Neil deGrasse Tyson on the Webb Telescope and the Big Bang

So what has changed in terms of our understanding? The web has been in the million mile orbit or however far away it is. For how long now? Well, it got there and then we did some engineering. So I guess a year, year and a half. And what has changed in our understanding? So that's been people's first question and what I want to do is temper that to say something a little different. So yes, we expect James Webb to make great discoveries. We expect that. But the first order of business is hardly ever, let's discover something new today. It's here's something that we have limited understanding of, let's improve on that. And in so doing, we deepen our understanding of how things work in the universe. That doesn't always involve overturning a previous idea or discovering something that nobody ordered. All right? That will happen. We fully expect that to happen. But we targeted parts of the sky initially because we know other telescopes have gone there before. And we're going to say how can we further advance and deepen our understanding? One thing it's going to be able to do and it has already done, we have, you know how many exoplanets there are? I don't know how many of your audience was born after 1995. How many 27-year-olds and younger? Probably quite a few. Quite a few. Okay. So I will take this opportunity to night them. Generation Exoplanet. Ah, see what you did there. 1995 was the first exoplanet discovered, a planet orbiting another star. And I'll never forget that because it was my first time on national television. I was freshly minted as director of the Hayden Planetarium in New York City. And NBC sent the, New York City, this is the media news headquarters, right, of all the networks. So NBC sent an action cam. They interviewed me because of my title, not because they knew or gave a crap who I was. My title was director of the planetarium. And so I gave my best professorial reply. I said, well, it was the Doppler shift. This is how it's discovered and what we do and how we measure it. And I was describing the fact that when you discover these planets, you don't actually see the planet. You see the effect of the planet's gravity on the host star. And so if you'd watch the host star, the host star like jiggles, okay, just a little bit in response to the planet going back and forth around it. So you're measuring the star. I motioned that with my hips and that evening on the evening news, that's all they showed was me jiggling my hips. I said, oh my gosh, okay, that's how you're going to do this. Okay. You don't want me to be Professor Neil. You want me to be sound bite Neil. All right. So from then on, I practiced my sound bites and a sound bite is like three sentences. Oh, so you recognize that this is the format now. Correct. And I said, I can't just give them my stump speech as Professor of Astrophysics. It has to work in their medium. And so I went home and stood in front of the mirror and had people just shout out things to me, anything in the universe, any idea, object, person, place, or thing. And I would come up with like three sentences that are interesting, make you smile and be tasty enough to want to tell someone else the anatomy of a sound bite. So try it. Say anything in the whole universe. How do we know how- No, just one word. Just say anything. The Big Bang. Big Bang. Ooh, the birth of space time energy and everything we know and love about this universe. It occurred 14 billion years ago and we have no idea what happened before it. And we're still expanding, as we will forever. I read an article- That's my sound bite for the Big Bang. That's a good sound bite. I read an article about the Webb Telescope and what they were taking into consideration is the possibility that the Big Bang may be incorrect and that the universe might be larger and older than we think. So I hesitate to ask what pages on the internet you hang out on. It wasn't saying the universe is older. It's saying as more data and new information comes in, there is a distinct possibility that the Big Bang might just be the- it just might explain the reach of the technology and not the actual scale of the universe itself. Okay, so the way to think about this is, and this is the way science has worked since basically the year 1600 where Galileo sort of starts codifying what people knew probably should be happening but no one really did it in large scale. If you have an idea about something, then you test it multiple ways and get other people to test it. And if the tests give you consistent results, you have a new understanding of the universe. When that happens, that knowledge of the universe doesn't go away. It doesn't get undone. What happens typically is you have a deeper understanding of the universe in which that understanding gets embedded and you realize that you only understood a small part of a larger whole. But the small parts you did understand where you had multiple experiments that confirmed it, that doesn't change. So the cleanest example of this, and I'll get back to your question, is Newton's laws of motion and gravity. Did anyone see anything move faster than a galloping horse in his day? Probably not. And so the Newton's laws of motion and gravity worked. They worked not only for galloping horses, it worked for the moon in orbit around the Earth and the Earth in orbit around the sun and Jupiter's moons in orbit around Jupiter, and for the planets. So okay, but wait a minute. It doesn't work for Mercury. Mercury's orbit is not following Newton's laws. Is there something wrong with the data? Let's check it. That's correct. Oh my gosh, what's happening? Einstein comes along and says, I have a new understanding of gravity and a new understanding of motion and it accounts for this weirdness in