Light shot up to the sky

  • B
  • Thread starter terryds
  • Start date
  • #1
392
13
If I shot/flash lights up to the sky, will the lights or photons fly up to the sky then to the space then to the top of the universe?? Will it stop?
 

Answers and Replies

  • #2
Nugatory
Mentor
13,317
6,250
If I shot/flash lights up to the sky, will the lights or photons fly up to the sky then to the space then to the top of the universe?? Will it stop?
The light will travel until one of two things happens to it: Either it will be absorbed because space is not completely empty, or it will spread out until it becomes too weak to detect. That's assuming that it makes it past the atmosphere of the earth, which it won't on a cloudy day.
 
  • #3
541
145
And the effect of the clouds is to scatter the light.
 
  • #4
Vanadium 50
Staff Emeritus
Science Advisor
Education Advisor
26,737
10,319
And the universe doesn't have a top.
 
  • #5
392
13
The light will travel until one of two things happens to it: Either it will be absorbed because space is not completely empty, or it will spread out until it becomes too weak to detect. That's assuming that it makes it past the atmosphere of the earth, which it won't on a cloudy day.

And the effect of the clouds is to scatter the light.

And the universe doesn't have a top.

Thanks for your answers.
One more question..
If I flash the light onto the wall which is far from myself, why does the light become weak or even disappear?? But, if the wall is near, why does the light become strong?
What absorbs the light in its travel to the wall?
 
  • #6
davenn
Science Advisor
Gold Member
9,474
8,424
Thanks for your answers.
One more question..
If I flash the light onto the wall which is far from myself, why does the light become weak or even disappear?? But, if the wall is near, why does the light become strong?
What absorbs the light in its travel to the wall?

as nurgatory said in as earlier answer, it spreads out
like this ......

inverse_square_law.jpg




Dave
 
  • #7
541
145
If I flash the light onto the wall which is far from myself, why does the light become weak or even disappear?? But, if the wall is near, why does the light become strong?

What determines how "strong" the light is, to use your term, is how much light falls on a given area on the wall. As davenn showed, the further you put the wall, the more the light has spread so the amount of light per unit area is less compared to when the wall is closer, so it doesn't look as strong.
 
  • Like
Likes terryds and davenn

Related Threads on Light shot up to the sky

  • Last Post
Replies
16
Views
4K
Replies
3
Views
826
  • Last Post
Replies
2
Views
1K
  • Last Post
Replies
15
Views
4K
  • Last Post
Replies
23
Views
4K
  • Last Post
Replies
18
Views
11K
  • Last Post
Replies
3
Views
1K
  • Last Post
3
Replies
51
Views
6K
  • Last Post
Replies
2
Views
2K
Top