Why a Group of Physicists Watched a Clock Tick For 14 Years Straight (wired.com)

An anonymous reader writes: If you drop your phone today and it falls to the ground, you can be fairly certain that if it slips from your grip again tomorrow (butterfingers!), it won't suddenly soar into the sky. That's thanks to one of the basic ideas in Einstein's theory of general relativity, which posits that the laws of physics don't change over space and time. But to actually know that for a fact, you'd have to perform the same task over and over again, in as many locations as possible, and watch closely for any change in outcome. That's why, as Sophia Chen reports, a group of physicists has spent the past 14 years -- or 450 million seconds -- watching clocks tick.

Their results would have made Einstein heave a sigh of relief. The physicists were observing the 12 atomic clocks to see whether their subatomic particles' behavior changed over those 14 years -- but it was completely consistent, even as the clocks moved with the Earth around the sun. Now, these findings don't necessarily mean that the laws of physics are absolutely not changing across time and space. They only definitively show that the laws of physics stayed constant over the 14 years of the experiment. "Still, they can now say this with five times more certainty than they could a decade ago," Chen writes. "And if it holds true for Earth's location in the universe, it's not too much of a leap to imagine it's true elsewhere."

Comments

Waiting for Godot

[Registered Coward v2]

The physics version...

Re:Waiting for Godot

[HornWumpus]

Richard Feynman famously dropped his pencil as part of his quantum mechanics lectures.

Would look up, explain: There is a chance the pencil will fall up. When it did, he didn't want to miss it.

Re:Waiting for Godot

[Anonymous Coward]

What if "physics get weird for time", but weird in the same way for every sensor we can test with?

Re:Waiting for Godot

[TeknoHog]

Only for male physicists, though. (wiki for those not in the know)

Re:Waiting for Godot

[Registered Coward v2]

Only for male physicists, though. (wiki for those not in the know)

That was a piss poor excuse to stop some from staging the play....

Re:Waiting for Godot

[TechnoJoe]

They used atomic clocks -- which measure time in subatomic particles -- to see if there were changes in subatomic particles over time? It sounds to me like they did not think this one through.

talk about watching paint dry

[bobstreo]

now, this is a job that could easily be done by an AI program.

The article summary didn't say if the physicists were actually watching the atomic clocks, or just monitoring them, but I'm hoping they were able to do some other work during the years...

Re:talk about watching paint dry

[jellomizer]

A quote from TFA:
"Most of it is automated, but someone watches it all the time, and someone carries a beeper."

They are not watching the clock tick. but they are making sure the conditions stay consistent, and all parts are working.
A physical person watching a clock to see it going off by a nanosecond isn't possible.

Re:talk about watching paint dry

[Anonymous Coward]

Well, I had been watching the clock on my VCR for probably that long. But it hasn't changed from 12:00 since I got it. Why don't you come in; the sprinklers will start in a sec--

Re: talk about watching paint dry

[Anonymous Coward]

How does watching a clock help? It's the same local system. Physical processes run with the same speed in clock atoms and in fact in all atoms on earth.
Signals, when crossing boundaries, will change properties accordingly.

Re:talk about watching paint dry

[rpstrong]

Doesn't it start flashing '01:00' during the spring?

How would they know?

[Anonymous Coward]

Any change would also affect the observer and the measurement device.

It's the time thing I've been going on about: we should redefine change as t_new, a unit of time that does not change with gravity. Our definition of gravity will change instead of g(x,y,z,t...) it would become g(x,y,z,t_new), a few motion laws will be adjusted and so on.

It won't affect your observations. If you think of your mind in simplified terms, as a charge travelling along a neuron. And if you consider yourself observe a falling object, the charge is in the same place as the object, regardless of t_new or t is used.

The consquence of this change?

Instead of thinking of gravity 'bending' space time, you realize g'() vs g() just a fixup for faulty equations of motion. It no longer bends time because you've correctly defined your time unit.

Re:How would they know?

[Anonymous Coward]

This doesn't account for four-cornered cubic time.

Re:How would they know?

[Anonymous Coward]

There's no such thing as time. It's simply a parameter based on our perception, that we used to parameterize our equations.

Unfortunately it makes it impossible to define gravity, because having bent time by gravity, you can't then define gravity in terms stuff that depends on time. A circular reference.

