yego.me
💡 Stop wasting time. Read Youtube instead of watch. Download Chrome Extension

What is Space Time? | StarTalk


2m read
·Nov 11, 2024

What is space time? You already know. You have never met someone at a place unless it was also at a time. You have never met someone at a time unless it was-- OK, I get it. I get it. So we-- Whoa, well, wait a minute.

What happens to a photon from 13 billion 0.800 million years that comes this way and enters my eye so I can see it? Where's space involved in that? It entered your eye at a time and at a place right here. That's all that matters here. Is that all we're saying?

Well, once you have formalized space and time and know that they're conjoined, then you can make all kinds of fascinating calculations with relativity. Well, what is all that? The train's going and I'm walking down there. - Exactly!

I'm walking down the train. I'm walking on-- And the time change. And the time is going to change. What is all that? That's all the consequences of thinking about space and time as conjoined. But it's confusing. So?

And not only is it-- The universe is under no obligation to make sense to William Shatner. OK? No, but William Shatner's under the obligation to make sense of the universe, as you are doing. And why do I slow down as I approach the speed of light?

It doesn't apply to a photon 13 billion-- No. You want to freak out? I don't want your head to explode. You ready? - Yeah. - OK. - No, you're not ready. Are you ready? - No, I'm ready. I'm ready. - OK, OK.

The faster you go, the slower time ticks. Say that again. The faster you move, the slower time ticks for you as seen by others. Right. As you approach the speed of light, time continues to slow down.

WILLIAM SHATNER: Yes. At the speed of light, time stops. Which means for a photon moving at the speed of light, when it is absorbed in your retina, it is the same instant it was emitted at the Big Bang 14 billion years ago.

That's what I thought. The photon gets emitted. Bam! As far as it's concerned, it is in your eye in that same instant. Can we measure that photon and observe-- Yes!

WILLIAM SHATNER: --the Big Bang? I know that that came from the Big Bang, and I'm watching it. And it's taken 13.8 billion years to reach you. But if you are that photon, it does not experience that time delay.

What a great science fiction story. That-- Instantaneous. [applause]

More Articles

View All
The water cycle | Ecology | Khan Academy
Let’s talk a little bit about the water cycle, which we’re all familiar with. In fact, we’re all part of the water cycle every moment of our lives. We might not fully appreciate it, so let’s just jump into the cycle. I’ll start with evaporation. So, we c…
Millennium Falcon or Starship Enterprise? - Fan Question | StarTalk
[Music] Oh, that’s easy. Oh my gosh, no, the Enterprise! There’s no question. No question! The Enterprise has the benefit of being real, in the sense that there are real scientists and real engineers on staff on the ship monitoring its engines, its warp …
The Seventh Amendment | US government and civics | Khan Academy
Hi, this is Kim from Khan Academy. Today, we’re learning more about the Seventh Amendment to the U.S. Constitution. The Seventh Amendment guarantees the right to juries in civil cases when the value in controversy is greater than twenty dollars. To learn…
How to negotiate with billionaires.
I negotiate with billionaires every day in what I do. Everybody always asks me, “How do you negotiate with a billionaire, a big corporate executive, and things like that?” To tell you the truth, you negotiate with them just like you negotiate with anybod…
Prepositions of neither space nor time | The parts of speech | Grammar | Khan Academy
Hey Garans, we’ve talked about prepositions of time, and we’ve talked about prepositions of space. I couldn’t come up with a name for these because the following five prepositions are examples of what we would call prepositions that have connotations for …
SUPER RARE $34,000 Mont Blanc Will DOUBLE in Value | Kevin O'Leary |
[Music] From Germany, just send them straight out the door. Okay, thanks a lot, let’s go upstairs. Welcome to Miami. [Music] So, just coming from—well, we have the head of—we have the head of VP of retail, and I think one of the marketing people are brin…