Hawking Closer to the Sun

Our Sun imaged by STEREO, the Solar Terrestrial Relations Observatory. The twin STEREO spacecraft allow 3-D images of the Sun and surroundings. Best wishes to Stephen Hawking, for today was the day of his long-awaited zero-G flight. Desire to slip the surly bonds of Earth is far older than humanity, as symbolised by Icarus' flight. Hawking's biggest discovery may have a lot to do with the Sun.

There are many unsolved mysteries about the Sun. The temperature of its surface is thousands of degrees, yet the corona is millions of degrees. The corona is laced with magnetic fields which contribute to its high temperature. The sunspots which Galileo saw mark the locations of magnetic field lines. Solar flares related to sunspots affect communications on Earth and could be a great hazard for interplanetary flights. Solar variations are part of the debate on Earth's climate. Though life on Earth depends on the Sun, we are far from understanding it.

According to the standard solar model, when Earth was formed the Sun shone with only 70% of its present luminosity. Earth’s surface would have been frozen solid, making evolution of life very unlikely. Geology and the fossil record contradict this prediction. The very appearance of life on Earth conflicts with the model. This conflict with observations was the Faint Young Sun paradox. Because the Sun turns fuel into energy according to E=mc^2, change in c precisely accounts for this paradox. If c had not changed in precisely the amounts predicted, life would not have evolved to read this post.

Hawking's biggest discovery was that Black Holes are not completely black--they tend to radiate as blackbodies. Hawking first presented his results in a talk entitled "Black Hole Explosions?" When he had finished, the moderator said, "Sorry Stephen, but this is absolute rubbush." At least Hawking was allowed to finish. Within a few years people realised that Stephen was right, and scientific fame followed.

One big mystery about the Sun is how it formed in the first place. We know that stars form from collapsing disks of gas, but how the fusion reaction begins has been a complete mystery. If the gas cloud were heated, it would dissipate before a sustained fusion raction could begin. The disk's angular momentum would also be carried off into Space. Something else is needed to trigger a cloud's collapse into a star.

If tiny Black Holes collided with a gas cloud, they would not suck everything up. The tiny amount that they did eat would produce an immense amount of Hawking radiation. Heat and the gravitational pull of a singularity would ignite a star and keep it steadily burning for billions of years. A Black Hole could exist in the second last place humans would look for one, in front of our face each morning.