Could a photon, now or sometime in the future be found to have any data imprinted upon it recording all that which it has "hit" or ricocheted off of? — James Riley

We already do that. Each photon has a particular wavelength. We record the wavelength of a photon arriving at a digital sensor. That's how photography works.

In practice, sensors aren't sensitive enough to capture the arrival of a single photon. A consumer-grade digital sensor, like the one in your camera or phone camera, registers a hit when a bunch of photons show up. The sensor records their wavelength and plays it back to you in the form of a photograph.

If you're asking if we could store additional info besides wavelength, it seems unlikely. We'd have to hit the photon with energy, changing its wavelength. One photon is identical to any other except for its wavelength, there's no way to add information to it as far as I know, but I could be wrong.

But of course we can also just put a shutter in front of a lightsource and send a message in Morse code based on the light being on or off. They did that in the old days between ships at sea, before radio.

And of course there's optical fiber, which transmits digital signals in essentially the same way.

If you're asking if we could store additional info besides wavelength, it seems unlikely. We'd have to hit the photon with energy, changing its wavelength. One photon is identical to any other except for its wavelength, there's no way to add information to it as far as I know, but I could be wrong. — fishfry

Okay. I was thinking of something akin to reversing entropy. I was thinking that if that photon which hit my brown car and then went into my eye to register as such, the "brown" would not merely be in my interpretation of what I saw, but might leave a "brown" finger print on the photon. Thus, if it was caught before entering my eye and then studied, it would be found to have the marker. I know photography does this "at the time" but I'm talking about gathering up spent photons after the fact, putting them together, grabbing those finger prints and making the photo after one was not taken.

I knew it was a "reach" but whenever I think of something as a particle, I can't help but wonder what might be gleaned from it, based upon it's experiences.

Could a photon, now or sometime in the future be found to have any data imprinted upon it recording all that which it has "hit" or ricocheted off of? — James Riley

Actually, photons are the universal "carriers of information" in a manner similar to Shannon's "bits" & "bytes". Yet a single photon (bit) is too simple & generic (all identical) to carry much info. But, if you cram a bunch of photons together (bytes), they begin to look like the EverGreen EverGiven ship in the Suez canal. :nerd:


The photon is a fundamental carrier of information, possessing numerous information carrying degrees of freedom including frequency, phase, arrival time, polarization, orbital angular momentum, linear momentum, entanglement, etc.
https://www.darpa.mil/program/information-in-a-photon

A bulk information carrier :

I knew it was a "reach" but whenever I think of something as a particle, I can't help but wonder what might be gleaned from it, based upon it's experiences. — James Riley

You may be led astray by some interpretations of PanPsychism, in which every particle in the world has "experiences". But, I'm afraid that a lonely photon would experience a poverty of meaning. What does a photon remember of the "experience" of bouncing off of a proton? "Watch where you're going idiot!" :joke:

Could a photon, now or sometime in the future be found to have any data imprinted upon it recording all that which it has "hit" or ricocheted off of? — James Riley

'recording' requires encoding, meaning storage of information. As photons are simple, i.e. not composed of parts, how could they support a complex operation of this kind? They have no parts.

It is said that the distinctive attribute of living organisms, even the most simple forms of living things, is that they form and retain memory. But they're infinitely more complex than sub-atomic particles.

might leave a "brown" finger print on the photon — James Riley

Isn't that just the wavelength or frequency of the photon?

Isn't that just the wavelength or frequency of the photon? — fishfry

I honestly don't know. But if it is, can it be captured after the fact (i.e. not in the instant as part of a picture)?

I honestly don't know. But if it is, can it be captured after the fact (i.e. not in the instant as part of a picture)? — James Riley

After which fact? Its wavelength can be measured by a light-sensitive detector like the one you carry around in your smartphone.

