Why cant light be stored?

[humility]

If light doesnt degrade, can be used as a power source and can even be slowed down and takes up no space so can be stored in infinitely dense concentrations. Why dont they make batteries out of light? Sounds like they have the technology to do it. And I cant imagine cost is a factor, light is free.

[Silvestru]

1: Solar panels.

 

https://en.wikipedia.org/wiki/Solar_panel

 

A big problem with this free energy is storage.

Why dont they make batteries out of light?

2: I understand the energy source you provide is light but why would the battery be made out of light and how do you propose to create something from a particle that has no mass?

 

Sounds like they have the technology to do it. And I cant imagine cost is a factor, light is free.

 

Sounds like you are basing your opinions on little/no research.

Edited May 19, 2017 by Silvestru

[tar]

probably for the same reasons you can't catch lightning in a bottle

[studiot]

Of course light can be and is stored.

 

Ask any (pussy)cat for details.

 

The problem is the process is not efficient, certainly not as efficient as you envisage, but it does work.

[swansont]

If light doesnt degrade, can be used as a power source and can even be slowed down and takes up no space so can be stored in infinitely dense concentrations. Why dont they make batteries out of light? Sounds like they have the technology to do it. And I cant imagine cost is a factor, light is free.

 

 

Photons can be destroyed, since they are bosons. So it doesn't degrade, per se; it's more like a binary condition.

 

A photon in a cavity 3 cm long will bounce once every 0.1 nanoseconds. That's 10000 bounces per microsecond. Even with mirrors that are 99.9% reflective, if you start with a million photons you will be down to fewer than 50 photons in that time.

 

So no, we don't have the technology to do it.

[DanTrentfield]

If light doesnt degrade, can be used as a power source and can even be slowed down and takes up no space so can be stored in infinitely dense concentrations. Why dont they make batteries out of light? Sounds like they have the technology to do it. And I cant imagine cost is a factor, light is free.

Frankly, if Nikolai Tesla thought batteries that could contain light would be impossible or impractical I'm pretty sure that you couldn't prove him wrong. If we had batteries that could generate energy from photons the world would be a very different place. The existence of chemical batteries alone is almost enough to disprove any notion that photons could be stored in a battery that would produce energy. I'm pretty sure one day we will be able to trap light, but the ability to generate power from light other than the photovoltaic cell method and or store energy in photons will most likely not exist. To further prove what I say is not merely speculation here is some research: https://www.thenakedscientists.com/articles/questions/how-do-we-store-solar-and-wind-energy This particular article explains the three ways in which you can store harnessable energy: Chemical, Kinetic, and Potential. Photons do not have potential energy that is harnessable, they do not have chemical energy, and they do not have kinetic energy otherwise we would just be building photon sailing ships instead of using rocket engines in orbit. Also, do not confuse solar sailing ships with photon sailing, as solar sailing uses radiation pressure not merely photons, Wikipedia article on it http://en.wikipedia.org/wiki/Solar_sail As such, if there was a way to use photons to store energy I'm pretty sure we would be using it by now. While this does not concretely rule out the possibility, the probability of something like this being practical in any way shape or form is doubtful.

Edited May 27, 2017 by DanTrentfield

[StringJunky]

,.... Also, do not confuse solar sailing ships with photon sailing, as solar sailing uses radiation pressure not merely photons, ....

Radiation pressure is momentum transfer from photons.

[studiot]

I didn't say you could store light in a battery, I just said it could be stored.

[DanTrentfield]

Radiation pressure is momentum transfer from photons.

In physics, electromagnetic radiation (EM radiation or EMR) refers to the waves (or their quanta, photons) of the electromagnetic field, propagating (radiating) through space carrying electromagnetic radiant energy. Radiant energy cannot be harnessed practically to generate energy. You can build mirrors for days, and you're still melting salt. Photon batteries do not exist, You can store the energy from photons through other means, but photon batteries do not exist.

Edited May 27, 2017 by DanTrentfield

[studiot]

In physics, electromagnetic radiation (EM radiation or EMR) refers to the waves (or their quanta, photons) of the electromagnetic field, propagating (radiating) through space carrying electromagnetic radiant energy. Radiant energy cannot be harnessed practically to generate energy.

