Frozen light?

Post by **Delphine** » Fri Apr 15, 2005 8:14 pm

So, is The Register a reputable source? Because apparently <a href="http://www.theregister.co.uk/2005/04/12 ... ght/">some Harvard folks have discovered how to freeze light.</a>

Scientists at Harvard University have discovered how to freeze light, so that it can be used to build an optical computer, theoretically capable of processing information ten times faster than traditional electronics.

The researchers, led by Prof. Lene Hau, has calculated that controlled, coherent processing with light can be performed using ultra-cold atoms known as Bose-Einstein condensates (BECs). Hau outlined her research yesterday at the Physics 2005 conference in Warwick.

Hau has discovered, in her work on slow light, that a BEC can preserve the phase and amplitude of a light pulse. In normal matter, these properties would be smeared out, destroying any information content. If a device can be built that preserves that information, Hau argues, it could be developed into the CPU of an optical computer.

In 2003 Hau's research group slowed light from 186,000 miles per second to around the speed of a bicycle. Later, they froze light altogether, using a cloud of ultra-cold sodium atoms. Dr. Hau argues that frozen light could also have applications for memory storage on optical computers.

As well as frozen light, the group works on other very cold things, including cold atomic beams and superfluidity.

j-man · Post by **j-man** » Fri Apr 15, 2005 8:15 pm

IMPOSSIBLE.

Post by **Crazy Penguin** » Fri Apr 15, 2005 8:30 pm

I doubt much will come from this. Cool scientific discovery shit seems to make Internet news every other week only to quickly fade away and be forgotten. We just get better game consoles and music players. Where's my fucking hoverboard?

Baba O'Reily · Post by **Baba O'Reily** » Fri Apr 15, 2005 8:30 pm

Read it, never mind. I think it's just confusing and implausible.

Frieza2000 · Post by **Frieza2000** » Fri Apr 15, 2005 9:10 pm

Yeah, we've seen absolute zero. It doesn't freeze light.

Post by **Delphine** » Fri Apr 15, 2005 9:20 pm

One: RTFA. "a BEC can preserve the phase and amplitude of a light pulse."

Two: We have? I was under the impression that we couldn't get far enough away from the sun to do so.

Post by **Esrever** » Fri Apr 15, 2005 9:48 pm

For the record, the register often posts fake stories. I'm not saying this one is (haven't read it) but...

Post by **Delphine** » Fri Apr 15, 2005 10:45 pm

I did a google search -- which, you know, I should've done in the first place -- and it seems it's been posted at a number of places, including <a href="http://science.slashdot.org/article.pl? ... ashdot.</a> There's also <a href="http://www.physics.hku.hk/~tboyce/sf/to ... l">this</a> for anyone who's interested -- I think so, anyway. Past midnight that's some serious tl;dr for me.

Omni Hunter · Post by **Omni Hunter** » Sat Apr 16, 2005 4:47 am

If light can be frozen the DB's sabers for everyone!
Then again, you can't get much colder than space itself, the fact we can see stars obliterates this theory of "Static Light".
Edit: I am aware that some areas of space are hotter than others.

Baba O'Reily · Post by **Baba O'Reily** » Sat Apr 16, 2005 5:04 am

Well, that might just mean that it hasn't completely stopped. Light might be moving more slowly towards us if this idea isn't bullshit. But that would make the speed of light variable, and that would just fuck up everything in physics.

Omni Hunter · Post by **Omni Hunter** » Sat Apr 16, 2005 5:21 am

I was interested in the use of sound waves and other media of energy being transmitted. Maybe a sort of high frequency vibration could be used to create actual "Light sabers". I may be going too deep though.

Baba O'Reily · Post by **Baba O'Reily** » Sat Apr 16, 2005 6:00 am

Most of light's energy is spent radiating, so you'd need to focus the light into one color of the spectrum, then figure out how to generate enough energy to allow it to possess enough force to cut through something. Then you need to figure out how to expand the source enough so that you have some defensive ability (Let's face it, a 1mm thick beam doesn't quite cut it for parrying), and do all of this without blinding the wielder of the thing. Oh, and you also have to make it compact enough to fit in the confines of a 1 foot hilt.

Omni Hunter · Post by **Omni Hunter** » Sat Apr 16, 2005 6:05 am

It's plausible but quite a long way to go.

-wyvern · Post by **-wyvern** » Sat Apr 16, 2005 6:32 am

Don't worry about it screwing up physics - Einstien said that the speed of light in a vacuum was invariable; you can shine it through water to slow it down or bose einstien condensate etc. and it won't be inexplicable by special relativity.

Light photons do not lose energy moving from place to place, and upon hitting a surface they will either rebound (as in a reflection) or they'll get absorbed by an atom's electron shells, which will either heat up the surface or cause the excited electrons to emit photons of their own.

I'd recommend using small charged particles (heleum nuclei, electrons) rather than actual light photons in a lightsabre. For one thing, they would powerfully ionise anything coming into contact with them, which would destroy the bonds in a material and thus disintegrate it at a molecular level. And charged particles can be manipulated using electrical fields - if you managed to produce a set of electric and magnetic fields in the right shape, you could get the ions to form a lightsabre blade or a vase of flowers or whatever.

I have no idea how it could reflect laser gun bolts, though. I guess Lucas just didn't know what he was talking about.

EDIT: fixed a spelling mistake, or it will look like I won't know what I'm talking about. Which I don't.

Dash · Post by **Dash** » Sat Apr 16, 2005 6:56 am

We have the technology. Now let's smite some evil.

Baba O'Reily · Post by **Baba O'Reily** » Sat Apr 16, 2005 7:44 am

Eh. Maybe the blasters and lightsabers had the same polarity?

Omni Hunter · Post by **Omni Hunter** » Sat Apr 16, 2005 8:16 am

True, with magnetic fields energy can be catapulted and relflected.
Magnetic pulses could be used to catapult same polarity particles.
If both saber and blaster had the same polarity then the saber would reflect the blast or the magnetic field's radius would if strong enough.
Defensivewise it's better to have an opposite pole to attract and absorb the blast into the blade with possibly minimal effect. Heck, this theory could be used to make "photonic shields" which act the same.

-wyvern · Post by **-wyvern** » Sat Apr 16, 2005 8:56 am

True. Although you have to be careful when talking about poles and fields and things; ions, electrons, protons and other such charged particles produce an electric field; but when they move, they create a magnetic field. This is how electromagnets work - a coil of wire has electrons flowing through it, which produce the magnetic field that allows the magnet to do it's job. So if you moved your sabre in the wrong way, it could cause the ions from the enemy's weapon fire to spray off into your face or something... Fields and stuff like that are really, really difficult to explain without good diagrams. And by the time I'd found some, you'd all have lost interest in the whole thing anyway, if you hadn't allready.

Not that it matters considering the whole situation is completely imaginary, but hey.

Oh! And photons have no charge, so a laser would be able to go right through a particle blade like a lightsabre.

Post by **Delphine** » Sat Apr 16, 2005 10:04 am

-wyvern wrote:Don't worry about it screwing up physics - Einstien said that the speed of light in a vacuum was invariable; you can shine it through water to slow it down or bose einstien condensate etc. and it won't be inexplicable by special relativity.

I'm glad you said it, because if I got to the end of the thread without <i>someone</i> saying it I was probably going to start yelling.