2001-12-23 It is obvious from the method they use, they are using a very simple logic. They use the common belief that the distance from New York to Los Angeles is exactly 3000 miles, and going from there. And with a 1000 mile width of each time zone, it does make for an easy calculation. And who knows, maybe the earth's circumference is close to 24 000 miles at the mean latitude of the US.
They don't seem to reference what circumference they are looking for and might assume they are all the same. Or do I think they care. They seemed to have been trying to use a simple method to come to a very close guess. It is the method more then the numbers that were meant to be of importance. John The Nobel-prize-winning physicist, Enrico Fermi, came up with this simple and intuitive way to deduce the circumference of the earth. 1. How many time zones do you pass through when you fly from New York to Los Angeles? Answer, 3 2. How many miles is it, about, over that same distance? Answer, about 3000. 3. How many miles per time zone, on average? Answer, about 1000 4. How many time zones must there be around the world? Answer, 24 because there are 24 hours in a day 5. How many miles around the world? Answer, 24 time zones x 1000 miles per time zone = 24000 miles Yes, it is about 24000 miles around the world. So how do I get the diameter of the Earth 1. the formula for a circle is 2 pi r, right? where r is the radius and pi is about 3 2. so 24000 mi = 2 x 3 x r = 6 x r 3. therefore 24000 mi / 6 = r = 4000 mi 4. the diameter of the earth is 2 x r = 8000 mi, where the diameter is 2 times the radius 5. 1 mi = 1.6 km so 8000 mi x 1.6 km/mi = 12800 km (the correct answer is ~12742 km) So you can always figure out the dimensions from your basic knowledge of traveling! ----- Original Message ----- From: "M R" <[EMAIL PROTECTED]> To: "U.S. Metric Association" <[EMAIL PROTECTED]> Sent: Sunday, 2001-12-23 09:48 Subject: [USMA:16783] Earth's circumference:Is this correct > According to this website > http://http.hq.eso.org/outreach/spec-prog/aol/market/collaboration/erathoste nes/ > > the circumference of the earth is > 40,090 km in equatorial (radius is 6378 km) & > 39,958 km in polar (radius is 6357 km). > > But this website says > http://rainbow.ldeo.columbia.edu/courses/v1001/fermi.html > > it is 24,000 miles (which is 38,400 km) and they claim > that each time zone has 1,000 miles. > > Which 1 is correct. > > Madan > > > > > __________________________________________________ > Do You Yahoo!? > Send your FREE holiday greetings online! > http://greetings.yahoo.com >
