Scientists create light from a pure vacuum

[Analog]

Scientists at Chalmers University of Technology have succeeded in creating light from vacuum – observing an effect first predicted over 40 years ago. The results will be published tomorrow (Wednesday) in the journal Nature. In an innovative experiment, the scientists have managed to capture some of the photons that are constantly appearing and disappearing in the vacuum.

The experiment is based on one of the most counterintuitive, yet, one of the most important principles in quantum mechanics: that vacuum is by no means empty nothingness. In fact, the vacuum is full of various particles that are continuously fluctuating in and out of existence. They appear, exist for a brief moment and then disappear again. Since their existence is so fleeting, they are usually referred to as virtual particles.
Chalmers scientist, Christopher Wilson and his co-workers have succeeded in getting photons to leave their virtual state and become real photons, i.e. measurable light. The physicist Moore predicted way back in 1970 that this should happen if the virtual photons are allowed to bounce off a mirror that is moving at a speed that is almost as high as the speed of light. The phenomenon, known as the dynamical Casimir effect, has now been observed for the first time in a brilliant experiment conducted by the Chalmers scientists.
“Since it’s not possible to get a mirror to move fast enough, we’ve developed another method for achieving the same effect,” explains Per Delsing, Professor of Experimental Physics at Chalmers. “Instead of varying the physical distance to a mirror, we've varied the electrical distance to an electrical short circuit that acts as a mirror for microwaves.
The “mirror” consists of a quantum electronic component referred to as a SQUID (Superconducting quantum interference device), which is extremely sensitive to magnetic fields. By changing the direction of the magnetic field several billions of times a second the scientists were able to make the “mirror” vibrate at a speed of up to 25 percent of the speed of light.
“The result was that photons appeared in pairs from the vacuum, which we were able to measure in the form of microwave radiation,” says Per Delsing. “We were also able to establish that the radiation had precisely the same properties that quantum theory says it should have when photons appear in pairs in this way.”


http://www.physorg.com/news/2011-11-scientists-vacuum.html

 

[blackdogdeek]

holy crap that's crazy

 

[SlitheryDee]

I'm always happy when a theory is proven through experimentation, but I had another thought as well. Can this be used as an energy source, or is it one of those situations where you'll always use up at least the same amount of energy to make it happen?

 

[SunnyD]

I'm always happy when a theory is proven through experimentation, but I had another thought as well. Can this be used as an energy source, or is it one of those situations where you'll always use up at least the same amount of energy to make it happen?

Zero-Point energy? Yes. Do we have the technology to make it happen? (figuratively) Not in a million years.

My question is how can they be certain that it wasn't the particles of the SQUID being vibrated so fast that they weren't the ones emitting the photons?

 

[Ninjahedge]

I wonder what the rout of this virtuality is.

Is it really quantum physics and the fact that things like Electrons are not really in any one place or another, but simply in a "probable" place or time 9but not both)....


Or is this more along the line of the wave/particle duality of light and the curious time-independent rules it has in regards to interaction (such as the banding effect when released either in mass quantities, or one at a time, through a "slit"... i always found that mind bending...).

Our own perception of "time" may just be a chemical illusion brought to us by our own cascading cause-and-effect relations to the particles around us...


My head hurts...

 

[Born2bwire]

I'm always happy when a theory is proven through experimentation, but I had another thought as well. Can this be used as an energy source, or is it one of those situations where you'll always use up at least the same amount of energy to make it happen?

No. The Casimir force is an extension to the van der Waals forces. Think of it like a force like gravity. When you do work to separate objects, you inject work into the system and you get the same amount of work back out if you allow the objects to return to their original positions.

I wonder what the rout of this virtuality is.

Is it really quantum physics and the fact that things like Electrons are not really in any one place or another, but simply in a "probable" place or time 9but not both)....


Or is this more along the line of the wave/particle duality of light and the curious time-independent rules it has in regards to interaction (such as the banding effect when released either in mass quantities, or one at a time, through a "slit"... i always found that mind bending...).

Our own perception of "time" may just be a chemical illusion brought to us by our own cascading cause-and-effect relations to the particles around us...


My head hurts...

More or less, virtual particles are mathematical constructs in one formulation of quantum field theory. You can think of them as being analogous to energy fluctuations in the vacuum energy that occur due to the Heisenberg Uncertainty Principle. If the fluctuations are large enough, a particle-anti particle pair is produced but to preserve energy conservation the pair must annihilate eachother after an incredibly small amount of energy. Still, this is just an analog to the mathematics that is being used to describe these processes. You do not need virtual particles for QFT, including the Casimir Force (Jaffe has a paper on this for those that are interested). But virtual particles act as a nice mnemonic for ease of calculation.

 

[JTsyo]

Photons have no mass so conservation mass is OK but there's still conservation or energy and momentum. Are these particles appearing from no where or do they exists elsewhere?

Any mention on how long the virtual particles exist for?