As long as you realize that redefining time to be independent of gravity changes nothing, because its just a way we parameterized equations and changing the equations to use a different parameter changes nothing in the real world. The equations don't control the real world, they just model it.... then you're free to then define gravity as what it is... a not very special attractive force.

Re:How would they know?

[lgw]

Any change would also affect the observer and the measurement device.

Ever tried to debug a problem from timestamps in log files, where the problem turned out to be clock drift? Non-trivial for sure, but possible.

What this experiment shows is that the clocks kept the same time as one another). That's something. It doesn't really show that the laws of physics are the same everywhere, just that any gradient is quite shallow across the small area the Earth traversed during the experiment. Still, it's worthwhile to do such diligence, because the underlying assumptions are so very fundamental to scientific thought that no one questions them in other work.

Experiments that confirm what everyone assumes to be true, assumes at such a deep level that its below conscious thought, those are valuable.

Still, Feynman one talked about how we could be sure there was not another fundamental force because of a similar experiment: the attraction between two uncharged masses was measured over months with extraordinary precision, and the results were as expected. That was wrong. The experiment simply wasn't accurate enough to detect dark energy, pulling the masses apart every so slightly. And dark energy is the dominate force at work in the universe, so it's a heck of a thing to miss.

So, keep doing experiments to confirm our most basic assumptions, because we can never be sure we aren't missing something.

Re:How would they know?

[arth1]

Experiments that confirm what everyone assumes to be true, assumes at such a deep level that its below conscious thought, those are valuable.

The unwashed masses on the right that oppose "wasting" money on science like this really don't understand that science isn't just about discovery, it's also about validation. Without the validation part, it's not science, but faith, with a high risk of being wrong, incomplete, or useless for further discoveries. This is money exceptionally well spent.

Re: How would they know?

[Anonymous Coward]

No, we should re-define it as CPU load. Whenever you get a lot of matter/energy in one place it takes longer to crunch the numbers and the simulation slows down.

Re:How would they know?

[kencurry]

yeah, time only occurs to us because we have memory. Without memory, there is no time. Only now.

Re:How would they know?

[MrLogic17]

>The unwashed masses on the right that oppose "wasting" money on science like

Slashdot isn't exactly a bastion of conservative thought, and the vast majority of comments here are "but muh tax dolarz!"

Name calling someone who disagrees with your views doesn't help.
Perhaps you'd be better off attacking the click-bait title of TFA.

Re:How would they know?

[Anonymous Coward]

Solly Charlie ... no such repulsive "dark" force. No Princess Leia either. It's only a statistical fluctuation in motion of the infinite number of multiverse extants.

Re:How would they know?

[cnaumann]

Some of the clocks were of different construction and used different time-keeping mechanisms. Some were hydrogen maser, some were cesium fountain. In 14 trips around the sun, they all kept time with one another.

Re:How would they know?

[Anonymous Coward]

His assumption was wrong, but my understanding is that such a test wouldn't ever be able to find dark energy. Dark energy doesn't causes things that are bound (whether gravitationally or via electromagnetism) to move away from each other. Only unbound systems will experience that.

A rough analogy is that a magnet sticking to the fridge doesn't move downward because gravity is too weak to overcome the electromagnetic force. In the analogy, dark energy would be the gravity pulling down on the magnet and binding forces (EM and gravity) would be the magnetic force holding the magnet to the fridge. Dark energy is so incredibly weak compared to binding forces that it could only be observed over astronomical distances.

Re:How would they know?

[Anonymous Coward]

libertarians are right-wing in the US and there are a fuckload oh them here.

Re:How would they know?

[Bengie]

The test was less useful than the research required to do the test. Physics has been confirmed to work the same to a certain degree in many different ways. A simple example is spectra lines. If the speed of light, strength of gravity, energy levels or particles, and a slew of other things were at all different, we'd see something that does not match what we see locally. But even if a star is 40 billion light years away, it still has the same laws and constants, to within the ability of what we can measure, which is a lot.

Re:How would they know?

[lgw]

Sure, but if the question is "do the laws of physics change over time", well, you have to keep testing over time.

Re:How would they know?

[Anonymous Coward]

But faith makes you feel better! Let's spend all our money on faith.

Re:How would they know?

