Suppose you wanted to be able to see astronauts on the moon. what is the smallest diameter of the objective lens required to resolve a 0.67 m object on the moon? assme the wavelength of the light is near the middle of the visible spectrum: 550 nm yellow light.

r = distance of moon from earth = 3.84 x 10⁸ m

R = size of the object on moon = 0.67 m

D = diameter of the lens = ?

= wavelength of light = 550 x 10⁻⁹ m

Using the equation for Rayleigh criterion

R/r = 1.22 /D

inserting the values

0.67/(3.84 x 10⁸) = 1.22 (550 x 10⁻⁹) /D

D = 384.6 m

sleep paralysis is a parasomnia, events associated with sleep.

sleep paralysis happens when you are in the middle of waking up or falling asleep. it is the feeling of being conscious but unable to move. it definitely involves hallucinations.

i had a friend that had sleep paralysis and he told me a story one time where he was laying in bed and he couldn't move his body no matter how hard he tried and there was someone standing in the corner of his room coming towards him. he couldn't move and you can't "wake up" because you are already conscious. sometimes sleep paralysis can be triggered by frequent waking up during the night based off of multiple trips to the bathroom, or if you had ever been abused, sleep paralysis can start happening from things like that.

the answer is a. at the equator