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Skip to 0 minutes and 14 seconds Hi, we are here with George, in order to discuss his own discovery– the discovery of fluctuations in the cosmic microwave background– and the context of a discovery, but also his own personal reaction. I thank you. So let me start immediately with a question about the context. What was the spirit of the community at the time where you were preparing the COBE mission? So you have to remember things were very different then. It was more than 25 years ago now, and there was a lot of uncertainty in cosmology. We didn’t know nearly as much as we know now. And there were lots of doubts and competing ideas, and lots of uncertainty about things.

Skip to 1 minute and 2 seconds And there were even some people doubting that we could make galaxies. We had first thought that galaxies would be in the way of our trying to observe and understand the universe. And then we came to realise that understanding what galaxies– how they came into existence and what caused them was a major problem. And there were people saying their calculations show that the Big Bang couldn’t make them. It must be wrong, there must be something else. So there was a whole lot of uncertainty in the community. And that set the stage for new observations to make the progress.

Skip to 1 minute and 37 seconds So you prepare the mission. The mission is launched. You wait for a few months, I guess. And then there is one day where you think, OK, this is the moment of discovery. I’ve discovered the fluctuations. So was there such a moment? There was such a moment, but a lot of things led up to that. First, there was a huge team of people that put the satellite together, put the instruments together, tested everything, and eventually launched it. And I had been arguing– please turn my instrument on as soon as possible– because we want to know if it survived the launch. And they’re saying no, no, we’re going to systematically check out the satellite.

Skip to 2 minutes and 13 seconds But by the time we’re part of an orbit– we were passing over Antarctica– the extra reflected sunlight produced too much electrical power on the solar cells, and they turned the instrument on. So immediately we were able to see– as the satellite rotated around, we swung past the moon. We saw a signal from the moon. We saw the noise from our receiver, and the automatic calibration came on. So right away we knew the instrument was working. And by the end of the first day we were processing the data. We had our first map. It only covered about a quarter of the sky. Six months we had our first full map, and we were able to analyse it.

Skip to 2 minutes and 50 seconds You get a big gain when you get the whole maps and everything ties together. But it took us a year of working analysing because we had to be sure we had the software right. We had to be sure that we had all the calibrations right. We had a whole number of things to do. And we wanted to be absolutely sure that we weren’t making some mistake, or misinterpreting something– that we really were seeing signals from the universe. And so there was a long effort when I tried to keep everybody focused on showing that we had it right.

Skip to 3 minutes and 21 seconds And then, finally, when we saw that everything seemed to be right, then people could turn to analysing the discovery and see what it means. And so during that time– when it was very busy and exciting– but we got to the point where we’re looking at it, and we’re saying, oh, these extra features we’re seeing in the map, they’re probably coming from the universe. What do they look like? What do they mean? And it didn’t look quite right, and I’m trying all these different things. And I finally realised that if we looked at things a certain way, it wouldn’t work that way. So I ran my programme, and it looked OK. So I had a grad student.

Skip to 3 minutes and 54 seconds And I said, please, try and analyse the data this way. He said, well, all right. And I said, don’t go home until you try it this way. And so 1 o’clock in the morning he finally came to me and said, I’ve analysed it. What does it mean? It looks interesting. And I saved the note– somewhere I have it in a notebook. And at that point I knew we made a discovery, and it was a matter now of processing through. But the first part was we had to show it was the radiation from the Big Bang. We had to show what we’re seeing were real features on our map. Then we could treat ourselves to the discovery.

Skip to 4 minutes and 26 seconds And so you make this discovery– what is your personal reaction, immediately? So my immediate personal reaction was here it is 1 o’clock in the morning. I can finally go home, but it didn’t matter. It was late. I’m walking down the hill towards my house, and the traffic lights have gone from changing the normal way to blinking. But I’m just sort of floating along, I don’t even notice my footsteps. I’m thinking, ah-ha, we found something. We know something about the universe. We have this tool we can use to see what the universe is like. And so that was really very exciting. And that was exciting in a professional level and also a personal level.

Skip to 5 minutes and 4 seconds But in a much deeper way it came some months later when we had explained to NASA. And NASA had said you have to prepare a public press release when you make the announcement. Then we’ll have a press conference and do that. And then we were writing up in plain terms. And at that point, I realised not only was it important to us scientifically, but it was going to have huge impact on the world’s view.

Skip to 5 minutes and 29 seconds And so, how did the community react to this? It was somewhat expected, but people had been waiting for it for a long time. So how did they react? So we tried to keep everything quiet until we had the big announcement, which was at the annual American Physical Society meeting in Washington, DC. And we had the whole team there, and each one gave a little short speech. And we did that. But we invited our colleagues to come. And then we had a press conference scheduled for the afternoon after the morning announcements. And that was so that our colleagues could hear the results, But, also, they could do that.

Skip to 6 minutes and 3 seconds And some of the people on our team who couldn’t go and visit– they were having seminars at their own universities. And so there was an immediate response because we released the papers. We gave these talks. There were press release, and people were reading the papers and having conferences. There was tremendous response both from the scientific community that, finally, there’s some order. We see the direction we should be going. But, also, the public response was really tremendous. And that had a reinforcing impact. Scientists were excited. That got the reporters and the public excited. And they went back and forth. Many new people came into the field, the field grew quite a lot.

Skip to 6 minutes and 40 seconds And it also convinced the funding agencies this was a very important, exciting thing to do. So we had second mission, and a third mission. And now we’re talking about possibly even a fourth mission. And so it made a huge difference. It created a huge industry– brought a lot of people into cosmology. And we learned a huge amount in those 25 years. Our understanding of cosmology is much, much stronger and much better now. In the end, it comes down to gravity and understanding things. And gravity turns out to be the most important force in the universe. But it still teaches us a lot about what we would have thought was unknowable, but now is routine. Well, thank you very much.

Skip to 7 minutes and 21 seconds I think it’s interesting to have first hand testimony on this sort of groundbreaking discovery. Quite often we talk about results, but not so much about the way we find results. And I think this experience, personal experience of what is a big discovery– I think it might be interesting to all of us, Thanks a lot. Thank you.

An interview with George Smoot

In this interview, George Smoot gives us a recollection of the moments of his discovery of fluctuations in the Cosmic Microwave Background, what was his personal reaction, and how the scientific community reacted to this major discovery.

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Gravity! The Big Bang, Black Holes and Gravitational Waves

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