How Do EM Waves Stretch and Interact in Space?

[hareeshgnair]

Hi,

I am not a student of physics, asking the question as it came to mind as I read certain articles:

1. When EM Waves is emitted by a source say star it spreads in vacuum. How does the waves Stretch? What fills in the gaps as the sphere of spread grows? If light emission is continuous does the density of light in the sphere has any relation to the distance from source? Basically I doubt how can the light spread continuously without breaking up..or something like that.

2. If all the light from different stars are accounted for..do different light spheres interact and say cancel or reinforce each other?

Advance thanks for the replies,
Harish

 

[Dr Lots-o'watts]

1. Does the density of light in the sphere has any relation to the distance from source?

2. If all the light from different stars are accounted for..do different light spheres interact and say cancel or reinforce each other?

1. Yes, for a sphere, it is an inverse square relation [photon density = constant/(distance)^2]. If sufficiently far away, a detector may see a single photon, or none, within a certain time period.

2. At a given observing point, starlight just adds up.

 

[hareeshgnair]

So does it imply:
1. That lot of information from around the universe is lost, as we may not receive any photons from the light sources.
2. That if two starlight adds up..I won't be able to distinguish that these are two stars?

I hope its not so simple to conclude!:)

 

[Drakkith]

Remember that light is emitted in quanta's called Photons, the particle of light. When something such as a light bulb or a star emits light, it emits each photon in a random direction. The light in your living room emits trillions upon trillions of photons, and a star has many many many more. This means that given enough time you WILL see at least one photon from a light source as long as there is nothing to interfere with it on the way to your detector.