Sunday, January 28, 2007

We are stardust

Nature is amazing. For example, did you ever think that all of us are basically made of star dust?

When the cosmos began, current evidence suggests that just about the only elements present were hydrogen and helium, with traces of lithium. Gravitation pulled clumps of dust and gas together until there was enough mass to begin to form a star, and when the mass was great enough for gravity to squeeze and heat the mass enough, thermonuclear fusion began to fuse hydrogen into helium. Late in a star’s life, when it runs out of hydrogen, it shifts to fusing helium, and then carbon and then heavier elements. Finally, at the end of its lifecycle, it blows out much of this material into the surrounding void, and that becomes the gas and dust from which the next generation of stars are born.

So our world, unusual in its concentration of heavy metals, is no doubt the product of several generations of stars, each generation fusing more of the lighter elements into heavier elements before blowing them back into the cosmic dust to be recycled into another star.

It’s awesome to think that we, and almost everything around us in our world, have been created in the massive thermonuclear furnaces of stars. It’s interesting that the creation myths in so many cultures have the first human being made of dust scooped up by some deity or other. In a sense they were right, we are all made of dust - star dust.