I get some I dea why the light it dosnt retain back to the first source in the stronomy really if so that can explain for us why sky appear as atomspherical shape.
Anonymous
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Very intersting question.
Retains partially to keep the continueous flow. Like a hot cup of tea and it cools down. Smaller surface objects retain more then larger objects, that's why Sun is considered source of energy.
Anonymous
Because the universe is a 4 dimensional hypersphere and is therefore curved. So... if you send light wave out into the universe, it wll eventually come back to you as a result of that curvature.
We believe the universe to have positive curvature (a hypersphere). The other two possibilities, although unlikely are zero curvature (a plane) or negative curvature (a hyperbolic paraboloid).
Hope that helps...