[Anonymous Coward]

Slashdot isn't exactly a bastion of conservative thought

But of Trumputin trolls. No, they aren't conservatives. They want to destroy, not conserve.

Re:How would they know?

[arth1]

Us conservatives aren't against science. It stupid stuff like a 500K study to determine the difference in pleasure between condom and no condom.

That seems like a very cheap and worthwhile study. If greater understanding of that issue can lead to as little as one unwanted pregnancy less, the whole study has likely been a net gain for society.
Why would you be against that?

Re:How would they know?

[Anonymous Coward]

Only to rule out the one special snowflake case in which it changes with time and distance in exactly the combination necessary such that for any object the location based variance perfectly offsets the time based variance, as otherwise the light-speed delay combined with observing objects many thousands of light years apart in distance from us would revel the change with respect to time.

Re:How would they know?

[novakyu]

That's why people who do measure this sort of thing for a living measure unitless quantities, like fine-structure constant or mass ratios.

Having skimmed through the Nature article (I never trust popular-science paraphrases, because they're work of a bunch of people who failed their physics classes trying to translate what they couldn't possibly understand), it looks like they cast their result in terms of an upper limit on variation of fine-structure constant, which is the proper thing to do.

Re:How would they know?

[lgw]

Only to rule out the one special snowflake case in which it changes with time and distance in exactly the combination necessary such that for any object the location based variance perfectly offsets the time based variance, as otherwise the light-speed delay combined with observing objects many thousands of light years apart in distance from us would revel the change with respect to time.

Nah, the laws of physics will be the same from the dawn of time until next Tuesday. They they'll change.

Re:How would they know?

[f3rret]

So if we did not have memory radioactive atoms would not decay?
If we didn't have memory planets would not change position in orbit over time?

Serious Questions

[Anonymous Coward]

How much does this job pay, and where can I apply?

But on the 15th year...

[Anonymous Coward]

still nothing happened.

Sigh

[NoNonAlphaCharsHere]

Didn't Einstein also say that ALL clocks ran at different rates based (at a minimum) on the speed they were traveling? And isn't "on the Earth" (or even "the orbit of the Earth") literally the same point in space-time compared to the size of the rest of the universe? I'm sorry, but the assumption that space-time is flat everywhere and everywhen based on this experiment is still a simplifying assumption and not some kind of bedrock fact.

Re:Sigh

[brantondaveperson]

The bedrock fact, or at least, the theory that they're trying to investigate, is the symmetry of the physical laws. So that, no matter where in the universe you perform an experiment, you always get the same result. This is important because the laws of the conservation of energy, and angular momentum, and so-on, can be proved mathematically if you assume this symmetry. This was proved by Emmy Noether in 1915. And yes (although that's not what Literally means, so if you'll forgive me I'll use a different word), the orbit of the earth is virtually the same place when you consider the size of the universe - but the measurements made were orders of magnitude more precise than prior experiments, so if there are any symmetry-breaking phenomena out there, then we know at they are very, very small.

Re:Sigh

[Anonymous Coward]

Both speed and gravity can affect time. It's observable on earth that if you sync 2 atomic clocks at sea level they'll stay in sync. If you then take one to the top of a mountain for a few days (so not even very high up) and then come back down you'll see they have gone out of sync. Even at the same altitude your head will age slightly faster than your feet.

As we go around the sun the Earth's gravity and speed won't vary much so a stationary clock won't vary. The gravitational force of other solar system objects will but this'll be very weak. But that'll affect everything on Earth.

It all depends on your frame of reference. The clock will drift relative so a clock anywhere else in the solar system / universe, but 2 stationary clocks on Earth at the same altitude. I think they were only checking within the frame of reference nothing weird happened. You can calibrate for differing altitudes and the speed on the Earth's surface doesn't really vary, but if the physics meant they were randomly drifting that's not something you can correct for.

Re:Sigh

[gaiageek]

Didn't Einstein also say that ALL clocks ran at different rates based (at a minimum) on the speed they were traveling? And isn't "on the Earth" (or even "the orbit of the Earth") literally the same point in space-time compared to the size of the rest of the universe? I'm sorry, but the assumption that space-time is flat everywhere and everywhen based on this experiment is still a simplifying assumption and not some kind of bedrock fact.

