... and then there was light.

Globe · #1 by **Globe** » Nov 22, 2011 8:03 am

Well.... Swedes have always been on the forefront of science.....

http://www.dw-world.de/dw/article/0,,15 ... l-1573-rdf

Swedish scientists create light from almost nothing

Scientists at Chalmers University in Sweden have proved that a vacuum is not, in fact, empty, by capturing light in it. It is an experiment confirming a theory of quantum mechanics first proposed over 40 years ago.

Physicists at Chalmers University in Gothenburg, Sweden, have managed to turn "virtual" light particles, flickering in and out of existence in a vacuum, into measurable, material particles.

The experiment was based on one of the more confusing, yet important principles in quantum mechanics: that a vacuum is by no means empty. In fact, empty space is a seething ocean of infinitesimal particles that fluctuate in and out of existence, defying the laws of classical physics because they only exist for the briefest of moments.

The Chalmers team succeeded in getting photons to leave their virtual state and become real photons, e.g. measurable light. They did this by effectively tricking the photons into thinking they were bouncing off a mirror spinning at close to the speed of light.

Their results were published in the journal Nature, on Thursday.

.....more

cavarka9 · #2 by **cavarka9** » Nov 22, 2011 8:29 am

Globe wrote:Well.... Swedes have always been on the forefront of science.....

http://www.dw-world.de/dw/article/0,,15 ... l-1573-rdf

Swedish scientists create light from almost nothing

Scientists at Chalmers University in Sweden have proved that a vacuum is not, in fact, empty, by capturing light in it. It is an experiment confirming a theory of quantum mechanics first proposed over 40 years ago.

Physicists at Chalmers University in Gothenburg, Sweden, have managed to turn "virtual" light particles, flickering in and out of existence in a vacuum, into measurable, material particles.

The experiment was based on one of the more confusing, yet important principles in quantum mechanics: that a vacuum is by no means empty. In fact, empty space is a seething ocean of infinitesimal particles that fluctuate in and out of existence, defying the laws of classical physics because they only exist for the briefest of moments.

The Chalmers team succeeded in getting photons to leave their virtual state and become real photons, e.g. measurable light. They did this by effectively tricking the photons into thinking they were bouncing off a mirror spinning at close to the speed of light.

Their results were published in the journal Nature, on Thursday.

.....more

casimir effect,virtual particles, must be in physics thread

Globe · #3 by **Globe** » Nov 22, 2011 9:33 am

I am not taking a physics-angle on this one.

byofrcs · #4 by **byofrcs** » Nov 22, 2011 10:10 am

I'm thinking extremely small scale optical signalling on chip substrates.

Globe · #5 by **Globe** » Nov 22, 2011 10:22 am

And here I thought that the double Headline mentioning both "God" and a quotation from the bibble would prevent it from becoming a physics-discussion. :nono:

chaggle · #6 by **chaggle** » Nov 22, 2011 10:29 am

They did this by effectively tricking the photons into thinking ...

That doesn't sound very scientific to me.

trubble76 · #7 by **trubble76** » Nov 22, 2011 10:44 am

chaggle wrote:
They did this by effectively tricking the photons into thinking ...

That doesn't sound very scientific to me.

I wonder if they can effectively trick some creationists into thinking? :ask:

Sovereign · #8 by **Sovereign** » Nov 22, 2011 11:24 am

Globe wrote:And here I thought that the double Headline mentioning both "God" and a quotation from the bibble would prevent it from becoming a physics-discussion.

You had to have an inkling that a physics experiment would get moved to the physics section unless it was being used in doctrine, which hasn't and probably won't happen for a few months. If it does, creationists will use it in passing fearing that their kids will want to know the truth if it sounds too miraculous.

chaggle wrote:
They did this by effectively tricking the photons into thinking ...

That doesn't sound very scientific to me.

I remember hearing that photons might have a form of intelligence to know when to be a particle and when to be a wave. I think that wooish statement was the basis of the Dark Materials Trilogy.

trubble76 wrote:I wonder if they can effectively trick some creationists into thinking?

That would be a Nobel prize in the making!!!

zaybu · #9 by **zaybu** » Nov 22, 2011 12:12 pm

deleted, see below

Globe · **#10** by **Globe** » Nov 22, 2011 12:14 pm

Sovereign wrote:
Globe wrote:And here I thought that the double Headline mentioning both "God" and a quotation from the bibble would prevent it from becoming a physics-discussion.

