The Crisis in Cosmology: We Don't Know How Big the Universe Is

Scientists are unsure about the age of the universe. Two methods of measuring the universe's expansion have yielded different results, leaving scientists in a crisis of cosmology. The discrepancy in the two different calculations is known as the Hubble tension. Recent data has only further widened the gap between the two values. This means the math might be wrong or our current understanding of physics is incomplete.

[danidavis]

I had to send this link to my dad. He was an astronomer for the USAF and for AAVSO (American Association of Variable Star Observers) for many years. Even when I was a kid and we would go out to his backyard observatory to record observations of star brightnesses, the Cepheids were the most fascinating to me. Thanks for yet another great presentation, sir.

[e-moshe]

The different measured age of the universe might be a crisis in science and knowledge, but it’s actually exciting. The universe might then still have amazing physics and effects to be discovered, which we still have no idea about.

[diyeana]

I love space and the universe. There's no doubt we're wrong on many things, but that's why we keep searching for answers. This is a great script, Kevin and a fantastic read, Simon.

[arthorim]

"We don't know, but more important we don't know why we don't know"
Such a enlightening frase!!

[Google_Does_Evil_Now]

I'm so old that stuff I learned in physics when I was young has been proven incorrect. Which is excellent. And keeps me interested and intrigued.

[ignitionfrn]

1:35 - Chapter 1 - The distance ladder
6:35 - Chapter 2 - Cosmic microwave background
9:00 - Chapter 3 - The implications

[RaySpillane]

Excellent delivery, Simon communicates all this like he knows what he's talking about. So much information, even more confused now than ever!

[elliotsmith]

Really well done Simon. A seriously complex issue well handled. I really think you do much better when you are a bit more serious. The more flashy, jumpy episodes are less credible in my eyes (as a sometime science and engineering educator).

[Clearlight]

It seems to me the weakest link in the distance ladder is type 1a supernovae, being such massive and complex phenomena and likely affected by so many factors - some of which we probably don't even know yet. How can these events be used in any kind of standardisation? Great presentation Simon, thank you!

[royfeely]

Thanks, I didn’t understand any of that but it sounded really interesting. If I keep listening to this type of content I might eventually start to remember and relate to a few bits. I suppose that’s how learning works.

[martinstallard]

1:30 the distance ladder
6:30 cosmic microwave background
8:56 the implications

[thedayidied]

I would like to note that not only did we used to believe that the Milky Way was the entire Universe - we believed it less than 100 years ago! It was 1928 when it was finally realized that the Andromeda Nebula was actually a galaxy. My grandfather was 8! That's so bonkers to me, that not even 100 years ago we knew NOTHING of anything outside the galaxy!

[myusername]

im so happy when you release new videos honestly they are fun to watch and i appreciate you

[Steve]

As always, amazing work explaining a complex, multi-factorial situation in clear, accessible terms; so well done!

[voltaries]

The problem isn't the maths, it's the initial starting assumptions. Maybe the "red shift" isn't what we think it is. If that's true, all the other assumptions are false.

[davidtatro]

Part of me really hopes that the problem lies with the CMB calculations. That would give us the simultaneous comfort that we kind of know our place in the universe relative to other objects while also opening up very intiguing possibilities for new physics.

[rebeccadubois]

It gives us something to work towards almost indefinitely. This is amazing

[OmegaVideoGameGod]

Everything in space is bigger than we think it’s beyond amazing when we can explain it!

[korinogaro]

I don't see how this is a crisis. It changes nothing for us, there is new stuff to learn and understand just like there always was...

[RedfishCarolina]

We aren't sure how big or how old the universe is and every day what we don't know keeps getting bigger.