How does light propagates in space and reach earth?

Answer 1

Almost all light in space is produced through nuclear fusion within stars. The light released through fusion is able to travel through the vacuum of space because it is part of the electromagnetic spectrum, which doesn't require a medium in which to travel unlike mechanical waves such as sound.

Answer 2

The term "how" is not really appropriate. It is a simple fact of nature that light travels through a vacuum at the speed of light. Empty space is vacuum.

Light does not require a material medium to propagate. (In a material medium, light slows to a speed of less than the vacuum speed and can be absorbed.)

The light from a star goes off in all directions and some very tiny part of that light gets to our planet and an even tinier part gets to our eye so we can see it.

If you want a physics answer, then light is an electromagnetic wave and electromagnetic waves in a vacuum can only exist if they are moving at the speed of light. Maxwell's equations described this in the late 19th century.

Alternatively, one can say, it is an intrinsic part of the nature of the space-time continuum that light travels at the speed of light. These are fundamentally intertwined in the structure of the universe in which we live. There is no "how" to be explained.

Answer 3

Light travels through space as electromagnetic waves, which do not require a medium to propagate. The light emitted by the sun travels across space in a straight line until it reaches Earth, which is about 93 million miles away. The photons of light travel at the speed of light and take approximately 8 minutes and 20 seconds to reach Earth from the sun.

Answer 4

Most solar energy is carried by electromagnetic radiation. For example, light is electromagnetic radiation. It is simply a property of electromagnetic radiation that it can travel thru space.

Answer 5

It slows as the medium changes from a near-vacuum to the earth's atmosphere.