Slow Light Question/Discussion

[Hurrikane 1]

Just started a basic Physics class in college and we began talking about the speed of light, I asked my teacher what would happen if the speed of light was some different speed that we could reach like 40mph or something and he couldn’t give a definite response. Any ideas on what might happen to the earth/universe if the speed of light was altered to this rather slow speed, like 40 mph?

[sumthingnice60 3]

I have to think about this a bit. But I do know that some physicist in the eastern US was nominated for the Nobel Prize a few years ago when she was able to slow down light. She could actually see it moving across a room and study its properties more in depth.

EDIT: Judging from formulas involving c, stuff like energy would be different. Also, distances would seem a lot larger to us. I am not sure what would be happening at the atomic level though.

Edited February 5, 2008 by sumthingnice60

[Legatus Legionis 2]

I have to think about this a bit. But I do know that some physicist in the eastern US was nominated for the Nobel Prize a few years ago when she was able to slow down light. She could actually see it moving across a room and study its properties more in depth.

EDIT: Judging from formulas involving c, stuff like energy would be different. Also, distances would seem a lot larger to us. I am not sure what would be happening at the atomic level though.

umm.. based on the Bold text could you provide any links on that.. please.. thanks.

[Czero 101 2,700]

umm.. based on the Bold text could you provide any links on that.. please.. thanks.

The physicists name is Lene Hau. Using superfluids she managed to slow light to 38 miles per hour in 1999, then in 2001 she was able to momentarily stop a beam of light.

From The Harvard University Gazette - February 7, 2007

Lene Hau has already shaken scientists' beliefs about the nature of things. Albert Einstein and just about every other physicist insisted that light travels 186,000 miles a second in free space, and that it can't be speeded-up or slowed down. But in 1998, Hau, for the first time in history, slowed light to 38 miles an hour, about the speed of rush-hour traffic.

Two years later, she brought light to a complete halt in a cloud of ultracold atoms. Next, she restarted the stalled light without changing any of its characteristics, and sent it on its way. These highly successful experiments brought her a tenured professorship at Harvard University and a $500,000 MacArthur Foundation award to spend as she pleased.

Now Mallinckrodt Professor of Physics and of Applied Physics, Hau has done it again. She and her team made a light pulse disappear from one cold cloud then retrieved it from another cloud nearby. In the process, light was converted into matter then back into light. For the first time in history, this gives science a way to control light with matter and vice versa.

See also:

Wikipedia - Lene Hau

Wikipedia - Slow Light

Harvard University - Hau Lab

NPR Interview with Lene Hau - February 9, 2007

Cz

[Legatus Legionis 2]

The physicists name is Lene Hau. Using superfluids she managed to slow light to 38 miles per hour in 1999, then in 2001 she was able to momentarily stop a beam of light.

From The Harvard University Gazette - February 7, 2007

See also:

Wikipedia - Lene Hau

Wikipedia - Slow Light

Harvard University - Hau Lab

NPR Interview with Lene Hau - February 9, 2007

Cz

Thanks.. all clear now..

[greggK 7]

Just started a basic Physics class in college and we began talking about the speed of light, I asked my teacher what would happen if the speed of light was some different speed that we could reach like 40mph or something and he couldn’t give a definite response. Any ideas on what might happen to the earth/universe if the speed of light was altered to this rather slow speed, like 40 mph?

A lot of thought is generated from questions like that.

Everything is set. The speed of light is . . . etc. If the speed of light were to slow down, wouldn't that mean the rest of the environment has sped up?

That is the only way I can see something like that happening. Now, the speed of light was determined when? Before that what was it? Faster or slower?

The minds of mankind have been getting faster and faster; faster than the speed of light to begin with. The 'speed of thought.'

[ethereal scout 0]

The minds of mankind have been getting faster and faster; faster than the speed of light to begin with. The 'speed of thought.'

I wonder if there is (or should be) a diferentiation between the concept of the 'speed of light' - and the concept of the 'speed of information'.

With light being considered more as a medium (like water) - with the waves being information travelling through the medium (like pressure waves).

ie sound - sound is a pressure wave travelling through air (a gas) - the same is possible from liquids and solids.

We consider time as a means for providing logical steps (in my mind) in order to measure the 'distance' between events in a linear way. For the speed of this information transferal in normal circumstances (ie on earth) simply having a couple of in sync reference points is enough (atomic clocks etc) - for all intents and purposes 'pairs' of events happen instantly. ie - if a ball is dropped from a tower at 'x' - someone watches a mile away and measure when it hits the ground 'y' - everything is so quick that for practicalities sake - its instant.

