Binesh from Harlow asked:
If earth is rotating why do we need to travel in an airplane? Can we not arrive our destination if we stay static on the sky and land when the earth spins and when we spot on our destination place during the spin?
Hannah - So, using the Earth’s natural spin to help long distance travel across its surface? Engineer, Professor Hugh Hunt from Cambridge University.
Hugh - The air around the Earth is moving at the same speed as the Earth. How fast is the Earth moving due its rotation? Well, it’s moving at about 1,000 miles an hour which means that if we did sort of hover at rest above the spinning Earth, the wind speed we’d feel would be 1,000 miles an hour. And that would be impossible to deal with unless you had an aerodynamic object like an aircraft with engines to hold yourself against the wind and that's exactly what an aircraft is. Concorde for instance could fly the equator at about 1,000 miles an hour and could stay still essentially. It would hover above the Earth. The Earth would be spinning around underneath it and it would then land somewhere else. If there were no atmosphere, it doesn't solve the problem because we then don't have aerodynamic lift to hold the plane up. So, we have to go into orbit and going to orbit, well the speeds there are even bigger – 20,000 miles an hour and that requires a lot of fuel and a spacecraft.
Hannah - So you, the Earth and the atmosphere are constantly moving very fast as the Earth rotates. If you jump up and somehow managed to stop, you'd be faced with a whopping 1,000-mile per hour winds. Get out of the wind and up into orbit and the fuel you'd have to consume to get there would far exceed the fuel used by a plane which uses the wind currents to their advantage. Another point is that as Newton worked out, objects keep moving at the same velocity unless a force is applied. So, stopping from speed is just as tricky as starting to get to speed in the first place. So even on an airless world, elevator style travel across the Earth using its spin would still use up energy and wouldn't be that different to other modes of transport.
We answered this question on the show...
If you are talking about down on the surface of Earth, then one's frame rotates with the rotation of the Earth, and it is essentially impossible to move independently of the already moving frame without exerting energy..