Uploaded October 2025 | Updated September 2026, 1 week ago

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I've upgraded! It took almost a year, but today I finally get to show off a TWO billion frame per second camera! I really want to record refraction, interference, and other awesome stuff with this camera, but today I'm looking into a really strange quirk of the speed of light. In a way, understanding this weird phenomenon is kind of a prerequisite for everything else I want to do with this camera - I hope you find it as interesting as I have!

MANY more technical details for the curious:
youtube.com/playlist?list=PLAYHMTkuzdT3Zwk3UialNtxXrpkmaC_ZI

bonus points to hakonjdjohnsen for advice on colormaps, R520 for a typo, and @dl33 for the top suggestion in last video's comments!

Massive thanks to my top Patreon supporters!
birdiesnbritts
John Sosa Trustham
Vladimir Shklovsky
Aloysius Sparglepartz
Jason Whatley
Lohann Paterno Coutinho Ferreira
nothings
Eugene Pakhomov
Glenn Willen
R520
Nick F
Mirko Rener
Chris Connett
Tyler Filla
Chandler Freeman
Benjamin Manns
MPG
Seth Reuter
Danny Thomas
Lucy Fur
tiaz
David Antoš
Chris Duvarney
Nick Wage
John T
Jack Serrino
Ethan Sifferman
Dit55
Ashley Hauck
Scott Schlesier
Steve
James K
Allan Adams
Usama
Cody and Sara
Doug Strain
Justin McCaskill


Chapters:
0:00 Bouncing light is actually complicated!
5:35 The mirror
11:50 The optics train
13:51 The sensor
19:40 The cables?
23:02 Seeing the past


Media Credits:
I Dunno by grapes is licensed under a Creative Commons Attribution license
ccmixter.org/files/grapes/16626
Arcadia - Wonders by Kevin MacLeod is licensed under a Creative Commons Attribution 4.0 license. creativecommons.org/licenses/by/4.0
Switched on Carcassi by Brian Bolger, YouTube Music license
Future Freeway by Adam MacDougall
Disco Knights by Quincas Moreira
This Close by half.cool
Gemini by half.cool
Mountain by Text Me Records / Bobby Renz
Local Elevator by Kevin MacLeod is licensed under a Creative Commons Attribution 4.0 license. creativecommons.org/licenses/by/4.0
Meme from The Spongebob Movie