Physicists Find That As Clocks Get More Precise, Time Gets More Fuzzy (sciencealert.com)

Physicists "have combined two grand theories of physics to conclude not only is time not universally consistent, any clock we use to measure it will blur the flow of time in its surrounding space." An anonymous reader quotes ScienceAlert: A team of physicists from the University of Vienna and the Austrian Academy of Sciences have applied quantum mechanics and general relativity to argue that increasing the precision of measurements on clocks in the same space also increases their warping of time... [W]hile the theories are both supported by experiments, they usually don't play well together, forcing physicists to consider a new theory that will allow them both to be correct at the same time...

In this case, the physicists hypothesized the act of measuring time in greater detail requires the possibility of increasing amounts of energy, in turn making measurements in the immediate neighborhood of any time-keeping devices less precise. "Our findings suggest that we need to re-examine our ideas about the nature of time when both quantum mechanics and general relativity are taken into account," says researcher Esteban Castro.
The article opens with the statement that "time is weird," noting that despite our own human-centric expectations, "the Universe doesn't have a master clock to run by."

Comments

It's all a simulation

[goombah99]

The think about time is we have no idea how long it really takes to go one second in the simulation we all live inside of. It could be years on the wall clock in the simulators universe.

Re:It's all a simulation

[goombah99]

It's interesting that all the funny bits of quantum theory and relativity and light are infact identical to what you would expect to be the rules of any simulation.

For example, if you aren't looking at something in a video game it doesn't get rendered, ergo schrodingers cat like phenomena. The moon in fact is not there if you don't look at it.

Bells theorem rules out local hidden variables (that is variables that are in the game but are not coupled to you the observer) but it allows global hidden variables to explain all spooky action at a distance by means other that quantum entanglement. that is to say it's what should happen in any simulation in which you are part of the simulation too.

diffraction and the heisenberg uncertainy relationships come from discrete binning. For example, in a pixelated universe you can'e actually resolve angles of far away objects since they are pixelated. hence there's a direction-position uncertainty.

Likewise the more finely you allow a simulation to measure time the more finely you have to bin or divide the external clock requiring more energy.

Re:It's all a simulation

[fahrbot-bot]

I suspect it's the other way around: simulations look like the universe because the simulations are confined to the universe.

Or contained within a box, including the box itself.

Re:It's all a simulation

[fahrbot-bot]

... the tank rotated every few minutes on top of the 11.57 microradians/second rotation of the Earth.

Or, at least, in oscillating directions tangent to the surface of the Earth.

Re: It's all a simulation

[hackwrench]

There is no canonical universe to which all others are a simulation.

Re:It's all a simulation

[Greyfox]

Yes! And time is so problematic because the simulation is being run on a massively parallel system. While each processor is able to handle the physics and timing of a small area reasonably well, keeping time synchronized for the entire universe would slow the entire thing down far too much. Moreover, since the project was designed as a simple demonstration of how to convert hydrogen to plutonium over time, making an effort to do so was deemed unnecessary. We also had a problem with some particles being uninitialized upon creation and going off at a very high velocity, so the top speed in this particular universe simulation was capped to prevent anything too untoward from happening.

The simulation has been running reasonably well for the amount of effort put into it, although there are still some issues of localized processors crashing when mass values in specific locations go too high, and some number of processors have been having to synchronize their timing signals across boundaries for reasons we do not currently understand. There is also the minor issue that eventually the plutonium degrades back to hydrogen, along with everything else, but we had no intention of ever allowing the simulation to run that long anyway.

Re:It's all a simulation

[wonkey_monkey]

Another thing I read mentioned that the size of the estimated universe (they provided some math which I don't recall) would actually fit almost exactly into a 64 bit unsigned integer for X,Y,Z.

Measured in what units?

You see?

[Jawnn]

Yet another example of how science can't prove anything. No, wait. This is another example of how the science lobby is trying to protect their jobs by, you know, doing experiments and shit, and trying to understand how stuff works.

Re:You see?

