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kelsey59

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    Astronomy, Cosmology, and Telescopes

    in Hangout Club

    Posted

    A question I can't get an answer to.

    1) Gravitational time dilation according to Einstein's theory of relativity states that the farther a clock is from the source of gravitation the faster time passes.

    2) We exist in the local group of 54 galaxies. With the center being between the Milky Way and Andromeda.

    So, wouldn't the gravitational "weight" of the local group distort our view of the age of the Universe because we are seeing it a changing quicker then it really is?

    Ok I went a website called ask a physicist. Here is what he wrote back to me. Turns out the guy that answered works at GSFC.

    -------------------------------------------------------------------------

    Yes, there is such a distortion - but noticeable only when one

    works with precise measurements.

    The gravitational potential of the local group is shallow. As you

    remember from physics classes, the gravitational potential for a

    point-like object is M/R, mass divided the distance from the center

    of that object. The calculations are trickier when you're inside

    an extended object, but the "M/R" formula gives you a sense of how

    it scales. The gravitational time dilation depends on the same M/R

    type gravitational potential:

    https://en.wikipedia.org/wiki/Gravitational_time_dilation

    and it's large only near compact objects (such as black holes,

    with large M/R), and mostly negligible for extended objects.

    Also, for precision work, there is a standard definition of

    time that cosmologists use:

    https://en.wikipedia.org/wiki/Cosmic_time

    and they know how to treat the small complication due to the

    local group gravitational field and the peculiar motions of our

    Galaxy and of our solar system.

    Astronomy, Cosmology, and Telescopes

    in Hangout Club

    Posted

    A question I can't get an answer to.

    1) Gravitational time dilation according to Einstein's theory of relativity states that the farther a clock is from the source of gravitation the faster time passes.

    2) We exist in the local group of 54 galaxies. With the center being between the Milky Way and Andromeda.

    So, wouldn't the gravitational "weight" of the local group distort our view of the age of the Universe because we are seeing it a changing quicker then it really is?

    The Orioles, 10 games at a time

    in Orioles Talk

    Posted

    We are treading water, but that is OK all things considered. We just need a few things to break our way, a couple positive surprises and we can go on a run I think. Of course, a few more bad breaks and?

    I agree. Get some players healthy and get a few good breaks our way (law of averages) and we will be on a roll (I am always an optimist this early).

    Orioles win; Yankees lose

    in Orioles Talk

    Posted · Edited by kelsey59

    Orioles don't play, Yankees lose isn't bad, either.

    For all our shoddy play, we're two games out in the loss column.

    That's the important thing. Eventually they will go on a run. They just have to keep everyone close while they figure you things out.

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