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

[Place a name here]

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

[hey!]

My wife did a physical simulation for her thesis of the ocean halocline by using an 8' wide rotating tank filled with water and sugar solution. Now the tank was a body of water rotating every 24 hours by virtue of being on the surface of the Earth, but the angular velocity was much too low to have an observable effect, so the tank rotated every few minutes on top of the 11.57 microradians/second rotation of the Earth.

It was a real time experiment in which a short but fixed period represented a much longer one -- and if you think about it this would likely be the case for any kind of simulation of a macroscosmic universe. The bigger the physical scale of the thing being modeled, the longer the time periods.

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

[Anonymous Coward]

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.

Lazy processing means time ticks only when something "happens to, observes, or changes" an object... Then we realize time ticks differently for objects in outer space moving very quickly vs something only updating less often which matches that behavior.

I also think another logical idea is that we could just be very very small. Our big bang could just be a piece of dirt hitting the "ground" and it bounced up into the air and shattered. Then time relativity means everything we know and see to be outer space, is just this expanding blast debris. The fire and heat of the unfathomably (to us) large object diminishing is the "heat death" we see happening in bajillions of years.

Then in our own normal sized world, we peek at small things and see very small life spans of things that live on small particles of dust and whatever.... Perhaps those small life forms are experiencing time many times slower than us and studying what appears to be many small rocks flying through an empty space with a diminishing energy level. So maybe next time you kick up a piece of dirt while running, an entire trillion year universe was just created and evolved intelligent life over eons before all heat energy cools from the impact and it's all dead and over before you even could think to observe it.

That also makes sense and it's not a simulation theory... I think we are just floating on dust particles to a real "huge world". And like small bacteria seems "dumb" compared to large creatures..... Maybe we are "dumb" compared to gigantic beings that laugh as we muddle around seemingly random on our planet. Maybe we are a classroom "pet" universe that they learn from.

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

[colinrichardday]

the 11.57 microradians/second rotation of the Earth.

So the earth only rotates one radian per day? 11.57 micrordians/second x 86,400 seconds/day = 1 radian/day.

Re:It's all a simulation

[Raenex]

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.

There's a difference between what we observe in quantum mechanics and a classical simulation using global hidden variables, and that's the no-communication theorem.

Re:It's all a simulation

[Cyberpunk Reality]

Obligatory xkcd:

https://www.xkcd.com/505/

Re:It's all a simulation

[mlyle]

Fine:
72.9 microradians/second * 86164 seconds/day = 6.281, close enough for me.

Re:It's all a simulation

[goombah99]

No you can have all of quantum mechinics in a classical world as long as you allow hidden variables. Bell's theorem just says there are no Local Hidden variable but it allows Global Hidden variables. Those are variables coupled outside the simulation.

Re:It's all a simulation

[wonkey_monkey]

Whut

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?

Re:It's all a simulation

[SuricouRaven]

This is easily worked out. There is only one unit that would make any sense: The planck length. The smallest unit of length there can be in the universe. 1.6E-35 meters.

Now you need the size of the universe. Unknown. But the observable universe is 8.8E26 meters across - and yes, due to expansion of space, that is a lot wider than the age expressed as light years.

A little division puts this at... a crashed calculator. But a better calculator says that makes the universe 5.5E61 planck-lengths across. While an unsigned 64-bit number gets you up to only 1.8E19. Not even close. A 128-bit unsigned gets you 3.4E38, still not enough. A 256-bit unsigned is 1.2E77, too much.

Unless our simulators have a strange liking for 205-bit integers, this does not work.

Re:It's all a simulation

[arglebargle_xiv]

The fact that we can't build a truly accurate clock is actually a safety mechanism built into the universe. As Professor T.Pratchett demonstrated in his groundbreaking analysis "The Thief of Time", the one thing we don't need is a perfectly accurate clock.

Re:It's all a simulation

[Place a name here]

As a concrete example: suppose P != NP. Then no simulation can solve NP-hard problems in polynomial outside time, so most simulations will have the same constraint as the parent universe (where we reside) and also be unable to solve NP-hard problems in polynomial inside time.

The "hey, this universe looks like a simulation too!" argument would be: every simulation we make has P!=NP. Our universe has P!=NP... sure looks like what a simulation would be like. Obviously, every simulation's rules is heavily correlated with the rules of the parent universe. But that doesn't mean that the parent universe is also a simulation.