[bugs2squash]

And yet I see among the first reactions to us having put misogynists and racists into power is "this is not who we are". Turns out it is who we are, we need to own it and find a way to collectively become better people.

Re:You see?

[Anonymous Coward]

When Obama mocked climate skeptics as the "flat earth society", he was correct. Only one in four people in the US are solid skeptics (and the US has by far the highest percentage of skeptics of any country in the world). AGW has scientific consensus and is not controversial outside of the US. The US population has by far been subjected to the most propaganda and lobbying by oil and coal companies, which neatly explains why such a high percentage of the general public beliefs on the subject contrary to the science. The US is also unique in having high numbers of believers in other fringe/lunatic conspiracy theories like alien rods, faked moon landing and yes, flat earthers. The analogy was spot on.

When he had the insight to to say that small towns overlooked by the government where jobs had not been created turned to guns and religion, he was correct. You're taking someone trying to understand their problems and turn it into an insult. When he spoke about small towns, does that figure sum to include even a fraction of the population of the US? Of course not.

When Clinton insulted (yes, she insulted) half of the Trump voting base, was that half the country? No, less than a third of the US voted for Trump (most people, in fact, did not vote), so that would make it... around 1/6th, give or take. Are they proud to live up to that name? Yes.

After Trump has finished insulting every other nation on the planet, how much support do you think the US now has amongst even its closest allies? Whether it is apt or not, most countries are seeing a huge increase in curiosity and questions regarding the last days of the German Weimar Republic, there's a horrible "wait and see" attitude to see if sane Republicans can ditch Trump and his utterly insane inner circle before the US becomes an enemy to the free world.

Spare us the Red vs Blue US political idiocy, nobody cares about an ex-US president, or a former candidate. They care about what is going on right now.

never

[Anonymous Coward]

Is when I'll have time to give a shit about this.

Re:never

[hey!]

You must mean approximately never.

Re:never

[sims 2]

What about the nice new ads that cover half the page?

If I wasn't using adblock before I sure would be now.

Re:Heisenberg uncertainty?

[goombah99]

this is the "usual" Time-Frequency uncertainty. Frequency relates to energy by the plank constant. hence there is a time-energy uncertainty.

Re:Is there a thing called time?

[david_bonn]

I suspect strongly that the universe does have a clock.

Consider the Cosmic Microwave Background. The average temperature of the CMB is a function of the age of the universe, and should be pretty close to the same for any given reference point. Yes, I'd agree it isn't a very accurate clock, but it is indeed a clock.

Similar arguments work with the distance to the cosmic horizon.

Hmm...

[Whooty McWhooface]

So if their clock turns out not to be accurate. it's the universe's fault?

It's a poor scientist who blames the universe for their shortcomings.

Re:Hmm...

[Anonymous Coward]

Or it's Heisenberg up to his usual antics. Time and energy appear as conjugate variables in the quantum wave function solution to the Schroedinger equation for an oscillator (like a ticking clock), so the precision of your clock (delta-t) is inversely proportional to the precision of your energy measurement (delta-E), in the same way that the precision of position and momentum measurements are limited by the uncertainty principle.

Energy curves its surrounding space under General Relativity. This would imply energy of whatever system does the ticking in your clock is constantly being "measured" by, at a minimum, the fabric of space-time, independent of how well you isolate it from the rest of the clock. So that puts a limit on the uncertainty in the energy measurement of whatever does the ticking. If delta-E is limited to be below a certain size, then delta-t is forced to be above some size, so you necessarily get some small variation in the time between ticks of the clock.

This results in a tradeoff between precision and accuracy. Precision requires many small ticks, so delta-t makes up a larger fraction of the duration of each clock's tick. A clock which ticks less often becomes more accurate (delta-t is a smaller fraction of the total time between ticks), but fewer ticks limits the precision of your measurement.

At least, as a physics grad student, that's how I've interpreted the result that TFA is utterly failing to convey properly.

Schrodinger's clock?

[zm]

Or is it Schrodinger's time? Oh, sweet entropy...

Forget time

[little1973]

https://arxiv.org/abs/0903.383...