However over far far larger distances (outer space) the 'speed' refered to perhaps the maximum speed of information transferral through light - rather than 'light' itself.

What I'm wondering if is space is more a vast ocean of latent energy - and that stars, planets etc are manifestations of this ocean of energy tying itself in knots.

[greggK 7]

What I'm wondering if is space is more a vast ocean of latent energy - and that stars, planets etc are manifestations of this ocean of energy tying itself in knots.

I believe space to be an ocean of charged particles and the galaxies are at the intersections of two existences.

The speed of thought vs. the speed of light is photons vs ions. Do the ions in your brain create photons in the jump across synapses in their collisions?

Edited February 6, 2008 by greggK

[JohnnyRush 0]

wouldnt we not be able to see distant galaxies and stuff cuz the light wouldnt have gotten here?

[ships-cat 15]

wouldnt we not be able to see distant galaxies and stuff cuz the light wouldnt have gotten here?

It's even worse than THAT.

We wouldn't be able to see distant galaxies.. because THEY wouldn't have 'got there'. (assuming everything started from a "big bang" singularity).

In accordance with the Lorentz transformations, nothing would (easily) be able to go more than a few miles per hour (the amount of energy to go much beyond 20 MPH would start to become prohibitive). Hence no birds, winds, or even tides as we know them.

I suspect that under these conditions, the universe would never have been able to expand in the first place.

Meow Purr.

[Tiggs 4,479]

Light is just an information transfer mechanism. If you could move faster than the speed of light, you would appear to an observer to be moving backwards in time:

[greggK 7]

First, put everything into its own perspective. Every little star that your child wishes on up there is so small, right? The sun is just so much larger than those little things zipping across the night sky. But, you can go out to your backyard and play basketball with the sun. . . .

Well, no not really. At one time in the history of this globe, everything was close together, if there was a 'Big Bang.' Milliseconds after the 'Big Bang' everything was tending toward one direction and that is outward. Then collisions, secondary explosions, etc. making more chaos; debris started to be flung sideways behind the leading wave of force.

As time, maybe a second or half, went by the exploding Ball slowed down in its forward momentum.

Now, at this time, probably four seconds past that 'Big Bang,' everything is so spread out, there is a few secondary collisions, but the magnetic atrraction of the galaxies is starting to pull the galaxies together. Probably in another three or four seconds, the galaxies will start colliding.

Now, down here on this huge earth, time has stopped. That little Bang happened 4.6 Billion years ago.

Now, we're trying to figure out what happened.

The question is 'Does light slow down?'

What causes light? If that that causes light slows down, what happens to the light?

Tiggs example shows three types of light. You cannot say a color of light because there is no color outside of your brain, there's intensity.

If, in the example, Bob were a very small light and George in the back were a large bright light, you wouldn't see Bob out there in front, so #3 of the diagram, in this case would be opposite.

QUOTE (JohnnyRush @ Feb 8 2008, 10:45 PM)

wouldnt we not be able to see distant galaxies and stuff cuz the light wouldnt have gotten here?

No, the nearer galaxies are brighter and therefore that is what you see.

There is so much debris between this

solar system

and the closest

solar system

, and with the hugeness of your eyeball it just seems that it is a clear shot with easy passage if you could see it, but you can't.

There could be a huge object coming toward this humongous earth giving off no light and we would not know it until we started not seeing some of those little bitty stars out there.

Edited February 9, 2008 by greggK

[Killer Moth 0]

So they slowed the light down by passing it through something... that doesnt seem so weird by itself. But to change it to matter and back to light now thats strange.

[PsiSeeker 164]

This topic has given me a hell of a lot to think about on the nature of light. Will contribute if I think of anything interesting.

I don't understand why time and the speed of light effect eachother in the ways they do. If something travels away at you at the speed of light then fair enough, any information you receive from there at that point will be limited to the time it takes the light to reach you, however their actual state in reality would be different from what you are seeing. If they travelled back to you at the speed of light it would appear like they're speeding up through time. I don't understand why the "twin" paradox and the "clock on a jetplane" ie high velocities slow down time. If something was travelling around Earth at the speed of light wouldn't you just see the object speeding up and slowing down because of the time it takes the light to hit your eyes? (Assuming you could understand information given to you by your eyes that fast.)

[Xeaphon 1]

If the speed of light were to slow down to 40mph, then traveling at around 5mph would probably need around asmuch energy as an atomic bomb. We wouldn't be able to see the stars, as their light wouldn't have got to us yet. The universe itself wouldn't have evolved to a point where life has originated yet

[I Am Will 0]

guess it would alter every aspect of our universe. including time, so would we actually notice any difference?

if everything was proportionally affected by the speed of light slowing then would the effects be unnoticable?