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A comment on If the universe is 13.8B years old, how can we see 46B light years away? (2018). Parent comment

Re:If the universe is 13.8B years old, how can we see 46B li... by lmilcin on Saturday December 07, 2019 @01:25PM (#21731730)
Except the galaxies do not travel. Galaxies are more or less stationary, it's the space inbetween that expands. Think in terms of raisins in a dough or points on expanding baloon. Neither of them could be said to travel, yet they can be seen to become more and more far away.
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Re:If the universe is 13.8B years old, how can we see 46B li... by wahern on Saturday December 07, 2019 @02:10PM (#21731963)
Technically, galaxies do travel:

> In physical cosmology, peculiar velocity refers to the components of a galaxy's velocity that deviate from the Hubble flow. ....

> Galaxies are not distributed evenly throughout observable space, but are typically found in groups or clusters, where they have a significant gravitational effect on each other. Velocity dispersions of galaxies arising from this gravitational attraction are usually in the hundreds of kilometers per second, but they can rise to over 1000 km/s in rich clusters.

-- https://en.wikipedia.org/wiki/Peculiar_velocity

Granted, 1000 km/s isn't even 1% of light speed, so clearly this motion couldn't contribute much to a distant object's recession.

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Re:If the universe is 13.8B years old, how can we see 46B li... by lmilcin on Saturday December 07, 2019 @03:52PM (#21732475)
That's why I wrote "more or less stationary", which is describing 1000km/s compared to double the speed of light that would come from naive calculation.
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Re:If the universe is 13.8B years old, how can we see 46B li... by wahern on Saturday December 07, 2019 @04:08PM (#21732570)
Ah, fair enough. I glossed right over that qualification, which is not a smart thing to do on HN--a credit to the quality of discourse here :)
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Re:If the universe is 13.8B years old, how can we see 46B li... by KoftaBob on Saturday December 07, 2019 @02:08PM (#21731957)
and yet you stated nothing about this factor in your original comment.
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Re:If the universe is 13.8B years old, how can we see 46B li... by corrund on Saturday December 07, 2019 @02:08PM (#21731956)
No, space inbetween is stationary. It's galaxies that shrinks. Think of ice in water.
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Re:If the universe is 13.8B years old, how can we see 46B li... by saagarjha on Saturday December 07, 2019 @04:07PM (#21732558)
What’s the difference, observationally?
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Re:If the universe is 13.8B years old, how can we see 46B li... by troubler on Saturday December 07, 2019 @04:34PM (#21732713)
Shrinking releases energy. Expanding consumes energy.
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Re:If the universe is 13.8B years old, how can we see 46B li... by saagarjha on Saturday December 07, 2019 @08:44PM (#21733878)
Energy from where?
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