I'm imagining an electromagnetic wave that could deliberately alter its wavelength. It would be a totally unfamiliar type of creature, but actually, we material beings act because of the electical neuro-signals in our bodies. So assume that it's a wave that could change its wavelength. I'm also thinking about its trajectory. I'm uncertain whether it's actually physically possible, but suppose it could change directions at will. (If the ray actually has a two dimensional cross section, it could 'heat up' one side of it to expand it, therefore turning to the opposite side). If so, then, if it had a device similar to a speaker it could pass through it to make sound. So it would communicate, but that means energy losses, so would it be slowly killing itself by 'speaking'?

Also, if it passed through a human being at a certain wavelength, it would in theory be warming him up. So if a person was stuck in the middle of the arctic desert with one of those he would not die of hypothermia, but he couldn't send a message out either because the wave would be busy passing through his body.

In theory (in my head) it makes sense, I'm just trying to understand whether I made some fundamental logical steps (maybe about the speaker, those things are pretty complicated).

This might be complete nonesence, but they do have a particularly intelligent shade of blue in The Hitchhiker's Guide to the Galaxy...

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    $\begingroup$ There is the start of a good question in here. I think the question needs to be a little more clear, what specifically are you asking? It is a paragraph full of questions. Generally we need a little background or accepted aspects you have already decided on as well as what specifically you are looking for in an answer. Please take a few minutes and review your question a bit. And welcome to the site. $\endgroup$
    – James
    Commented Jan 11, 2015 at 22:30
  • $\begingroup$ Haha thank you, ok I'll try to narrow it down $\endgroup$
    – L.R.
    Commented Jan 11, 2015 at 22:32
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    $\begingroup$ Polaritons might interest you (also see here and here), though unfortunately they're really just quasiparticles. $\endgroup$
    – HDE 226868
    Commented Jan 11, 2015 at 23:09
  • $\begingroup$ Unfortunately, the physical laws describing electromagnetic waves are some of the most accurately verified and studied in all of physics, and they wouldn't allow the behavior you describe for a purely electromagnetic being. However, if you add some other sorts of energy into the mix it might become possible to support a system complex enough for conscious thought. $\endgroup$ Commented Jan 12, 2015 at 2:53
  • $\begingroup$ Might have more luck with a magnetic field than with an individual photon. $\endgroup$ Commented Jan 12, 2015 at 3:27

7 Answers 7


There are cases where this has been done. A few of the masters (Assimov, Clarke) dabbled in it.

The hardest part is defining a "living creature" without using matter. The actual definition of a "living creature" is not well defined in science. However, it is well defined in the minds of readers, so you have to unshackle them first.

Science recognizes several traits of living creatures, of which some of the important ones are:

  • Metabolism. They fight entropy by consuming energy.
  • Reproduction. There is some "next generation" for the creature
  • Homeostasis. The creatrue roughly keeps its form.

If you want an exotic creature such as a non-material creature, you should fall back on my favorite law, Sanderson's First Law of Magic. "An author's ability to solve conflict with magic is directly proportional to the reader's ability to understand it." A non-material creature is going to be unusual enough that treating it as magic might be wise. Make sure you give the reader enough time to make sense of your non-material creature before solving problems with it

  • $\begingroup$ Sure, one could discard it with magic, but now it's a personal matter and I won't rest easy until there is a solution. For metabolism, could it maybe use energy of nearby stars, sort of like photosynthesis? It could maybe absorb solar rays, sort of like a battery, which would partially solve the 'suicide' problem $\endgroup$
    – L.R.
    Commented Jan 12, 2015 at 21:32
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    $\begingroup$ @L.R.: Forgive me, I may have been too brief. I also should have quoted Clarke's "Any sufficiently advanced technology is indistinguishable from magic" as well to give you my opinion on magic in sci-fi. As for metabolism, its hard to absorb solar rays directly without matter, but I believe Asimov played with the idea of pulling energy from the magnetic fields around the sun. $\endgroup$
    – Cort Ammon
    Commented Jan 12, 2015 at 23:39
  • $\begingroup$ I didn't remember this... see, this is a very good point. I didn't remember the details in Asimov's books because they fitted so well with the story / atmosphere, it sort of flowed past. But my real concern is that if the universe this wave would live in wouldn't be advanced enough to consider it 'normal', and a scientific explanation would be needed. Like I mentioned in the question, I wouldn't be surprised at or question anything in H2G2, but I remember reading Dune and regretting the lack of explanations. $\endgroup$
    – L.R.
    Commented Jan 13, 2015 at 17:02

I am embarassed at how old this question is that I didn't see before, but I don't regret writing all this. Hopefully someone may find it useful.

I came into this question thinking that a being made entirely out of immaterial stuff (not composed of fermionic matter like we are) would be impossible, but upon further reading I'm not so sure...! This is quite interesting, at least. The following is based on my amateur understanding of quantum mech, so I welcome corrections.

