Newton and Galileo never questioned that time is independent, but it is!

Just need to think like Einstein!

Setup

• Two identical light bulbs, A and B, are placed at equal distances on either side of a person standing still at the center on a train platform.
• The bulbs are programmed to flash at the same time (in the platform frame).
• The person sees both flashes arrive simultaneously, so they say: “Yup, they happened at the same time.”

Now enter: a second person running at high speed past the platform, from bulb A toward bulb B.

Because they’re moving toward B and away from A:

• Light from bulb B reaches them sooner than light from bulb A.
• But light travels at constant speed ccc, so to reconcile the different arrival times, they must conclude: Bulb B flashed before Bulb A.

What If These Bulbs Trigger Events?

Let’s add a causal link:

• Bulb A is wired to launch a rocket.
• Bulb B is wired to disable it.
• The logic is: if B flashes before A, the rocket doesn’t launch.

Now imagine:

• To the runner, B flashed first → rocket is disabled.
• To the platform person, A and B flashed together → rocket launches.

We’ve got a conflict of causality — one observer says it launched, another says it didn’t.

This breaks physics — unless we accept that:

Time and space are relative to the observer.
And simultaneity is not absolute.