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So over 100 years ago, Einstein came up with this geometric theory of gravity, which deforms space-time. Matter deforms space-time, and then space-time tells matter in turn how to move around it. You can get enough matter into a small enough region that it punctures space-time, and even light can't escape the force of gravity. Light is kept inside. Before that, the reason the Earth moves around the Sun is not because the Sun is pulling the Earth as we think, but because the Sun has literally changed the shape of space so that the Earth just falls around it. The geometry of space-time tells the Earth how to move around the Sun, and so you're almost seeing a black hole puncture through space-time. When it goes so deeply in, there's a point at which light orbits the black hole.
So this is what's happening here, right? This is not an image. This is a computer simulation of what we always thought one thing going into the event horizon around a black hole would look like. Yes. Until last week, we had no idea what a black hole really looked like. The best we could do were simulations like this in supercomputers. But even here you see this ring of light, which is the orbit of photons. That's where photons literally move around the black hole. Around that is hot gas, which is drawn to the black hole, and it's hot because of friction. All this gas is trying to get into a very small volume, so it heats up.
A few years ago, you embarked on this mission to try and actually image one of these things, and I guess you focused on this galaxy way out there. Tell us about this galaxy. This is the galaxy where we're going to zoom into, galaxy M87, which is 55 million light years away, which is a long way. At its heart there's a six and a half billion solar mass black hole. That's hard for us to really fathom: six and a half billion suns compressed into a single point. It is governing some of the energetics of the center of this galaxy. Even though that thing is so huge, because it's so far away, to actually dream of getting an image of it is incredibly hard. The resolution you would need would be incredible.
Yes. Black holes are the smallest objects in the known universe, but they have these outsized effects on whole galaxies. But to see one, you would need to build a telescope as large as the Earth, because the black hole we're looking at gives off copious radio waves. It's emitting all the time. Tell me exactly what you did.
So what you're seeing here is that we've used telescopes all around the world. We synchronized them perfectly with atomic clocks so they received the light waves from this black hole, and then we stitched all of that data together to make an image. To do that, the weather had to be right in all of those locations at the same time, so you could actually get a clear view. Yes. We had to get lucky in a lot of different ways. Sometimes it's better to be lucky than good. In this case, we were both, I like to think. But light had to come from the black hole. It had to come through intergalactic space, through the Earth's atmosphere, where water vapor can absorb it. Everything worked out perfectly. The size of the Earth at that wavelength of light, one millimeter wavelength, was just right to resolve that black hole 55 million light years away. The universe was kind of telling us what to do.
So you started capturing huge amounts of data. I think this is like half the data from just one telescope. Yes. This is one of the members of our team, Lindy Blackburn. He's sitting with half the data recorded at the Large Millimeter Telescope, which is atop a 15,000-foot mountain in Mexico. What he's holding there is about half a petabyte, which, to put it in terms we might understand, is about 5,000 people's lifetime selfie budget. It's a lot of data. So this was all shipped. You couldn't send this over the internet. All this data was shipped to one place, and the massive computer effort began to try and analyze it.
Yes. You didn't really know what you were going to see coming out of this, right? The way this technique works, imagine taking an optical mirror, smashing it, and putting all the shards in different places. The way a normal mirror works is that light rays bounce off the surface, which is perfect, and they focus at a certain point. At the same time, we take all these recordings, and with atomic clock precision we align them perfectly later in a supercomputer. We recreate an Earth-sized lens. The only way to do that is to bring the data back by plane. You can't beat the bandwidth of a 747 filled with hard disks.
So a few weeks or a few months ago, on a computer screen somewhere, this started to come into view, this moment. It took a long time. Look at this. That was the first image. So tell us what we're really looking at there. I still love it. What you're seeing is that last orbit of photons. You're seeing Einstein's geometry laid bare. The puncture in space-time is so deep that light moves around in orbit. The light behind the black hole, as I think we'll see soon, moves around and comes to us on these parallel lines at exactly that orbit. It turns out that orbit is the square root of 27 times just a handful of fundamental constants. It's extraordinary when you think about it. When I initially thought of black holes, I was thinking that the event horizon was lots of matter and light whirling around in that shape, but it's actually more complicated.
