Sunday, August 10, 2014

The black hole at the birth of the universe

http://phys.org/news/2014-08-black-hole-birth-universe.html
I wrote about something like this in a college term paper in cosmology - a generalization of the donut shape in 4D.

Friday, August 1, 2014

Traffic Equations

If you are like me, during a long drive you'll drift into thinking about traffic. Seems to me there is an important function that relates speed and density of the cars, this is the minimum_safe_distance( s ) for a speed s. Below this distance you cannot stop in time. The average distance between cars is >= min_safe_dist(s). If we think of density as the reciprocal of average distance then
  • (1/traffic density) >= min_safe_dist(s)
  We can add a few other rules of thumb:
  • higher density lanes tend to merge into lower density ones
  • as many cars enter an interchange as leave it. 
  • people usually drive as fast as they can