 

Wave v corpuscular doesn't really matter for the purpose of light storage.

[swansont]

EM waves and photons are the same phenomenon, just different descriptions.

[DanTrentfield]

 

Wave v corpuscular doesn't really matter for the purpose of light storage.

Right, but the question is how can you practically store photons? Why not just build a flashlight?

EM waves and photons are the same phenomenon, just different descriptions.

Yes indeed, due to me not reading into that enough I made that mistake. However radiant energy couldn't really be used as a pure power source through conversion to electricity like the OP is suggesting.

[studiot]

Right, but the question is how can you practically store photons? Why not just build a flashlight?

 

No the question was

 

Why can't light be stored? (which, of course, contains an incorrect assumption)

 

not

 

how can it be stored?

Edited May 27, 2017 by studiot

[DanTrentfield]

 

No the question was

 

Why can't light be stored?

 

not

 

how can it be stored?

Ok, simplify it, How could you store light without converting to to chemical, kinetic, or potential energy? Otherwise we just have a flashlight again.

If light doesnt degrade, can be used as a power source and can even be slowed down and takes up no space so can be stored in infinitely dense concentrations. Why dont they make batteries out of light? Sounds like they have the technology to do it. And I cant imagine cost is a factor, light is free. -OP

 

'Why don't they make batteries out of light?' That calls into question practicality because batteries are practical ways of storing energy that can be harnessed to do work.

[studiot]

What is the battery in your car?

Do you think you get the same electrons out that you put in when charging?

 

So how to store photons as I outlined in post#4.

 

That is photons in and later photons out.

 

All afternoon my car has been sitting on the drive absorbing all those nice yellow photons.

 

Tonight, after dark, members of the local furry fraternity will sunbath by basking in the infra red photons radiated under my car.

 

There ya go, photons in photons stored, photons out.

 

I never said they were the same photons, any more than Mr Chloride said the electrons from the car battery are the same.

Edited May 27, 2017 by studiot

[swansont]

Yes indeed, due to me not reading into that enough I made that mistake. However radiant energy couldn't really be used as a pure power source through conversion to electricity like the OP is suggesting.

We convert radiant energy to electricity all the time. It's becoming more and more prevalent.

[tar]

So, we are talking about pumping photons into a cavity of some sort, with 100% reflective internal surface, to keep them bouncing, or being absorbed, and reemitted to the point that when we uncork the bottle, a very strong pulse of photons would come out, that could then do work, in a short time, equal to the work the steady stream of photons, over a long time, could have done.

Might as well initially turn the steady stream of photons into chemical, potential or kinetic energy and store it in that form.

however, the idea of focusing seems to have some potential

 

that is, if one could focus the infrared wavelengths coming from the car, heated in the sun, like a magnifying glass focuses the sunlight and catches a piece of paper on fire, then the car itself becomes a photon battery, as studiot suggests

I never fully proved my theory or consistently reproduced the effect, but I once noticed a helium party balloon, shaped like a lens felt like a little warmth was coming off it, as if the balloon was focusing unordered infrared energy on the other side of balloon, on a point where I had my hand.

can not remember the surfaces of the balloon as in which side was silver or purple so I can not suggest an experiment, but theory wise, I wonder if infrared photons can be focused

Edited May 27, 2017 by tar

[studiot]

So, we are talking about pumping photons into a cavity of some sort, with 100% reflective internal surface, to keep them bouncing, or being absorbed, and reemitted to the point that when we uncork the bottle, a very strong pulse of photons would come out, that could then do work, in a short time, equal to the work the steady stream of photons, over a long time, could have done.

Might as well initially turn the steady stream of photons into chemical, potential or kinetic energy and store it in that form.

however, the idea of focusing seems to have some potential

 

that is, if one could focus the infrared wavelengths coming from the car, heated in the sun, like a magnifying glass focuses the sunlight and catches a piece of paper on fire, then the car itself becomes a photon battery, as studiot suggests

I never fully proved my theory or consistently reproduced the effect, but I once noticed a helium party balloon, shaped like a lens felt like a little warmth was coming off it, as if the balloon was focusing unordered infrared energy on the other side of balloon, on a point where I had my hand.

can not remember the surfaces of the balloon as in which side was silver or purple so I can not suggest an experiment, but theory wise, I wonder if infrared photons can be focused

 

 

The problem is

 

Of course light can be and is stored.

