But it doesn t mean that they can t be modelled into Joel Primack s theoretical universe. The idea is that these wimps clump together in their zillion zillions to make the haloes of invisible dark matter that float around each and every galaxy. By making up a model Universe this way, with the right amount of gravity, galaxies fall into line and create the long chains, filaments, and sheets of galaxies that astronomers tell us are really up there. The obvious candidate for hot dark matter is a particle called a neutrino. A Model Universe.
Neutrinos turn up all the time in nuclear reactions.
And they re in the cosmos in huge numbers. A billion pass through each one of us every second. Actually, they re not supposed to have any mass at all, but some people think they do, so into the computer model they go. California USA Ph. The site includes useful instructions on how to download the images from the Visualisation Gallery, according to which browser you have.