The Crisis in Cosmology

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The Crisis in Cosmology 5
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The search for a single number: the hubble constant, which is the rate of expansion of our universe, has consumed astronomers for generations. Finally, two powerful and independent methods have refined its measurement to unprecedented precision. The only problem is that they don’t agree. This calls into question some of our most basic assumptions about the universe.

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Previous Episode: Why String Theory Is Wrong

Hosted by Matt O'Dowd
Written by Matt O'Dowd
Graphics by Luke Maroldi
Directing by Andrew Kornhaber

In 1929, Edwin Hubble discovered the universe. He gave us our first incontrovertible proof that there are galaxies outside the Milky Way by measuring the distances to the spiral nebulae. They were many millions of light years from us –far outside the Milky Way and so must be galaxies in their own right. Combined with the Doppler-shift velocity measurements of Vesto Slipher, Hubble revealed that the galaxies are not only receding from us, but they are receding at a rate proportional to their distance.

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سلطان الخليفي

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💬 Comments on the video

*An engineer walks in*
Just take the average of the results and call it a day...

Author — Ahmed Appas


Man I'm smart.

*watches PBS video*

Man I'm stupid.

Author — Hugo Joubert


"Dark Energy = Dark matter * (Speed of Dark)^2" got me laughing for much longer than I should have

Author — Vellyxenya


Well the answer is obvious isn't it?
Hubble Constant = 42

Author — Draeas


we could just cut the photons in half and count the rings

Author — Antoine Roquentin


I think it's fair to say the calculation based off the CMBR relies on more assumptions than that of Type 1a Supernovae.

Author — Lee


I get excited when there’s an argument between prediction and observation at this level — because it means we are missing something. And that means more science!


Author — Jes Ewers


It would seem that the "constant" would prefer to be a variable.

Author — Lloyd Hargrove


Socrates: Shall we set down astronomy among the objects of study?

Glaucon: I think so, to know something about the seasons, the months and the years is of use for military purposes, as well as for agriculture and for navigation.

Socrates: It amuses me to see how afraid you are, lest the common herd of people should accuse you of recommending useless studies.
— Socrates

Author — Joseph Campbell


It's possible that the universe is a woman and is just lying about her age

Author — Mike O


"He reveals to us that D.E.=dark M x the speed of dark, squared!"

Agree with Matt, genius on so many levels.

Author — Philip Melton


"We know everything, as long as we can prove this number is constant"
"... damnit."

Author — TheBendejo


Whether you use standard candles or cosmic microwave, your frozen burrito is still going to have a great cold spot.

Author — R R



Author — 33DavePaton33


I really do wish you'd include links to the papers you cite.

Author — Michael Sommers


Question: Does the Local equation assume it starts from a singularity?

What if it didn't? How big would the initial universe need to be to make the two equations align?

Author — Dorian Lust


Hear me out ok, what if, the acceleration is accelerating?

Author — Pursuits of Life.


Don't judge a cosmologist until you've walked a megaparsec in his SHOES.

Author — Pan Darius Kairos


Hat's off to ya, Mr. Nation. You cracked the case! ;)

Author — agiar2000


This was actually discovered by Georges Lemaitre some years before. He was a boss and the true father of cosmology.

Author — Fiore Deutchmark