You had to have an inkling that a physics experiment would get moved to the physics section unless it was being used in doctrine, which hasn't and probably won't happen for a few months. If it does, creationists will use it in passing fearing that their kids will want to know the truth if it sounds too miraculous.

Consider my OP as an attempted "preemptive" strike at the creationists. An opportunity to have the arguments in place before they hi-jack the science for their own purposes.
Solidly foiled now as it's going to end up in a few nerds (Don't take it badly. I love nerds :grin:

) discussing commas and points in each others posts. :what:

zaybu · **#11** by **zaybu** » Nov 22, 2011 12:15 pm

cavarka9 wrote:

Physicists at Chalmers University in Gothenburg, Sweden, have managed to turn "virtual" light particles, flickering in and out of existence in a vacuum, into measurable, material particles.

Take that, Twistor... you and Matt Strassler :grin:

EDITOR: For the uninitiated, see: http://www.rationalskepticism.org/physi ... 25530.html

cavarka9 · **#12** by **cavarka9** » Nov 22, 2011 6:52 pm

zaybu wrote:
cavarka9 wrote:

Physicists at Chalmers University in Gothenburg, Sweden, have managed to turn "virtual" light particles, flickering in and out of existence in a vacuum, into measurable, material particles.

Take that, Twistor... you and Matt Strassler

EDITOR: For the uninitiated, see: http://www.rationalskepticism.org/physi ... 25530.html

well I wanted to post this day before yesterday, was busy. And It was Globe who posted it. Very interesting

Globe · **#13** by **Globe** » Nov 22, 2011 7:02 pm

cavarka9 wrote:
zaybu wrote:
cavarka9 wrote:

Physicists at Chalmers University in Gothenburg, Sweden, have managed to turn "virtual" light particles, flickering in and out of existence in a vacuum, into measurable, material particles.

Take that, Twistor... you and Matt Strassler

EDITOR: For the uninitiated, see: http://www.rationalskepticism.org/physi ... 25530.html

well I wanted to post this day before yesterday, was busy. And It was Globe who posted it. Very interesting

Check my sig....

Every time something like this happens Globe Jr pesters me till I pay attention. :grin:

cavarka9 · **#14** by **cavarka9** » Nov 22, 2011 7:07 pm

And globe, a creationist would say that this is evidence for God, because who moved the first mirror! :lol:

twistor59 · **#15** by **twistor59** » Nov 22, 2011 8:07 pm

zaybu wrote:
cavarka9 wrote:

Physicists at Chalmers University in Gothenburg, Sweden, have managed to turn "virtual" light particles, flickering in and out of existence in a vacuum, into measurable, material particles.

Take that, Twistor... you and Matt Strassler

EDITOR: For the uninitiated, see: http://www.rationalskepticism.org/physi ... 25530.html

Hmm, we discussed the Dyamical Casimir effect before here.

I don't have access to the Nature paper, so I can't be sure what it said, but someone on physicsforums looks as though they read it: http://physicsforums.com/showthread.php?t=552148

alxm wrote:As far as the debate on the 'reality' of virtual particles goes, this does not change anything. It's just yet another correct QED result. Nobody seriously disputes that QED works, or that the vacuum exists, or that it behaves quantum mechanically. I don't agree with the view stated in the article's abstract:

One of the most surprising predictions of modern quantum theory is that the vacuum of space is not empty. In fact, quantum theory predicts that it teems with virtual particles flitting in and out of existence.

But in the main text they switch to the term "vacuum fluctuations", which is a less contentious term, IMHO. The non-relativistic, non-quantized-field analogue of the Casimir effect is the London force, which is also often described as quantum mechanical "charge fluctuations" (even though it's time-independent). Similarity, it can also be calculated through perturbation theory invoking "virtual" excited states of the non-interacting atoms. Although people do not tend to say the London force "proves these virtual excited states exist" or that the London force is 'mediated' by them.

Naturally you never measure the atoms in actual excited states (presuming they started out in their ground states). Nor have I ever seen someone invoke the "time-energy uncertainty principle" to explain why they're not. And I think it's quite possible that those virtual excited states could "become real" in some extreme circumstance, although it'd certainly be extremely difficult to get an electronic excitation out of such a weak force.