Talk us through this animation, because it's like being lensed around it. You'll see here that some light from behind it gets lensed, and there's a loop to loop around the entire orbit of the black hole. When you get enough light from all this hot gas swirling around the black hole, you wind up seeing all of these light rays come together on the screen, which is a stand-in for where you and I are. You see the definition of this ring begin to take shape, and that's what Einstein predicted over 100 years ago. Yes, that is amazing. So tell us more about what we're actually looking at here. First of all, why is part of it brighter than the rest?
What's happening is that the black hole is spinning, and you wind up with some of the gas moving towards us below and receding from us at the top. Just as a train whistle is a higher pitch when it's coming towards you, there's more energy from the gas coming towards us than going away from us. So you see the bottom part brighter, because the light is actually being boosted in our direction. How physically big is that? Our entire solar system would fit well within that dark region. And if I may, that dark region is the signature of the event horizon. The reason we don't see light from there is that the light that would come to us from that place was swallowed by the event horizon.
When you think of a black hole, you think of huge rays jetting out of it, which are pointed directly in our direction. Why don't we see them? This is a very powerful black hole, not by universal standards, but it's still powerful. From the north and south poles of this black hole, we think jets are coming out. We're too close to really see all the jet structure, but it's the base of those jets that are illuminating the space-time, and that's what's being bent around the black hole.
If you were in a spaceship whirling around that thing, how long would it take to actually go around it? At first I would give anything to be in that spaceship, so sign me up. There's something called the innermost stable circular orbit, if I can get wonky for one moment. That's the innermost orbit at which matter can move around the black hole before it spirals in. For this black hole, it's going to be between three days and about a month. It's so powerful, yet weirdly slow at one level. I think you were saying before that you wouldn't even notice falling into that event horizon if you were there. Yes. You may have heard of spaghettification, where you fall into a black hole and the gravitational field on your feet is much stronger than on your head, so you're ripped apart. This black hole is so big that you're not going to become a spaghetti noodle. You're just going to drift right through that event horizon. It's like a giant tornado. When Dorothy was whipped by a tornado, she ended up in Oz. Where do you end up if you fall into a black hole? Vancouver. Oh my god. It's the red circle. That's terrible.
Black holes really are the central mystery of our age, because that's where the quantum world and the gravitational world come together. What's inside is a singularity, and that's where all the forces become unified, because gravity finally is strong enough to compete with all the other forces. But it's hidden from us. The universe has cloaked it in the ultimate invisibility cloak, so we don't know what happens in there. There's a smaller one of these in our own galaxy. Can we go back to our own beautiful galaxy? This is the Milky Way. This is home, and somewhere in the middle of that there's another one, which you're trying to find as well, right? Yes. We already know it's there, and we've already taken data on it, and we're working on that data right now. We expect, or hope, to have something in the near future. I can't say when. It's way closer but also a lot smaller, so maybe similar science to what we saw. It turns out that the black hole in M87 that we saw before is six and a half billion solar masses, but it's so far away that it appears a certain size. The black hole in the center of our galaxy is a thousand times less massive but also a thousand times closer, so it looks the same angular size in the sky.
Finally, I guess a nod to a remarkable group of people, who are these guys. These are only some of the team. We marveled at the resonance this image has had. If you had told me it would be above the fold in all of these newspapers, I'm not sure I would have believed you, but it was, because this is a great mystery and it's inspiring for us. I hope it's inspiring to everyone. But the more important thing is that this is just a small number of the team. We're 200 people strong, with 60 institutes in 20 countries and regions. If you want to build a global telescope, you need a global team. This technique we use of linking telescopes around the world effortlessly sidesteps some of the issues that divide us, and as scientists we naturally come together to do something like this. Well, that's inspiring for our whole team this week. Thank you so much for what you did and for coming here. Thank you.