16 replies to this topic

[matto]

I was just thinking. About light. Suppose there existed a room that was made up of ONLY walls, and there existed nothing except pure air inside the room, and there was a single hole in which it was one of those 1-sided mirrors (light goes in, but not out). If you shined a laser, or any light, into the hole, would the light keep on reflecting on and off the mirrors forever? I believe it would. What do you guys think?

My reasoning for thinking that it would is that there are a certain amount of options. 1) The light is absorbed by the air (which is conceivable after a long amount of time of reflection, i suppose...) and the air is heated; 2) The light is absorbed by the mirrors, and the mirrors are heated (but should not happen if they are real mirrors); 3) The light somehow exits the room and is absorbed by other stuff; 4) the light keeps on reflecting.

I don't thinkt hat the first three would happen, and that leaves only the fourth one left. Perhaps it wouldn't reflect FOREVER, as the air would probably absorb it eventually... but, if that's the case, then what would be the case if there was NOTHING inside the room except the light that enters it? What if it was a vacuum, with literally NOTHING inside it? Assuming that is possible, then it is even less arguable that the light could do anything else besides keep reflecting.

What are all your opinions? Keep in mind, I'm just thinking. I haven't done much research at all in this field, but it crossed my mind and interested me.

[Moolkye]

Nice thought. I liek this weird thinkign kind of stuff. I think that the light would be reflected until it ran out of space to be reflected by. Meaning that it would bounce back and forth until every inch of the mirrors occupied space to reflect from. And it would be bright as heck. But how would we know?

[Cerebral Stasis]

Light in a mirrored room would not reflect indefinately, since the light would lose energy (meaning it would be converted to heat energy) and spread out every time it bounced, so, no, it wouldn't continue on indefinately.

[tdm]

Interesting one there. Ive tought that many a time and im geussing it would go on for a long time, not forever. If you find out what really would happen please keep me informed.

[Reaper]

that is quite a cool idea but i think it would stop reflecting eventually as from what a can gather light is made up of waves and how long it would carry one reflecting would be dictated by the initial frequency of the light the higher the frequency the longer it would carry on reflecting but it would stop eventually.

But yeah good idea about that

[tidewell]

Well every theory should point to yes. if you shine a light in a mirror it shines back, so why wouldn't it continue to shine? Its simple really, it's just people like to think about it so they get confused about things like that.

[epox]

hey dude, you really put my brain to work, nice thinking, i think in ideal conditions the light will reflect forever, like in the emptiness.

[Helium]

It won't keep reflecting, mirrors don't reflect every bit of light, they absorb light, just like any object although it isn't much in the end there would be no energy left.

[brainless]

If there is air in this room, the light would eventually be absorbed (i.e. the light's energy would be passed to the atoms/molecules which make up the air, thereby the temperature in this room would increase).

Using a perfect vacuum and perfect mirrors, the light would be trapped between the mirrors. There would, however, be now way to measure exactly how much light there is in this room since this would require a certain amount of light to leave this room.

This thinking reminds me of Schroedinger's cat: During the initial phase of research on radioactivity, a guy named Schroder put a cat and some radioactive material (enough to kill a living being) into a box and closed it.
How do we know whether the cat is still alive after a minute, an hour, a day, a week, a month? ok, the latter ones maybe guessed by the amount of food the cat had...

[Justin S.]

Well that is very confusing I wouldn't know the answer to it lol.