Interesting talk by Richard Feynman on Light:
(The following is an YouTube video embed)

Very interesting - Dyson Spheres

The BBC (where, incidentally Mary is now working!) reports about a “tsunami” on the Sun. The more interesting part is that for the first time ever, astronomers have captured this on video.
You can watch the “tsunami on the Sun” movie here.
An idea of the energy involved:

Co-author David Long, from Trinity College Dublin (TCD), Ireland, commented: “The energy released in these explosions is phenomenal; about two billion times the annual world energy consumption in just a fraction of a second.

Link obtained via: Slashdot.org

Time may not exist, writes Tim Folger in the Discover Magazine.

This is an interesting article that probes deep into the concept of time and the perception that we hold of this supposedly omnipresent entity.

Excerpts:

Krausz uses ultraviolet laser pulses to track the absurdly brief quantum leaps of electrons within atoms. The events he probes last for about 100 attoseconds, or 100 quintillionths of a second. For a little perspective, 100 attoseconds is to one second as a second is to 300 million years. But even Krausz works far from the frontier of time. There is a temporal realm called the Planck scale, where even attoseconds drag by like eons. It marks the edge of known physics, a region where distances and intervals are so short that the very concepts of time and space start to break down.

Efforts to understand time below the Planck scale have led to an exceedingly strange juncture in physics. The problem, in brief, is that time may not exist at the most fundamental level of physical reality. If so, then what is time?

Rovelli, the advocate of a timeless universe, says the NIST timekeepers have it right. Moreover, their point of view is consistent with the Wheeler-DeWitt equation. “We never really see time,” he says. “We see only clocks. If you say this object moves, what you really mean is that this object is here when the hand of your clock is here, and so on. We say we measure time with clocks, but we see only the hands of the clocks, not time itself. And the hands of a clock are a physical variable like any other. So in a sense we cheat because what we really observe are physical variables as a function of other physical variables, but we represent that as if everything is evolving in time.

Another important and strange fact that the article refers to is that time always points towards the future:

All the laws—whether Newton’s, Einstein’s, or the quirky quantum rules—would work equally well if time ran backward. As far as we can tell, though, time is a one-way process; it never reverses, even though no laws restrict it.

People busy building time-machines might just want to visit these revised theories of time.

Article link.