 

Ask any (pussy)cat for details.

 

The problem is the process is not efficient, certainly not as efficient as you envisage, but it does work.

 

What I am referring to in emboldened sentence is the thermodynamic idea that heat is the 'lowest grade of energy'.

That energetic processess degrade higher forms like electricity or potential or motion energy to become heat.

And the problem is that recovering light is trying to reverse this.

 

Of course it can be done, but it costs you a lot in energy efficiency terms.

 

 

 

Perhaps swansont knows more about this than I do but can't you contain laser light between mirrors and open on demand with a kerr cell shutter?

Edited May 27, 2017 by studiot

[swansont]

Perhaps swansont knows more about this than I do but can't you contain laser light between mirrors and open on demand with a kerr cell shutter?

Yes, therecwoukd be ways of doing that but refer to my earlier post about how many bounces you get. You can improve the situation by going to a longer cavity, but what would be the end game, as has been asked? What good is energy storage that degrades so quickly?

I wonder if infrared photons can be focused

Yes, of course they can. I've done it in the NIR, at 780 and 852 nm. However, depending on the wavelength, it may be difficult to find a material with good transmission.

What I am referring to in emboldened sentence is the thermodynamic idea that heat is the 'lowest grade of energy'.

That energetic processess degrade higher forms like electricity or potential or motion energy to become heat.

And the problem is that recovering light is trying to reverse this.

 

Definiely a problem for a thermodynamic solution, but if they can do work you can still recover the energy.

[Raider5678]

So for the sake of a thought experiment, related to what I think the OP is referring to.

 

Imagine you had a 1 way mirror. One way, light could move right through without a problem.

On the other end, it would be reflected at 100% efficiency. (obviously an impossible component at current technology, but lets say it was real.)

 

If you shined a laser into the box, where one end was the one way mirror, and every other side was 100% reflective.

They would bounce back and forth.

What would happen as more and more photons kept joining the box?

[tar]

Some memory of mine suggests that because of some of the wave aspects of light, there would be a lot going on in the cavity, and depending on the wavelengths​ ​going in, and the angles of reflections and the geometry of the cavity, there could be some canceling out and doubling up, in terms of amplitude of the waves, and I am not quite sure thought experiment wise, if you can rely on just imagining more and more particles, or rely on imagining stronger and stronger waves. Especially since waves have peaks and troughs and polarization characteristics and the like, that would have to be taken into consideration.

Edited May 28, 2017 by tar

[swansont]

Some memory of mine suggests that because of some of the wave aspects of light, there would be a lot going on in the cavity, and depending on the wavelengths​ ​going in, and the angles of reflections and the geometry of the cavity, there could be some canceling out and doubling up, in terms of amplitude of the waves, and I am not quite sure thought experiment wise, if you can rely on just imagining more and more particles, or rely on imagining stronger and stronger waves. Especially since waves have peaks and troughs and polarization characteristics and the like, that would have to be taken into consideration.

 

 

You can make resonant cavities where there is no cancellation and the reflections are all along the axis. That's generally the whole point of making one.

[Carrock]

So for the sake of a thought experiment, related to what I think the OP is referring to.

 

Imagine you had a 1 way mirror. One way, light could move right through without a problem.

On the other end, it would be reflected at 100% efficiency. (obviously an impossible component at current technology, but lets say it was real.)

 

If you shined a laser into the box, where one end was the one way mirror, and every other side was 100% reflective.

They would bounce back and forth.

What would happen as more and more photons kept joining the box?

Don't bother with the laser; connect a heat engine between the inside and outside of the box and you have a perpetual motion machine.

[John Cuthber]

 

 

Imagine you had a 1 way mirror. One way, light could move right through without a problem.

On the other end, it would be reflected at 100% efficiency. (obviously an impossible component at current technology, but lets say it was real.)

 

You have attached this disclaimer "(obviously an impossible component at current technology, but lets say it was real.)" to the wrong end of the box.

[Raider5678]

You have attached this disclaimer "(obviously an impossible component at current technology, but lets say it was real.)" to the wrong end of the box.

?