How Does Gravity Affect Light?

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We know that gravity exerts its pull on light, and we have an explanation for why. Actually, we have multiple explanations that all predict the same thing. And at first glance, these explanations seem to describe completely different causes. So what is the true connection between light and gravity, or is truth, in fact, entirely relative?

Sabine Hossenfelder's episode "Do we travel through time at the speed of light?"

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Hosted by Matt O'Dowd
Written by Matt O'Dowd
Graphics by Leonardo Scholzer, Yago Ballarini, Pedro Osinski, Adriano Leal & Stephanie Faria
GFX Visualizations: Katherine Kornei
Directed by Andrew Kornhaber
Assistant Producer: Setare Gholipour
Executive Producers: Eric Brown & Andrew Kornhaber





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[inlegivel]

I love how my brain is now conditioned to predict when he's going to end the video. It can sense the "space time" coming.

[realBeltalowda]

My life has been made immeasurably better due to the very fact that PBS Space Time exists.

[Pope_iShovel]

The best part about this channel is that some of us can watch it endlessly due to not understanding much. Me for example - I could rewatch any episode, and it would be fairly close to the same as the first time watching.

[r-pupz]

That was a particularly good episode from my frame of reference, just been binging old episodes & finally got my head round relativity enough to really appreciate the new info. I only understand it relative to my prior ignorance, but that is more than enough for me. Thanks Matt & PBS!

[MargoMB]

I love that whenever there isn't a comment section at the end of the video, the explanation always has something to do with the video's topic. It's such a little thing that really adds to the quality of the whole thing, imo.

[Sayuri-crcy]

Props to the graphic designers on this show lol without them I’d never understand anything

[AdilKhan-gdsc]

Gravity, “I met space and time, and couldn’t tell one from the other.”

[pinfarmer]

Thank you for doing these! I feel spoiled that I've had 4 years of this consistently excellent content.

[gracekerns]

when you use the wrong assumptions to get the right answer: "task failed successfully."

[delusionalluy]

PBS Space Time: * post a video *

Me: Cool! it's time to melt a few neurons

[gvidasbrilius]

Ok, I watch quite a lot of your videos, but this one is weird because i actually feel like i understood it all. Props to you guys for making such worth-while entertainment, I bet it's a hassle to make it understandable.

[RyuuKageDesu]

I am relatively uncertain about our shifting times, but I can easily observe the gravity of how enlightening these episodes are.

[Eyerleth]

"These giant alien spiders are no joke."

You got your FTL in my Space Time! You got your Space Time in my FTL!

[dexterrity]

The closing statement is pure Space Time poetic brilliance

[Tiberius]

I have a slightly different definition of the Theory of Relativity: *"That temporal phenomenon whereby time seems to slow down whenever relatives come to visit".*

[DJHastingsFeverPitch]

Your point at the end makes an interesting point about the function of beliefs in general. That is, that from the perspective of human beings, beliefs only need to be accurate enough to successfully predict future events. In that sense, beliefs don't necessarily need to give a comprehensive account of that aspect of reality, but merely need to give an accurate enough account to be comprehensively pragmatic.

[paulperkins]

Some physicists think that the idea of time flowing at different rates is more confusing than helpful in explaining relativity. They prefer to compare time to the length of a path, but a path through space-time, not just space. Different paths that connect the same two points in space-time can be different length-analogues.

[riverground]

I believe this is the first time Space Time has made me go "Hmm" in a way that is both simultaneously satisfied with the explanation yet dissatisfied with our incomplete understanding of the universe.

[danieljensen]

As a physics PhD student who doesn't do GR, these past couple videos on this subject have been eye opening. Now instead of acceleration I'm just thinking about rotating 4- vectors.

[jamesb]

Relativity did much more than I think initially intended. It opened a door to a whole new level of understanding