Question

Which things are visible in dark

Answer 1

Whe we see an object, we are actually seeing the light that is reflected off of it. Different materials reflect different frequencies of light in different ways and we interpret this as color. Things that don’t reflect light look black (they absorb rather than reflect light, that’s why your black pants will feel warmer than your white T-shirt on a sunny day). When it’s dark that means that there is no light (from the sun or bulbs) to be reflected so no objects reflect light, so everything looks black.

In summary, our eyes are like antennae for light waves and our brain uses that info to “see”, if there are no light waves to receive then we can’t see.

Just like a radio can’t play a song if it’s not receiving any radio waves. Maybe it’s not receiving waves because the station isn’t broadcasting ( comparable to the sun going down and the lights turned off) or because the antenna is broken (blindness).

Or you can think of it as not being able to load a webpage when your internet is shut off. The webpage still exists but you can’t see it because you don’t have a signal.