Suppose you want to store energy in empty space rather than a battery. It's easy to think of compacting lots of photons into space. What you need, is either a black hole, or a superreflector.
All modern materials have non-100% reflectance. For example, silver has 98.2% for 550 nm wavelength.
So, a hypothesis: a material exists with very close to 100% reflectance.
(Similar to superconductivity, and superfluidity.)
If exists, just imagine how light batteries could be....-- Inyuki, May 09 2015 98.2% - for silver, from here. http://www.kayelaby...sics/2_5/2_5_9.html [Inyuki, May 09 2015] can you permanently capture light? https://m.reddit.co...ntly_capture_light/ [xaviergisz, May 09 2015] Total Internal Reflection http://www.physicsc...Internal-ReflectionPartway to Maxwell's daemon [csea, May 09 2015] Wikipedia - Reflectance http://en.wikipedia.org/wiki/Reflectance [Inyuki, May 10 2015] Slow light down to 60 km/s http://news.harvard...999/02.18/light.htm [AusCan531, May 11 2015] attenuation in optic fibre http://upload.wikim...-Zblan_transmit.jpgfrom wikipedia [xaviergisz, May 11 2015] Yeah, I agree, these are big questions, [bigsleep]. Light explosions, among the risks.
But before even having these questions, the biggest one is -- would such material be possible.-- Inyuki, May 09 2015 Interesting.
A company called Newport makes mirrors with reflectivity >99.7%, but this is a bit like the difference between a good conductor and a superconductor.-- MaxwellBuchanan, May 09 2015 Problem is, even with 99.7% reflectivity we get just 100 bounces till we drop to just 74% left. So, if we have mirrors 3 m apart, that would give 0.000001 second to drop from 100% to 74%. (with mirrors 3000km parat you could see something of macroscopic time though)
To sustain for 1 second for mirrors 3 m apart, we'd need reflectivity 99.9999997% to sustain 100000000 bounces till we drop from 100% to 74%.-- Inyuki, May 09 2015 [bigsleep], very interesting! I wonder, what's the transparency/resistence of fiber optic cables.-- Inyuki, May 09 2015 Could a geometry be derived within a series of steps in or graduated indexes to create multiple / infinite TIR [link] ?-- csea, May 09 2015 Hmm, [xaviergisz]' link says no. Oh, well...-- csea, May 09 2015 Maybe, this will be the battery that you have to put a small % of energy into, for a structure and enviroment that can store the light.-- wjt, May 09 2015 If you had a very small black hole, you could just place the light In orbit, not thought of how to get it out though.-- bs0u0155, May 10 2015 The graph that shows reflectance curve in Wikipedia looks asymptotic to y==100 line.
Seems like the longer the wavelength the higher the reflectance.
I wonder if there's a sweet-spot for some wavelength and material.-- Inyuki, May 10 2015 It seems like you could see back into the past with this.
Eventually, I'd think the light would heat up the medium and dissipate.-- RayfordSteele, May 10 2015 [bigs], the Wikipedia article says TIR can get up to 99.999%, which is four nines short of what's needed here and many more short of perfect.
If a perfect mirror doesn't exist, you might need achieve the same thing by letting the light go in a straight line and bending space. A couple of very tiny black holes a few mm apart would do the job - just launch the light into a figure-8 orbit that skirts the two event horizons.-- MaxwellBuchanan, May 10 2015 [bigsleep] Does this mean the exotic materials, once flooded internally to saturation with light, would have novel behaviours?-- wjt, May 11 2015 //To sustain for 1 second for mirrors 3 m apart, we'd need reflectivity 99.9999997% to sustain 100000000 bounces till we drop from 100% to 74%//
Only when light travels a full 300,000 km/s If you could slow it to down to 60 km/s as per the linked article sustainability increases markedly.-- AusCan531, May 11 2015 //[MB] Read it again carefully. "Perfect mirrors exist as TIR//
Ah yes, it seems you are right and I was wrong. Howevertheless, you're then left with the problem that the light is travelling through a dense medium (such as glass or water). I'm not sure how transparent a material can be, but optical fibres generally have boosters every few tens of kilometres. This suggests that light in an optical fibre is attenuated (presumably by absorbance) by a significant factor over that sort of distance.-- MaxwellBuchanan, May 11 2015 //Some cores are better than others.//
True, and I agree that surface defects probably account for some of the losses. We need an estimate of the losses due to absorbance by the glass.-- MaxwellBuchanan, May 11 2015 You're assuming that all the losses are reflectance losses. How much light is lost through absorbance?-- MaxwellBuchanan, May 11 2015 //About 50% as I just mentioned. // Wait - I'm meant to be paying attention?-- MaxwellBuchanan, May 11 2015 Don't pay anything! Does TER work? A vacuum fibre...-- Ling, May 12 2015 No - the light will bounce back and forth between the sticky-outy bits of the E and get absorbed.-- MaxwellBuchanan, May 13 2015 Is there a limit for the maximum photon density in a defined volume for the natural world? say inside the sun or a black hole.-- wjt, May 14 2015 Send the idea to Elon, Im sure Solar City would like make their home batteries a bit more flashy and prestigious.
P.S everyone please buy more Solar panels. II need to make sure my investments meet their targets this year.-- bob, May 15 2015 random, halfbakery