Mercury's orbit. What was the weirdness? Its shape was not exactly what Newton's laws of gravity would give you. Its shape could only be accounted for when you throw in Einstein's theory of general relativity. Why? Because the sun's gravity is so monstrous and Mercury's orbiting close enough to it that it's being influenced by extra phenomenon going on in the universe that's the product of very high and significant gravity. And so then do we throw Newton out the window? No actually. You know what Newton's laws are? They're what Einstein's laws look like when you put in low speeds and low gravity. If you put in low speeds, they become Newton's laws in that limit. Newton's laws don't stop working where they used to work. Apollo to the moon used only Newton's laws because Einstein didn't matter at those scales. The moon and earth and rockets, we're not going fast enough for any of that to matter. But when you start going fast enough, you cannot use Newton's laws. You have to use a deeper understanding. Now where does Einstein take us? You go into the center of a black hole, you get black holes from Einstein. Center of a black hole is a singularity. All the theories say the matter occupies zero volume thereby having infinite density. And that's kind of weird. What? No, you can't have infinite. No. That's a limit of Einstein's theory. That's where it breaks down. It's some of the joke that's where God divides by zero. Remember in math class, you can't divide by zero. It's not defined or not allowed. So in Einstein's equations, we're dividing by zero at the singularity. So we all know that as brilliant as Einstein was and as successful as his general theory of relativity has been, it has limits. And one limit is the center of a black hole and another limit is the very birth of the universe itself. Getting back to your question, the Big Bang. So we have top people working on trying to resolve the singularity problem. And in so doing, you get to some ideas that, well, maybe our Big Bang, because the Big Bang is not going to go away. All the data support this. So now I've got this Big Bang thing. And well, is this embedded in something bigger? So when you put like quantum physics and general relativity and you try to come up with some bigger understanding, deeper understanding, strength theorists have been all into this, you get a multiverse. We didn't pull that out of our ass. That came out of the equations. So how old is the multiverse? I don't know. It's definitely older than our universe because it birthed our universe and it birthed other universes and it birthed the way the equations drive it and infinity of universes. This is the idea that maybe there's a version of us and another where I'm bald and you got the afro and who is, but everything else is the same. And also a version where everything's the same. Where everything would be the same, yes. Everything you've ever said has been said before exactly in the same order. Correct. There's no reason to presume that everything in this universe isn't or hasn't already played out in the exact way in another one of these infinite universes. And in an infinite number of different ways. Correct. And so that is what comes out of the equations. So that makes the big bang a kind of a small part of a much larger whole. And so yeah, we're ready for that. But the fact that the universe had a beginning 14 billion years ago and there's the cosmic microwave background, all of these features are intact. They're not going to all of a sudden not apply. That's my point. That's my long answer to your very clean question. This thing that happened 14 billion years ago, what is the predominant theory of why? So this multiverse concept gives us a reason why. So it's like, imagine you're rolling around in a basin. And you're stable there. You're just fine. But then something kicks you out of the basin and you didn't know that there's a huge hill to roll down after you come out of that basin. But you didn't know that. You thought everything was just fine. You roll down that hill, you're gaining energy. At the bottom of the hill, something stops you. And then where does all that energy go? One of the hypotheses, and I'm highly simplifying here, is that the energy gained by rolling down a hill, and these are energy hills that would exist in this sort of higher dimensional space that we're talking about, that energy has to manifest in that object somehow and it becomes an explosion and gives birth. With enough energy, it gives birth to matter, everything that we know and love, and it expands. Because when you concentrate that much energy in a small spot, that's the only thing you can do. I understand that you're simplifying it, but I don't understand it. But in the sense that by using this basin analogy and rolling down a hill, there are equations of the energetics of a system, and this is called a false vacuum. So you can be in a place that's not the true bottom energy state of the system, but you think everything is fine, but it's not. And so if you move around among these hills and valleys, you end up birthing universes out the other side. And this multiverse concept actually delivers this for you, basically for free. That thought would be that the Big Bang is just one of many events that happen in the multiverse. Correct. And to me that, it could be that other Big Bang events might have a slightly different laws of physics in it. So you want to watch out for that if you cross over from one universe to the other, and the charge on the electron is slightly different. All your atoms could just scatter or compress into a pile of goo. Yeah, so take something to test first. Yeah, send a chicken out there. Chicken's getting no respect. What happened to guinea pigs? Well, guinea pigs are cute and furry. They're cute and furry. Oh my gosh.