We have noticed that certain people are not entirely clear why flying in the opposite direction of Earth’s rotation does not result in shorter flight times.
In a post by someone who denies the Earth spins, a confused person writes:
“Plane flying from east to west at 300 mph… The Earth rotates from west towards east at 1,400 mph under the plane… How does the plane not reach its destination 1,400 mph faster? Nor is the return trip longer or shorter. How? Answer: The Earth is not spinning.”
To be fair, the Flat Earth group’s post is a hot mess of incorrect beliefs about physics.
To begin with, picture yourself being able to make a huge jump into the air at the equator, where the Earth spins at a speed of approximately 1,670 km/h (1,037 mi/h). This would be best done on a day with no wind at all. Let’s put you on a trampoline and assume you can get about 3 seconds of airtime.
Where do you expect to land? If you believe in flat-Earth physics, the answer should be 1.39 kilometers (0.86 miles) west of your trampoline.
In their question, airplanes appear to be stationary in the air while the ground below them moves at 1,670 kilometers per hour (1,037 miles per hour), or 27.83 kilometers per minute (17.29 miles per minute) and 0.46 kilometers per second (0.29 miles per second). According to their – for lack of a better word – logic, jumping into the air for 3 seconds would take you 1.39 kilometers (0.86 miles) west of where you were before.
You’ll notice that the world isn’t full of children jumping off trampolines and hurtling through the air at speeds faster than commercial airliners. This does not happen. But not, as they claim, because the Earth is not spinning.
You move with the Earth due to inertia, which is the tendency for objects in motion to continue moving in a straight line at the same velocity unless another force acts on them. This is why when you leap directly into the air, whether from the ground or inside a windowless truck, you land exactly where you started.
Moving in another direction requires a force. Planes do not have magical properties that excuse them from inertia, so when they take off from the spinning Earth, they must expend energy to move you (e.g., to Hawaii).
Another misunderstanding in the post is the assumption that our atmosphere is static while the Earth spins beneath. This is clearly not the case. Frictional forces cause the Earth to drag the majority of its atmosphere with it as it spins. If the atmosphere were not dragged along with our planet, you could utilize insane relative wind speeds to reduce flight time, but you wouldn’t be concerned with such issues as “long flights” when you’re constantly battered by extremely high winds every moment of your waking life.
In fact, flying west (against the rotation of the Earth) takes slightly longer than flying east.
“The reason for quicker flights while flying eastwards is jet streams,” Simple Flying explains. “Put simply, these are fast-flowing, narrow air currents in the atmosphere found at high altitudes.”
This does have a little to do with the Earth’s rotation, as well as the atmosphere being heated by the Sun. The closer you are to the equator, the faster the Earth spins, and this affects jet streams.
“The closer you get to the poles, the smaller the track a point takes in its daily rotation,” NASA explains. “At 60° North or South latitude, the track is only half the distance that it is at the equator, and so a point travels only half as fast. Air (or water) moving from high latitudes to low then tends to lag, and a person on the surface would feel a wind blowing out of the east. On the other hand, air moving from low latitudes to high is deflected westwards. This also means that moving air or water is deflected to the right in the northern hemisphere, and to the left in the southern hemisphere.”
So the rotation of the Earth does (indirectly) affect flight times through its effect on wind speed and direction. We don’t live in Looney Tunes, so taking a plane into the air and waiting for the Earth to pass beneath us is not an option.
