Sunlight in a jar

uzless
Posers and Puzzles 08 Feb '07 15:43
1. uzless
The So Fist
08 Feb '07 15:43
What if you took the inside of a jar and lined the inside with a seamless mirror, then angled the jar so that sunlight entered the jar and keeps reflecting back and forth in the mirror, then extremely fast put the lid on the jar that also had a seamless mirror on the bottom. Theoretically the sunlight is reflecting back and forth inside the jar so....

If you were then to carry the jar inside your house, turn the lights off, and then quickly open the jar, would sunlight shoot out?
2. 08 Feb '07 16:19
The only thing i would say, is that you would need to put the lid on faster than the speed of light... which i would suggest is probably impossible
3. 08 Feb '07 16:191 edit
Originally posted by uzless
What if you took the inside of a jar and lined the inside with a seamless mirror, then angled the jar so that sunlight entered the jar and keeps reflecting back and forth in the mirror, then extremely fast put the lid on the jar that also had a seamless mirror on the bottom. Theoretically the sunlight is reflecting back and forth inside the jar so....

If ...[text shortened]... inside your house, turn the lights off, and then quickly open the jar, would sunlight shoot out?
No idea, I guess so in theory if you had a very very fast shutter that worked chemically, but I would guess that the light would be so scattered too much, so that you wouldn't be able to see it. Perfect mirrors have been developed, and you may find this interesting:
http://web.mit.edu/newsoffice/2006/omniguide.html
4. 08 Feb '07 16:421 edit
Originally posted by uzless
What if you took the inside of a jar and lined the inside with a seamless mirror, then angled the jar so that sunlight entered the jar and keeps reflecting back and forth in the mirror, then extremely fast put the lid on the jar that also had a seamless mirror on the bottom. Theoretically the sunlight is reflecting back and forth inside the jar so....

If ...[text shortened]... inside your house, turn the lights off, and then quickly open the jar, would sunlight shoot out?
I'd say that unless the mirror is not exactly 100% effective the incoming sunlight will quickly transform into heat and in visible light it will be completed dark inside.

I don't think it is possible to trap sunlight in a jar.

But hypothetically what would happen *if* it worked the way you described? *And*, say that the jar had a size of 300 000 km (one light second)? *And* the mirrors are not losing any ligh in the reflection process?
Then you could actually trap the light and move the jar and when you removed the lid again, it would shine out the light again during a period of 1 second.

If your jar is a billonth of the size of the jar above, it would be like 3 dm wide (a foot wide). You have to shut the lid within a nanosecond. When you open the lid again you will se a soft flash of a nanosecond. You will not be able to see that flash, anyway.

So I say no. You will not be able to do this experiment and notice the effect of letting the light off the jar. Buy a ordinary pocket flashlight instead, its more effective.
5. 08 Feb '07 17:01
Originally posted by uzless
What if you took the inside of a jar and lined the inside with a seamless mirror, then angled the jar so that sunlight entered the jar and keeps reflecting back and forth in the mirror, then extremely fast put the lid on the jar that also had a seamless mirror on the bottom. Theoretically the sunlight is reflecting back and forth inside the jar so....

If ...[text shortened]... inside your house, turn the lights off, and then quickly open the jar, would sunlight shoot out?
Instead of using sunlight use a laser, and in theory if the material were to be perfect ie won't diffuse the laser beam into heat, then yes light may be transported in a vessel. As far as containing the material would probablly need to work like mirrored sunglasses the coppers wear.
6. 08 Feb '07 21:15
I think that the amount of light trapped would be so insignificant that when you opened the jar it would be very difficult to detect the light.

Interesting thought!
7. 08 Feb '07 21:17
Originally posted by FabianFnas
But hypothetically what would happen *if* it worked the way you described? *And*, say that the jar had a size of 300 000 km (one light second)? *And* the mirrors are not losing any ligh in the reflection process?
Then you could actually trap the light and move the jar and when you removed the lid again, it would shine out the light again during a period of 1 second.
Hypothetically speaking, I think it would shine for more than one second. The photons that you've trapped would end up with their positions and directions scattered pretty randomly after a while. When you take the lid off some of them would take longer than a second to reach the entrance again.

(Maybe not entirely relevant - never mind)
8. 08 Feb '07 21:23
Originally posted by mtthw
Hypothetically speaking, I think it would shine for more than one second. The photons that you've trapped would end up with their positions and directions scattered pretty randomly after a while. When you take the lid off some of them would take longer than a second to reach the entrance again.

(Maybe not entirely relevant - never mind)
A good point though.

My strongest objection is that there would be no perfect mirroring material. I think that the light turns into heat pretty fast.
But *if* the mirroring is 100% effective, this experiment will be quite interesting!
9. 09 Feb '07 07:04
Originally posted by FabianFnas
I'd say that unless the mirror is not exactly 100% effective the incoming sunlight will quickly transform into heat and in visible light it will be completed dark inside.

I don't think it is possible to trap sunlight in a jar.

But hypothetically what would happen *if* it worked the way you described? *And*, say that the jar had a size of 300 000 km ...[text shortened]... f letting the light off the jar. Buy a ordinary pocket flashlight instead, its more effective.
solar powered cars, and sunstations instead of gas stations. hmm
10. sonhouse
Fast and Curious
09 Feb '07 18:331 edit
Originally posted by uzless
What if you took the inside of a jar and lined the inside with a seamless mirror, then angled the jar so that sunlight entered the jar and keeps reflecting back and forth in the mirror, then extremely fast put the lid on the jar that also had a seamless mirror on the bottom. Theoretically the sunlight is reflecting back and forth inside the jar so....

If ...[text shortened]... inside your house, turn the lights off, and then quickly open the jar, would sunlight shoot out?
Actually, this kind of experiment has already been done. The idea here is storing light. Here is one story about that:
http://tinyurl.com/2ynd9o
Even with ordinary reflectors, there are reflectors extremely close to 100 % reflectance, multiple layers that constructively add to the reflections, laser diodes work that way. One edge of the light path has a near 100% reflective surface and the other end has a 98% reflective surface by design. That means that inside the laser diode light path, the actual light intensity is some 50 times stronger than what actually is released, so it is storing light in its own way. If you have a 5 milliwatt laser, about the same as a laser pointer, the internal light intensity is about 250 milliwatts. Thats why laser diodes don't last forever like high intensity LED's, the internal light intensity of a one watt LED is one watt not 50 watts like it would be in a one watt laser diode because there is no internal reflection in an LED, just one pass and out. 3M company has already come out with a thin mylar plastic film with a coating nearly 100% reflecting so something like what you envision could maybe actually be built with ordinary materials. Most regular mirrors are at best 90% reflective besides having birefringance which means the light splits into two paths which doesn't help the return light path at all, it make things worse, reflectance wise. You get around that by using whats known as a surface reflector, like a telescope mirror, it has a micron thick layer of aluminum and gold which reflects from the surface and thus avoids the problems of ordinary mirrors where the reflective coating is on the backside of the glass.