To take this example with respect to time: it might be that time is fuzzy in our universe. If so, it puts a constraint on how "sharp" time in a simulation can be as well without excessive penalties to runtime (like the poly inside time = exponential outside time example above for any simulation with P=NP). But if time is fuzzy inside and time is fuzzy outside, that doesn't mean that the outside is also a simulation, at least not unless you've controlled for the effect that every simulation in this universe will be greatly biased towards being like the universe.

Now, the outside (our universe) might seem to be like the inside (a simulation) in surprising ways, e.g. things seeming to be lazy-evaluated with how quantum mechanics weirdness works. But mathematical patterns might persist in seemingly disparate structures. So it may be, say, that it's easier to lazy-evaluate small systems (like simulations in RAM) because it's hard to change large amounts of information at once, and it's hard to change large amounts of information at once because that's how our universe works.

In a way, not taking this correlation into account when speculating about whether the universe is a simulation begs the question.

Re:It's all a simulation

[wonkey_monkey]

The planck length. The smallest unit of length there can be in the universe. 1.6E-35 meters.

Except it's not. It might be in some theories, but it may also have no physical significance.

Re:It's all a simulation

[syntotic]

Lazy evaluation implies homogeneous?

Re:It's all a simulation

[q4Fry]

"When you look into the abyss, it's not supposed to wave back."

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?

[Anonymous Coward]

In these times of our first Troll President, we must all Troll Harder for great justice.

Re:You see?

[fph il quozientatore]

You are too easy to troll. You need to have a thicker skin to survive on the internet.

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.

Re:You see?

[tehcyder]

Another interesting subject turned to trash by the Slashdot comments.

It used to be that you could go to the Slashdot comments and see some extremely insightful analysis by people who were seemingly highly knowledgeable on the subject. Now, this is what you get from the current highest ranked comment.

Why do I even bother coming here?

There is a difference between posting seriously stupid shit and making a joke.

A big ball of wibbly wobbly, timey wimey stuff

[marcus.ilgner]

Didn't they know? https://www.youtube.com/watch?...

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.

Re:Hmm...

[Tablizer]

poor scientist who blames the universe for their shortcomings.

This fake universe won't run my fantastic experiments right. It's a low energy universe and has the worse ratings of all. I will defund it, build a sphere around it, that's a roundish wall by the way, and make God pay for it!

Schrodinger's clock?

[zm]

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

Re:Schrodinger's clock?

[Fire_Wraith]

It might not be Schrodinger's time. Or it might not be. We won't know until Schrodinger checks his watch.

Re:Schrodinger's clock?

[hawk]

wouldn't that let the cat out of . . .oh, never mind

hawk

Re:Schrodinger's clock?

[JoeMerchant]

I was going to ask: how is this any different from Heisenberg's Uncertainty principle? Time is just another dimension, measure it precisely enough and you disturb it too much to make an accurate measurement.

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:Forget time

[Calydor]

So basically the Frames Per Outside Second drops, but the Frames Per Inside Second remains constant?

Re:Forget time

[wonkey_monkey]

Time is exactly as real as space. That's why we have spacetime.

Re:Wow!

[Anonymous Coward]

They like to say things like "a second after the big bang..." but there is no way for them to know that because the cesium atom would decay at a different rate in that environment and cesium didn't exist then anyway.

time does not actually exist in the universe

[FudRucker]

only man's devices for measuring the concept of time, the past goes on for eternity and the future goes on to eternity, it is just that we humans have the audacity to think we are smart enough to count it or measure it, we can make devices that do this but they will never be absolutely accurate as these scientists found...

Re:time does not actually exist in the universe

[Anonymous Coward]

The past most certainly does not go on for eternity. Thus far, current best understanding is that time had a definitive starting point, which you'd know as the big bang. It makes no sense saying "before that", as there was no before. This isn't just semantics or wordplay, time literally came into being at that point.

Re:time does not actually exist in the universe

[colinrichardday]

What do you mean by eternity?

Re:time does not actually exist in the universe

[PoopJuggler]

the past goes on for eternity and the future goes on to eternity

Prove it.

Re:time does not actually exist in the universe

[wonkey_monkey]

Okay, wait right there.

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.

Re:Is there a thing called time?

[fahrbot-bot]

I suspect strongly that the universe does have a clock.

Ya, but given Relativity, it can't be a reference clock, so it can't be used it with NTP. (also, I don't see The Universe in any of the header files)

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

[Anonymous Coward]

Just clearing some pseudoscience: Uncertainty principle deals with VARIANCES OF MEASUREMENTS. It's Var(X)Var(P) >= hbar/2.

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).

Re:Makes sense

[colinrichardday]

Special relativity says that space and time are partially interchangeable. You cannot substitute a spacelike geodesic for a timelike one.

