![]() ![]() ![]() Not all of them have beaches per se, and some that do, have only very short beaches. Whoa, not really! First off, the best estimate I could find is that there are about a million and a half kilometers of shorelines on Earth. Now all I had left to do was determine the volume of all the Earth's beaches! Simple, right? To further simplify matters I considered that each sand grain is a perfect cube, which allows for efficient packing. I chose, arbitrarily, to consider sand grains of 0.25 millimeters as an average. One standard definition is that medium sand is 0.25 to 0.5 millimeters in diameter, and fine sand is 0.25 to 0.125 millimeters. Of course, sand comes in a variety of sizes. ![]() Obviously I couldn't count all the sand grains, but I could do an order of magnitude calculation. After all, there must be a really big number of sand grains on all the planet's beaches! Then one day began to wonder if it is really true. In my astronomy classes I have often used the claim that there are "more stars in the heavens than all the grains of sand on all the beaches on Earth." The claim is certainly not original with me, but I had always accepted it without question. Proper credit includes the Internet address: Re-distribution with credit is permitted and encouraged. ![]()
0 Comments
Leave a Reply. |