this post was submitted on 05 Apr 2025
413 points (99.8% liked)

Science Memes

14181 readers
2618 users here now

Welcome to c/science_memes @ Mander.xyz!

A place for majestic STEMLORD peacocking, as well as memes about the realities of working in a lab.

Rules

  1. Don't throw mud. Behave like an intellectual and remember the human.
  2. Keep it rooted (on topic).
  3. No spam.
  4. Infographics welcome, get schooled.

This is a science community. We use the Dawkins definition of meme.

Research Committee

Other Mander Communities

Science and Research

Biology and Life Sciences

Physical Sciences

Humanities and Social Sciences

Practical and Applied Sciences

Memes

Miscellaneous

founded 2 years ago
MODERATORS
[email protected]
[email protected]
[email protected]
[email protected]
413
It's the law! (mander.xyz)
submitted 1 week ago by [email protected] to c/[email protected]
18 comments fedilink hide all child comments
 
you are viewing a single comment's thread
view the rest of the comments
[–] [email protected] 1 points 1 week ago (2 children)

There’s classics like measuring how long it takes to send a network packet from one device to another

That one is on your clocks quality, not on physics. People do it all the time.

Probably on equipment that is orders of magnitude more expensive than yours, but the post isn't about costs.

[–] [email protected] 4 points 1 week ago (1 children)

That's just shifting the problem. There is no known way to reliably sync remote clocks except by sending packets and assuming the round-trip time is symmetrical. This is a known problem in physics: https://en.wikipedia.org/wiki/One-way_speed_of_light

[–] [email protected] 1 points 1 week ago (1 children)

Sure, but if we take it as true that light speed is the same in every direction – which is perfectly consistent with everything ever measured – you can measure speed between two endpoints using two atomic clocks and a synchronised experiment, with corrections for the relativistic effect of moving the clocks to the different places

[–] [email protected] 1 points 1 week ago

if we take it as true that light speed is the same in every direction

This is the crucial assumption, that to my knowledge hasn't been proven or disproven. Because the alternative, light goes faster in one particular direction, is also perfectly consistent with everything. And if you're moving atomic clocks, correcting for time dilations requires you to make assumptions about the one-way speed of light (which we only know from measuring roundtrip times)