What If The Cosmological Constant Is NOT Constant?

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We know that the universe is getting bigger. And we know that the speed that the universe is getting bigger is also getting bigger. The standard assumption is that the acceleration rate is itself constant, which will surely result in ultimate heat death. But a recent survey of primordial sound waves frozen into the way galaxies are sprinkled through the universe reveals that this fate is now in question.

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Hosted by Matt O'Dowd
Written by Richard Dyer & Matt O'Dowd
Post Production by Leonardo Scholzer, Yago Ballarini & Stephanie Faria
Directed by Andrew Kornhaber
Associate Producer: Bahar Gholipour
Executive Producer: Andrew Kornhaber
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Director of Programming for PBS: Gabrielle Ewing
Assistant Director of Programming for PBS: John Campbell

Special Thanks: Adam Schwartz & Kurt Ritta

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[isaacbrown]

It's pretty crazy thinking i used to watch children's shows on PBS on my big boxy TV as a kid, and now i watch grown-up stuff on PBS on my phone.

[unvergebeneid]

Change in acceleration is called jerk. So we're looking for the ultimate jerk in the universe.

[tumultuouscornucopia]

I'm so glad he gave the warning at 14:00 about this not yet crossing statistical significance. I had got so excited that I was about to make a whole string of life decisions based on this finding. (I'm sure you can imagine the sorts of things).

[chrismpbuchholz]

The only universal constant is how great your videos are 💯

[halsteadart]

I want to see an episode of SpaceTime that wraps up the last sentence without saying "spacetime, " and Matt starts to walk off-screen. Then at the last second he pokes his head back in and just says "spacetime"

[Paul-A]

Pro: this may be a new phenomena in physics
Cons: it may give string theorists more material

[OtherTheDave]

The title is a question I’ve been wondering about since I first heard of it.

[NewMessage]

As long as y'all remain a YT constant, I'm happy enough.

[wdavis]

DESI is a really impressive piece of scientific engineering.

[diga]

Got my blanket, my hot tea, my weed, northern lights on a comfy couch outside.. enjoying some good ol' space time

[Mentaculus]

11:02 Thank goodness, I was really sweating the “BIG RIP”, so RIP BIG RIP‼️

[HebaruSan]

Thank you for explaining where the primordial sound waves came from. I think this is the first time I've understood that.

[dragonfiremalus]

Wow, the presented method for discovering those acoustic rings is astounding, epic, and would have required a ton of computation! I love it!

[newrever]

I can't believe videos like this are available to us for free. What an incredible age this is.

[tm]

Wouldn't they very fact that inflation occurred, proves that the expansion constant has changed more than once (1. Initial inflation 2. Post inflation) and would it be a fair assumption to make that since it has changed that it maintains potential to change again for any number of reasons?

[bakedpotatojoe]

Favourite youtube channel ever please never stop posting

[reinux]

I'm so proud, I've been watching Space Time for years and I finally understand an episode in full

[TheTurbobond]

Panning cloud is an awesome upgrade to a show that just keeps upgrading. Love it!❤

[ericwadebrown]

What about the recent James Webb confirmation of Hubble and Spitzer's confirmation of a 74 km/s. Then a discovery of 3x type 1A supernova - SN H0pe which shows that even 10 billion years ago, the hubble constant hasn't really changed.

[PhilipMurphy]

Thursday is always a good time for PBS Space Time