5
« on: March 10, 2016, 03:27:32 AM »
Flat-earthers often say that it's unbelievable that we would be moving through space so fast. They say that the earth seems solid and stationary, and we would be able to feel if it was whizzing through space or spinning at 1000 mph.
However, this is not the case. Consider for a moment that you are riding in a bus. While it is moving at a constant speed, you get up and move to the other side. Why don't you get thrown to the back? The reason is that you retain momentum, and you can only feel acceleration.
Now, about that "1000 mph" statistic. The equation for centripetal/centrifugal acceleration is a=v2/r. The radius r is 6371 km, or 6371000 m. THe velocity v is about 1000 mph, or 460 m/s. So our function is 4602/6371000 which gives us...
.033 m/s2
For comparison, acceleration due to gravity at the poles is 9.83 m/s2. You certainly wouldn't be flung off by that, but it has been measured.
So why does the atmosphere stay with the earth's surface? Well, it too has initial momentum. This confines it to earth's reference frame.
This initial momentum also explains the Coriolis effect. Since the surface is spinning faster at the equator, and slower toward the poles, air that moves away from the equator is deflected to the east relative to the surface. So, if you have an area of low pressure, air is drawn toward it, but air from the equator is deflected east, and air from the poles is deflected west. That causes hurricanes to rotate clockwise in the southern hemisphere and counterclockwise in the northern hemisphere. The deflection is measurable and consistent, and weather forecasters have to take it into account in their simulations. It is also visible in the bands and storms of Jupiter.
So what do you, the Flat Earth Society, have to say about that? Can you find a better explanation that accounts for the weaker gravity at the equator and the Coriolis effect? Good luck.