How Can the Universe Be Flat?

Can geometry predict the future? Cosmologists think the overall curvature of universe can tell us secrets about how it will eventually end.

Host: Reid Reimers

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[uhohhotdog]

If the earth was round it would roll off the flat universe.

Checkmate roundies

[killerkueen]

I'm still confused.. What do you mean when you say "flat"? Can any 3D object ever be truly "flat"? Does "Flat" imply no thickness? Genuine questions, because im stupid.

[marionpettersson]

"Flat Universe Society"???😈😈😈

[tagwowm]

Because we have to satisfy The flat earthers some how

[donerpate]

Don't worry universe, your cup size doesn't matter.

On a more serious note: Great explanation, as always, thank you!

[sebastianelytron]

If the whole universe is flat how can the Earth be a sphere??? 🤔 #FlatEarthLogic

[etahhcumosevahi]

This is old, they’ve recently confirmed the universe is actually NOT flat. The observable universe seems flat. But in actuality, the universe has a very slight positive curvature.

[annaliseoconner]

I'm sooo glad to see more Reid. He's the perfect level of enthusiasm.

[fractalnomics]

Anyone else here on the 5th November 2019? They say it is closed.

[darylhenry]

Maybe dark matter and dark energy are 4th dimensional and that's why we can't see it but can measure its effects

[MrBruh-ndgt]

To a flat earther the universe is round while the earth is flat

[simonschalbers]

I was really curious how you were going to fit THIS topic in ~5min. That was actually pretty impressive

[sakura]

What happened to the theory of the donut shaped universe?

[bm-ubzc]

But if the universe is flat, what is above and below the universe? And how long does it take to reach the "surface" of the universe?

[FlesHBoX]

Not sure if it was intentional or not, but the subtle jab at the flat earth was kinda funny.

[jamesrobinson]

Come up with a better word than flat. Most of us consider flat to be equal to 2d... I get that we're discussing spacetime but there's got to be a better word than flat.

[bajajoes]

The Universe is a Bubble. Gravity will not allow it to be flat.

[michaelbeholder]

This is the first time in my life someone explains so clearly why we think the universe is flat. I finally get it! Thank you!

[jettmthebluedragon]

The only reason the universe is flat beacuse their is no mass 😐 no mass it means it’s flat only thing that has mass bends the fabric of space not space time 😐Beacuse every black hole every planet every star is not the same it’s different mean thing that everything expirences a different time 😐it’s not the same if the universe was the same EVERYTHING would be the same age every universe every planet every star would be the same age but it’s not

[SnowblindOtter]

The real question is not 'Is the universe flat?', it's 'How do you define flat?'. The universe may be flat, but the reality of it is that in that flat universe there are still three spatial dimensions(X, Y, and Z) and space is expanding in all three of these dimensions. So if we live in a universe that is supposedly flat, exactly how do we define it when we can see galaxies and galaxy clusters from pretty much all angles(barring those hidden behind the central bulge) moving on all three of these dimensions relative to our position?