We were signed up for more sessions today, and Teresa and I had made separate choices over the Internet a while back to get what we wanted before they sold out.
First on my agenda was a WSF Salon, “Refining Cosmology.” At the World Science Festival, a salon is a smaller session in which there is more of an opportunity for interaction between the panel members and the audience. It is usually a follow-on to a much larger session. In this case the main session had been the prior evening, which I did not make, and apparently covered the basics of the big bang, inflation and the which had occurred at the beginning of our universe, and cosmic microwave background radiation (CMBR), which provides much of the evidence for what happened. Since I was familiar with the topic, missing the main session was not too much of a problem.
The participants in the Salon were: Suzanne Staggs who is making ever more refined measurements of the CMBR, John Carlson, who leads the 10-meter telescope project at the south pole of all places, Britt Reichborn-Kjennerud, who is organizing a ballon-borne telescope project to measure the polarization of the CMBR, and John Kovac, who is also looking for polarization in order to possibly find evidence of gravity waves which have yet to be detected experimentally. The session was moderated by Lawrence Krauss, author and physicist who is investigating the origin of matter in our universe.
To summarize, they are all working to get ever more detailed and sophisticated measurements of the CMBR to detect primordial influences that give clues to what happened back then, and what has happened to the radiation since then, such as gravitational lensing, passage through ionized gases, spectral shifting, etc. It seems like there is a lot of information in the CMBR, and these people are determined to get it. It takes extremely sophisticated instruments to tease out the data because we are talking about variations of one part in a million and even less.
Many of the experiments are carried out at the South Pole. Theree are three reasons they work there: The polar cap is at a high elevation, about 10,000 feet, and the air is very dry and very cold. In response to one questioner on the subject, the response was, “It’s an act of desperation.”
It was good to hear these people talk about their work, and what they hope to learn.
Teresa and I met to go to the next session together. Although there was a no pre-session, it was another Salon, “Alan Alda’s Burning Question, What is a Flame”? At age 11 Alda had asked a teacher what a flame was and had been given a dismissive answer, “It’s combustion”. As a result of that non-answer, only two months ago he organized a contest in which scientists were asked to explain a flame in a way that was correct, and which would enlighten, interest and stimulate an eleven year old. We heard several written and video responses to the question from finalists and honorable mentions, but the winning answer, based on evaluations from over 6,000 11 year olds would not be revealed until the following day. [The winner was Ben Ames and you can check out his video answer here: http://flamechallenge.org/.]
In the evening, Tersesa went to a session about t tress and inventor, Hedy Lamarr, and her associate Antheil. They invented frequency-hopping secure communications.
I went to a wonderful session to hear about how experimentalists are looking for the neutrino. I had no idea how many different approaches were being used to examine their behavior. Interactions with ordinary matter are so rare,
This evening I went to a session on “The Elusive Neutrino and the Nature of the Cosmos” followed by a Salon on the same subject. A neutrino can go through 10,000 light years of lead without hitting anything. Up to now I had been under the impression that neutrinos
were so hard to detect that once it had been done, there would be no point in spending more time looking for such rare events. That’s not the case at all, and there are at least several experiments going on to learn more about them. Nuclear reactors are a good source of neutrinos so Janet Conrad has placed her detector, a 30 foot cube of mineral oil right next to one. Supernovas are rare but a good source of neutrinos, and a world wide system has been set up to give investigators a few hours notice of when to look for neutrinos. Another experiment uses a block of ice with a volume of 300 billion cubic feet. I calculate that’s a cube of ice 1.3 miles on a side. Hmm.
Neutrinos are wrapped up in the issue of particle mass in part because it was originally thought to have no mass, and the Standard Model does not include masses. Having detected the mass of a neutrino allowed research to progress in a variety of directions to learn more about them. It is inevitable that the Standard Model will be updated to account for particle masses.
There was much more discussed, but I cannot do justice here to what I learned from the scientists. It was a good evening.