Description
Transcript: Galileo was the first to show that sunspots are surface features on the Sun carried around by its rotation. Be very careful ever observing sunspots with the naked eye. Galileo spent the last twenty years of his life blind from careless observations of the Sun. The best procedure is to magnify the Sun’s image with a small telescope and project it into a viewing chamber shielded from outside light. Sunspots are magnetic disturbed regions cooler than the surrounding areas. They have temperatures of four thousand to forty-five hundred degrees Kelvin versus fifty-seven hundred degrees on average for the solar photosphere. The gas motions in a sunspot are controlled by intense magnetic fields.
Transcript: Physicists in the nineteenth century made various estimates of the age of the Sun, but they were fundamentally unaware of the most efficient energy source known. Early in the twentieth century physicists Rutherford and Becquerel began a systematic study of the phenomenon of...
Published 07/24/11
Transcript: Chemical energy cannot power the Sun, so what is the energy source? Inspired by an idea by the German physicist Hermann von Helmholtz the English physicist Lord Kelvin explored the idea of gravitational contraction. In this mechanism the Sun is slowly shrinking and gravitational...
Published 07/24/11
Transcript: Above the solar chromosphere is the corona, a diffuse outer layer of gas at the amazing temperature of two million degrees Kelvin. Both the chromosphere and the corona have higher temperatures than the photosphere. How can this be? One way for gas to become hot is pressure. Higher...
Published 07/24/11