MICHELLE THALLER: So, Danial, you have actually asked a question that I have never gotten before and that is: What is the most boring thing in space? Can astronomers agree on what the most boring thing is? I normally get asked about what's the most interesting things are in space, but I've never been asked about what the most boring thing is. And actually this gives me a chance to talk about how science works.
We have a saying in science that everybody's data is somebody else's noise and everybody's noise is somebody else's data. Let me explain what that means. When you're taking a measurement – say you want to observe a star that's very far away – there's stuff that can get in the way. There's a lot of gas and dust in space between you and the star so when you observe the light from the star you need to correct out all that crud that got in the way. You don't want to look at that, you want to look at the star. But people who want to study the gas and the dust itself can use the starlight as a probe to actually go through it. Some people will be interested in different parts of the data. Everything you do in science, there's a bit that's inconvenient, noisy, you want to actually correct it out from your data. Somebody else wants to know about that. And some of the most amazing discoveries in the universe have been what people assumed were noises, things that had to be corrected, things you didn't want.
Most spectacularly, there's something called the microwave background radiation. Now there were some astronomers back in the 1960s and '70s who wanted to study the sky in microwave light. The Sun emits microwaves, the planets emit microwaves – everywhere they looked on the sky there was noise, there was a bit of background noise that they wanted to correct out; they did not want that noise at all. And they thought it was a problem with their telescope at first. Famously, there were pigeons roosting in the telescope and they thought that the pigeon poop might be generating this noise so they scrubbed out all the pigeon poop. The noise never went away. It stayed there through every attempt they had to make it go away and all of a sudden people realized what they had detected, what this noise was, was a signal from the Big Bang itself. It was actually the farthest observation of the universe we've ever been able to make.
It was from light shining from a distance of 13.7 billion light years away: the cosmic microwave background. So the answer is that there are plenty of things in astronomy that I'm not interested in, plenty of things that get in the way of my data that I want to correct out and not know about. And there are other astronomers who want that specific data. Everybody's junk is somebody else's treasure.