# Orbital momentum of light

• September 22nd, 2010, 05:29 AM
Dwayne Dibley
Orbital momentum of light
Take a laser and spin it in a circle and once the light reaches a certain distance from it's source, the outermost point of light will be rotating around the source at faster than the speed of light. This does not mean that the light is actually moving faster than the speed of light as it still takes the light time to create a radius for a big enough circle. But if it was already that far and the light was being constantly emitted, then couldn't you send instantaneous messages by manipulating the source's direction (lets say from side to side) and applying a value for the degree of manipulation?

I may not quite understand light correctly.
• September 22nd, 2010, 05:48 AM
Cold Fusion
Mmm...I think I understand what you are saying, but the light if put in a circle like that would 'fall apart' since the area near the middle of the circle would make more revolutions per minute than the outer portion, causing it to degenerate. So no, this wouldn't allow for instantaneous messages. The speed of light if it could be, would be EXTREMELY difficult to pass. No standard form of thought would get you to such a result...you would need theory upon theory upon radical theory all piled on top of each other to get such a result. In other words, you would need to create an entirely new field of science.

Anyway, you should be careful with handing out ideas. If you were in fact right, you would have just screwed yourself out of quite a bit of money for that idea; but you at the very least probably subconsciously doubted yourself, which is why you asked here and did not hesitate more. In that case, its good to ask such questions since being proven wrong can prove constructive as you learn more things about the subject.
• September 22nd, 2010, 06:02 AM
Dishmaster
The photons that are emitted by the laser when spinning it actually still need some time (distance/speed of light) to have an effect on the reflecting object. So, if you had a very strong and highly focussed laser that could produce a point on a planet very far from us, any change of direction still needs the light travel time to propagate through. The movement is not instantaneously reflected on the distant surface.

It is like water that comes out of a water hose. If you shake and wiggle the hose, you see how this movement leads to a bent path of the water.
• September 22nd, 2010, 12:51 PM
DrRocket
Re: Orbital momentum of light
Quote:

Originally Posted by Dwayne Dibley
Take a laser and spin it in a circle and once the light reaches a certain distance from it's source, the outermost point of light will be rotating around the source at faster than the speed of light. This does not mean that the light is actually moving faster than the speed of light as it still takes the light time to create a radius for a big enough circle. But if it was already that far and the light was being constantly emitted, then couldn't you send instantaneous messages by manipulating the source's direction (lets say from side to side) and applying a value for the degree of manipulation?

I may not quite understand light correctly.

No, you cannot send an instantaneous signal in that manner. Think about it. Anything that you do to modulate that signal only propagates at c.
• September 22nd, 2010, 12:52 PM
DrRocket
Quote:

Originally Posted by Cold Fusion
Mmm...I think I understand what you are saying, but the light if put in a circle like that would 'fall apart' since the area near the middle of the circle would make more revolutions per minute than the outer portion, causing it to degenerate. So no, this wouldn't allow for instantaneous messages. The speed of light if it could be, would be EXTREMELY difficult to pass. No standard form of thought would get you to such a result...you would need theory upon theory upon radical theory all piled on top of each other to get such a result. In other words, you would need to create an entirely new field of science.

Anyway, you should be careful with handing out ideas. If you were in fact right, you would have just screwed yourself out of quite a bit of money for that idea; but you at the very least probably subconsciously doubted yourself, which is why you asked here and did not hesitate more. In that case, its good to ask such questions since being proven wrong can prove constructive as you learn more things about the subject.

This total rubbish. Is there any tiny element of physics that you actually understand ?
• September 23rd, 2010, 07:30 AM
Dwayne Dibley
so from what I gather, the light is limited by the angular momentum of it's source as opposed to being bound to the source like a spoke. would that then mean if you could see the light from the laser from a top-down angle that it would create a spiral wave pattern?
• September 23rd, 2010, 02:48 PM
Sindrato
If you could ever see the light that is passing, yes.
• September 24th, 2010, 03:25 AM
kojax
Quote:

Originally Posted by Dwayne Dibley
so from what I gather, the light is limited by the angular momentum of it's source as opposed to being bound to the source like a spoke. would that then mean if you could see the light from the laser from a top-down angle that it would create a spiral wave pattern?

Yeah. It would be kind of like the way water looks when it gets thrown around by a spinning sprinkler.