Wednesday, June 06, 2012

Why Do I Walk The Length Of Every Beach I Encounter?

I am fascinated by the whole universe and everything that it offers, some of the more enchanting jewels of life are our beaches around the world. People naturally flock to them for the water is our genesis. But, have you ever wondered about grains of sand and the correlation to the number of stars in our universe? You have heard the expression loosely thrown around that there are more stars in the universe than there are grains of sand on all the beaches on the planet; well what I have here are some numbers that have been crunched down so that the lay person can really "wrap" their fingers around; check this out: Our Milky Way Galaxy is a fairly average sized galaxy. There are galaxies that are 1% the mass of the Milky Way, and there are galaxies of which the Milky Way is 1% of its mass. So we can agree that the Milky Way is a nice, safe medium to use. There are approximately 400 billion stars in the Milky Way alone. In our night sky, we can make out about 5,000 of them. And about 100 billion galaxies in the observable universe, which is an extremely conservative estimate that dates back to the 1970's. so 400,000,000,000 x 100,000,000,000 = 40,000,000,000,000,000,000,000 stars in the observable universe. The total coastline of the world is about 1,000,000 kilometres, of which about 36 percent is sandy. So there are 360,000 kilometers of sandy beaches on Earth. We will assume 50 meters width and 4 meters depth. There are 8,000 grains of sand per cubic centimeter (which means you get at best 50,000 grains of sand in a handful.) Do the math, and you get 600,000,000,000,000,000,000 grains of sand on the Earth. There is some variation, such as sand dunes, as well as extragalactic stars and star clusters, so we will assume that the variation cancels each other out. 600,000,000,000,000,000,000 grains of sand on the Earth 40,000,000,000,000,000,000,000 stars in the universe in other words, for every 1 grain of sand, there are 66 stars in the universe. Think about that next time you are on a beach that stretches from horizon to horizon...