As I'm guessing you know, as soon as you talk about speed, you're talking about motion - and motion is relative. Unless these scientists were observing clocks in orbit while they were on the ground, I don't think this would factor in - nor do I think it's what they were trying to test. I think it's safe to assume each clock and its respective "observer" was at rest relative to one another.

I imagine there would have been fluctuation of the acceleration both experienced, due to the shifting relative positions of the moon and sun and their gravitational forces. But again, since the clock and "observer" were both experiencing this from the same reference frame, I don't think this would affect the experiment (one wouldn't observe the clock running slower / faster).

This said, your point is totally valid about there still being an assumption, and the summary acknowledges that. While the change of the location of the Earth through its orbit is microscopic compared to the size of the universe, they were still measuring in different places in the universe and detected no change, which does support Einstein's assumption. Until we've mastered intergalactic travel or have evidence otherwise, I expect that will be the working assumption.

Re:Sigh

[Dog-Cow]

Your head (if upright) is further from the center of the Earth, so it's traveling faster than your feet. Should it not age more slowly?

Re:Sigh

[Anonymous Coward]

I think you are confused as to the nature of the experiment. It was not checking that they stayed "synced" it was checking that the physics stays the same as expected.

Re:Sigh

[Anonymous Coward]

Ha ha, Baby Head, Grandpa Feet!

Re:Sigh

[Anonymous Coward]

> So that, no matter where in the universe you perform an experiment, you always get the same result.

This isn't truly guaranteed, nothing is. However that's not a particularly useful way to think so we don't think like that most of the time. It does frustrate me when people insist these things are absolute in an absolute sense rather than within a specific field of understanding.

If you want to say this is guaranteed because you have resolved it to maths and you can prove maths the problem with that is that you can't prove what you resolved or rather reality. You can't prove reality wont one day simple say screw following maths for any reason or no reason at all.

This is still usually an unproductive mode of thinking but it's also needed to remind people and break them out of various traps of having gone down a path on something and then working within a box you've created which is especially problematic when you have systems that you can't genuinely be certain are entirely enclosed or exposed to something you can't or have yet to observe.

Re:Sigh

[CrimsonAvenger]

Your head (if upright) is further from the center of the Earth, so it's traveling faster than your feet. Should it not age more slowly?

Yes. And, according to Relativity, it does. By an infinitesimal amount (on the order of 1E-25 - in other words, all else being equal, your feet, over the period since the beginning of the Universe, will be as much as 0.03 microseconds older than your head). Note that there's a much larger (though still infinitesimal) difference between you and your parents, assuming your parents don't live at the same latitude you do, of course.

Insane pedant mode: OFF

Re:Sigh

[Bengie]

We now have atomic clocks so precise and accurate, that they cannot keep time with each other even if they're literally touching. The gravity experienced is different even though so incredibly minutely different.

It doesn't need to be proven

[nine-times]

First, I'm going to preface this by saying that I'm not objecting to this experiment being carried out. I'm mostly in favor of any ethical experiment being carried out because you never know what you're going to discover. But just to raise the question...

On a certain level, I question how valuable this confirmation is. They're amount of space that they're measuring is minuscule compared to the size of the universe. The amount of time they're measuring is tiny compared to the total span of possible time. I'm not sure how they would establish that their sample size is representative of the whole.

And even if it were larger, it's one of those things where it's impossible to prove a negative. The assertion is that the laws of physics don't vary at all in any time or any place. What if there was just one little corner of the universe where, for the briefest of moments, the laws of physics were different? How would this test rule that out? I'm not even sure how you could possible rule that out, since we don't really know what that would mean.

I'd say that they haven't contributed significantly to prove that physics holds in all places and in all times. Instead, they've created an experiment that simply failed to capture anything interesting. And that's fine! It makes sense to have experiments that try things out, and a lot of experiments won't come up with anything very interesting.

Anyway, I'd posit that the idea that "the laws of physics don't change" is more of a philosophic tautology that underlies the science of physics, rather than a property of time and space that is part of physics to be tested. Because, in a sense, the laws of physics *do* change depending on where you are. Things are weigh more in some places int he universe than others. Time passes more quickly in some places than others. It's just that, whenever we discover that the rules are different from one place to another, we find some new set of rules under which we can unify the rules.

