We can measure the speed from A to B back to A. We can’t measure the speed from ... | Hacker News

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j16sdiz on Oct 1, 2023 | parent | context | favorite | on: Pulsars, not dark matter, explain the Milky Way’s ...

We can measure the speed from A to B back to A.

We can’t measure the speed from A to B directly (without sending something from B back to A wrt speed of light).

https://en.wikipedia.org/wiki/One-way_speed_of_light

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