SCIENCE BOND

When the sky is blue and clear it is because molecules in the air reflect blue light from the sun more than they are reflecting red light. The sun has all the colors of the rainbow in it; when reflected through a prism or these little molecules, you see different colors. All those colors you see in the sky are based on this principle. So just like when you shine a white light through different angles of a prism, the molecules reflect different colors when the sun is lower in the sky, such as sunset when you see the red and oranges. At sunset, the blue is then out of your line of sight.  This can be a very deep subject. You have to understand prisms and even which kinds of molecules reflect the different colors. So many really technical things to consider. In about 1859 man named John Tyndall took steps in the name of science to explain the sky's color. He proved that light passes through clear fluid and acts like a prism by polarizing the light with specific qualit...

Because of their abundance of stars, these "globular clusters" were an early favourite in the Seti field.  But recent efforts to scour the sky for planets orbiting alien stars have had little success within star clusters.  Now, two astronomers say there is good reason to keep up the search.  Rosanne Di Stefano from the Harvard-Smithsonian Center for Astrophysics, US, and Alak Ray from the Tata Institute of Fundamental Research in India, have described what they call the "globular cluster opportunity".  At an average age of 10 billion years (much wrinklier than the Sun, at four billion), globular clusters don't have many young stars, rich in the metallic elements needed to build planets. But Dr Di Stefano, speaking in Florida at the 227th meeting of the American Astronomical Society, pointed out that recent discoveries had placed exoplanets - especially small, rocky ones like Earth - around stars much less metal-rich than our Sun."When Seti first ...