And so I'd say that this test is probably worthwhile, but not because it provides any real proof that "the laws of physics don't change over space and time". Instead, it's worthwhile because if they had found some deviation, it might have lead to new discoveries in physics. Those discoveries would eventually be explained and incorporated into physics, and so the same laws of physics would still apply in all places and at all times.

In other words, the "laws of physics" are a set of mathematical rules that we developed to explain the behavior of physical objects. That the laws apply to all things, all the time and in all places, is not something we need to prove, it's an assumption that's required to develop physics. When we find an anomaly, whatever that anomaly is, the laws must change, not the assumption. If you change the assumption, then we basically need to toss physics and as we know it and start over.

Re:It doesn't need to be proven

[brantondaveperson]

Anyway, I'd posit that the idea that "the laws of physics don't change" is more of a philosophic tautology that underlies the science of physics

This isn't true. It does underly physics, in a very important way. Because of this

Re:It doesn't need to be proven

[gtall]

"because you never know what you're going to discover" So, we might find that this experiment could tell us about the sex life of goats? Funny business aside, your experiment is usually prepared in such a way that your detectors will detect something you expect to find if it is there, not just anything.

Re:It doesn't need to be proven

[Anonymous Coward]

If a system has a continuous symmetry property, then there are corresponding quantities whose values are conserved in time.

This does not say that the laws of physics are immutable, it says that IF there is a certain kind of reliable relationship in a closed system, that the system will have certain relevant values that do not change. The human understanding of physics is based on the assumption that this is valid in reality, supported by two main arguments:
1) Our test results are close to those expected in an enormous but closed system with continuous symmetry on a few relationships.
2) Because it has not been proven irrelevant, Noether's theorem provides useful boundaries to analyzing reality.

Theoretical proofs are proofs of consistency, not any guarantee that reality is bound by the theoretical model.

Re:It doesn't need to be proven

[Anonymous Coward]

Many great discoveries in physics have come from experiments that were designed to confirm what we already "knew"... but didn't. The Michelson-Morley experiment is a famous example. Had this experiment found minute changes, it could well have revolutionized physics. As such, it was worth doing.

Re:It doesn't need to be proven

[nine-times]

So, we might find that this experiment could tell us about the sex life of goats?

Well if it did, that would be quite a scientific discovery. Prove that ghosts exist, prove that they have sex, and tell us something about their sex lives, all with one experiment?

I mean, look, a lot of experiments turn out to be valuable not because of what they discover about the thing they're trying to measure, but because of some unexpected result that leads to some new hypothesis. There's some truth to that idea that the phrase that heralds new scientific discoveries isn't "eureka", but "that's odd." Sometimes it's worth developing a highly precise experiment to confirm the results you're pretty sure you should get.

Re:It doesn't need to be proven

[RevDisk]

Larger area than you think. The planet is going around the sun is 940 million km, per orbit. So, just shy of a billion km. And the solar system is moving. So they have roughly a helix of 14 billion kilometers worth of data. That's... not insignificant data.

Tiny tiny tiny drop in the bucket, but it's a start. A good start for our current level of technology. The positive results are not show stopping. Negative results would have changed most of our understanding of the universe.

Re:It doesn't need to be proven

[religionofpeas]

So they have roughly a helix of 14 billion kilometers worth of data. That's... not insignificant data.

If you'd take a boat, and go out on the ocean, you wouldn't be able to detect the tides by comparing two points on the boat.

Re:It doesn't need to be proven

[thegarbz]

They're amount of space that they're measuring is minuscule compared to the size of the universe. The amount of time they're measuring is tiny compared to the total span of possible time.

As others have pointed out the space isn't as small as you think, but there's something more fundamental about physics here. We don't conclusively prove much of anything by observation in physics. What we do is increase our confidence.

This experiment increased confidence significantly due to the duration of time and the movement of the earth during this time.

Re:It doesn't need to be proven

[Anonymous Coward]

In a way, the failure of Michelson-Morley revolutionized physics - explaining the failure lead to Relativity theory.

Re:It doesn't need to be proven

[Agent0013]

Nor could you detect it by comparing the boat yesterday to the boat today, since you are on the boat.

Too much of a leap

[Anonymous Coward]

it's not too much of a leap to imagine it's true elsewhere.

Yes it is. This is an assumption based on meager evidence that doesn't even support the unfalsifiable hypothesis.

