(Disclaimer: This transcript is auto-generated and may contain mistakes.)

so um lasers lasers are great because it proves that we went to the moon oh oh yeah so how does that work so there's something called retro reflectors on the moon did you know that who put them there uh neil astronauts neil neil armstrong now i don't know who put them there astronauts they put it they put them there you could shoot a laser at a at a retro reflector and it will reflect back and no matter where you shoot on the on the mirror because it's like have you ever seen like the corner of like a bathroom mirror like you could you you could see it like but imagine i'm four ways yeah so that's what you could shoot it from any direction and it'll come back to you yeah i'm saying yeah that's that's what's on the moon so if you shoot a laser at the moon and you hit the retro retro reflector at any angle and you should be able to get that same frequency light back back in the same position yeah and if if you're just hitting the moon and it's like a reflective surface or you know people say stuff like that it would it would uh it would come back at a different frequency but it hit a mirror whatever right yeah yeah refraction it breaks it down basically yeah it'll be at a different frequency yeah so did nasa put those there just to prove they went to the moon is that like why no they put it there to to measure the distance oh so they know the speed of light well so the amount of time it takes for it to come back is the distance but