Dark Energy and the Vacuum Catastrophe

In this video I would like to discuss one of the great unsolved problems in fundamental physics, the famous vacuum energy catastrophe (also known as the cosmological constant problem). What makes the problem so fascinating is that it weaves together two of the most successful theories of the 21st century, quantum field theory and general relativity, and demonstrates that something has gone catastrophically wrong in our attempt to understand the origin of our expanding universe.

The reason that we know something has gone horribly wrong is because our most successful theory of physics predicts that the universe should be doubling in size every millionth of a trillionth of a trillionth of a trillionth of a second! But this is clearly not happening. In fact, our best experimental observations suggest that the universe is in fact doubling in size every ten billion years. So what has gone wrong? And why? In order to answer this question we are going to need to take a journey through some of the most exciting ideas in modern physics, from the smallest quantum fluctuations of the vacuum, to the mysterious dark energy which is driving the accelerated expansion of the universe.

References:

Introduction to Cosmology - Ian Morrison
A Universe from Nothing - Lawrence Krauss
Introduction to Cosmology - M.Pettini
Introduction to Cosmology - Matts Roos
Introduction to Cosmology - Barbara Ryden
The Cosmological Constant Problem and (no) solutions to it - Wolfgang Hollick ()

[Scrogan]

“Let’s take a deeper look at the vacuum of space”
You say, pushing me out the airlock.

[JG-zstr]

when in doubt, just slap a cosmological constant onto the end of the equation

[Mechadude]

Sure "the universe should have torn itself apart in a minute fraction of a second" sounds bad but I maintain that "ovens should produce limitless energy and radiation" is still the worse prediction.

[JC-zwvs]

Loving the fact you get straight into the equations....and give really clear narrative about how they work and what they mean. I'm not a physicist, just have an interest. So many lectures aimed at folk like me avoid the equations; wrongly in my view. Keep it up!!!

[jakebramhall]

"We are now in a position to combine all of our previous results"
Oh yeah, it's all coming together.

[JyChau]

Me preparing to sleep at 3am:
youtube: DARK ENERGY AND THE VACUUM CATASTROPHE

[monday]

Love the way you show how the most important findings and problems in physics can be derived from basic equations. Thank you!

[realcygnus]

Pretty much equivalent to about a dozen+ hours of Lenny Susskind's/Stanford lectures(which are superb in their own right imo) but amazingly condensed to well under an hour. A priceless EDU Gem !

[jeffk]

Thank you so much. This is incredible content. Your technical explanations are at a perfect level for a lot of us who enjoy deeper dives into physics. I hope your channel grows.

[johnopalko]

Brilliant job! I was really disappointed when the video ended after only 49 minutes. I could have listened to you for another couple of hours, at least.

[flockofwingeddoors]

As someone starting a physics degree soon, I just wanted to say that you are an incredible content creator. Your work is inspiring and clear, keep up the amazing effort!

[jimlbeaver]

This must have taken an incredible amount of work to create. It was very thorough and clear. Thanks and great job!

[fburton]

Squeezing a billion trillion trillion trillion Andromeda galaxies into one cubic metre... He's 'avin a laugh!

[jimpollard]

I make an error this big on my paper: get it marked wrong.
PhD's make an error this big: write grant proposals.

[timgabby]

If you walk into a room and find a pencil's standing on it's point - you're in a freefalling elevator! Who would have thought :)

[richardsilva-spokane]

New sub: Back in the sixties when I attended high school, I was drawn to read Scientific American in spite of the fact that I comprehended very little of the content. In the same way—as a layperson—I am enchanted by the production values and teaching methods of this video.👍👍👍👍👍

[scottrobinson]

I wish I had this video when I was in the middle of my cosmology module at university... I've always been bad at seeing the 'whole picture' as I'm learning and studying for an exam, but when I revisit summaries later on, it all fits together nicely.

Your videos are excellent.

[albadarqamar]

Thanks again man for this quality content

[scottrobinson]

For any fans of SixtySymbols, you may like to know that Ed Copeland refers to the Friedmann equation as the "Cool Dude" equation in his lectures and notes. You have to love him

[thjnz]

Amazing, as always. Thanks for taking the considerable time to cogently summarize and relate these concepts - I always learn something from your videos.