Re:Your tax dollars at work

[GoTeam]

You know, I've always been concerned about that. I think I need to be part of that study. Where do I pick up my grant $$?

And the continents didn't move, either...

[Anonymous Coward]

What's the point? Someone explain it to me.

All it could possibly prove is that the laws of physics didn't appear to change by an observable amount for the extremely short period of time the experiment ran.

It's like watching for continental drift - for a few minutes.

"Nope, I didn't see Africa move in the past 10 minutes, so that makes continental drift unlikely!"

Re: And the continents didn't move, either...

[Anonymous Coward]

I'm glad you're not a scientist.

it's true elsewhere

[Anonymous Coward]

FTA: " it's not too much of a leap to imagine it's true elsewhere"

That's not what Space Nutters believe. They believe physics is local to the Earth, and that aliens around other stars will have better materials.

Re:it's true elsewhere

[Anonymous Coward]

aliens around other stars will have better materials

Trump will levy tariffs on them.

William Proxmire is spinning in his grave...

[Anonymous Coward]

These lazy gold-bricking scientists take feather-bedding to a whole new level! Wasteful spending like this is why we need Trump to drain the swamp.

"Not too much of a leap" ????

[smishra]

From the blurb "And if it holds true for Earth's location in the universe, it's not too much of a leap to imagine it's true elsewhere." It is a big leap. We have experienced only a miniscule of space time. The conditions may be remarkably different in other parts of the Universe - say the center of a black hole, or the fringe of the universe, or at some point in past (like the big bang), or in future.

Re:"Not too much of a leap" ????

[Diss Champ]

The blurb you quote as saying that it's not to much of a leap to _imagine_ it's true elsewhere. I'd say it is indeed likely that it doesn't require much imagination to think that might be possible.
Being able to imagine it, and stating that it is true, are two very different statements:). I can imagine many things that are much less likely, but which I don't have enough evidence to make a truth statement about. I don't think the blurb and your view are as much in disagreement as your statement implies.

Re: "Not too much of a leap" ????

[Anonymous Coward]

If only we had some sort of lensing device to observe these remote bodies and examine their content and behavior...

Re:"Not too much of a leap" ????

[Anonymous Coward]

It's a giant leap for mankind.

No!!!

[cascadingstylesheet]

"And if it holds true for Earth's location in the universe, it's not too much of a leap to imagine it's true elsewhere."

That's just what the lab coat wearing aliens would want you to think!!!

Re:No!!!

[93 Escort Wagon]

“Pay better attention, Zwwrkjlp! You almost forgot to wind Group 3’s atomic clock. If they’d noticed the key, that would’ve ruined everything!”

Better than WATCHing for this guy

[Anonymous Coward]

https://cdn.newsapi.com.au/ima...

The Reg. for more.

Re:Your tax dollars at work

[arth1]

Next experiment, we're going to explore whether rocks can spontaneously roll uphill if they are watched long enough.

The current quantum mechanics theories and interpretations are in favour of that possibility, but that the odds are so long that even if you watched every rock in the entire universe until all rocks have decayed, you would never see one of them move.
Smaller scale experiments, though, confirm the predictions of the theory.

One

[JustOK]

So, they didn't find a damn thing. Repeatedly. Therefore, time is NOT one damn thing after another.

Comment removed

[account_deleted]

Comment removed based on user account deletion

Re:Still failing to prove...

[HornWumpus]

Science NEVER proves anything true. You are thinking of math.

Not necessarily

[Chrisq]

They only definitively show that the laws of physics stayed constant over the 14 years of the experiment.

What if there were two changes which canceleld out in the measured effect?

Then the laws of physics breathed a sigh of relief

[SharpFang]

...and promptly made up for the lost time changing according to schedule.

You don't know a watched pot never boils?

Excuses from clock watchers

[avandesande]

I have heard them all but this one takes the cake!

Re:Still failing to prove...

[Anonymous Coward]

Let me rephrase that. Science has made no progress toward supporting the hypothesis that the laws of physics stay constant over vast timescales.

I call BS

[Anonymous Coward]

How do we know that the laws of physics aren't changing - from our own obervations? Within that same system of laws?

Hogwash, I say. I say this experiment is completely and utterly invalid because it depends on the wild, completely unsupported assumption that our observation methods are static irrespective of any change in the underlying laws of physics. Our observations depend on the same laws of physics we are trying to measure, which makes those observations invalid on their face.

