Sunday, September 20, 2015

Earth spins faster than the speed of sound



We agree that any object that is travelling faster than the speed of sound in air (330m/s) creates a shock wave that causes an explosive noise called a sonic boom. I just calculated that some points on the Earth's surface travel faster than the speed of sound when it rotates about its axis (e.g places on the equator move at about 460 m/s when the earth rotates) but there is no sonic boom. When the earth revolves along its orbit which has a circumference of about 942000000 km it travels at about 29870 m/s (which is way more than the speed of sound 330 m/s) but we don't hear any explosive noise or sonic boom. Can someone please explain why these events doesn't cause a sonic boom?

How Fast Does Earth Spin? - What if Earth stopped spinning?

science.howstuffworks.com/...vs.../what-if-earth-stopped-spinning2.htm
Read about what could happen if the Earth's rotation gradually ground to a halt. ...That's faster than the speed of sound, and one of the reasons we tend to  ...

Faster than the sound? Our velocity due to Earth's rotation.

sciengsustainability.blogspot.com/.../faster-than-sound-our-velocity-due-...
We need two data in order to get the relative velocity due to Earth's rotation: Distance to the rotation axis ... Which is faster the the speed of sound (340.29 m/s).

How Fast does the Earth Move? - StarrySkies.com

starryskies.com/articles/2007/11/earth-speed.html
Most everyone on the planet knows that the Earth is rotating, but not so many ... an ice skater spinning and pulling their arms in to make themselves spin faster. ... You can use this formula to find the speed of rotation at any latitude. Of course, there's more motionsthan Earth's daily “spin” on its axis to consider. ... Sound fast?