An EM wave is just one or more photons. It's hard to say whether they could change their wavelength and direction of their own will without getting more specific about what our Being is made of. An individual photon travels at lightspeed so it does not experience any passage of time, and therefore its properties cannot be changed except by interaction with something else.

But multiple photons can interact with one another -- indirectly. This is two-photon physics. In short, one photon in a pair possessing high enough energies (extremely short-wavelength gamma rays) can spontaneously fluctuate, or change, into a pair of temporary "virtual particles". The other photon can then be absorbed by (or, coupled to) one of the virtual particles, and re-emitted in a different direction before the virtual particles change back into a photon.

In this way, we might perhaps conceive of... let's call it "hard light", composed of gamma-ray photons, arranged in such a way that two-photon interactions constantly loop back around in predictable ways, forming stable "matter" that is actually gamma photons constantly fluctuating, bouncing and re-intercepting one another. This seems VERY questionable under the uncertainty principle, but maybe it's doable, somehow. Humans would certainly not want to go anywhere near this thing, and just as well, since it probably wouldn't survive long in human living conditions either.

So we have some kind of material to work with. Would our hard light be capable of forming a creature with a metabolism?

I think so. Maybe. Photons do not have any electrical charge, and I have no idea what interesting physical properties might arise from a unit of "hard light", so I cannot say that their "chemistry" would work like human cells (which essentially do work by exchanging electrons around in chemical reactions). But you could still build a mechanical computer.

Humans are chemical circuitry, and I see no reason why mechanical parts of arbitrary composition could not also form a living being. Clockwork computers on Earth are limited by the fact that they are made of metal: high energies and complex operations are required to turn refined metal into cams and circuits. It has been done before, but gears made of refined metals don't occur naturally on Earth the way amino acids spontaneously form from carbon chemicals. But maybe our hard light is different, and microscale gear-shaft machinery forms quite naturally from it.

Our being would probably require some extraordinary living conditions:

  1. A source of extremely hard gamma rays.
  2. Staying far away from large concentrations of fermionic matter, like the stuff that makes up humans. Hard light gamma rays could be quickly absorbed by atomic nuclei, disrupting the being's structure.

So where could they live? I have no idea. My best guess is somewhere in the vicinity of a pulsar, or an active galactic black hole, that has happened to avoid contact with lots of regular matter somehow, for some time. It's possible we could contact them if we built our own strong gamma emitters, perhaps a GR laser, and they might be discovered using gamma ray astronomy.

So that's the basic mechanism of it: Hard light by way of two-photon physics. As for the details, go wild.


When I started thinking about this question, I thought about how information is sent through the the internet in packets of light. 16 separate wavelengths can be combined without losing any of data contained in each. So could an A.I. program be contained in 16 packets? Is there any reason aside from infrastructure upgrade issues that it couldn't be 256 or 1024?

Since energy is expressed in packet called quanta, it isn't unreasonable to imagine the information of life contained in a quantum of energy. I'm going to continue to treat it like a program for simplicity's sake; though I don't expect it to be artificial life, I imagine this is a decent model for energy based life.

Every time my quantum encounters another packet of energy, it takes it as input (it eats it). It parses the information this packet contained. It might only have information on energy level, wavelength and spectra, or it could be another energetic life-form analyzing it simultaneously. It determines whether it needs to alter its program in response to the data it read (more on that later), and afterward expels (excretes) a packet of energy. Increasing or decreasing its total information will change its energy level and its vector.

It may even absorb the entire packet and significantly increase its energy level. Doing that a few time could cause it to "reproduce" by encoding its information onto the packet it releases. This is pretty much how an amoeba reproduces.

But you want more from this life-form than just that. Communication and intelligence. I don't think you are going to get a scenario where it walks through a speaker and can be heard speaking. Nor is it likely that they can warm someone up by passing through them. Remember that as a creature of pure energy, it is traveling at the speed of light. But it can collide with atoms of the air to be absorbed by its electron cloud and be expelled again in the opposite direction thousands of times per second so that it can stay in close proximity to your hero. Colliding with him with the intention to warm him up would be an ignominious suicide, and ineffectual since, depending upon its energy level it could warm up a single cell, burn it out, or wreck its DNA.

As far as communication goes, lets hand wave the first part where it learns to speak English. It picked up radio packets of our communication, determined that they were of value to it for whatever reason, and pieced together enough of them to determine that it was a language and it learned it.

Now it has to communicate with us. First it would gather enough energy to reproduce, but instead of creating a clone, it would write a program, encode that on the outgoing packet and aim it at a radio receiver. The program wouldn't be sentient, so it would have no moral issue with sending it to its doom.

So, what would happen to a random file received on a random radio antenna? Probably nothing. It would be filtered out as noise. My quantum would probably try multiple times before giving up. Perhaps it would try synthesizing a voice eventually, but I wonder what we would make of it? Perhaps it would be the beginning of meaningful contact, or perhaps it would give up in frustration after being ignored.