How do we know our observational perceptions and measurements do not change along with the laws of physics, in a way that would make those changes invisible to us? We don't, and we can't, because we cannot step outside the system.

Different theories

[DrYak]

Your head (if upright) is further from the center of the Earth, so it's traveling faster than your feet. Should it not age more slowly?

That's what is predicted by the theory of special relativity (the first one coming from Einstein, the one that posits that the speed of light remains constant in all referentials, no mater their speed).

The above post mentions prediction comming from the theory of general relativity (the second that Einstein made, the one that looks how space time is distorted by mass)

The final delta in aging that you'll be observing (the whole couple of fractions of nanoseconds of it) will heavily depend on the effect of both speed and gravity.

This has actually been measured for real (but at much larger scale) with GPS satellites (which orbit at a much higher altitude and much farther away from Earth's grativy well's center, compared to the head in your example) : They are basically glorified orbital atomic clocks, and once you factor in relativity, taking into account both speed and gravity, you can explain the observed drift over time with a convincing precision.

Re:Different theories

[tlhIngan]

This has actually been measured for real (but at much larger scale) with GPS satellites (which orbit at a much higher altitude and much farther away from Earth's grativy well's center, compared to the head in your example) : They are basically glorified orbital atomic clocks, and once you factor in relativity, taking into account both speed and gravity, you can explain the observed drift over time with a convincing precision.

One should also note that GPS is one of the few things in the world we use daily that requires compensating for both special AND general relativity at the same time. The satellites are in motion relative to us, leading to special relativity compensation, and the satellites are high enough up that gravity is a factor, so they too need a general relativity compensation.

And the GPS designers were smart enough to realize this from the get-go and order appropriate atomic clocks that compensated for the drift.

And the drift is relatively big - if you did not compensate, after a day, you'd be a mile off. That's how precise everything is. And the compensation happens all the time - part of the GPS data includes almanac data, and the USAF (operators the ground portion) are constantly measuring and adjusting the drifts of each satellite to keep every one on time.

And it all fits in a tiny little chip cost only a buck or so that does all the fancy computations.

Re:Still failing to prove...

[HornWumpus]

Science has made no progress _disproving_ the hypothesis that the laws of physics stay constant over vast timescales.

The only 'evidence' anybody has against that hypothesis is 'the bible' (and other traditional beliefs of illiterate shepherds). Which routinely gets laughed out of the room. But young earth creationists have two choices: Admit they're wrong, or the laws of physics _must_ change with time and distance.

NOPE

[Anonymous Coward]

First of all, it's not a "law of physics", it's a THEORY that remains unproven; that's why it's called a theory.

Second, treating it as a LAW and conducting experiments as if it is is extremely dangerous.

Third, Einstein was wrong and Tesla was right. There is no particles, gravity is nothing more than a form of magnetism, and the speed of light is nothing but a rate of induction.

The evidence is mounting very quickly, and I'm working on a experiment which will prove it.

If you wish to research this yourself, I suggest you download the FREE electronic PDF of the book "Uncovering the secrets of Magnetism" by Ken Wheeler

You can also see his youtube channel for more details. Here is one of his videos.
https://www.youtube.com/watch?v=q29KjrV9FOI

Laws of physics changed over time.

[140Mandak262Jamuna]

That is a fundamental axiom in Young Earth Creationism to explain away science predicting universe older than 6000 years. "You see, physical laws changed over time, and the time itself slowed. "

This is different from "Last Thursdayism Creationism" which supposes the universe was created as is 6000 years ago, with buried dinosaur skeletons and starlight already in transit for several billion light years to give the "appearance" of very old Earth.

Re:Laws of physics changed over time.

[Anonymous Coward]

Also in the "God can do whatever he wants" proof.

Re:Laws of physics changed over time.

[Areyoukiddingme]

This is different from "Last Thursdayism Creationism" which supposes the universe was created as is 6000 years ago, with buried dinosaur skeletons and starlight already in transit for several billion light years to give the "appearance" of very old Earth.

Which is effectively indistinguishable from solipsism, at which point why does anybody bother to listen to these clowns? They're as useless as college freshman philosophers.

Re:Laws of physics changed over time.

