Notes
A retroreflector uses 3 mutually perpendicular mirrors to reflect light rays directly back to their source.
Lots of animals have natural retroreflectors in the back of their eyes. This allows light to travel through the vision cells (rods and cones) in their retinas twice, improving their night vision significantly.
SciShow – Why Do Cat Eyes Glow in the Dark? (2:14)
Why you should not feed wild animals such as raccoons:
What could go wrong playing with raccoons?
Alligator eyes have retroreflectors and appear to glow in the dark at night
Alligator eyes glowing at night
Pigeons and owls also have retroreflector eyes. Owls are known for being able to fly almost soundlessly, allowing them to swoop in on their unsuspecting prey.
Mythbusters Moon Hoax Retroreflectors (4:42)
Buzz Aldrin was one of the first astronauts on the moon. He does not like it when people claim the moon landing was fake.
Buzz Aldrin Punches Guy
Activity
In a group of 3, use 3 plane mirrors to make a retroreflector
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- Put the first mirror face-up on the table
- One person should hold the second mirror perpendicular to the table, with one edge aligned right against one edge of the first mirror
- The second person should hold the third mirror perpendicular to the table, with one edge aligned right against one edge of the first mirror and another edge aligned right against one edge of the second mirror
- The third person looks into the retroreflector
- Close one eye and observe where your open eye is located in the retroreflector
- Move your head around with one eye closed and observe what happens