Here’s a heavyweight Origins Symposium: Leading physicists/cosmologists try to tell us what they know about the universe, and I must say, it isn’t much, which they readily admit.

We get from them the concepts of “dark matter” and “dark energy”, where of course the adjective “dark” means it’s out of sight, i.e. not visible, in other words not understood. In fact, the universe is roughly 2/3 dark energy and 1/3 matter most of which is dark matter. The bottom line is that about 96% of the universe is dark, i.e. not understood.

These dark things were not predicted theoretically but were determined from astronomical measurements using well understood theory.

I’ve been spending a lot of time the last couple days listening to these discussions. The quality of the presentations varies quite a bit. These people may be well trained in esoteric science but they’re merely human after all, and of course what they’re talking about isn’t so easy to explain.

A very good introduction to the symposium is the discussion moderated by Ira Flatow of NPR’s Science Friday here.

Left to right in this picture are Ira Flatow the moderator, Lawrence Krauss, Michael Turner, Brian Greene, Steven Weinburg, the latter four being all prominent physicists and good presenters.