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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."

3 of 106 comments (clear)

  1. Waiting for Godot by Registered+Coward+v2 · · Score: 5, Funny

    The physics version...

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  2. Re:Sigh by brantondaveperson · · Score: 5, Informative

    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.

  3. Physics Does get weird with time. by Grog6 · · Score: 5, Interesting

    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. :)

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