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back to article Berkeley Lab proposes 4D clock

It’s not quite a perpetual motion machine: scientists at the US Lawrence Berkeley National Laboratory have proposed a design for a timing crystal they say would theoretically outlast the universe. In this paper, published on Arxiv, the researchers propose a design for "a 4D crystal that has periodic structures in both space and …

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Ours is an essentially infinite universe

And in such a universe, it's almost certain that these entities have already arisen by chance. One may just have to look very hard to find them- I can imagine a cloud of these somewhere in interstellar or intergalactic space.

If they emit no energy, so as to not break the laws of thermodynamics*, how does one use them as a crystal? Currently crystals are used by energising them and allowing them to oscillate, but they do emit energy.

* The Laws Of Thermodynamics, to wit:

Law 1: You can't win, you can only break even.

Law 2: You can only break even at absolute zero.

Law 3: You can't reach absolute zero.

Law 0: You must play the game at all times.

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Pint

Re: Ours is an essentially infinite universe

Thank you Jonski for restating those Laws. I'd forgotten them even as I obey them.

As you age, you realize you are not perpetual, nor infinite. However a pint does remove the sting of realization.

"Malt does more than Milton can

To justify God's ways to man."

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Happy

Ah, but can it re-sharpen razor blades as well as keep time?

"a spatial ring of trapped ions in persistent rotation will periodically reproduce itself in time, forming a temporal analog of an ordinary spatial crystal. With a periodic structure in both space and time, the result is a space-time crystal."

Sorry I could not resist that. It is in fact a very interesting concept, it is just that the description had a certain "new age" ring to it.

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Headmaster

"how does one use them as a crystal?"

I think that part of the conundrum is explained in this paragraph:

"However, there’s an escape clause at the quantum level: the ions can be given a push with a weak magnetic field, to get them rotating, and since they lose no energy to the outside world, that rotation should continue forever – even, according to research leader Xiang Zhang, after the “heat death” of the universe. And since there is no energy output from the crystal, it doesn’t break the rules to offer a perpetual motion machine."

However, what is not clear to me is how one is meant to "read" this clock. The action in so doing would surely impart energy to the system, a sort of "observer effect"? If by observing one imparts energy to the system is it not then above the zero state referred in the article? It is of course highly likely that I am missing something here because this is not my field. Is there a physicist in the house?

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Re: "how does one use them as a crystal?"

If there are enough ions in the ring, you can read the ion positions without exciting the ring into a higher state, using laser pulses. The more ions there are, the greater the perturbation it can tolerate. However, a nonzero temperature does cause the "clock" to slow down. It's all in the paper.

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Re: "how does one use them as a crystal?"

And what about quantum effects (quantum fluctuations, virtual particles, tunneling particles, etc) that make a closed system impossible in our universe? Wouldn't they eventually cause the system to go into a higher state like the inflaton field did during the start of the big bang?

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Re: "how does one use them as a crystal?"

Reminds me of the early 20th solution of how to synchronise mechanical slave clocks from the finely tuned master. Instead of a mechanical pick-up they had a slot on the pendulum through which a light shone. This nominally frictionless method created an electrical sine wave on a detector.

The same reference book concludes with a chapter on "Quartz Crystal Clocks":

"But I see no prospect of a popular domestic clock in a quartz crystal. [...] This is of enormous value to science and I see no objection to leaving it alone to fulfil its lofty functions which seem to me to be its true destiny. It would be an impertinence for a clockmaker to covet it and attempt to harness it to his mundane purposes."

"Electrical Timekeeping" by Frank Hope Jones published 1949 - facsimile reprint 1976.

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@Tim Starling Re: "If there are enough ions in the ring"

Thank you - :)

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why does it does it remind me of a clock on the disc world!?

Everything was fine, but then the administrator moved in.

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kbb

Ions in the ring, tra la-la la-la.

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Oh, but

Show me your motion, tra la la la la la

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Interesting mathmatics, but not a practical clock.

Heisenburg says no.

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Anonymous Coward

Re: Interesting mathmatics, but not a practical clock.

"When an old man says something can be done he is probably right.

When an old man says something can not be done he is probably wrong"

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Boffin

Sounds familiar...

"...particles of the same charge in space using an electrical field. Their Coulomb repulsion forces them into a ring configuration, at their lowest possible energy state."

Sounds just like any (filled) electron orbital around any atom, only with ions in place of electrons.

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Mushroom

And we shall call our new creation...

Dilithium.

Star Trek FTW

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multipole energy loss

because these are ions in a ring they have a multipole moment, like dipole but higher order, lets say 12-pole for 12 atoms. This will radiate electromagnetic energy as the ring rotates, you could pick-up a signal much as the way a gear-tooth magnetic sensor does in your car. You can detect the rotation, hence energy is being lost, and it will slow down to a stop.

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Re: multipole energy loss

Like the paper says, there is no radiation because the ring is already in its ground state. It's like an atom, where the electrons can orbit without radiating.

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Zyton Crystals

Do they go whoomph whoomph whoomph though? They're not proper time crystals if they don't and no self-respecting time lord would touch them with a ten foot hand of Omega.

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Perpetual motion machine

I'd also like to point out that there's nothing in the laws of physics that forbid perpetual motion. They just forbid perpetual motion machines. A machine does work. A spinning mass in isolation from anything else cannot do any work, therefore it could keep spinning forever. However it wouldn't be a machine because it couldn't do work. As soon as the system starts interacting with something else it could be put to work, but its energy would be dissipated in the process.

Spinning forever? Quite possible. Perpetual motion machines? Not so much.

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Alien

Gene Ray has been on this shit for years

Earth body 4 corner time equals 4 leg mobility. Your ignorance of Harmonic Cube is demonic.

http://en.wikipedia.org/wiki/Time_Cube

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Re: Gene Ray has been on this shit for years

The incomprehensible Time Cube!

I thought the internet forgot this nonsense.

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Coat

Cork hats for sale

Procrastinator run-time at competitive rates.

mine's the one next to the broom

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Go

I want one before Apple sue them for having curved corners on time!

Or should that be Swiss Railways?

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Soooo....

This ion structure would presumably be used to replace the current Atomic Clocks and would regulate the setting of "normal" clocks around the world, right?

One (ion) ring to rule them all?

Mine's the one with the various circular bands in the pockets.

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Anonymous Coward

this reminds me of two things

The first is something I read somewhere, somewhen about using the Casimir force at ever-decreasing scale as a method of tapping into the zero point potential.

The second, which is probably quite closely related and maybe inspired by it, is Greg Egan's The Planck Dive [sic] where a group of astronauts facing a kind of entropy death aim to get around the problem by transferring themselves into self-replicating nano machines and firing themselves at a black hole's event horizon. The idea being that relative time slows down enough for them that they can construct a new shell slightly closer to the event horizon and transfer their conciousness into it further down into it so that even in an (absolute) finite time they still experience (relative) immorality.

Both stories wilfully ignore the fact that even though zero point energy might be infinite, the usable energy approaches zero. Planck scale and all that. No perperpetual motion today, then (or yesterday, or whenever).

But what does it all mean, Jimmy? Fucked if I know, Terry.

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Happy

Re: this reminds me of two things

...'they still experience (relative) immorality' - incest Down Below?

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Happy

Infinity is a very long time indeed

The authors do assume the nuclei have infinite life span. This might not be correct. And anyway, some klutz in a lab coat is bound to drop it at some point (he might even be called Ponder Stibbons).

Interesting work, otherwise

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