Time is just the sequence of events. And events on the smallest scale are particle interactions.

What if there is an unknown quantum field which creates a barrier between particles? And particles have to "tunnel" through it in order to interact?

When this quantum field is more disturbed (warped, etc) this barrier will be greater and it would be harder to particles to interact with each other. The end result is "time" slows down since the number of interactions drops.

Note that an observer (in its own reference frame) will not notice anything (in the same way as in general relativity) since the observer just counts the number of interactions. To that observer the same number of interactions means the same amount of "time" passes.

And yes, this means this quantum field would be a distinguished reference frame.

Re:Forget time

[slashkitty]

Indeed. Time is just a man made invention. How it's defined and "measured" is what can get wonky. Take out time from all physics to see the real core of how things work.

Re:Heisenberg uncertainty?

[See Attached]

Are you saying the Planck Constant is not constant, or that the observed frequency is not constant? Perhaps the closer we look at something, the more we are likely to observe variability? Maybe we are sampling over a smaller number of events/atomic-interactions or too short of a time slice? There are few things that are absolute, so we use the observed average as a constant, but in reality, its a curve-distribution.

Re:Is there a thing called time?

[Anonymous Coward]

As I get older, I age too. However, I'm also pretty confident that I'm not a clock. If I ever do start thinking I'm a clock, it's probably due to age, however.

Re:Heisenberg uncertainty?

[goombah99]

All the uncertainty relationships in QM come from fourier conjugate variables. So for example, if you measure a low frequency for a short time you will be uncertain about the exact frequency. If you restrict a wave to a narrow slit then it take more direction forier terms to represent the truncated plane wave.

time and frequency are fourier conjugates. and plank's constant, which is constant, has the units that convert frequency to energy. This is why we say that time and energy are conjugates.

Makes sense

[Solandri]

Einstein's theory of relativity tells us that time and space are the same thing (your perception of the two skews with your relative velocity, which causes all of relativity's time dilation effects). So I would expect there to be a time-corollary of Heisenberg's Uncertainty Principle. Just as extremely precise measurements of position lead to poor measurements of momentum, extremely precise measurements of time should result in poor measurements of... something else.

Re:Makes sense

[Baloroth]

So I would expect there to be a time-corollary of Heisenberg's Uncertainty Principle [wikipedia.org].

There is, but it's probably not what you're thinking of. Technically speaking, the Heisenberg uncertainty pair applies to any two pairs of non-commutating quantum variables (or, depending on how you look at it, any two Fourier partners). Position and momentum happen to be one such pair. Another is time and energy. What that means, however, is that the energy of a particle in an unstable state (i.e. a state that can spontaneously decay into a lower energy state) is not perfectly well-defined, and the variance in energy is inversely proportional to the average decay time. In other words, the faster a particle (or state) decays, the wider the range of energies that particle/state is allowed to have, so that only long-lived states of physical systems have well-defined energies (by "long lived" I mean something like microseconds or even nanoseconds, which is long by quantum standards).

In the case of time measurements, this would generally mean the energy of our clock becomes less well defined as we make more and more precise measurements of the time. That's not really a problem, though: we just have to be greater that 1/2 h_bar, which is ~3e-16 eV*s. That means if the uncertainty in our time is 1 part in 10,000,000,000,000,000 (modern atomic clocks are very roughly in that range), we have an uncertainty of about 1 eV in the energy of our state. That's decently large (in terms of atomic scale physics), but pretty negligible in terms of everything else (nuclear physics involves energies a million times greater than that).

Heisenberg

[flargleblarg]

"I am the one who clocks."

Re:Is there a thing called time?

[lgw]

We cannot "sample" time.
We cannot "stop" time.
We cannot evaluate the opposite of time, or "not-time".
We cannot directly "measure" time.
We cannot directly "see" time.
If we cannot evaluate these things, does time exist?

