Light "trapped" in a box ?

[Zant555]

Hello,

my question may sound ridiculous, but I'd REALLY like to know :

if you send light into a "box" , the sides of the box being covered, inside, with mirrors : how long will light "survive" in the box ?

If you drill a side of the box 20 years later, for example, will you see a beam of light ?

I DO want to know the answer ( which probably depends on the quality of the mirrors ).

Thanks in advance for your answers,

        Zant555.

 

 

 

 

[arc]

The light source must remain constant. Once the box is sealed the light energy ends and is absorbed, as the rest was previously by the mirrors, as heat.

[Strange]

45 minutes ago, Zant555 said:

if you send light into a "box" , the sides of the box being covered, inside, with mirrors : how long will light "survive" in the box ?

With the best mirrors we can create today, I guess it would be picoseconds at best.

Actually, there was another thread about this recently (it is quite a popular question) and I have a vague recollection of someone estimating how long it could last ...

Edited January 6, 2018 by Strange

[Zant555]

Ok, thanks for your answers ( I must admit I didn't look for any previous similar thread, I was so eager to get an answer : I promise I won't do that again   ).

 I'm so disappointed, I thought mirrors wouldn't absorb much light, not that fast : I saw yesterday, mirrors with 97 % reflection capacity ( sorry for my English ? ).

The text I saw yesterday was about LASERS, in fact : does it change anything ?

I know it's not the same subject, but : have you ever heard about "Starlite" ? ( this is the correct spelling ). It's very interesting ( assuming it's not fake... ).

 

[Strange]

3 minutes ago, Zant555 said:

I'm so disappointed, I thought mirrors wouldn't absorb much light, not that fast : I saw yesterday, mirrors with 97 % reflection capacity

So you could use the to estimate how long the light would last. If you decide on a size of the box, you can work out how long the light will take to bounce from one side to the other using the speed of light. Each bounce will reduce the level. Two bounces will reduce it by 97% x 97%. After 100 bounces it will be reduced to about 5% of the original level. After 1000 bounces it will be 0.0000000000059% (pretty much gone!). So work out how long 1000 reflections take and that will give you some sort of answer.

9 minutes ago, Zant555 said:

The text I saw yesterday was about LASERS, in fact : does it change anything ?

I don't think so.

[Zant555]

Here's an example of a mirror with a 99% reflectivity capacity :

http://www.directindustry.fr/prod/korea-electro-optics-co-ltd/product-180853-1837801.html

With a 97% reflectivity, isn't it : ( 100 - 97 ) = 3 ---> 3 x 3 , etc... ?   If 97% of the light is conserved.

( omg, I didn't figure out how to delete my double posts... )

Edited January 6, 2018 by Zant555
double post

[Zant555]

Here's an example of a mirror with a 99% reflectivity capacity :

[John Cuthber]

This topic seems to pop up from time to time.

 

[adam24786]

The only way you’ll get the result you want is if you have a mirror with no loss at all. With any loss, light moves so fast that losing .00001% per bounce will seem instant. Also, if you had this perfect mirror box and the light lasts 10 years, you won’t see anything when you punch a hole in it you wouldn’t see a flash of light. All of the light would leave and disappear far too fast for you to detect. 

[Moreno]

There is a large difference between "practical" and "theoretical" answer to your question. I suspect that theoretically it may stay inside for indefinite period of time if we would be able to master box creation on quantum level. There exist such things as a "total internal reflection" and similar quantum phenomenon. The problem is we cannot rule the matter on the atomic scale for now. Even better if your ray of light would stay inside of box as a standing wave.