this post was submitted on 07 Sep 2026
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xkcd

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xkcd #3295: Semaphore

Title text:

The speed of light in air is 50% faster than in fiber, but it's a challenge to get the arms to move fast enough to realize the latency advantage.

Transcript:

Transcript will show once it’s been added to explainxkcd.com

Source: https://xkcd.com/3295/

explainxkcd for #3295

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[–] mamg22@sh.itjust.works 8 points 2 days ago

Didn't get the semaphore part and thought those were fans with a wind speed sensor below, glad there's explainxkcd lol.

Using fans would make for a far worse connection than the one on the comic, at least that one is easily full duplex and somewhat free of interference.

[–] sbv@sh.itjust.works 12 points 3 days ago

worst air gap evar