Living in Interesting Times
As far as particle physics and big questions about how the universe works, we are living in very interesting times, I’m happy to say. We’ve all been waiting for the Large Hadron Collider (LHC) for over two decades, and now it turns out (I’ve been hearing from a number of people in various conversations here at the center) that the machine is running really well – impressively so. That alone is great, but an interesting thing is that we are almost certainly going to know something significant before the end of the current scientific run next year, maybe even by the end of 2011!
Recall (see posts like this one) that the primary goal is to understand the physics responsible for the Higgs mechanism – the physics that gave mass to those elementary particles that have mass. The particle that does this is called the Higgs particle, and exactly how Nature implements the Higgs mechanism is what we hope to learn. There’s sort of a vanilla version of the story, that fits into the Standard Model of particle physics without any further adornment than just doing the basic job. Then there are more complicated versions of the story, where, in some cases, the Higgs comes as part of a bigger physics story that leads the way to what’s generally called Beyond the Standard Model Physics. As the machine searches toward higher and higher energy that probes higher and higher mass, the simplest possibilities will begin to fall by the wayside pretty soon if nothing is seen. An exciting thing is that it seems that whether or not we have the Standard Model Higgs might be known soon.
Now that’s exciting enough, but there’s more. Actually, a lot of people, for various […] Click to continue reading this post
It was a fun week in the string theory class this week, as we got to some major landmarks that are always fun to teach. We’ve uncovered the extended objects called D-branes (see numerous previous posts for how useful and important these objects are in string theory research) in all their glory in the lectures before, and deduced lots of their properties, such as the form of the action that determines how a D-brane moving in spacetime responds to the various fields (including the geometry) created by the string theory. That’s all fun, but then the key thing to do next is to compute the mass of these dynamical objects, or the mass per unit volume – the tension. Computing it fully, with no hand-wavy factors. Your mass measures how strongly you interact with gravity. So you can measure it by studying the gravitational interaction between masses. (You do that when you step on a scale to measure your weight… well the scale does it by showing how much force it takes to stop you from falling through the floor toward the center of the earth…) 
This always catches people off guard (myself included), so I thought I’d post a little reminder. The deadline for applications to the Summer workshops at the Aspen Center for Physics is January 31st. That’s coming up soon, so to physicists interested in doing a research stay, start thinking about the dates you want to attend, finding funds for support, planning for things like childcare or summer programs for children if you have any, and so on and so forth. There’s a wide variety of excellent […] 
