Events at Physics |
Events on Tuesday, February 22nd, 2011
- Chaos & Complex Systems Seminar
- Chaos in the Three-Body Coulomb Problem
- Time: 12:00 pm
- Place: 4274 Chamberlin Hall
- Speaker: Vladimir Zhdankin, UW-Madison Dept. of Physics
- Abstract: The three-body problem is one of the most famous examples of a chaotic system. In the traditional case, the goal is to determine the motion of three massive bodies interacting through Newton's law of universal gravitation. Similarly, the goal in the three-body Coulomb problem is to determine the motion of three electrically charged particles interacting through Coulomb's law. Among other things, this can be used as a classical model of the helium atom (where the effects of quantum mechanics are neglected). This talk will describe and present some numerical solutions to the three-body Coulomb problem. The general solution has a short transient chaotic phase until one particle is ejected from the system, but special initial conditions are found to give chaotic orbits that remain bounded.
- High Energy Seminar
- Searching for the Identity of Dark Matter
- Time: 3:00 pm - 4:00 pm
- Place: 4274 Chamberlin
- Speaker: Lauren Hsu, Fermilab
- Abstract: Astrophysical observations have confirmed that ordinary matter<br> makes up only ~15% of the observable matter in the universe. The composition of the remaining non-luminous (dark) matter is<br> unknown. This is a time of great excitement. Efforts on<br> various fronts are racing to elucidate the particle nature of<br> dark matter. With a collection of germanium and silicon<br> crystals cooled to ~50 mK, the Cryogenic Dark Matter Search is<br> looking for the possible rare collision of a prime dark matter<br> candidate, the weakly interacting massive particle (WIMP), with<br> ordinary matter. I will report on recent results from CDMS<br> and discuss the status of the future experimental phases. These include the 10-kg phase of SuperCDMS, which is beginning<br> now, the 100-kg stage at SNOLAB, which has a projected start<br> date of 2013, and looking forward into the future, the 1-ton<br> GEODM.<br>
- Host: Karsten Heeger