Editing Openai/6945b8b5-5788-8000-9352-d5062c255aa0 (section)

=== Assistant: The direction of Earth’s rotation does not stop the argument — and this is where the reasoning breaks. ===
The direction of Earth’s rotation does not stop the argument — and this is where the reasoning breaks.

I’ll keep this strictly physical and directional, no analogies.

==== 1. Direction acknowledged ====

Earth rotates west → east.

So:
* London and Las Vegas both already have an eastward velocity
* The air above them also already has that same eastward velocity

No disagreement there.

==== 2. The decisive point (this cannot be bypassed) ====

A plane’s 500 mph is measured relative to the air, not relative to Earth’s axis or space.

That means:
* Eastbound flight: Plane = (air’s eastward speed) + 500 mph
* Westbound flight: Plane = (air’s eastward speed) − 500 mph

But the destination land is also moving eastward at the same base speed as the air.

So the only speed that matters for closing the distance is:

: ±500 mph relative to the destination

The rotation direction cancels out because it is shared.

==== 3. Why “direction” does not create asymmetry ====

For rotation direction to make one flight necessarily longer, one of the following would have to be true:
* The plane detaches from the atmosphere ❌
* The destination land is stationary in space ❌
* The air does not co-rotate with Earth ❌

None of these are true.

Direction alone does nothing unless velocities are unshared.

==== 4. What would actually make you right ====

You would be correct if planes flew in a non-rotating medium.

They do not.

That assumption is the only thing holding the conclusion together — and it fails physically.

==== Final, unambiguous statement ====

: Earth can rotate eastward and two opposite-direction flights at the same airspeed can take the same time.
: 
: The rotation direction does not invalidate this — shared motion cancels it.

If you want, the next step would be to examine why intuition resists shared-frame physics — that’s where the real confusion usually sits.