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My collaboration with Geoff is here:
   • Cube Reflectors on the Underground  

Retroreflectors send light back in the direction it came from. They are useful in lots of way. But accidental retro reflectors need to be avoided sometimes.

Thanks to these amazing patrons on Patreon for supporting my channel:

Glenn Watson
Peter Turner
Joël van der Loo
Matthew Cocke
Mark Brouwer
Deneb

You can buy my books here:

https://stevemould.com/books

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