― UART variations (ex machina), Monday, 22 January 2007 22:12 (eighteen years ago)
― UART variations (ex machina), Monday, 22 January 2007 22:14 (eighteen years ago)
― am0n (am0n), Monday, 22 January 2007 22:17 (eighteen years ago)
― UART variations (ex machina), Tuesday, 23 January 2007 03:55 (eighteen years ago)
― caek (caek), Tuesday, 23 January 2007 15:36 (eighteen years ago)
http://en.wikipedia.org/wiki/Comet_mcnaught
― UART variations (ex machina), Tuesday, 23 January 2007 15:39 (eighteen years ago)
― caek (caek), Tuesday, 23 January 2007 15:39 (eighteen years ago)
― caek (caek), Tuesday, 23 January 2007 15:40 (eighteen years ago)
― caek (caek), Tuesday, 23 January 2007 15:41 (eighteen years ago)
http://news.bbc.co.uk/nol/shared/spl/hi/pop_ups/07/sci_nat_enl_1169636484/img/1.jpg
Latest from my PhD (angular momentum of gas in my model galaxy, should ideally be constant, i.e. this is not cool)
http://img183.imageshack.us/img183/2646/gasangmom0002be.gif
― caek (caek), Wednesday, 24 January 2007 23:30 (eighteen years ago)
― UART variations (ex machina), Wednesday, 24 January 2007 23:34 (eighteen years ago)
http://img148.imageshack.us/img148/7541/star9ky.gif
It's modelled by solving some differential equations numerically. The stars can be dealt with quite simply by treating them as point particles (like one million of them) and the forces between them as simple 1/distance^2 gravity, i.e. Newtonian. Relativity's effects are negligible. However, the gas is a serious complication. In most galaxy's it's an insignificant component by mass, but in the one's I'm interested it's quite important so you have to model it. You can't treat gas as point particles in this situation, and there's much more than gravity (there's also pressure, viscosity, etc.) which complicates things.
The code is a godless mixture of C, C++ and Fortran, with reduction/animation scripts in Python, commented in a mixture of English, French and Italian. It's run on Beowulf clusters. It won't compile against modern versions of gcc or run on 64bit machines. It's a mess. It pays the bills though.
― caek (caek), Wednesday, 24 January 2007 23:43 (eighteen years ago)
― caek (caek), Wednesday, 24 January 2007 23:45 (eighteen years ago)
― UART variations (ex machina), Wednesday, 24 January 2007 23:52 (eighteen years ago)
― caek (caek), Wednesday, 24 January 2007 23:53 (eighteen years ago)