflating "electricity" and "electric fields", or at least not really understanding the distinction between them. Electricity is the movement of electrons, or generally charged particles. Without magnetic monopoles, magnetism doesn't have a direct analogue, so in that sense, you can't convert light into "magnetism" the way you can convert it into "electricity". It doesn't really make sense as a question in this context. If you mean converting light to magnetic fields, sure, that's possible. You can use light to jiggle electrons, which you implicitly noted in your radio example, which necessarily creates magnetic fields as well. If you mean using light to magnetize a material, that's been done.

Grin - this was a play on my own knuckleheadedness. 

It's pretty easy for people to think of electricity as distinct from light and both as distinct from magnetism.  Our words for these concepts - and even the concepts themselves go way back before Maxwell.  There's a lot of cultural inertia at play - and as I quipped / implied - it's easy to think of things as distinct when we experience them differently.  To be fair, I did hint that I knew the answer.

I have a weird sense of humor sometimes.

 

On 10/24/2020 at 12:26 PM, JoeSchmuckatelli said:

...

 

Or are these questions merely exposing how the general public does not understand how these are all expressions of the same thing? 

[NFUN]

12 hours ago, JoeSchmuckatelli said:

Grin - this was a play on my own knuckleheadedness. 

It's pretty easy for people to think of electricity as distinct from light and both as distinct from magnetism.  Our words for these concepts - and even the concepts themselves go way back before Maxwell.  There's a lot of cultural inertia at play - and as I quipped / implied - it's easy to think of things as distinct when we experience them differently.  To be fair, I did hint that I knew the answer.

I have a weird sense of humor sometimes.

 

thought you were including yourself in the "general public" 

[Bill Phil]

Well in a sense if you can get photons to provide current (say, in a solar panel) and then power an electromagnet you’ve converted light into magnetism.

[Arugela]

I'm sure I'm missing the nuances of this, but if electricity can be turned into magnetism. Then the answer is yes. You can simply convert to electricity then magnetism. Make an electromagnet from the solar power. Which I assume we do all the time.

Couldn't you use electricity to power permanent magnets also and use them like batteries. I'm assuming they are less efficient than other sources unless they can stay powered longer than normal batteries. Either way maybe they could be used for both electricity and magnet features? No idea what amount you need to power such magnets though.

Edited October 28, 2020 by Arugela

[sevenperforce]

1 hour ago, Arugela said:

Couldn't you use electricity to power permanent magnets also and use them like batteries.

Motion, electrical current, and magnetism have a very close relationship.

If you put motion into a magnet you get electrical current. This is a dynamo.

If you put electrical current into a magnet you get motion. This is a motor.

If you put electrical current into motion you get magnetism. This is an electromagnet.

Edited October 28, 2020 by sevenperforce

[burner_brown]

I thought of a hypothetical idea this question could help, but then realized maybe it is relevant. If we wanted a battery operated vehicle roving around at the bottom of the ocean, it would be nice if it could recharge itself automatically and not have to come to the surface all the time. Maybe a large solar panel floating on the surface of the ocean and a long cable going down to the bottom. The vehicle could charge whenever it needed. However, a copper wire 6 miles long would have high resistance and weight a lot. But sending light though a fiber optic cable could be an answer. Because the charging station is 6 miles down in the water it couldn't have electrical contacts, but could use magnetic charging similar to wirelessly charging your cell phone. How would you convert the light energy from the fiber optic cable into something that could charge the vehicle under water? If it could be done, it would be extremely slow charging but still better than traveling 12 miles round trip just to charge. Be nice when you rip this apart :)

[darthgently]

Why not use the small nuke heated sterling engine designed for use for deep space probes?

But if you insist on fiber optic cable, yes it can be done at power levels above what you seem to be imagining.  The fiber (or probably multi-fiber bundle) is basically a light pipe and very small PVs at the rover could handle fairly intense light if kept cool (not hard with ocean all around) and their output is proportional to the light received.  The lifespan of the tiny bottom-side PV would suffer being used like this, but seems doable 

One more thing, light is electromagnetism, not sure what is meant there so addressed what I thought you were trying to get at

Edited October 6, 2023 by darthgently

[NFUN]

God, some things never change

[kerbiloid]

If put the nuclear-powered stirling on ground, and attach it to the spacecraft with enough long optical fiber cord, we can keep winding the onboard rubber motor by mechanically pulling the cord.

The advantage is: no limitations on the nuclear reactor size and mass, and no nukes onboard.

P.S.
That's exactly the way I was using to play Incredible Machine game series. It works.

[farmerben]

A magnetic field generated by a spacecraft is probably a better way to slow down from interstellar speeds than a solar sail.  A solenoid of superconductor powered by solar panels is a useful device.

[kerbiloid]

12 hours ago, farmerben said:

A magnetic field generated by a spacecraft is probably a better way to slow down from interstellar speeds than a solar sail.  A solenoid of superconductor powered by solar panels is a useful device.

First https://en.wikipedia.org/wiki/Magnetic_sail to slow down from interstellar to interplanetary by reflecting the solar wind (i.e. radial slow of protons),
then https://en.wikipedia.org/wiki/Electric_sail to make a Sun-Jupiter-Earth slalom and slow down from interplanetary speed to planetary, by interaction of the electric net with their magnetospheres,
then https://en.wikipedia.org/wiki/Electrodynamic_tether to circularize orbit.

Interesting fact: all three can be the same expandable radial structure, and it can be an extension of the magnetic nozzle used for acceleration.

Edited October 7, 2023 by kerbiloid