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[–] 50 points 1 year ago (22 children)

Ah, but using the cosmic microwave background we actually can determine a universal coordinate system to fix a point in space.

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  • [–] 61 points 1 year ago (3 children)

    cosmic microwave

    Oh, so that's why Earth is spinning!

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  • [–] 43 points 1 year ago (5 children)

    But only related to the cosmic microwave background, which, while more universal than most other reference frames, is ultimately still arbitrary

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  • [–] 2 points 1 year ago (2 children)

    It can be as arbitrary as it wants it still allows you to use relative positioning to determine a fixed point.

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  • [–] 9 points 1 year ago (10 children)

    Why cosmic microwave background radiation? Is that any less arbitrary than e.g. the sun?

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  • [+] 4 points 1 year ago* (last edited 1 year ago) (2 children)
  • [–] 2 points 1 year ago (6 children)

    Well, it's the only thing we know of that can be used in the whole universe.

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  • [–] 2 points 1 year ago (5 children)

    Use it how? I've never heard about this, and I can't seem to find anything about it by searching

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  • [–] 1 point 1 year ago (2 children)

    Apparently it is just the slightest bit warmer on one side. It's called the dipole of the cmb. I don't fully understand it, but as far as I know astrophysicists don't understand it either. ;-)

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  • [–] 2 points 1 year ago (1 child)

    But how would you use the dipole to specify where you are? Isn't the dipole the same everywhere? I'd think the dipole could possibly specify a fixed direction, but that's hardly enough to specify a fixed point referencing only the CMB.

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  • [–] 1 point 1 year ago (1 child)

    In the sense that the Cosmic Microwave Background (CMB) is visible from every point in space. No matter where you are you can determine your position relative to the CMB, making it a common reference point for the entire universe.

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  • [–] 3 points 1 year ago

    I understand that it is visible from all of space, but doesn't it look the same from all points in space? Wouldn't everyone looking at it simply conclude "I am at the center of the CMB"? How would you use it to specify a certain point?

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