[Anonymous Coward]

different from "Last Thursdayism Creationism"

The Creationists are trying to obfuscate the truth, and the truth is just that... at some point contemporary with landing on the Moon, near there or after within a positive error of up to 50 years, the Universe suddenly existed when nothing existed before. And I have seen no one describe how clever and difficult to comprehend or believe it better than you. That bit about starlight put a tear in my eye. It really is quite something, but easier to understand if you think of existance as the output of a printer: something, data, existed before, but it wasn't physical.

Re:Laws of physics changed over time.

[Agent0013]

But if the universe was smaller in the past (big bang theory), then wouldn't gravity have been more intense leading to different rate of time flow.

In fact, how do we know that the early inflation isn't just an artifact of a different rate of time? Since we are moving through time at a different speed now, looking back it looks like things moved apart faster in the past.

laws of physics constant?

[yes-but-no]

How can you prove something is constant if you yourself is a product of those laws? It's like you hacked a server and obtained root access; now you can cover your tracks anyway you wish (like erase contents in log files n things like that). So if laws of physics conspire to give you an illusion that they are fixed, you can't uncover it. Unless you are operating out the box.. outside the confines of physics; how can you tell anything concrete about it.

Re:Your tax dollars at work

[OneHundredAndTen]

No wonder you are posting as an Anonymous Coward.

Re:Still failing to prove...

[Anonymous Coward]

Not true, they can also believe that the universe was created aetatis specie (i.e. with the appearance of age).

It is impossible to prove that the universe didn't come into being 6 minutes ago with the appearance that everything has been around for billions of years (including putting memories into your brain).

Then again, it is more likely that it did not.

Physics Does get weird with time.

[Grog6]

Consider that the rate that time elapses here is different that in orbit, due to the distortion from Earth's gravity.

It can be measured in tall buildings, if you use a good enough clock. :)

If you're in a different gravitational field than Earth, time is passing at a different rate; the larger the gravity field, the slower time progresses, coming to a stop at the event horizon of a black hole.
(That's the Singularity thing; all the equations go bonkers at that point.)

During a drunken Physics conversation, I once postulated a situation where very near the Speed of Light, a person in a spacecraft would have problems moving his chest wall enough to breathe, because of the immense energy it would take to increase the speed of his chest; you could move away from the direction of travel easier, (slowing rather than increasing speed) so you would end up pressed to the rear wall of the spacecraft as you tried to breathe.

Everyone thought about it for a bit, and one of the guys mentioned the time dilation effect; in effect, you would never notice it, because time would be passing slow enough to hide the effect from you.

Your 'Reference Frame' would be approaching the time stoppage point.

Physics is really cool. :)

Re:Physics Does get weird with time.

[Anonymous Coward]

relativity doesn't work that way. the speed of light is relative to your reference frame.
see every dumb question about turning on your headlights at the speed of light...
drunk physics is as useful as drunk driving.

Re:Still failing to prove...

[Grog6]

I've heard people argue "God put those dinosaur bones there to find!"

That argument is a complete waste of time; you cant reason with those people.

Tesla knew about particles.

[Grog6]

He discovered X-rays before Rutherford; his images are available with a search.

Magnetism is mediated by Photons, same as every other Electro-Magnetic interaction.

Learn real physics; it's WAY more entertaining that whatever drugs you're on.

Re:Then the laws of physics breathed a sigh of rel

[Anonymous Coward]

A watched pot never boils? Perhaps.

But after watching the clock tick for 14 years, we can now probably say that a watched clock never tocks.

I've been watching the clock tick for decades

[Anonymous Coward]

And I can assure you it seems to tick slower and slower as I wait each day for time to go home.

A minute passed

[Anonymous Coward]

http://www.montypython.net/scripts/minutepassed.php

Re: Your tax dollars at work

[Anonymous Coward]

Why? Is he one of the clock "scientist" that the article is discussing?

Re:Your tax dollars at work

[Anonymous Coward]

... In which the shitposter says something so stupid, I'm pretty sure it's not even possible to explain how they're wrong in a way they can understand.

Reference

[manu0601]

Clock ticks remained regular over 14 years, but compared to what? If law of physics evolved over the course, all atomic clocks would have drifted the same way.

What if it stopped?

[ebvwfbw]

Suppose the clocks stopped for 5 minutes last December. How would they know?