Light rays from a distant source __________________, assuming the light does not pass through any cloud-like nebulae.
A)are perpendicular
B)focus to an image
C)focus to a point
D)are parallel

Question

Quizplus · Accepted Answer

Light rays from a distant source (such as a star) are nearly parallel by the time they reach Earth. This is because the distance between the source and Earth is so great compared to the source's size. However, strictly speaking, they are not exactly parallel due to the curvature of spacetime caused by the star's mass (though this effect is extremely small). If the light passes through any intervening objects, such as a cloud-like nebula, then the rays may be scattered or absorbed, which can result in them no longer being parallel.

Light Rays from a Distant Source __________________, Assuming the Light