Where Is The Center of The Universe?

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Today we’re going to ask a simple-seeming question that will lead to so pretty wacky places. The question is this: If the universe has a center, where is it?

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Hosted by Matt O'Dowd
Written by Matt Caplan & Matt O'Dowd
Post Production by Leonardo Scholzer, Yago Ballarini, Pedro Osinski, Adriano Leal & Stephanie Faria
GFX Visualizations: Ajay Manuel
Directed by Andrew Kornhaber
Assistant Producer: Setare Gholipour
Executive Producers: Eric Brown & Andrew Kornhaber
Executives in Charge (PBS): Adam Dylewski, Maribel Lopez
Director of Programming (PBS): Gabrielle Ewing

Spacetime is produced by Kornhaber Brown for PBS Digital Studios.
This program is produced by Kornhaber Brown, which is solely responsible for its content.
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[ardag]

Duh, it is at (0, 0, 0) obviously. I'll have that Nobel prize now.

[tycro]

Nobody has ever made me feel more passionate about things I can’t remotely understand than Matt.

[technocore]

The explanation of how 2d person can point anywhere and be pointing at the center of the universe and it's applicability to a 3d universe was sublime. Thank you. I understood it.

[hsadreamerofrlyeh]

After about 2 years of trying to properly understand this topic, this is the video that finally made it click for me. Excellent job!

[OleOlson]

I consider myself pretty well versed for an amateur who has only taken a half dozen classes on Astronomy, but the material on PBS SpaceTime is way beyond me. And I love it.

[DrZedDrZedDrZed]

I love this show so much. Thank you Matt ands PBS and everyone who helps make this real. I'm having a kid and I can't wait for the day that I start watching the whole back catalogue of Space Time with him.

[peristanom]

If "closed", "open", or "flat" applies to the spatial shape of a universe, would that in any way also apply to its temporal shape? That is, would a spatially finite "closed" universe eventually and necessarily recollapse? Would a spatially infinite "open" universe necessarily expand forever? Would the expansion rate of a spatially infinite "flat" universe necessarily approach zero? Or are these entirely different properties?

[jeffreymartin]

Love this guy. You know new possibilities will be discovered listening to him because he says "But, I'm not sure" fairly regularly. Sometimes I have to watch an episode twice (unavoidable since he goes a bit beyond a documentary for us average brains). I think I've watched all of them since they started !

[frasercain]

Finally, now I can point people at this video for the answer.

[StrifeGarza]

This episode brought me back to why I loved space time. Rethinking geometry between flat and curved space-time is one of the first episodes I ever watched with Gabe. I don’t know of a stronger way to like this video then just hitting the like button

[concernedspectator]

Love these segments both questioning and reaffirming assumptions, leading to a deeper understanding

[LMarti]

The reason why this is the best physics channel is that every other channel would simply put out a video explaining that there is no center. The same old stuff. When this channel asks a question, even if it's a "basic" one, I know I'm going to learn a ton.

[Malkovith]

You can take simple questions, explore topics I'm sure I've heard plenty about and yet you always manage to give me new insights. I love it!

[jeffpkamp]

I remember asking my friend who was doing an astronomy PhD if you could differentiate between expanding space and an expanding cloud of sufficient size. He didn't have an answer for me and I'm glad to see that someone with the math skill looked at the question, and I wasn't off.

The question I have is, with the distance to the CMB, what is the lower limit we can set on the possible size of our "cloud" if it were that and not expanding space?

[KittyRenee]

I've watched this show for years, but learning advanced algebra with my mom, I understand the mathematics a bit better, and I appreciate what I learn a bit more

[zeroformsora]

You should do an episode on Chirality versus Helicity!
The whole the imaginary number line is fundamental to how the universe works is just wild to me, I would love to hear your explanation

[abj]

Finally an explanation of the topology of the universe and why there might not be a center. The obvious layman assumption is that the big bang meant a 3D-ish colossal black hole going kablooie into a universe. In this scheme, it makes sense to have the present universe be simply a multibillion lightyear sized 3D ball, with an obvious center. Can you explain why such a notion can’t be right? I mean beside the detail everybody already knows that black holes can’t explode.

[onebylandtwoifbysearunifby]

As someone who's studied a bit of cosmology,
I found your explanations well done.
Good job on this episode folks.

[px]

So, along with the 2D surface on a sphere analogy, would that also mean that sending two ships in opposite directions, approaching the speed of light, that they might run into each other again at the "opposite side" of our universe? Or maybe we could look in two different directions and see the same ancient star?

[honda]

Thank, I confirms exactly what I was accused of by my parents when I was 14 - that I thought I was the center of the universe. It's great to be proven correct, especially since all energy and matter is centered around me.