Oldest Galaxies

[Johnny]

Researchers have recently increased the speed of light beyond c [the speed of light in a vacuum].

To clarify, the group velocity exceeded c, but no information can be transferred through the standing wave nor did any individual photons move faster than the speed of light.

One way to understand this is to imagine a light source covered by a dark bag with a single hole in it. In a dark room, there is a single point of light on the wall produced light source shining through the hole in the bag. Now imagine that the bag is placed on a rotating device so that the whole bag rotates. The light point produced on the walls of the room will appear to be moving around the room as the bag rotates. If you move the walls of the room back far enough, the light source will even appear to be moving faster than the speed of light between any two points on the wall. However, no photons are actually moving faster than the speed of light, nor can information be transmitted between two points on the wall faster than the speed of light (because the information has to be sent at the speed of light from the light source to the wall). However, group velocity of the photons exceeds the speed of light.

This, in theory, can be done with any wave.

 

[JustinFoldsFive]

Johnny, have you read anything about researchers who increased the speed of light past c by passing it through some sort of gas/substance? Someone in my Philosophy of Science class brought in an article to that effect, but I haven't been able to find it online.

 

[zoo22]

To clarify, the group velocity exceeded c, but no information can be transferred through the standing wave nor did any individual photons move faster than the speed of light.

One way to understand this is to imagine a light source covered by a dark bag with a single hole in it. In a dark room, there is a single point of light on the wall produced light source shining through the hole in the bag. Now imagine that the bag is placed on a rotating device so that the whole bag rotates. The light point produced on the walls of the room will appear to be moving around the room as the bag rotates. If you move the walls of the room back far enough, the light source will even appear to be moving faster than the speed of light between any two points on the wall. However, no photons are actually moving faster than the speed of light, nor can information be transmitted between two points on the wall faster than the speed of light (because the information has to be sent at the speed of light from the light source to the wall). However, group velocity of the photons exceeds the speed of light.

This, in theory, can be done with any wave.

Right, it wasn't really "speeding up" light. Though I'd never heard it explained that way.

 

[JustinFoldsFive]

OK, here's what I was looking for.

Is that the same as what you were just describing?

 

[zoo22]

Wow! I've reached the speed of light on my mountain bike! In fact just yesterday, I got home before I even tried to mount my cycle. Amazing

The only thing is that if you had to pedal home through the "super-cool goo" they slowed light down with, you'd never make it home.

Also, you and your bike would probably have shattered, because the temperature of the atom concoction was 459.67 degrees below zero Fahrenheit. Brr.

lain:

 

[zoo22]

Yes. Researchers have recently increased the speed of light beyond c [the speed of light in a vacuum].

That doesn't mean that the speed of light has changed, it just means that we've managed to change it ... slowed light down and (kind of) sped it up. The speed-up experiments aren't quite as cut and dry as "speeding up light." It's been sped up, sort of. The information in the light waves has not moved faster than c.

But light has definitely been slowed down to very slow speeds, which is cool. And stopped.

There are even fiber optic experiments that have moved light backwards. In reverse. But like the speed-ups, it's kind of slight of hand. Or eye.

But I don't think I've ever seen this article you just posted, I will check it out (... I'll do some tests :chuckle: )

 

[Vern Reed]

The only thing is that if you had to pedal home through the "super-cool goo" they slowed light down with, you'd never make it home.

Also, you and your bike would probably have shattered, because the temperature of the atom concoction was 459.67 degrees below zero Fahrenheit. Brr.

lain:

Honestly, I tried it just last week. Putting me back together was, in the words of the surgeon, 'bloody hard, mate!' :zoomin:

 

[zoo22]

Honestly, I tried it just last week. Putting me back together was, in the words of the surgeon, 'bloody hard, mate!' :zoomin:

:chuckle:

The wonders of modern medicine are astounding.