B Light and the black matter (Dark Matter)

AI Thread Summary
Light from the sun illuminates objects but does not illuminate space itself, which lacks matter. This is similar to how a flashlight lights up surfaces in a dark room, leaving the air unlit. Dark matter is not visible because it does not interact with electromagnetism, leading to the suggestion that it could be called "transparent matter." Its presence is inferred through gravitational effects on visible matter and light paths. Understanding dark matter remains a significant challenge in astrophysics.
angela
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what happens if our whole universe which is enclosed by black matter lights up or if there's a source to emit light so the whole universe is visible...
Originally Answered: If light reaches the Earth from the sun, why is the space between the sun and the Earth dark?
Because light illuminates surfaces, objects. Space is not an object, is the lack of matter. If you turn on a flashlight in a dark room you will illuminate the floors and the walls, the light from the wall will bounce and illuminate the room a bit more, but if the air is clean, not too much dust, you are not illuminating the air.

In a room we are talking small distances, just a handful of meters, so once the light bounces from a wall the entire room seems to light up, even though what lights up...
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I understand but what if something bursts in the universe the particles might scatter so we will be able to see the covered or dark matter.
 
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Are you asking why we can't see dark matter? It's because it doesn't interact with electromagnetism. Perhaps it would be better named "transparent matter" because light passes through it - so we can't see it directly. We can only see a slight curving of light paths near large amounts of datk matter due to its gravity, and its gravity's effects on normal matter.
 
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thanks
 
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