After which fact? — fishfry

Like the next day. Where light is streaming into a room and no one is there to photograph it today. The next day, a scientist shows up and starts collecting the heat energy from the sofa, or back-tracing the photosynthesis in the fern on the table, reconstructing what the previous day's light had "seen". There, in the frame, we see the housekeeper who came in and watered the plants, some of the light having shined upon her was reflected, while other light was absorbed by her where it finally "died." And maybe, since some of it hit her, was absorbed by her cloths and she left, there was a negative on some features in the room where the light never hit because she was in the way.

Where light is streaming into a room and no one is there to photograph it today. The next day, a scientist shows up and starts collecting the heat energy from the sofa — James Riley

In what fundamental way is the sofa different from a photodetector in this scenario?

I do not know, other than the large, overwhelming majority of rooms in the world don't have photodetectors in them, unless sofas are not different, in which case can we do with a sofa that which we can do with a photo detector? And, how far back could we go? Could we see what happened in that room 100 years ago?

I do not know, other than the large, overwhelming majority of rooms in the world don't have photodetectors in them, unless sofas are not different, in which case can we do with a sofa that which we can do with a photo detector? And, how far back could we go? Could we see what happened in that room 100 years ago? — James Riley

I suppose light jiggles the electrons in a sofa in such a way that a sufficiently sensitive detector could tell. But I'm sure it's not possible in practice. Why are you asking? This is far from your original question. You asked if we could imprint data on a photon. Now you're asking if we can use a sofa to detect the past presence of a photon.

In theory I don't think there's anything fundamentally different between a photodetector and a sofa, except that photodetectors are especially sensitive to impinging photons and sofas aren't.

But it's not actually the momentary impingement of a photon on a photodetector that allows us to record the arrival of the photon. Rather, a photodetector turns the photon's energy into electrical energy that can be stored in a memory chip. Sofas presumably don't turn light energy into electricity. On the other hand plants do turn light energy into chlorophyll, so perhaps in principle we could make cameras out of plants. These are interesting questions, perhaps asking on physics.stackexchange would generate some good answers. We really need a physicist at this point.

ps -- Ok suppose we could focus light onto a plant leaf. After a period of time, would the leaf have a different color or appearance where the light was focused? Or does the light energy get diffused and the chlorophyll spread around evenly? Now we need a biologist.

This is far from your original question. You asked if we could imprint data on a photon — fishfry

If that is what I said, that is not what I meant. I don't want to imprint data on a photon. Rather, I want to know if data has been imprinted on a photon that we can glean after the fact. I tried to use the analogy of a bullet. One can sometimes take a bullet and determine that it first went through a shirt with X thread count, then glanced off a bone before passing through guts, out and into some kind of wood. This is data recorded on the bullet. I thought maybe, someday, we might be able to look into the past by finding evidence of what light "saw" in it's journey. I don't suppose a whole lot happens to it in flight from that distant star. Maybe it bends around some curve of space or whatever, but that may not leave a print that stays after the flight is over. And, while it might tell us something about the past regarding the star it came from, I'm thinking closer to home.

I want to know if data has been imprinted on a photon that we can glean after the fact. — James Riley

It seems unlikely, as I and others have already noted. The only attributes a photon has are its wavelength and frequency (which are inversely related, so there's only actually one attribute). It has no other attributes that can be altered to store any other information.

Thank you.

I don't want to imprint data on a photon. Rather, I want to know if data has been imprinted on a photon that we can glean after the fact. I tried to use the analogy of a bullet. One can sometimes take a bullet and determine that it first went through a shirt with X thread count, then glanced off a bone before passing through guts, out and into some kind of wood. This is data recorded on the bullet. I thought maybe, someday, we might be able to look into the past by finding evidence of what light "saw" in it's journey. I don't suppose a whole lot happens to it in flight from that distant star. Maybe it bends around some curve of space or whatever, but that may not leave a print that stays after the flight is over. And, while it might tell us something about the past regarding the star it came from, I'm thinking closer to home. — James Riley

I don’t have the physics background of fishfry, so I can only offer my poorly informed thoughts...

