What is General Relativity? Lesson 6: Introduction to compact coordinates

This video is about What is General Relativity? Lesson 6: Introduction to compact coordinates

[justanotherguy]

I like that you do not assume that your students know, and go into great detail about the steps that you are taking. So the whole point of the coordinate transformation is to compactify the new coordinate system to a flat spacetime metric?

Between you and eigenchris, god willing, I will one day be able to tell the difference between butter and I can't believe it's not butter.
Thank you!

[keshavshrestha]

Wow such a great lecture about conformal-compactified coordinate Really really Thank you Sir from the bottom of my heart.. Sir at last of the video when you transform the original coordinate( t and r) to t telda and r telda and draw a triangular spacetime diagram for t telda and r telda including the trajectories of light Ray does those t telda and r telda spacetime diagram resemble the Penrose diagram..?? And another Question is that you said that the conformal-compactified coordinate system is still flat spacetime but we get non zero Riemann curvature tensor from metric of conformal-compactified coordinate system how is that possible..?? Eagerly Waiting for your reply sir.

[deepakkhanna]

Towards the end of the videa at about 1:04:20 ( and around that), you show that worldlines that were straight in (t, r) ( original co-ordinate system) are not straight lines in the new compactified coordinates (t tilda, r tilda). Since the worldlines which were straight in the original coordinates are not straight in these new coordinates, does it mean that these new coordinates are not coordinates of an inertial frame. Am I correct in interpreting this. Please let me know.