Brian Cox

The fact that they all fit with the picture of a universe that's 13.8 billion years old, a sun that's 4.5 billion years old, a planet that's 4.5 billion years old, the fact that it all fits is quite an intricate model. And so you could say, well, I argue with the measurements of the age of the Earth. Maybe I don't like the radioactive dating or something, and people will say that.

But the thing is, it's a consistent picture with multiple different observations. And same with dark matter. So the standard model of cosmology is you have, as I said, about 5% matter, 25% dark matter, 70% dark energy. It might be wrong, but it fits loads of different independent observations. So it's a consistent picture.

But the thing is, it's a consistent picture with multiple different observations. And same with dark matter. So the standard model of cosmology is you have, as I said, about 5% matter, 25% dark matter, 70% dark energy. It might be wrong, but it fits loads of different independent observations. So it's a consistent picture.

But the thing is, it's a consistent picture with multiple different observations. And same with dark matter. So the standard model of cosmology is you have, as I said, about 5% matter, 25% dark matter, 70% dark energy. It might be wrong, but it fits loads of different independent observations. So it's a consistent picture.

There are theories that people try to build where you modify our theory of gravity. So many of these observations, not all of them, so the cosmic microwave background are different observations, but many of them depend on gravity and how gravity works, Einstein's theory of general relativity. So you could try to modify that theory to say, well, our observation's wrong.

There are theories that people try to build where you modify our theory of gravity. So many of these observations, not all of them, so the cosmic microwave background are different observations, but many of them depend on gravity and how gravity works, Einstein's theory of general relativity. So you could try to modify that theory to say, well, our observation's wrong.

There are theories that people try to build where you modify our theory of gravity. So many of these observations, not all of them, so the cosmic microwave background are different observations, but many of them depend on gravity and how gravity works, Einstein's theory of general relativity. So you could try to modify that theory to say, well, our observation's wrong.

Maybe, because the way we measure how the expansion of the universe is, is to look at light from supernovae is one way, and see how it's stretched over time. Because the light, let's say you have a supernova, and it happened a billion years ago, then the light has been traveling for a billion years across the universe.

Maybe, because the way we measure how the expansion of the universe is, is to look at light from supernovae is one way, and see how it's stretched over time. Because the light, let's say you have a supernova, and it happened a billion years ago, then the light has been traveling for a billion years across the universe.

Maybe, because the way we measure how the expansion of the universe is, is to look at light from supernovae is one way, and see how it's stretched over time. Because the light, let's say you have a supernova, and it happened a billion years ago, then the light has been traveling for a billion years across the universe.

And so the universe has been expanding for a billion years, so the light will be stretched. And so you can measure how much stretch there is. You just measure the color of the light from the supernova. So you can argue that maybe if you go for light that's been traveling 12 billion years across the universe, then maybe there was something different. Maybe the light was emitted a bit different.

And so the universe has been expanding for a billion years, so the light will be stretched. And so you can measure how much stretch there is. You just measure the color of the light from the supernova. So you can argue that maybe if you go for light that's been traveling 12 billion years across the universe, then maybe there was something different. Maybe the light was emitted a bit different.

And so the universe has been expanding for a billion years, so the light will be stretched. And so you can measure how much stretch there is. You just measure the color of the light from the supernova. So you can argue that maybe if you go for light that's been traveling 12 billion years across the universe, then maybe there was something different. Maybe the light was emitted a bit different.

Maybe the speed of light changes over time or something. So you can invent theories that would allow you to change the data or the interpretation of the data. But what you always find, I think it would be fair to say, is that you can change a theory and explain one bit, but all the wheels come off the other bits. Got it. So that's why it's quite difficult.

Maybe the speed of light changes over time or something. So you can invent theories that would allow you to change the data or the interpretation of the data. But what you always find, I think it would be fair to say, is that you can change a theory and explain one bit, but all the wheels come off the other bits. Got it. So that's why it's quite difficult.

Maybe the speed of light changes over time or something. So you can invent theories that would allow you to change the data or the interpretation of the data. But what you always find, I think it would be fair to say, is that you can change a theory and explain one bit, but all the wheels come off the other bits. Got it. So that's why it's quite difficult.

Yeah. So it fits. Yeah. But then there are some mysteries. Not least, what is this stuff? Right. And so until you know what it is, you don't have a complete theory.

Yeah. So it fits. Yeah. But then there are some mysteries. Not least, what is this stuff? Right. And so until you know what it is, you don't have a complete theory.

Yeah. So it fits. Yeah. But then there are some mysteries. Not least, what is this stuff? Right. And so until you know what it is, you don't have a complete theory.

Yeah. Yeah. And so that's what I love about. One of the things I love about science is it often gets presented, you know, because I talk about science a lot in public and it can often seem arrogant. I think it can seem, you know, like these people are saying, well, this is the way the world is. And you might say, well, you know, how are you to say this?