 

[Born2bwire]

Photons have no mass so conservation mass is OK but there's still conservation or energy and momentum. Are these particles appearing from no where or do they exists elsewhere?

Any mention on how long the virtual particles exist for?

They don't last. If they did, then they would be real (haha, they're virtual as long as they aren't real...). You could think of them as very momentarily popping in and out of the vacuum due to the energy fluctuations. Over a very small time period, the energy fluctuations can be large enough that there is enough energy to create a photon pair. Then, this pair annihilates itself. So the net energy does not change across this event but the presence of these virtual photons does affect the environment.

In the case of the Casimir force (though I am more familiar with the static version), the virtual photons are a way of describing the fluctuating electromagnetic fields of the vacuum. One can represent these fields as virtual photons that are popping in and out that create the associated fields.

 

[Jeff7]

I wonder what the rout of this virtuality is.

Is it really quantum physics and the fact that things like Electrons are not really in any one place or another, but simply in a "probable" place or time 9but not both)....
...

Some guy on the other side of the galaxy is wondering why his microwave isn't heating up his Hot Pockets anymore.

Stealin ur microwave photons.

 

[Analog]

This should help bolster Hawking's black hole radiation theory.

 

[911paramedic]

Some guy on the other side of the galaxy is wondering why his microwave isn't heating up his Hot Pockets anymore.

Stealin ur microwave photons.

With my SQUID.

 

[DrPizza]

This should help bolster Hawking's black hole radiation theory.

First thing I thought of when reading one of the other posts in this thread.

 

[DesiPower]

So we can have light and hence energy from vacuum? nothing?? a perpetual machine??? wow!!!

 

[zoiks]

What kind did he use. Dyson?

 

[Analog]

First thing I thought of when reading one of the other posts in this thread.

yes, making virtual particles real. And I thought we needed to go to a black hole to find out if it was possible. Wow!

 

[bfdd]

Didn't Tesla theorize on creating any particle out of "thin air" with enough energy? This experiment sounds a lot like what Tesla claimed to be possible before people were even really talking about Quantum this or that.

 

[maniacalpha1-1]

So how many of us say ZPM and how many ZedPM?

Also, does it have to be a vacuum for this to happen or do these particles appear in an atmosphere or even solid earth and just don't get noticed?

 

[SunnyD]

So how many of us say ZPM and how many ZedPM?

Also, does it have to be a vacuum for this to happen or do these particles appear in an atmosphere or even solid earth and just don't get noticed?

I'm not Canadian, so ZPM.

Also, theoretically it should be able to occur anywhere. Even with solids, there's plenty of "empty" space between atoms and subatomic particles. Odds are the physics of it will be somewhat different because of the proximity to other forces though.

I mean honestly, what's stopping all matter from not simply being these virtual particles, just combined with some sort of localized stabilizing force keeping them from "evaporating"?

 

[snowridge]

A theory is only a theory until you become a God.

 

[maniacalpha1-1]

I'm not Canadian, so ZPM.

Also, theoretically it should be able to occur anywhere. Even with solids, there's plenty of "empty" space between atoms and subatomic particles. Odds are the physics of it will be somewhat different because of the proximity to other forces though.

I mean honestly, what's stopping all matter from not simply being these virtual particles, just combined with some sort of localized stabilizing force keeping them from "evaporating"?

Another thing...are photons the only particles that appear, or is it simply that photons are the only thing they were able to to capture? What about electrons and whatever are the component particles of protons and neutrons? The article only refers to photons, and I'm hardly interested enough to go researching it lol...

And more importantly...is it only photons etc or also antiphotons etc that blink into existence? Surely that would be one way to create zero point energy...matter/antimatter reactions.

Or even if it is only normal and not antiparticles, if we could manufacture antimatter and simply put a certain quantity of it in a vacuum unit, enough to react with these particles but not enough that it's no longer a vacuum...

 

[snowridge]

How can a matter blink out of existence. Isn't it that the matter just happens to not be detectable by us rather than that they disappear out of thin air?

 

[Analog]

How can a matter blink out of existence. Isn't it that the matter just happens to not be detectable by us rather than that they disappear out of thin air?

The whole point is that vacuum is not empty. There are quantum fluctuations that are happening all the time. These virtual particles pop into existence then annihilate and pop back out of existence - thus a vacuum is really not empty. Hawking said that if such particles popped into existence right on the edge of a black hole's event horizon, then one particle would be absorbed by the black hole, while the other would escape, thus nullifying their ability to annihilate. The one sucked in would then annihilate a particle inside the black hole, while the other would radiate away (Hawking Radiation). This lends credence to his theory that an isolated black hole could eventually evaporate by this process...

 

[bfdd]

mania, they should be able to create any particle given sufficient energy.

 

[crownjules]

So how close are we now to having replicators? Sometimes I really just don't want to put in all the time and effort in cooking.

 

[Analog]

So how close are we now to having replicators? Sometimes I really just don't want to put in all the time and effort in cooking.

be careful, this might happen: