What if Singularities DO NOT Exist?

Roy Kerr, being almost 90 years old, had been looking at this debacle for half a century, and then said “fine, I’ll do it myself”. What a chad.

Kerr is still shaking things up at 90 years old. What a beast.

I've been watching PBS for 40 years. From 3-2-1 contact to Spacetime and more. You're a kids and now a mans best friend.

I'm glad PBS is still going after all these years. And still has decent content.

Man, he's 90 and still contributing to physics. That's life goals right there.

10:45 It can’t be put into words how utterly disappointed I am that this isn’t called a Ringularity.

Unfortunately I was taught in school to not ask what if questions because they are endless and most instructors do not have the knowledge or time to tell you an answer. I LOVE PBS thanks so much for giving us these in depth analysis' on topics like this. It's really great seeing the scientific method being practiced real-time and gives you an inordinate amount of respect for all the beautiful minds thinking of these things.

I'm really glad that the PBS channels exist, but especially Space Time. Physics has always been something that fascinated me, but I was forced to drop out of my physics class in high school in order to graduate on time (due to a slew of problems caused by my guidance counselor) despite being one of only 3 people who grasped the material we covered in the first month or so, and unfortunately I was never able to pick it up even recreationally in college due to scheduling conflicts with my required courses. This channel does a great job of breaking down complex concepts in a way that is easy to follow with a basic understanding of physics and allows to me to still be able to learn and understand more on my own time without shoveling money into further education. Seriously, thank you guys for taking the time and effort to make these videos and in an easily accessible way.

I read the paper with ever-increasing levels of incomprehension. Eventually I came to  "Since we had a preprint of Papapetrou’s paper we put the Kerr metric into his canonical form. The covariant form of the metric, ds2, is then a sum of squares of a suitably weighted orthonormal basis, ds2 = Σ dr2 − ∆ 􏰀dts + a sin2 θ dφs􏰁2 , ∆Σ + Σdθ2 + sin2θ 􏰀(r2 + a2)dφs − adts􏰁2 (13) Σ We stared at this metric for a very short time, gave up and went for coffee. " I did the same.

Here's an observation that I think a lot of people here are getting wrong: Many comments are saying "I didn't believe in singularities anyways!" and yeah, many physicists agree. It's been said even on this series that singularities are simply gaps in our math. The point is that we didn't have a solution, and that's why this is important. Of course you didn't believe in singularities. But while the problem was obvious, the solution was not. What the cited paper is saying is "What if singularities don't exist *even within the current theory*." As stated in the video, everyone wanted to get rid of this problem, but assumed we needed a new Theory of Everything that combined GR and QM. But this is a potential solution that shows that GR might still be functional. Is a new Theory of Everything still the goal? Of course. BUT, maybe GR and QM are not scrap that needs to be thrown out, but maybe 2 puzzle pieces that CAN fit together, to show the full picture. And even if GR is thrown out eventually, the more we refine it, the better our eventual understandings will be.

I’m not a physicist but I am a huge space nerd. When I’ve pictured a black hole, Kerr’s model seems to be the most logical. I’ve just always imagined a black hole is more of a spherical/ pancake shape just like in the model. Great to see this!

"One Ring to rule them all, One Ring to find them, One Ring to bring them all and in the darkness bind them." At least now we know what Tolkien was talking about...

Dear whoever edits/does music for these, ✨ PLEASE make the outro quieter! I love listening to these before bed and the last 15 seconds are so much louder than the entire episode. THANK YOU! 🙏 ✨ Sincerely, A mom who just wants to peacefully learn and fall asleep to science

"Singularity-free spacetime!" - Sounds like a great slogan for a T-shirt.

This is one of the things I've been thinking for quite long time. The concept of the existence of a point where there's infinity density and infinity gravity sounds quite implausible. The center might be a place with unimaginable density but it doesn't mean it is infinite. The most obvious answer is that our mathematical models are not developed enough to comprehend what's truly happening at the center of a black hole. I am glad I found this video to shed light on this topic!!

It does make sense a black hole could be an extremely dense object that we can't yet conceive instead of a single point with some infinit density.

This is one of the best videos Space Time has ever produced. Technical, succinct, refers to sources, gives references, and great graphics. Whoa! Well done.

Although I barely understand 5% of the mathematics and physics behind it, I enjoy watching this show. Very relaxing! Thank you!

Dr. Matt -- as usual -- another fabulous and educational vid... I usually view them multiple times... keep on keeping on... best vid on the net!

That's great and all, but I'm still not jumping into a black hole.