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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."
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."
The physics version...
I'm a consultant - I convert gibberish into cash-flow.
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...
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.
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.
This doesn't account for four-cornered cubic time.
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 $$?
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.
Socialism: a lie told by totalitarians and believed by fools.
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.
So, they didn't find a damn thing. Repeatedly. Therefore, time is NOT one damn thing after another.
rewriting history since 2109
Comment removed based on user account deletion
yeah, time only occurs to us because we have memory. Without memory, there is no time. Only now.
sigs are for losers (except to point out that sigs are for losers)
Science NEVER proves anything true. You are thinking of math.
John McAfee 'It was like that time I hired that Bangkok prostitute; to do my taxes, while I fucked my accountant'
>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.
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?
...and promptly made up for the lost time changing according to schedule.
You don't know a watched pot never boils?
45 5F E1 04 22 CA 29 C4 93 3F 95 05 2B 79 2A B2
I have heard them all but this one takes the cake!
love is just extroverted narcissism
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.
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.
"Sufficiently advanced satire is indistinguishable from reality." - [Tips: 1DrYakQDKCQ6y52z6QbnkxHXAocMZJE61o ]
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.
John McAfee 'It was like that time I hired that Bangkok prostitute; to do my taxes, while I fucked my accountant'
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.
sed -e 's/Chuck Norris/Rajnikant/g' joke > fact
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.
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.
No wonder you are posting as an Anonymous Coward.
Sure, but if the question is "do the laws of physics change over time", well, you have to keep testing over time.
Socialism: a lie told by totalitarians and believed by fools.
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. :)
Truth isn't Truth - Guliani
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.
Truth isn't Truth - Guliani
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.
Truth isn't Truth - Guliani
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?
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.
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.
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.
Socialism: a lie told by totalitarians and believed by fools.
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?
Admit nothing. Deny Everything. Make Counter-accusations.
Suppose the clocks stopped for 5 minutes last December. How would they know?