### Mike Stay

Shared publicly -Clocks deeper in a gravitational field run more slowly. An observer outside a black hole would see light emitted from an infalling clock become redshifted; the clock itself would appear to run more and more slowly, asymptotically grinding to a halt at the horizon. The view from the infalling clock is reversed: the light from the universe outside becomes more and more blue-shifted, turning to ultraviolet and then x-rays and gamma rays, culminating in a fantastic burst of hard radiation from the entire future of all the stars in the universe as the clock falls through the horizon.

This scenario is certainly far from everyday experience, but physicists are now able to verify even the subtle deviations from Newtonian physics due to Earth's feeble gravity over the size of a human and due to time dilation at the speed of residential traffic. In this paper from 2010, Chou, Hume, Rosenband, and Wineland report,

http://www.sciencemag.org/content/329/5999/1630.full

This scenario is certainly far from everyday experience, but physicists are now able to verify even the subtle deviations from Newtonian physics due to Earth's feeble gravity over the size of a human and due to time dilation at the speed of residential traffic. In this paper from 2010, Chou, Hume, Rosenband, and Wineland report,

**"We observed time dilation from relative speeds of less than 10 meters per second by comparing two optical atomic clocks connected by a 75-meter length of optical fiber. We can now also detect time dilation due to a change in height near Earth’s surface of less than 1 meter."**http://www.sciencemag.org/content/329/5999/1630.full

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John Baez

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+Panu Viljamaa - I suspect that the true theory of quantum gravity will combine the strangeness of general relativity and quantum theory in a very nice way, which will make quantum theory make more sense. I have fairly detailed speculations on how:

http://math.ucr.edu/home/baez/planck/

http://math.ucr.edu/home/baez/planck/

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