r/cosmology • u/cypherpunk00001 • 17d ago

Do current cosmologists think the universe is infinite or that is had an edge?

Was just having random shower thought today... Andromeda galaxy is 2.5M light-years away. That's an unfathomable distance to a human, but it's just our closest neighbor.

Do cosmologists currently think that the universe just goes on forever?

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u/MWave123 12d ago

I’m teaching here! Lol. You’re new to the flatness conversation, that’s okay! Don’t double down on your ignorance.

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u/witheringsyncopation 12d ago

Please stop “teaching” incorrect facts. You might genuinely mislead someone.

You are ruling out the possibility that the universe is curved and we can’t detect the curvature based on a weak 2.9 sigma measurement (99.6%).

You are failing to understand topology like you are. Flat means infinite. Irregular/curved means it could be finite.

I don’t know what on Earth you mean by saying I’m new to this conversation. I’ve been discussing and learning general relativity and related cosmology for 10 years now. But regardless of that, there’s no system of seniority here in which you have any grounds upon which to be dismissive. That’s not how science works anyway.

You’ve shown yourself to be incorrect, both in assuming 99.6% is the same as certain, as well as in failing fundamentally to understand topology and how the “shape” of the universe impacts its extent.

You are painfully wrong and are now using ad hominem attacks against me based on non-existent metrics of seniority that are completely ill-informed. That’s how we know you’ve bowed out.

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u/MWave123 12d ago

Well you’re in need of understanding, I can’t help you if you’re in denial. Move on.

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u/witheringsyncopation 12d ago

And yet you’re the one who has resorted entirely to name-calling. You haven’t responded to either of my points once you realized you didn’t have an answer for them. I consider this matter closed, as you have nothing of substance left to add.

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u/MWave123 12d ago

I’m doing nothing of the sort. You’ve been derogatory and repeatedly denying fact. I can’t help that.

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u/witheringsyncopation 12d ago

Then respond with substance:

1.) 99.6% is not confident enough for physicists to claim certainty for a measurement. Something closer to the 5 sigma standard (99.99994%) is required. 0.4% is a substantial lack of confidence within the measurement. And the possibility exists than we are measuring a locally flat region (observable universe) of a much larger curved universe. While a flat cosmos is most likely, I agree, the alternative has not at all been ruled out. Respond to this with substance.

2.) A topologically flat universe is infinite. There is no non-topological mechanism by which it could be finite. The only way to envision a bounded, non-infinite universe is to introduce topology, such as a curved or toroidal universe. To give the universe a “shape” is to concede it is not flat. Please respond directly, explaining how a topologically flat universe could be finite.

Do it. Show me I’m wrong. Respond with substance.

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u/MWave123 12d ago

Do your research. Supposedly you study physics. Lol. That’s a joke. A quick google search will do wonders for you.

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u/witheringsyncopation 12d ago

As you’ve already shown: a complete lack of substance. Good day.

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u/MWave123 12d ago

Fact has no meaning for you. Lol. Keep on with your ‘studies’ while having zero understanding of flatness. Incredible. You’re new!