This will blow ur brains How do we know that we don't live in a box and the stars are just poked in holes so we can breathe and that the holes were poked in paterns so that the early astronomers didn't get bored. ALSO what if the star is just a big flashlight and the moon is a big glow stick in a ball And what is the pictures of space are just drawings i mean we have good drawers in this box. AND how do we know that the video of the first man on the moon wasn't on a green screen

People with normal vision cannot focus their eyes underwater if they aren't wearing a face mask or goggles and there is water in contact with their eyes. in a simplified model of the human eye, the aqueous and vitreous humors and the lens all have a refractive index of 1.40, and all the refraction occurs at the cornea, whose vertex is 2.60 cm from the retina.with the simplified model of the eye, what corrective lens (specified by focal length as measured in air) would be needed to enable a person underwater to focus an infinitely distant object? (be careful-the focal length of a lens underwater is not the same as in air! assume that the corrective lens has a refractive index of 1.62 and that the lens is used in eyeglasses, not goggles, so there is water on both sides of the lens. assume that the eyeglasses are 2.05cm in front of the eye.)