Neil deGrasse Tyson - Can We Go Back in Time Using a SpaceTime Machine?

On the bright side, at least we can go back in time in a way through YouTube, music, movies, and art

As a kid I wanted to go back in time to see a dinosaur. Now I wanted to go back in 2020 to appreciate, and save someone. I would do anything to bring him back. I just wanted to see him even one last time.

"I want to go back in time. Not to change anything, but to feel something again.”

I desperately wanna go back to January 2019 to enjoy my good times again. I really wish we can refresh time and enjoy life again.

I desperately want to go back in time.

If going back in time is possible, then that means the past still exists. If the past still exists, then that means we are functionally immortal. We exist within our frame of reference ( our lifetime) and we always will.

Neil explains in a way that anyone can understand 🙌🏽

I love to listen to Neil explain stuff. Most of the time it's a struggle just to keep up but every now and then a light goes on in my brain (which doesn't have any of this higher knowledge in it) and I actually understand and see what he's saying.

Time travel is such an interesting topic

Blows my mind how our interpretation of the universe mathematically makes us right in solving and making calculations on hypothesis

Would have loved him as a science teacher

I wish the same. My fiance just passed away and not even have the time to say goodbye. She died before I can say it one more time😢😢😢

I always assumed that if you managed to go back in time, you'd probably be in a separate reality, not the original one you were from. Basically a branched reality where things and events transpire differently. That would explain the grandfather paradox.

A new thing I just thought of: what if it's only possible to view the past, but the second you stop moving, your real time catches back up with you?

I wonder if this could be done on a "micro" scale instead of using light years and endless space (not knowing exactly where you will end up) but something much smaller where you could control precisely where you enter and exit the "wormhole" in question required to travel back and forth in time (miniature black hole etc)

I have a very basic question that I have wondered for a very long time. If I travel at the speed of light from earth. This would mean everyone on earth is also travelling at the speed of light relative to me. So how can my clock tick slower (or not tick at all) while Earth's clock tick normal. I mean why would time stop/slow down for me and not for Earth? Why and how would I travel in future in that case? I mean who is to say who is travelling at the speed of light? Since it is all relative?

A hypothesis: time does go backwards but that started with antiparticles at the "big bang" and they are going backwards in time from there, we only can see the forward traveling particles. We can see the backwards type particles very rarely but most are at the other end of time.

I think the paradox would be dealt with, IF each movement back in space-time then created a whole new branch of space-time at that point. So, you go back to 1900 and from that point there becomes now two divergent space-time branches. The original branch then remains unchanged because your self is no longer on that branch after whatever point you leave. Each time you move forward or backwards a new branch is created, meaning you keep moving `forward` in a relative sense through each new branch you create, regardless of where it is on the timeline. In that case, you could kill your parents before they had you and avoid a paradox, because `you` weren't born on the space-time branch you killed them on and that space-time branch still exists unchanged to the point you left it. There's not a shred of scientific evidence to support that idea though, so it's kind of just mental fluff. What would it take to overcome that paradox?

I have no real interest in actually learning about space but boy do I enjoy listening to Neil explain things.

Awesome. I understood nothing from this video.