Why Time and Space swap in a Black Hole

What is the difference between time and space? Why do time and space swap roles in a black hole? What is a Penrose diagram? All these answers in 12 minutes!

0:00 - Light cones
2:45 - Space and time
4:56 - General relativity
6:20 - Black holes
10:13 - Collapse diagrams

This video is narrated by Octave Masson.
And if you liked this video, you can share it on social networks !

Alessandro Roussel,

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[labplay]

I like how you take pauses for us to grasp and figure everything out

[mrdre]

People underestimate how important good visualization graphics are to a complicated subject; I've understood the concepts of what you're saying for a while theoretically, but seeing it laid out so clearly definitely clarified things and I understand Penrose diagrams better as well so thank you...hopefully science educators can unlock the secrets of clear and understandable graphic design

[MrHopecoreOfficial]

"The horizon of the black hole is no longer a place in space, but a moment in our past. And the centre of the black hole is no longer a point, but an event in our future... a destiny we cannot avoid" Something about this gives me chills

[igbaccin]

"If the apple falls, although it was motionless at first, it is because its future points downwards". This! This encapsulates the role gravity plays on time wonderfully. It felt like everything I read and watched on the subject suddenly clicked. The "aha!" moment! I deeply thank you for the insight.

[rikschaaf]

It's quite enlightening to see what is meant with time and space flipping when NOT looking at a penrose diagram. The 45 degree angle of time at the event horizon really makes it easier to understand.

[ARIY]

This is the best video I have ever watched. The moment when you described how Space Time works visually was like an epiphany for me. Thank you for spending the time to create a video with such clear explanations. I hope you are able to continue making high quality videos.

[kato_dsrdr]

The science community really need to give awards to people who teach us, ordinary people about science.. It's honestly a HUGE contribution for humanity..

[studypurposeonly]

This just blew my mind honestly! Since we can't access past events and the fact that space and time switch each other at the black hole, the outside of the black hole actually becomes an event in the past from a point in space! This is another elegant way of saying "Nothing can escape a black hole". Mind-boggling video as always

[Blackhole_T]

This has got to be the most interesting and terrifying video I’ve ever seen
“The center of the black hole is your future” is an amazing phrase lol

[marcelo.pastorelli]

This is arguably the best science channel out there. Thank you for your efforts in sharing knowledge!

[HodsBroo]

I've watched hundreds of hours of content and videos regarding 4D Space Time and I'm once again reminded at how the representations in your content are of the very best possible. You have a way of making things so simple and elegant, that they become easy to relate to and digest. Very good work.

[martyd]

I'm a 50 year Old Irish man and has actually made me feel intelligent. What a fantastic way to illustrate the concept. The light cones have made everything fall into place. It's taken me 50 years to find something that allows me to grasp it!!!!

[eneafrancesco]

Holy Moly! This channel has created by far the pedagogically highest quality way of teaching extremely complex subjects.

Thank you so much for the great work that goes into these videos: they inspire me again and again in my interest in the universe, its rules, and in my efforts to inspire other people too!

[ayushvyas]

I never truly understood the meaning of light cones concept... mentioned many times in other videos but never elaborated so beautifully....as soon as you turned that 2d to 3d...clarity was there ...
Thanks a lot bro, you are a gift to this world 👍👍👍

[C_Corpze]

I love how this is done, little pauses to allow us to catch up, simple explanation and good visuals that help picture it better. Thank you very much!

[goga]

Your videos are criminally underrated. Such a masterpiece!

[horizonvariations]

Fascinating to hear that it is not a black hole's huge amount of force that drags us to its centre, but a future event in time instead. Brilliant stuff!

[sgringo]

I've watched this video several times over the past two years. Each time, I'm amazed anew at how brilliantly this nonintuitive concept is explained. This is, by far, the clearest description of time's relationship to general relativity that I have seen.

[timothynoll]

1) This BLEW MY MIND because it gave me a whole new and much better perspective on how general relativity, space, time, gravity, and black holes work. 2) Thank you for the pauses between sentences because I would have been lost as heck otherwise.

[ltsecondincomand]

This has got to be the best explanation of how light cones and gravity are related I've ever seen. Its so good it made me retroactively understand videos I've watch before.