MIT Theory Retreat 2005

I just came back from MIT Physics Theory Retreat. This is an annual three-days-out-of-the-city event. Two distinguished lecturers present cutting-edge theoretical research in an introductory level.

First speaker was Lakshminarayanan Mahadevan from Harvard to tell about the physics of wrinkles. No, they are not new, fancy high energy physics objects. These are the wrinkles you see in everyday life, everywhere. He started the discussion with the wrinkles in a stretched rubber band and draping table cloths. After some math and lots of insight it turned out that methods for finding the characteristic length scale of bending is extremely universal in a sense of material and scale. We have seen various systems that can be understood along a similar reasoning; like in curtains, skin wrinkles, crumpled paper, Japanese maps, finger prints, leaves, petals, folded insect wings, carnivore plants, dripping honey patterns (see the photo), fluid catenaries...

To quote him: "Is it useful? I don't know and I don't care!" But certainly fascinating. As a cosmology student, seeing the physics that we don't really understand at the centimeter scale and centimeters far from us was an incredible fun. Maha is certainly an original and illuminating scientist.

To learn more about his research, you can look at this Harvard Gazette article, his last work on Venus flytrap and his group page.

Second speaker was Max Tegmark of MIT. He is a man of great enthusiasm, ideas and source of first-hand-up-to-date knowledge in cosmology. I'm serious; I'm not saying this because I'm working with him :)

He talked about many aspects of modern cosmology that I should have already known, but nevertheless it helped me polish things a lot.

First conundrum in cosmology is the dark energy. Among many cosmological parameters made precise in the last few years, dark energy is the most interesting one. We know it observationally only for about six years now but it is already one of the biggest problems in physics. Nobody so far has a good idea why the vacuum weights such ridiculously small amount but not exactly zero. Either changing gravity or changing high energy physics, the solution will be a revolution. I am also spending much of my research time working on alternative gravity theories to understand dark energy. There is much to say about the (short) history and possible future scenarios, but may be later.

Second point is the dark matter. Although the problem itself is very old, we still suffer lack of understanding. Here we have at least two very promising candidates, neutralinos and axions. (My supervisor Frank Wilczek named axions after a detergent brand!) They both wait for direct observation. May the LHC help us.

And finally there is the inflation. It was invented by Alan Guth more than twenty years ago to create the quite unlikely initial conditions of the universe. Today it beautifully fits many data but the details of the mechanism is still unclear.

In the last few years cosmology developed and used many new techniques like cosmic microwave background fluctuations, galaxy clustering observations, Lyman-a forest, weak gravitational lensing to measure the properties of the whole universe. Since these totally different physics all led us to the same point we are very confident about the parameters we have today and the improvement in just few years is unbelievable. Will it continue with the new instruments? Or will nature play us a dirty game and stop showing her secrets so fast? We will see.

We also had a very interesting late night bar discussion on Mach principle with Max. I hope to write more about it when things get clarified in my mind, if it ever happens.

I must say that I enjoyed in this years retreat very much. Last year I didn't get much. I hope this means I am getting ready to learn. There are scary rumors that we may not have it next year because of the budget cut. Although MIT CTP is considered one of the best theory centers in the world, it still get a budget cut because somebody up there wants a clown in Mars. I hope they realize the importance of real science done at CTP or the Beyond Einstein mission series which is totally halted. Anyway I shouldn't say more, YET.