Re:Makes sense

[doug141]

What the two of you are discussing the sounds a lot like the Casimir Effect and Vitual Particles.
https://en.wikipedia.org/wiki/...
https://en.wikipedia.org/wiki/...

Re:Understood Long Ago

[mrbester]

"Time is an illusion, lunchtime doubly so." Ford Prefect.

Wait, what?

[JustAnotherOldGuy]

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."

What, so God doesn't own a wristwatch? No wonder he's always late to the party. Or the rape, or robbery, or molestation, or murder. If only he had a watch he could've gotten there in time to stop that shit. Fuckin' slacker.

Re:Wait, what?

[Nemyst]

I mean, he was three days late for his son's execution, had to resurrect him to make up for it. That's just rude.

Re:Wait, what?

[JustAnotherOldGuy]

I mean, he was three days late for his son's execution, had to resurrect him to make up for it. That's just rude.

I know people who actually believe that fairy tale, but who swear the Moon landing was a hoax. Some of them aren't even sure whether or not satellites are real, but that doesn't stop them from using the GPS in their car.

I've tried to find out at exactly what altitude their disbelief takes over but I've never gotten a good answer.

Re:Can't submit stories anonymously any more?!

[Ol Olsoc]

I don't want to waste my time creating an account.

Because creating an account takes less time than that screed you just posted. Thanks for playing.

Constraining the concept of time

[geekmux]

Perhaps the best thing to do when using this metric we call "time" is to constrain it within the boundaries of its inventors.

Hell, I'm surprised that the concept of time is universally accepted on the planet, when we can't even come to an agreement on the metric system.

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.

Re:Constraining the concept of time

[Anonymous Coward]

The world agrees on the metric system. There are only three backward third world hold-outs: Myanmar, Liberia and the United States.

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:Is there a thing called time?

[Immerman]

Huh, you just got me thinking - if you were traveling at relativistic velocities, wouldn't you see red- and blue- shifting of the CMB as you looked around? It would seem to me that could be used to determine the original velocity of the universe - an absolute reference frame. Of course that reference frame wouldn't necessarily have any special physical properties compared to any other reference frame, but it would be something everyone in the universe could agree on as being especially noteworthy

The alternative would seem to be that the CMB is infinitely broad spectrum, such that the R&B shifting would have no effect on observations and everyone sees the same uniform CMB regardless of velocity - but I'm fairly certain the CMB exists at a fairly narrow range of frequencies - hence "microwave".

Re:Is there a thing called time?

[mukinrestak]

We need a mod option for nostalgia tripping.

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.

Re:Can't submit stories anonymously any more?!

[colinrichardday]

I'm not here to collect useless Internet karma points.

Then what's the point?

Re:We see the red/blue shift already. And correct

[Immerman]

So, correct me if I'm wrong, but as I understand it one of the interesting things about the CMB is that it seems to be a uniform temperature in all directions.

However, assuming it was non-uniform, with a single directional bias, such as you would expect to see if there were originally a single more intense "hot-spot", and our local space had been positioned pretty much anywhere other than the immediate vicinity, would that not look exactly the same as if it were red/blue shifted along that axis?

How could we possibly distinguish between such a thermal gradient in the CMB, and frequency shifting due to our own motion relative to it?

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...

measurement vs action

[bugs2squash]

I can't say I understand it really, but I've always seen this as something that places limits on what we can measure. But can we use this phenomenon to force something to happen. That is, can we use precision clocks to force some weirdness to happen on a macro scale ? For example, can we make conservation of energy fail within a small volume if we measure time very accurately all around it ?

Again, Art trumps Science: Thief of Time!

[profke]

Written by the excellent (and sadly deceased) Terry Pratchett, Thief of Time is a story about a clockmaker who makes the perfect clock to measure time exactly. At that time, time stops. Luckily in the books of Pratchett creatures can exist outside of time, so the day is saved - in the end... By the Small Gods, I love his books and dearly miss him... :-(

It's not the clock

[nospam007]

I'm the one who knocks.

M. White (Heisenberg)

Re: Wow!

[Zero__Kelvin]

Er ah no. He understands that all this "Time is different here than there" shit is bullshit, and it ALL comes down to our MISconceptions

Re:Is there a thing called time?

[Bengie]

Same thing with math. We can only use math to prove math. At some point we have to assume something without proof in order for everything to work. All science has a bootstrap issue. Time may not exist in the way we think it does, but we're pretty sure it is real.

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:This is NOT Quantum Physics!