I tend to think of a photon as a ‘light event’. If you consider that your own path through life is ‘imprinted’ to some extent on your physical body, then we might assume that the same sort of information might be retrieved from light at the end of its journey. But the ‘imprint’ on your physical body after death is interpreted only by understanding the potential in a human life to impact on the body, just as the imprint of a bullet’s trajectory is interpreted by understanding its potential to be impacted as it travels through a shirt, glances off bone or passes through guts. How do we know what ‘glancing off bone’ looks like to the bullet? This may seem anthropomorphic, but we’re really asking what would ‘glancing off bone’ translate to on the bullet’s surface?

If all that we can measure of a photon at the end of its life is wavelength and frequency, then there’s not a lot to differentiate in relation to its path. A bullet that has not been fired presents a smooth surface, and we must first differentiate between the marks made by firing, and those made after leaving the barrel. With a photon, we would need to start with known origins, and then group measurements of many, many different photons arriving at the same point to try and distinguish alternative trajectories. There are a lot of variables to consider along the way, not the least of which is that we cannot differentiate two photons arriving at the same point simultaneously, regardless of their journey...

A photon is a quantum particle that is massless and is thus composed of infinitesimal pieces of mass. All objects reflect wave modality to our measurements, but particles are fundamental. We still live in the world of Greek atomism. Now sub-atomic particles have infinite path integrals and can collapse in on themselves infinitely. Infinitesimals are a measurement phenomena, so light is like a cloud or rainbow in that it is a substance but because of its quality of speed, light is in another realm entirely (with regard to time). It lives in an infinitesimal of time

What does entanglement have to do with light. I know light can be turned into heat but I am not aware of it having spin

I don’t have the physics background of fishfry — Possibility

I know virtually nothing of physics. Watch a lot of Youtube videos, that's all. Would not want to give any other impression.

With a photon, we would need to start with known origins, and then group measurements of many, many different photons arriving at the same point to try and distinguish alternative trajectories. There are a lot of variables to consider along the way, not the least of which is that we cannot differentiate two photons arriving at the same point simultaneously, regardless of their journey... — Possibility

You can transmit enormous amounts of information using light as a carrier - that’s how fibre-optic cables work, they’re the backbone of the internet. But that’s not what the OP is proposing. It’s asking if a photon could have ‘information imprinted on it’ - to which, with my extremely limited physics background, I think the answer is ‘no’. (If anyone with specialised knowledge knows better I will happily concede the point.)

In double slit experiments they can predict light patterns, so it seems we can know the paths of light from its destination. I do not know if light picks up information from its environment

What does entanglement have to do with light. I know light can be turned into heat but I am not aware of it having spin — Gregory

Like any other quantum particles, Photons can become entangled. But I don't know if that coupled state can be used to record arbitrary information, beyond the historical fact of entanglement. Maybe you can dig deeper into the DARPA report. :smile:

Quantum entanglement :
One of the most commonly used methods is spontaneous parametric down-conversion to generate a pair of photons entangled in polarisation.
https://en.wikipedia.org/wiki/Quantum_entanglement

Could a photon, now or sometime in the future be found to have any data imprinted upon it recording all that which it has "hit" or ricocheted off of? — James Riley

The concept of recording historical information in waves of Photons, sounds similar to the notion of information "imprinted" upon gravitational waves of Gravitons. But since gravitons are still hypothetical, the question is moot. :chin:

Gravitational wave :
Gravitational waves transport energy as gravitational radiation, a form of radiant energy similar to electromagnetic radiation.
https://en.wikipedia.org/wiki/Gravitational_wave

Many years ago, I read a sci-fi novel that was based upon the fictional-but-seemingly-plausible notion of an alien machine "The Macroscope", which could read the entire history of the universe from enformed "gravitational" waves. However, the enformed particles were dubbed "macrons". That wild conjecture opened the entire universe to exploration, and allowed the author to weave a complex story that traversed all of space & time. :nerd:

The Macroscope
___Piers Anthony
https://en.wikipedia.org/wiki/Macroscope_(novel)

That's ultimately the way I was going, but hoping there was hope for baby steps; and I was thinking of light instead of gravitational waves. Cool.

