Activity Feed › Discussion Forums › Strictly Surveying › Theoretically useless knowledge. No. 1
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Bill93, post: 395339, member: 87 wrote: I still need to be convinced that west is faster than east. You have the same angular velocity as the earth at the equator plus or minus your powered flight. I don’t think you can jump up and have the earth move underneath you to gain any time.
The effect due to earth’s rotation around it’s own axis can be estimated as follows: At the equator, the circumference of the Earth is 40,000 kilometers, and the day is 86,400 seconds long, so the speed of earth’s surface at the equator is roughly 460 m/s. When during the jump you spend your time on average roughly one meter above earth’s surface, your velocity lags 460 m/s times 1/6.4×10^6 (the denominator corresponding to earth’s radius in meters) which equates to about 70 micrometer per second. So, when jumping exactly vertically, after a second you land roughly 70 micrometer west of where you started. So if you were traveling east at 70 micrometers a second; you wouldn’t be going anywhere….
I hope everyone has a great day; I know I will! -
RADAR, post: 395340, member: 413 wrote: The effect due to earth’s rotation around it’s own axis can be estimated as follows: At the equator, the circumference of the Earth is 40,000 kilometers, and the day is 86,400 seconds long, so the speed of earth’s surface at the equator is roughly 460 m/s. When during the jump you spend your time on average roughly one meter above earth’s surface, your velocity lags 460 m/s times 1/6.4×10^6 (the denominator corresponding to earth’s radius in meters) which equates to about 70 micrometer per second. So, when jumping exactly vertically, after a second you land roughly 70 micrometer west of where you started. So if you were traveling east at 70 micrometers a second; you wouldn’t be going anywhere….
You have momentum so you don’t instantly stop moving when you jump and you are in the atmosphere which is moving with the rotation of the earth so I don’t think the rotation of the earth is a factor.
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Dave Karoly, post: 395341, member: 94 wrote: You have momentum so you don’t instantly stop moving when you jump and you are in the atmosphere which is moving with the rotation of the earth so I don’t think the rotation of the earth is a factor.
If you were in a vacuum, and jumped, you would continue going the exact same speed as the earth’s movement and gravity is an acceleration rate. In essence you are travelling at the same rate of rotation as the earth and accelerating toward the earth. Of course some outside elements can play since we are not in a vacuum, but being in the same atmosphere, our reference to the earth is as though it’s virtually still. (I hope I said that right, since there are a lot of people here smarter than me. 😉
Look @ some of the answers about a fly flying inside a car keeping up with the rate of the car. https://www.quora.com/How-does-a-fly-in-a-car-can-keep-the-cars-speed-I-mean-that-nothing-really-holds-the-fly-in-the-air
Edit: I am agreeing with Karoly. (since I answered his post, it might appear that I am arguing his point).
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Bill93, post: 395339, member: 87 wrote: I still need to be convinced that west is faster than east. You have the same angular velocity as the earth at the equator plus or minus your powered flight. I don’t think you can jump up and have the earth move underneath you to gain any time.
You guys are over thinking this! It’s got nothing to do with angular velocity, quantum physics or anything else so esoteric. Two words: prevailing winds.
For the same reason it takes less time to travel east than west when you are north of about 35-40 degrees north or south latitude, it similarly takes less time to travel west than east at or near the equator. In general, for almost all of the year, the prevailing winds are easterlies, particularly just north and just south of the equator (the trade winds).
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