Well, welcome back. It's been a while, hasn't it? It's been way too long since I left you at that wonderful, wonderful cliffhanger.

If you haven't listened to the first episode in this series, you probably should because I really, really want you to understand what I'm saying and not listening to the first part of a multi-part series.

It's a serious detriment to that goal.

I mean, it's hard to have complete knowledge of time and space, which is this show's goal without having, you know, complete knowledge of time and space.

So if you haven't listened to the first episode, go ahead and do that now.

I will be here waiting.

Don't worry.

I am not going anywhere.

Now, I hope you're back.

Welcome back.

Last time I left you, we learned the state of the world in 1905, 1906, after special relativity had made its big splash and everyone's

saying, oh, now I get it. Now I get how space and time are related. Now I get how mass and

energy are related. Now I get, I need to go back through all the physical theories and make sure they're compatible

with this new thing that's going on called special relativity.

And the one thing that was missing from that, the big one that was missing from that, was

gravity itself.

So people were thinking, everyone was thinking, including Einstein, about how to make gravity agree with special relativity.

How do you cast the equations of gravity in a form that's compatible with this view of interlocked space and time on non-simultaneity of observers about all the juicy good stuff that lives in special relativity.

I also gave a mini rant about Einstein and how we perceive Einstein in the present day and how it

took years of toil to come up with what we call general relativity or modern theory of gravity.

And I introduced the key, the foundation, the cornerstone, the one absolute, what appears

to be fact about our universe that I want you to take away from these episodes.

...