  • $\begingroup$ This... actually makes sense. I'm rereading it over and over to fully intergrate the concept (it still isn't simple :) ) The problem is, a lot of users on here agree that a wave can't simply absorb another wavelength, and I don't see how picturing it as a program would help. Other than that, it seems possible, presuming that there was a reseiver and that the contact was awaited. $\endgroup$
    – L.R.
    Commented Jan 13, 2015 at 19:37
  • $\begingroup$ The similarities are in that data on the internet is sent through packets of light and so are photons. Both programs and DNA could be boiled down to "a group of instructions". Due to the wave-particle duality, a single photon could be expressed as a probability graph or an interference pattern. A photon can be absorbed by an electron, move it into a higher energy orbit, and the leftover energy is emitted as a new photon. This photon contains information from the original photon but altered by the info from the electron. $\endgroup$
    – IchabodE
    Commented Jan 13, 2015 at 22:21
  • $\begingroup$ Also, waves do combine all the time. I'm just anthropomorphizing the process. The wave is altered when it 'absorbs' another wave, and often 2 particles go into the reaction and 2 come out. But not always. $\endgroup$
    – IchabodE
    Commented Jan 13, 2015 at 22:24
  • $\begingroup$ You realize that light waves can't interact with each other on their own. $\endgroup$ Commented Oct 30, 2016 at 12:12

I'm not sure what you want to achieve but a reasonable explanation could be that there are material living beings that live in a 4th (or 5th ...) dimension perpendicular to ours but they leave traces of electromagnetic waves that propagate through our dimension. Basically think a bit like Flatland.

As some unification theories require extra dimensions it shouldn't be hard to argue they are there. Once that leap is made it only stands to reason that, if our dimensions are populated with matter and sentient beings that, those other dimensions would contain the possibility for life as well.


The science definition of Life was well stated by Schröedinger in his "What is Life?" book. Basically, it is any organized system that can extract energy from its surroundings to oppose its own decay caused by Second Law of Thermodynamics. Wikipedia cites:

Schrödinger explains that living matter evades the decay to thermodynamical equilibrium by homeostatically maintaining negative entropy (today this quantity is called information[9]) in an open system.

In light of that, the question is: Can an electromagnetic wave extract energy from its surroundings?

My answer is that not. Electromagnetic waves can be created, and enhanced, by their surroundings, but (with the exception of light-estimulated radiation in laser and related devices) they can not extract energy from the medium.

Moreover, there is a different consideration, that of Relativity. Something moving at the speed of light (like an electromagnetic wave) has an extreme time dilation making time effectively stop, so even if such a lifeform exist, it would notice all time to happen "at the same time", with no possibility for causality. This living being would be unable to react to events of any kind, since the event happens at the same time as the decision and the reaction, to say.

  • $\begingroup$ Excellent point about time stopping at light speed, and one I meant to bring up. But mathematically, a photon only exists between emission and collision. A brand new photon is emitted from bouncing a photon off a shiny surface, but some of the information from the original photon can be read from the new photon, and time passes between absorption and re-emission. In theory, enough time for a decision, and that's where the opportunity for life is. Are we not still us despite recycling all bodily cells every 7 years? $\endgroup$
    – IchabodE
    Commented Jan 13, 2015 at 22:31
  • $\begingroup$ Interesting theory that of time between absorption and re-emission. It works for photons, but it does not for waves, and due to duality... you know. Anyway, final decision for a fantasy world is on the hands of the Author ;) $\endgroup$
    – Envite
    Commented Jan 14, 2015 at 16:26

See the novel Macroscope by Piers Anthony. It features an intelligent (as in alive and thinking) broadcast. It was explained (if memory serves; I read it over 30 years ago) that reflected energy can interact with incoming signal to allow it to interact with the receiver.


I'm not certain whether this answers your question, but: short answer is No, with an If; long answer Yes, with a But.

There is no such thing as this so–called “non-material living being”. What people describe as Matter and Energy are simply two aspects of the same thing. Anything which has some properties of Matter has some properties of Energy.

All objects are a trifecta of matter, energy, and information. You could be describing a vast interstellar Mind which treats planetary bodies as its neural clusters.

When most people think of these so–called beings of pure energy, they are usually imagining something which certainly uses material bodies but is able to exchange matter much more freely than lifeforms which are more constrained.

So, with regards to my strict interpretation for the premise of your question: no, it could not.

  • $\begingroup$ That doesn’t really help. $\endgroup$
    – JDługosz
    Commented Oct 30, 2016 at 5:26
  • $\begingroup$ What do you mean? Off topic or too brief? I was saying that there is no such thing as a “non-material living being” so far as I understand. Should I make that clearer in the answer? The question being so old, it will probably be a while for the OP to come along and review it. $\endgroup$ Commented Oct 30, 2016 at 5:34
  • $\begingroup$ Have you read through the other answers? There are specific ideas advanced. This reads as “well, maybe you can” but doesn’t explain what you’re thinking of. $\endgroup$
    – JDługosz
    Commented Oct 30, 2016 at 5:41

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