TPhotos from the James Webb Telescope, which NASA has dubbed a “time machine” because it took billions of years for light to reach us, raise the question: Will we ever be able to see the big bang itself? I asked Dr. Matthew Bothwell, a public astronomer at the University of Cambridge.
How good is James Webb’s telescope?
First, it’s infrared. Firefighters wear infrared goggles because it helps them see through smoke and dust, and stars form behind lots of smoke and dust. Also, and this is a little technical, light coming from deep space is red-shifted. This is because as the universe grows and light passes through it, the light stretches and becomes redder. Finally, the telescope is really big.
If the universe is expanding, why isn’t the Earth? Why am I not stretching? Or me? Oh God, I thought I felt weird today.
We are held together by electrostatic forces, which basically means that the atoms of which we are all made sort of stick together. Expansion can only take hold where these forces, or gravity, are really weak. And this means the space between galaxies.
Ah, great little atoms stick together. So where is the universe expanding from? Would be in the center?
There is no center of the universe. It is wrong to think of space and time as a box inside which the universe resides. Space and time are properties within the universe. The Big Bang created the cosmos. There was a big explosion at every point in the universe.
Can a telescope ever see it?
I’m afraid not. From a cosmic point of view, light is quite slow. Light takes eight minutes to reach us from the sun, so when we look at the sun, we look at it eight minutes ago. When you look a million light years away, you get messages from a million years into the past. At the moment of the big bang, all matter and other things in the universe were compressed into a small volume. It was so thick it was opaque. Only as the universe grew did the density decrease and light could pass through it.
So if space is a pair of tights, when they stretch you can see through thembut before it stretches, is it too opaque to see anything?
Why is it important to see the early universe?
When you try to solve complex problems, you end up inventing things. A group in Cambridge is using millions of photographs to search for faint galaxies. It turns out the method they developed is just what you need to find tumors you can’t see with the naked eye. This has improved cancer detection rates.
Wow! I don’t usually like to talk about space; what worries me is how worthless and meaningless we all are.
There is a term for this – cosmological vertigo. I feel that too, but it can be a positive thing. This means that everything bad in the world is also meaningless, cosmic.
It’s worse than that! All the pain we cause each other is for nothing. But this cancer story was beautiful – how we reflect the universe in our bodies.
Oh, 100%. When we look at very distant galaxies, we see the same components that we are made of. Carbon, hydrogen, iron. It’s like that poem by Max Ehrman: “You are a child of the universe no less than the trees and the stars.”