*arXiv*, how a more accurate nuclear clock might be devised.

While the atomic clock is based on vibrations of electrons orbiting an atom, the nuclear clock would instead be based on tuning the spatial orientation of electrons that cause the nucleus of an atom to jump back and forth between high and low energy states using a very specific frequency of light. The result, the researchers say, would be a clock tuned by a laser that would drift only about one second in 200 billion years, or 14 times the believed age of the universe and 60 times more accurate than current atomic clocks. The only trick here apparently, is in figuring out just what that frequency would be.

For most people, the accuracy of a clock isn’t really all that much of a big deal. For this reason something called Coordinated Universal Time (UTC) is used for ordinary living. It’s derived from atomic clock measurements but also uses leap seconds based on the rotation of the earth to help keep everyone straight. For other applications though, more accuracy is needed. GPS is one such example. Because there are four satellites used for GPS tracking, some means of timing their signals must be used to coordinate data sent from them and relayed to Earth based navigation systems. The smaller the errors in timing, the more accurate the systems become.

The main reason the nuclear clock would be so much more accurate than the atomic clock is due to the fact that atomic clocks are susceptible to ambient magnetic and electric fields that can throw off the vibrations of the electrons a tiny bit. Using a laser to precisely control the nucleus bouncing between states however would not be nearly as susceptible to such interference.

**Explore further:**
Portable Precision: A New Type of Atomic Clock

**More information:**
A Single-Ion Nuclear Clock for Metrology at the 19th Decimal Place, arXiv:1110.2490v1 [physics.atom-ph] arxiv.org/abs/1110.2490

**Abstract**

The 7.6(5) eV nuclear magnetic-dipole transition in a single 229Th3+ ion may provide the foundation for an optical clock of superb accuracy. A virtual clock transition composed of stretched states within the 5F5/2 electronic ground level of both nuclear ground and isomeric manifolds is proposed. It is shown to offer unprecedented systematic shift suppression, allowing for clock performance with a total fractional inaccuracy approaching 1 x 10^-19.

via Newscientist

## antialias_physorg

Only if you believe in Zeno's paradox (specifically the one about Achilles and the tortoise)

## antialias_physorg

And no matter what type of cardinality you use: The length of an item doesn't change no matter how you subdivide it

(Only if you get to the point where the definition of length becomes iffy - but that doesn't change the length per se, only the applicability of the definition of the term)

## Nik_2213

## Chef

Heafty, Heafty, Heafty!

It would be interesting in how such Laser would be built that would keep a perfect frequency over time.

## antialias_physorg

By changing the units you use the length doesn't change. What are you on (about)?

## antialias_physorg

Reality, however, is not infinitely fractal.

And time, in particular, doesn't seem to be fractal at all since it is one dimension. For fractals you need at least two.

## antialias_physorg

Planck length (and by extension Planck time) takes a good stab at this. At least anything below those measures seems to be indistinguishable and hence assigning it a distinction (as having individual times/locations) seems meaningless.

With a finite number of quanta in this universe (including virtual particle pairs) there can also only be a finite number of interactions/state changes. So this already puts a large (but not infinite) upper bound on the number of locations/times that can exist.

As long as there are no infinities we won't have any infinitely fractal entities (and even if infinities existed fractal entities would not necessarily be a direct result of these).

With a fractal less than one you would notget infinite lengths but a length approaching zero (i.e. again a finite length)

## antialias_physorg

So a length on a fractal line with dimensionality of less than one between, lets say, one (at full dimensionality one - i.e. an unbroken line) and zero (at full dimensionality zero - i.e. a fully pointed line) can be infinite?

That's a bit of a bold statement. Care to explain (please include some sort of mathematically rigorous proof. I'm pretty sure I can follow it)

## rawa1

http://www.nature...64a.html

From perspective of dense aether model the determinism of observable reality goes through maximum at the middle of observational scale both bellow, both above the human observer scale, which is the domain of quantum electrodynamics and general relativity. Outside these scales the determinism of observable reality decreases, which explains, why the nearby reality is as complex and indeterministic, like the universe at Planck or cosmological scales.

