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Thread: Is there a Hubble constant to Hubble time converter?

  1. #1
    Join Date
    Nov 2004
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    Is there a Hubble constant to Hubble time converter?

    I can't seem to find one, and haven't really got my head around the maths.
    "Occam" is the name of the alien race that will enslave us all eventually. And they've got razors for hands. I don't know if that's true but it seems like the simplest answer."

    Stephen Colbert.

  2. #2
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    One is just the reciprocal of the other.

    Grant Hutchison

  3. #3
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    Sorry; I don't know how to convert km/sec/megaparsec to years.
    "Occam" is the name of the alien race that will enslave us all eventually. And they've got razors for hands. I don't know if that's true but it seems like the simplest answer."

    Stephen Colbert.

  4. #4
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    A megaparsec is about 3.1e19 km. So for 71 km/mpc.s the Hubble time is 3.1e19 / 71 = 4.4e17 seconds or 13.8 billion years.

    http://hyperphysics.phy-astr.gsu.edu...ro/hubble.html

    A quick search yielded this site: https://www.vcalc.com/wiki/sspickle/Hubble+Time
    I don't know if it is a good one or not but it gave the same answers as I got.

  5. #5
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    Another way to come at it is to figure that 1km/s is ~0.00102 Mpc/Gyr. So if your Hubble constant is given in km/s/Mpc, that's your conversion factor to convert it to reciprocal gigayears.

    Grant Hutchison

  6. #6
    Join Date
    Sep 2006
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    Ned Wright's Cosmology Calculator

    http://www.astro.ucla.edu/~wright/CosmoCalc.html

    is a very useful tool if you wish to convert redshift to some sort of distance or age or other factor.

  7. #7
    Join Date
    Nov 2004
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    Ah thank you!
    "Occam" is the name of the alien race that will enslave us all eventually. And they've got razors for hands. I don't know if that's true but it seems like the simplest answer."

    Stephen Colbert.

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