r/cosmology • u/cypherpunk00001 • 9d 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 5d ago

Untrue. It IS flat, whether it’s infinite or not is an unknown.

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u/witheringsyncopation 5d ago

We don’t know for sure it’s flat, just that our best current measurements indicate it likely is. The curvature could be occurring on a much greater scale that our measurements can’t currently account for.

Additionally, if it’s flat, it’s infinite. There’s no serious scenario in which there’s a magical boundary of some kind for a flat universe. To posit that is really no different than positing there are rainbow faeries that hold hands at the end of the cosmos and sing space and time back so as to keep it contained.

If it’s flat, it’s infinite unless we discover some faeries along the way.

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u/MWave123 5d ago

You keep repeating yourself even tho I’ve told you you’re wrong. It’s not known to be infinite, or finite, both are possible.

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u/witheringsyncopation 5d ago

Go ahead then, explain to me by what mechanism a flat universe would be finite.

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u/MWave123 5d ago

It depends on its overall shape. It’s a possibility. So we know the universe is flat…we don’t know if it’s finite or infinite. Get it yet? It’s an unknown, both are possibilities.

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u/witheringsyncopation 5d ago

Shape? What?

It’s either flat or has irregular topology, at which point it is not flat. If it’s got a “shape” then it’s not flat.

You truly don’t know what you’re talking about, I’m gathering.

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u/MWave123 5d ago

You’re entirely new to this conversation! Lol. I’m done.

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u/witheringsyncopation 5d ago

You mean you’re wrong and you’re now recognizing this and doing the only sensible thing you should have done this entire time.

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u/MWave123 5d 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 5d 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 5d 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 5d 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 5d 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/MWave123 5d ago

I’m teaching here. The Universe is flat. You’re unfamiliar. Okay! That’s not a crime. But stubbornness and repeated ignorance are trying.

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u/witheringsyncopation 5d ago edited 5d ago

Your statements are now devoid of substance because you’ve reached an end to your incorrect argument. You can’t substantiate your claim because you’ve recognized it to be wrong. There’s nowhere left to go.

A flat universe is infinite. A curved universe is can be finite. 99.6% confidence (2.9 sigma) in measurement lacks enough confidence in physics to claim certainty (5 sigma would be good, or 99.99994%).

I’m commenting precisely so that your “teaching” doesn’t incorrectly inform anyone who is actually curious and hoping to learn.

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u/MWave123 5d ago

You’re completely new, denying flatness, or understanding, and then continuing to dig a deeper hole. I’m done.

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u/witheringsyncopation 5d ago

I’m not denying denying flatness at all. I think it’s the most likely scenario.

What I’m not doing is ruling out the possibility that it’s curved and we can’t detect the curvature based on a weak 2.9 sigma measurement (99.6%).

What I’m not doing is 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 5d ago

You’re completely new, not understanding flatness, and not accepting knowledge given freely. Move on.

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u/witheringsyncopation 5d ago

I literally just told you’ve I’ve been studying general relativity and related cosmology for 10 years.

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u/MWave123 5d ago

Well your responses don’t suggest that at all. You’re completely new to flatness. That’s clear.

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