## hyongx

High quality lasers can be functionally monochromatic, that is, tuned to a single wavelength, to within an acceptable margin.

However, in this application, it is not the laser that is the source of the frequency - unit of time measurement. The system establishes only one accessible energy transition of the nucleus of the atom(s), and the energy released when the nucleus undergoes this specific transition is an absolute, always constant. basically, E=hv provides the frequency measurement that is the time constant.

## antialias_physorg

Sure:

Hypothesis: An infinite fractal universe exists.

1) A fractal level requires at least one state to represent it (otherwise one could not say whether that particular fractal depth existed or not).

2) The universe only has a finite amount of states (as explained before)

Conclusion: 1), in conjunction with the hypothesis, contradicts 2) (as an infinite fractal universe would require an infinite number of states for representation)

Therefore the hypothesis cannot be true.

Q.E.D.

Your turn.

## antialias_physorg

Since the universe has a finite age and a finite extent - and the energy density in a given volume of space isn't infinite (or we'd have a universe full of infinitely attractive black holes at every point) - how can you argue otherwise?

So are you going to caugh up on the proof that fractals with fractal dimension less than one can have infinite length?

## hyongx

I'm not sure if I agree that there are finite possible states in the universe, esp with probabilistic limits probed by QM. Given that a mathematical infinity can exist in 2-d, I find it highly believable that some ininity could exist in 3-4D in our universe.

I don't know what the 'dense aether' model is, but I agree that, from our human perspective, we like to beleive in a causal-deterministic universe, while physics describing other scales implies the possibility of some non-determinisitc properties. Unfortunately, all to often, people assume science theory=>reality

## hyongx

Ex: delta function. The delta function has a basically infinite value, but the integral over the function is finite (1). It's a mathematical concept, but basically i don't agree that an finite-extent and energy-density argument necesarily requires a finite number of possibles states. Quantum mechanics, and QED, "the jewel of physics" making some of the most accurate predictions of any theory, posits that systems can exist in superpositions of states. I.e., not in a single discrete state.

## daywalk3r

the whole Planck units concept is based on the apparent limits of energy propagation as viewed from our extrinsic perspective. However, despite the validity of energy quanta (and the hoards of die-hard QM "discretists" who would like you to believe otherwise), it doesn't really rule out sub-planck "reality" per se.

In other words, Planck units do not necessarily define the physical limits of reality, but they sure define the theoretical limits of QM.

You also outline some assumptions..

That Planck length/time is an absolute/discrete description of reality. That there is an absolute finite amount of quanta in the Universe. Didn't know those were allready considered hard facts nowadays..

From a proponent of discrete QM & finite Universe, that stance is quite expected & understandable though. Only time will tell who was right..

And hush has a point there..

If the "resolution" of reality is infinite, then all is only a matter of perspective. Fractal or not.

## daywalk3r

Finite age? Finite extent? :-O

Seem you have eaten the apple from the tree of knowledge allready :-)

And the energy density in a given (finite) volume of space is allways finite. But that has nothing to say about a fractal (and infinite) nature of the Universe, as no matter how many times you fractionate a finite amount, the total (energy density) remains unchanged..

Got a question for you though.. What was before the "Big Bang"? And what was before that what was before? :-)

## Callippo

This model is infinite-dimensional but it can be modeled in 3D with dispersion of surface ripples at the water surface. We people are corresponding the most complex and deterministic solitons at the 1.74 cm scale of wavelength, which are moving in lowest speed at the water surface, so that the neighboring Universe appears as large, as possible for us. With decreasing wavelength the spreading of surface ripples becomes indeterministic because of Brownian noise - it corresponds the quantum scale. With increasing wavelength the spreading of ripples becomes driven with surface tension and the influence of underwater is minimized. It corresponds the realm of general relativity.