Digression: does a photon lose anything for having reflected? I see a lot of indirect light coming into my house and yes, some of it lands and is absorbed/converted/dies or whatever. But if it were to reflect back out again, as in the case of snow, or a mirror, does it have less of an oomph (scientific term of art) or shine, than a photon straight from the source?

If gravity is not a force how can there be gravitational waves?

Digression: does a photon lose anything for having reflected? — James Riley

When light impacts matter it usually transfers some of its energy to the impactee. But a reflective surface, like a mirror, seems to act like rubber to bounce the light away without absorbing much of its energy. I don't know the physics behind mirrors, but I suspect it has something to do with smooth continuous surfaces and short wavelengths. A mirrored surface seems to work like the opposite of a black body, which absorbs almost all energy. :chin:

Does reflected light lose energy? :
Often it does not lose much energy on being reflected. It loses energy on being absorbed. Each reflected photon has the same energy as before. ... Light may lose or gain energy on being reflected from a moving mirror because of the Doppler shift.
https://physics.stackexchange.com/questions/373577/loss-in-energy-by-light-after-reflections

If gravity is not a force how can there be gravitational waves? — Gregory

Gravity is a strange property of "curved" space. Perhaps gravitational waves are merely regular short "curves" propagating through space. Unfortunately, the notion of curved emptiness is counter-intuitive. Go ask Einstein -- it's all his fault. :smile:

I'm thinking that the heaviness of objects causes a squish on spacetime and that actions that seem like a "force" are really radiations of energy. So we would have weight and energy that would account for what appears to be Newtonian force. Is that explanation sound in your mind?

I'm thinking that the heaviness of objects causes a squish on spacetime and that actions that seem like a "force" are really radiations of energy. So we would have weight and energy that would account for what appears to be Newtonian force. Is that explanation sound in your mind? — Gregory

That sounds OK intuitively. But it's not how a physicist would describe it. What we experience as a pulling or squishing Force, according to Einstein, is merely acceleration in space. It's the relative motion that we subjectively feel as gravity "squishing" us. Objectively, an object that is not moving relative to the weighing device has no measurable "heaviness" (weight), but it may still have theoretical Mass. It all depends on your frame of reference.

I haven't yet fully integrated gravity into my Enformationism thesis. But then, physicists haven't been able to reconcile Gravity with Quantum mechanics. Besides, ancient Greeks metaphorically equated Gravity with Love, as an attractive "force"..

Gravity is physically experienced (felt) as an attractive "pulling" force, but technically, it's an abstract spatial relationship. But then, energy is also a physical relationship (a ratio), that somehow causes things to move and to change. Sometimes, gravity is called a "pseudo-force", but that may be even more confusing.

I'm not so sure that even physicists really understand what gravity and energy are in essence. They define Gravity & Energy in specialized terms, such as Fields", that allow them to measure & calculate quantities of stuff, that is not really quantifiable in an ordinary sense. How many Gravitons to the pound? Here's a few Google-search quotes about Gravity and Energy that seem to be contradictory :

"Gravity is not a form of energy but gravity creates potential energy."

"Anyhow, the object responsible for the gravitational force is a tensor field called the metric, and when we quantise gravity we are quantising the metric not the force."

"Einstein argued that gravity isn't a force at all. He described it as a curvature of time and space caused by mass and energy." ..

"Gravity is a force of attraction that exists between any two masses, any two bodies, any two particles"

So now, what were you trying to say about Gravity? :grin:

As explained by Einstein, motion and even objects are metrical and not true substances