Universe's expansion 'is now slowing, not speeding up'

Re:Universe's expansion 'is now slowing, not speeding up' by jumploops on Friday November 07, 2025 @01:40AM (#45844075)

“We can’t observe the whole universe, so cosmology is not really about the universe. It’s about the observable patch and the assumptions we make about the rest.”

(paraphrasing George Ellis)

We’re in a bounding sphere, with a radius that’s roughly 46.5 billion lightyears, so any observation we make may be true for our local observable range, but there’s no (known) way to know what’s beyond that sphere.

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Re:Universe's expansion 'is now slowing, not speeding up' by alfiedotwtf on Friday November 07, 2025 @03:16AM (#45844501)

This is the thing that blows my mind the most with physics and cosmology

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Re:Universe's expansion 'is now slowing, not speeding up' by wtcactus on Friday November 07, 2025 @09:07AM (#45846538)

Right, but everywhere we look the universe is roughly the same at same distances, so it’s acceptable to extrapolate.

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Re:Universe's expansion 'is now slowing, not speeding up' by mr_mitm on Friday November 07, 2025 @11:07AM (#45847815)

Even if not, it's still worthwhile to explore everything as far as we can see.

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Re:Universe's expansion 'is now slowing, not speeding up' by wtcactus on Friday November 07, 2025 @11:11AM (#45847870)

Relativity restricts us to explore a very tiny sliver of the universe. We can observe, but we will never be able to interact unless Relativity is completely wrong.

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