You only think this because you have been educated stupid.
4 Simultaneous Days Same Earth Rotation.
Your dirty lying teachers use only the midnight to midnight
1 day (ignoring 3 other days) Time to not foul (already wrong)
bible time. Lie that corrupts earth you educated stupid fools.
Earth Has 4 Days In Same 24 Hrs., 1 Day God Was Wrong.
Einstein Was ONEist Brain. Try My Belly-Button Logic.
No God Knows About 4 Days,
It Is Evil To Ignore 4 Days, Does Your Teacher Know ?

Sigh - we miss you Gene Ray - Time Cube forever!

Re:Constraining the concept of time

[Greyfox]

Well, the passage of time was universally observed by the same set of side effects; time passes and the sun rises and sets, the stars come out, the moon progresses along its course and the seasons change, which it was probably very useful to predict. What these things have in common is that they are questions of geometry, moreover questions of geometry that involve things happening in spheres. The planet rotates 360 degrees (approximately, depending on where you're standing) every 86400 seconds, and as it progresses along its path the stars and other planets behave mostly predictably. These values are consistent no matter where on the surface of the planet you stand and have been observed by our ancestors as long as we've been around. We learned to navigate by them, and to predict the seasons. Those who did these things had much better odds of survival than those who didn't, to the point that by the time humanity was starting to develop civilizations, we were already designed to do those things. If we ever take to the stars in an appreciable way, we'll have to discard the planetary artifacts in the measurement of time, but we already have the tools to do so.

So really, it's not all that much of a coincidence. Every so often someone comes along and suggests that we should replace our system of measuring time with something more... elegant. But those people tend not to examine the reasons that gave rise to the way we measure it now, and such attempts inevitably come up short and ultimately fail.

We see the red/blue shift already. And correct it.

[Anonymous Coward]

That WMAP picture of the CMB is AFTER a sort of ying-yang red and blue shift pattern which is the result of our motion through space (the combination of our motion around the galaxy, our motion around our sun and our galaxy around the general mass of the universe) has been removed. And we're not moving relativistically.

It's just a very small difference.

Yet that is how even the CMB is, that you have to remove this effect of our proper motion to get a scale that will show up the detail difference in the CMB that caused the clustering of matter in galaxies we see today.

We already see that change in the CMB.

Then remove it so the remaining differences are inherent in the CMB and not our unsteady position in space.

Semantics matter

[93 Escort Wagon]

"Physicists Find That..."

Given that this wasn't a presentation of new research data, but rather an argument attempting to reconcile two theories - it is incorrect to claim that they "found" anything. Replacing that word with "argue" would fix that.

Although perhaps there's a Slashdot corollary to all this stating the more accurate a headline is, the more fuzzy the linked article will be...

This is NOT Quantum Physics!

[Roger W Moore]

For example, if you aren't looking at something in a video game it doesn't get rendered, ergo schrodingers cat like phenomena. The moon in fact is not there if you don't look at it.

This is NOT AT ALL how quantum mechanics works. Schrodinger's Cat was a gedanken experiment developed by Schrodinger to show how absurd the Copenhagen interpretation of quantum mechanics was when applied to everyday objects. Absolutely no physicist believes that this is how QM actually works: the cat is simply either alive or it is dead and is not in a superposition of two states. The point was to show that the prevailing interpretation at the time was wrong. The same goes for the world: QM does not say that things stop existing if they are not observed and nobody believes this. QM is strange and counter-intuitive, it is not crazy!

Re:Is there a thing called time?

[Roger W Moore]

Slow it down is not the same as stop, and "will stop" is a prediction.

Yes a prediction based on existing physical laws...welcome to a physics discussion this is what they generally involve: extrapolation of existing physics to situations you can dream up.

Really saddens me that you use an if statement in a physics discussion.

Don't be sad! Again this is a very common statement in physics discussions because of their nature. One of the fundamental reasons physics is so useful is that it can make predictions such as "if in situation X then Y will happen" so if statements are infused throughout physics discussions and as already mentioned they are based on extrapolating existing, experimentally well established laws to a particular situation.

You are pontificating.

Try looking up what pontificating means. I was not stating opinions but facts and stating facts which counter your beliefs might annoy you but that still does not make them opinions.