Quantize the field, take relativity into account, and you get additional effects at short range, which is what the Casimir effect is. Quantizing the field and introducing relativity causes a measurable physical difference, and requires a somewhat different approach, but I don't see how that justifies a different conception of what virtual states are.

I suspect it's all just because 1) popular accounts tend to talk of virtual particles in this way, and 2) A lot of physics students graduate to QED directly from basic non-relativistic theory, and miss how a lot of the same formalism (e.g. path integrals, second quantization) is applicable to ordinary non-rel QM.

The authors look line the same as the ones whose paper was discussed in the Ratskep thread, so I assume the paper we were discussing there contains the essential information. Moreover it switches from virtual particle terminology in the intro to vacuum fluctuations in the text. No "particles flitting in and out of existence" with vacuum fluctuations... :cheers:

Edit: Corrected the wrong link

zaybu · **#16** by **zaybu** » Nov 22, 2011 9:19 pm

twistor59 wrote:

I suspect it's all just because 1) popular accounts tend to talk of virtual particles in this way, and 2) A lot of physics students graduate to QED directly from basic non-relativistic theory, and miss how a lot of the same formalism (e.g. path integrals, second quantization) is applicable to ordinary non-rel QM.

The authors look line the same as the ones whose paper was discussed in the Ratskep thread, so I assume the paper we were discussing there contains the essential information. Moreover it switches from virtual particle terminology in the intro to vacuum fluctuations in the text. No "particles flitting in and out of existence" with vacuum fluctuations...

But on the same http://physicsforums.com/showthread.php?t=552148, someone referred to t' Hooft paper in which he states that " virtual particles, particles that are annihilated very shortly after being created" to make the point that virtual particles are not to sneeze at. I think that people who don't like the word "virtual particles" love semantic wars!!! :cheers:

twistor59 · **#17** by **twistor59** » Nov 22, 2011 9:31 pm

zaybu wrote:
twistor59 wrote:

I suspect it's all just because 1) popular accounts tend to talk of virtual particles in this way, and 2) A lot of physics students graduate to QED directly from basic non-relativistic theory, and miss how a lot of the same formalism (e.g. path integrals, second quantization) is applicable to ordinary non-rel QM.

The authors look line the same as the ones whose paper was discussed in the Ratskep thread, so I assume the paper we were discussing there contains the essential information. Moreover it switches from virtual particle terminology in the intro to vacuum fluctuations in the text. No "particles flitting in and out of existence" with vacuum fluctuations...

But on the same http://physicsforums.com/showthread.php?t=552148, someone referred to t' Hooft paper in which he states that " virtual particles, particles that are annihilated very shortly after being created" to make the point that virtual particles are not to sneeze at. I think that people who don't like the word "virtual particles" love semantic wars!!!

Well there are certainly (at least) two viewpoints that people passionately defend. In the end it makes no difference, you get the same numbers out however you think of it....

LucidFlight · **#18** by **LucidFlight** » Nov 22, 2011 10:20 pm

cavarka9 wrote:And globe, a creationist would say that this is evidence for God, because who moved the first mirror!

They'll most likely use this to defend Genesis 1:3.

What Was that “Light” before the Sun (Genesis 1:3)?

“In Genesis 1:3, the Old Testament records that God said: ‘Let there be light.’ Since the sun, moon, and stars were not made until the fourth day (1:14-16), what was the nature of the ‘light’ mentioned in verse 3?”

The Bible student must deduce that the “light” of Genesis 1:3 was not that which subsequently (three days later) emanated from the sun, the moon, or the stars. The fiat of verse 14, “Let there be lights,” expresses the same sort of creative activity — out of nothing came something by the command of God — that is affirmed in verse 3.

[Article continues...]

LucidFlight · **#19** by **LucidFlight** » Nov 22, 2011 10:25 pm

Globe wrote:
Check my sig....

Every time something like this happens Globe Jr pesters me till I pay attention.

I think panicking has a k in it. I could be mistaken, though.

Doubtdispelled · **#20** by **Doubtdispelled** » Nov 22, 2011 10:42 pm

LucidFlight wrote:
Globe wrote:
Check my sig....

Every time something like this happens Globe Jr pesters me till I pay attention.

I think panicking has a k in it. I could be mistaken, though.

Pedant.