back to article The secrets of spacetime revealed - on your workbench!

Laser source? Check. Lenses? Check. A suspended block of glass? Check. A single-photon detector? Check. Supercooling apparatus? Check. Congratulations: put that kit together, and you might be able to help resolve some of the most fundamental questions of quantum physics. OK, it might not be within reach of the backyard scientist …

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Bronze badge

Third paragraph, I think you missed the name of the "American theoretical physicist". A quick Google also suggests you're a few years out with the date.

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John Wheeler in 1955

The missing theoretical physicist is John Wheeler.

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(Written by Reg staff)

Re: John Wheeler in 1955

Thanks both, John Wheeler - 1955 - added!

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Silver badge

I'm having problems understanding this

"Photons interact poorly with matter – but they do interact. If the photon moves the block by more than the Planck distance (1.616199 × 10-35 meters), it will pass through."

If the photon passes through, surely it has not interacted with the matter of the block and so will not move the block?

If the photon is reflected or its path deviated by interaction with the block, resulting in movement of the block (which I assume is suspended and free to swing), how can such a small movement be detected? Does the detection rely on a build up, over time, of a 'classical' wave interference pattern? If so, surely the wavelength of any photon we can produce would be far too large to be effective in detecting such a small movement?

I'm lost here.

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Silver badge

It's Quantum

If you weren't lost or weren't having problems, then I'd say you were lying!

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Anonymous Coward

Re: I'm having problems understanding this

"Bootnote: As an aside, the experiment takes advantage of yet another bit of quantum strangeness. It proposes using a single photon – but the lenses I mentioned at the top are designed to focus the light wave so that it’s the same size as the block. Wave-particle duality in practice! ®"

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Bronze badge

Re: I'm having problems understanding this

Just thinking about the change in the photon's momentum as the refractive index changes had me stuck for a while. It turns out the there are two sorts of momentum, details being rather well explained here:

http://rsta.royalsocietypublishing.org/content/368/1914/927.full

As to detection of Planck space, I can't see how the block would move significantly before the photon had left. The compression wave from the incident photon's momentum transfer would only have transferred momentum to first few layers of atoms during the time that the photon was in the block, and the rear face wouldn't have even begun to move when the photon left.

But after the Royal Society paper I need a large cup of tea.

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Surely shome mishtake?

"As an aside, the experiment takes advantage of yet another bit of quantum strangeness. It proposes using a single photon – but the lenses I mentioned at the top are designed to focus the light wave so that it’s the same size as the block. Wave-particle duality in practice!"

Erm... isn't strangeness a property of quarks? How can a photon exhibit strangeness? Careful with the terminology now....

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Gold badge
Coat

Is anyone reminded of Charles L. Harness's story "The Rose"?

Just a thought.

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Headmaster

Derp!

> Berkenstein

Evidently a spelling mistake, but still. This is the Beckenstein from the "Bekenstein-Hawking black hole entropy", evidently.

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Silver badge
Headmaster

I hope I got this right.

"As an aside, the experiment takes advantage of yet another bit of quantum strangeness. It proposes using a single photon – but the lenses I mentioned at the top are designed to focus the light wave so that it’s the same size as the block. Wave-particle duality in practice!"

Of course!

In the excellent Feynman approach, the single photon probes/traverses all possible paths through the universe (even those that need FTL) from the point of emission to the point of absorbtion. Adding the relative phases for each path ("integrating" the relative phase over all possible paths, though this is not your standard integration at all) yields that photon detection at the lens focus is highly probable, as classically expected. If you increase Heisenberg's constant, the locus of detection becomes fuzzier, if you decrease it towards 0, it becomes sharper. Very nice! This is not very mathematically rigorous (the mathematics are still considered dodgy in 2012) and I am unsure whether it can be applied to all systems but at least it gives you a good algorithm to think by. Which is all that "understanding" really is.

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I don't believe in much, neither that this experiment will hold.

I don't think the qualities required for The Higgs particle to explain the standard model is there, and I don't think they will be found.

Neither do I think, that supersymmetry will be recognized in futuristic science.

I know I am a pain in the butt, but I believe in a complete different approach to high energy physics in the future. My vision is that future science will engulf consciousness. The mind and the spirit will be explainable through physics.

I have been a fan of Sir Roger Penrose for many years. He was the first scientist to say that consciousness should be found in the quantum field rather than in the brain. I am so much a fan, that I made my own theory out of the idea that consciousness might be explained through a better understanding of antimatter and multiverse dimensions.

My idea is that antimatter is the mirror of this universe, and that antimatter might be where memory is located.

I think that the subconscious mind and consciousness are located in multiverse dimensions in the form of antimatter.

The original standard model predicted no mass at all. That made no sence to scientists, so Peter Higgs predicted The Higgs Boson, purely from mathematics. I think the original standard model was right, particles does not exist. The physical universe is a flow of energy from minus infinite energy to plus infinite energy.

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FAIL

I just don't know where to start...

Fook it, you are a nutter and you are wrong.

There, nuff said.

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Anonymous Coward

Do not mock. That's probably Republican science. The other stuff will be cancelled to fund the tax cuts.

I'm pretty sure that during the US election Romney's recollection of what he last thought was stored in antimatter.

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Bronze badge
Holmes

Just a thought

But if you had a time dilation machine surely the photon could pass through the area in question using a time dimensional shift.

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