[myrdos2]

The point was to show that the prevailing interpretation at the time was wrong.

It was an epic fail, then.

Re:This is NOT Quantum Physics!

[Carewolf]

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!

While it was meant to demonstrate the absurdity of the Copenhagen interpretation, the Copenhagen interpretation still won.

Re:Is there a thing called time?

[Roger W Moore]

We cannot "stop" time.

Actually we can slow it down: time passes more slowly for an object moving at a high velocity relative to the observer. In the limit that this approaches the speed of light in a vacuum time will stop.

We cannot evaluate the opposite of time, or "not-time".

Yes we can. If the flow of time reversed we could do experiments which would unambiguously determine this. The oscillation of kaons and B-mesons show that physics is not the same if time is reversed. This is called T-violation and is closely associated with the difference between matter and anti-matter, something called CP-violation.

We cannot directly "measure" time. We cannot directly "see" time. If we cannot evaluate these things, does time exist?

Exactly the same applies to space: we "see" and "measure" space by looking at the physical separation between things in the same way that we "see" and "measure" time by detecting the time between events. Space is as real as time - it clearly exists because events happen at different times in the just the same way that they do not happen at the same place. In a universe with no matter or energy then there would be no way to detect the presence of space or time but then there would be nothing there to ponder their existence either.

Re:Is there a thing called time?

[wonkey_monkey]

Actually we can slow it down: time passes more slowly for an object moving at a high velocity relative to the observer.

Not exactly. After all, you can't measure how "fast" or "slow" something "passes" except by doing so... over time. Which leads to a bit of a circular definition.

I prefer to think of it as time being a different "direction" for different observers, just as "forward" and "right" can mean different directions to different people. This also makes it easier to reconcile the apparent paradox of two observers both appearing to run slower to each other.

Expand The Thought

[JimSadler]

If time is inconsistent according to location could we also say that physics is inconsistent according to location? That makes the entire observe and report method of study really shaky. If the laws of physics are indeed a variable we really know very little about what we observe in space. Try estimating the speed a star is traveling when you have no clue what time is doing in the area near that star.

Re:Heisenberg uncertainty?

[bughunter]

I'm thinking, is there any way we can turn this into a non-reactionary-mass thruster? Because that's what we need to go from monkeys throwing shit to real spacefarers.

Re:Wow!

[NicknameUnavailable]

Time definitely existed.

Nope. Time, much like space, doesn't exist, it's just a coordinate system. The universe is static.

Re:Is there a thing called time?

[SuricouRaven]

Almost the whole thing has been archived into IPFS now, as the original site ceased to exist.

https://ipfs.io/ipfs/QmRTVMsmt...

Re:Is there a thing called time?

[SuricouRaven]

The universe hand only goes round once.

Re:Is there a thing called time?

[iris-n]

You're quite right. The CMB is pretty much peaked at microwave frequencies, and you would absolutely be able to detect doppler shifting if you travelled at relativistic speeds with respect to it. For this reason the CMB is often picked up as the preferred reference frame when such a thing is needed: in speculative theories such as Bohmian mechanics, or by the very few sci-fi authors who want to have faster-than-light travel in their stories and know that a preferred reference frame is necessary to avoid problems with causality.

Re: Wow!

[bondsbw]

It is well proven that the measurement of time can and does differ based on circumstances such as relative velocity and gravitational influence.

The consistency of past measurements suggests that even if the issue is with how we measure time, until we can distinguish measurement from reality then there is no reason to treat them separately. So the two are equivalent and therefore it is not "bullshit".

2 theories at the same time?

[TeknoHog]

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 relativity, the entire notion of "at the same time" depends on the observer. So I guess for some scientists, GR and QM play well together, for others not so well.

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.

Re:Is there a thing called time?

[Roger W Moore]

Not exactly. After all, you can't measure how "fast" or "slow" something "passes" except by doing so... over time. Which leads to a bit of a circular definition.

Not really. Time is always determined as the period between two events just as space is always measured as the distance between two physical objects. If you have a physical process that you know takes a fixed amount of time to happen then, when you look at it in the moving frame, it will take longer to happen so, relative to you, time has been slowed down...or more correctly now partly coincides with one of your space directions. However since you now only perceive part of their taime axis as being parallel to your own it does mean that time is slowed for them relative to you.

Actually kinda makes sense

[foxalopex]

I think a good simple explanation is that to get higher and higher precision time measurements it takes more and more energy. At some point you're using too much energy in that it's having an effect on time itself. So there's probably some sort of limit on how far you can go.