What is Einstein's Equivalence Principle?

In this video I explain what the equivalence principle is, how it connects special relativity with general relativity, and why it's got nothing to do with the idea that the earth is flat.

A good starting point for the reference that I mention at 7:39 is this paper:

Nonequivalence of equivalence principles
Eolo Di Casola, Stefano Liberati, Sebastiano Sonego
Am. J. Phys. 83, 39 (2015)

[davidasher]

I was a Flat Earther for 4 years.... and then I turned 5..

[daveseddon]

6:41 "which is, excuse me, a sphere"
Nicely summed up Sabine!

[mrroneill]

It must be quite exhausting being a heroine fighting the demons of ignorance and intentional deception. But you do it beautifully! ❤️👼👍🏻👌✨🇮🇪☘️

[oisnowy]

I wonder how many brain cells Sabine had to sacrifice just to read the flat earth website and think about what they wrote. Hope the hurt's gone away by now.

[parthabanerjee]

"The flat-earthers - There is already a paradox in that incomplete sentence.

[booJay]

Really looking forward to your live stream on PBS Space Time next week, Sabine!

[uvofsam]

I just found your channel today, i am literally binge watching every video of you and also sharing it with my colleagues of my university.

Thanks for this great videos

[GRosa]

"The Flat Earth Society has members all around the globe." 😎

[MultiAstig]

She explains and throw shades with casual sassiness. I love it!

[DavidSaintloth]

" the Earth is, excuse me, a sphere. " LoL, love it.

[christianmartinez]

It's 4:14 a.m. here, but I'm glad I'm investing my time into the things I love, and I'm good at it. Physics is the best, and I'm happy channels like this exist in these moments.

[AChicShowBigganPodcast]

most remarkable collection of nonsense xD

[colfrancis]

Thanks, great video and Merry Christmas to you.
At 5:52 you stated "all kinds of energy densities (....) gravitate". Did you mean ALL kinds?
Does gravitational potential energy count as a form of energy that gravitates? Do we need to calculate and include gravitational binding energies as a contribution to the stress-energy tensor? Can we calculate that binding energy BEFORE you have the stress-energy tensor to tell you how spacetime curves?

[LoneIgadzra]

I never cease to be impressed by the graphic design of these videos. The costume + background combo is always super-effective at keeping my focus long enough to digest the concept.

[nbridge]

Best communicator of science as far as I am concerned, should be mandatory in schools and universities.

[dremaboy]

If Sabine says it... THAT'S IT.
Amazing, that she can turn wasted time (flat earth theory) into valuable information. fabulous.

[joethestack]

Another excellent video. Thanks for not showing the classic curved space diagram that is often somewhat misleadingly used in explanations involving general relativity - the one where a planet is resting on a rubber-like sheet and thereby curving the formerly flat sheet.

[filipgren]

I'm in love with popular science for long. Your style is refreshing. Keen and precise. No fantasy, just facts. Refreshing.

[RadioBat]

Sabine is looking so beautiful. And 174 likes/0 dislikes. Everybody likes her. One of the best physics channel. And the way she roasts the idiots in a cold way.

[JackClayton]

This reminds my of Velikofsky’s “When Worlds Collide”. He was ridiculed for his theories. Carl Sagan thought that the rebuttal should have been scientific (as Velikofsky was erroneous on many points), instead of just ignoring his hypothesis, regardless of how outlandish it seemed. After all, Wegener was ridiculed for the theory of continental drift, but accumulated evidence eventual proved his hypothesis was substantiated. Darwin seems to have erred in assuming evolution was gradual, whereas punctuated evolution is now gaining traction. Asimov’s essay “The Relativity if Wrong” address this basic scientific issue. Real scientists never assume they know an absolute truth, only that each successive hypothesis/theory is more correct than the last one. They knew over 2, 000 years ago the earth was not flat.