## Callippo

## Callippo

The same dependency, just in dual way is valid for cosmological clocks, like the Cepheids and pulsars. Too large variable stars are too irregular, whereas these too small ones are affected with neighboring objects too much.

## daywalk3r

Stop right there Sherlock..

When something drops bellow an observers sensitivity/resolution scope, it does NOT become indeterministic, just indeterminable (for the observer).

Those two terms sport a quite fundamental difference..

True, because the wavelength of the "macroscopic phenomena" would be too big to affect the clocks "gears" separately (e.g. affecting gear#1 differently than gear#2, and so on..) So the clocks tick away without disruption, as there is no distinct macro-induced change happening "inside".

Unless by "quantum foam" you also infer "a truely random process", I have to call BS on that :)

## Callippo

http://www.nature...120.html

Is the quantum mechanics indeterministic or just indeterminable after then?

Analogously, the remote Universe appears indeterministic in visible light, but it could appear quite deterministic in neutrino or gravitational waves detectors. Such detectors could even render the event horizons of black holes partially transparent.

## Callippo

After all, many of my insights appear like random babbling for the other people, because they're not aware of the evidence which I'm using for their reasoning. If they would increase the scope of their capabilities, they would recognize the same stuff like me quite clearly.

## hyongx

I don't know what antelopes on Neptune are doing, but you probably have some good points in there somewhere. Like, what appears to us as indeterminacy is only because of the limitations of our measuring instruments, or perception. Regardless of the validity of that point, I'm a holdout for indeterminacy, because I like free will. :/

## Au-Pu

Nuclear/atomic. They are the same.

All they are proposing is a different method of measurement.

## rwinners

## Ensa

It is a common misconception that free-will is more compatible with indeterminacy than erm... determinacy.

Indeterministic free will would mean your actions would have no consequences. This is not what we intend when we assert free will.

Deterministic free will means your choices are determined by their causes. While we like to think our choices are 'informed' by our circumstances, we deny they are determined by them.

The 'reality' is that it is not sufficient to assume that free will is 'indeterministic' friendly.

Personally, although I rarely post, I love following these interactions between the physorg regulars. There is a congruence of unrecognized genius and insight here, that for some reason I rarely see on the internet in general. Also a lot of people willing to unashamedly expose their smaller conceptual, spheres to the community for comparison, Or perhaps I don't intersect many of their dimensions.

## rwinners

## hyongx

Hmmm...

Without free will, the result of a choice is determined before we make that choice.

Let's say I have a quantum system, which can assume one of two states, and i can measure it (make a decision). The measurement collapses the wavefunction and the system assumes a discrete state.

I have a system in an undetermined state.

P=>Q I perform a measurement (choice) => reveals a discrete state.

Q=/=>P I measured a discrete state =/=> the state was determined before i measured (chose).

A choice (performing measurement) necessarily requires a system adopts a state. However, the result of the choice (measurement) is not determined before the action.

So choices have consequences, but consequences are not neccessarily predetermined.

Now whether quantum uncertainty translates to macroscopic world is a different beast entirely.

## Callippo

## gwrede

I see two writers filling this thread with 1/5 rated posts. I'm starting to see why the rank filter exists. Shame, though, because sometimes some valuable posts are not understood by readers, and then get bad votes. Oh well, I guess there are two sides to everything.

But constantly getting no other votes than 1/5 at all, should make one wonder whether posting here is only embarrassing.

## MorituriMax

2 2=4, "interpret" that. Is it anything other than 4 no matter how you "interpret" it?

## MorituriMax

So stop posting stupid shit. Problem solved. And stroking your ego by assuming one person is rating you is what really hilights that it IS stupid ego based BS.

earlier 2 2=4 should be 2 PLUS 2=4, stupid physorg filter.