To keep within the guidelines of only asking questions that have a definite answer, I will stipulate that I am asking about cases where the question has been considered in an academically respectable context.

The argument I have in mind goes something like this: Shannon's definition of information might be summarized as there being information wherever things are arranged one way, when they might be otherwise (this is a simplification, of course, leaving out how one measures it.) This simplified view appears to be agnostic as to whether the things in the arrangement are physical or not.

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    The information, the arrangement of objects, still needs physical objects. It has to be represented physically somehow, even if that somehow is the connections of neurons in a brain using ganglia, or bits on a HDD through the polarity of tiny spot magnets. Etc.
    – Dan Bron
    Commented Jan 22, 2020 at 14:48
  • @DanBron For all practical purposes, if there are no certifiably non-physical things, or if there is no sense in which they can be in an optional arrangement, then this is what it amounts to, and if nonphysicality is an incoherent concept, then the question is moot, but the definition of information itself seems to be very broad, and does not seem to either require or depend on metaphysical physicalism.
    – A Raybould
    Commented Jan 22, 2020 at 15:19
  • It is not agnostic, it is orthogonal to the question of physicality the same way any mathematical definition is so orthogonal. We can define "energy" for any Hamiltonian system of ODE, it only relates to physical energy when the system actually describes something physical. Moreover, Shannon's "syntactic" notion of information is basically hollow, it is not the concept of information that it even makes sense to ask the physicality question about.
    – Conifold
    Commented Jan 22, 2020 at 20:51
  • @conifold To help me follow your point, if someone had knowledge of a particular hamiltonian, would that only be physical knowledge if it was a description of something physical (and maybe also only if the person knew that it was?) Or perhaps would it be inappropriate to call it physical knowledge in any context?
    – A Raybould
    Commented Jan 22, 2020 at 23:36
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    Knowledge of a Hamiltonian as such is always knowledge of an abstraction, which is "non-physical" if you want. It provides knowledge of something physical only if the Hamiltonian represents something physical.
    – Conifold
    Commented Jan 23, 2020 at 0:01

5 Answers 5


Information is a non-physical concept, but it is very common to implement this information via organization of physical objects. For example, the 1's and 0's of a computer program are a non-physical concept, but the magnetic spins used to represent this information are very physical indeed. Information stored in the brain is implemented via neural connections and chemical balances.

For a physicalist, who believes everything supervenes on physics, this is a mere convenience. It lets us easily see how information can be converted from one representation to another without losing the information. I can argue very clearly why a particular process preserves the information stored on a hard-drive as I run sensors over the magnetic material and store the information in memory as a particular configuration of electrostatic charges.

For someone approaching the world in any other way, we find the non-physical nature of information to be more important. Consider one who believes that there is a mental substance which is not physical that makes up a mind. It is almost always considered possible for that mind to contain information, despite the mind being a non-physical entity. And likewise, we typically like to declare that it is possible to have information about a mind. Putting them together, it is reasonable to argue that there is non-physical information about a non-physical mind.

  • "it is very common to implement this information via organization of physical objects" it is in fact **always ** the case, not very common. When was the last time you encountered information that wasn't somehow implemented in a physical subtract (A human brain, a sound or electromagnetic wave all being examples of such subtract) ?
    – armand
    Commented Apr 26, 2022 at 2:58
  • @armand It occurs whenever I choose to approach the world in a dualistic manner, in which one believes that there is some other substance besides matter, such as "mind." Information can be expressed in such abstract terms that it becomes very reasonable to claim this other non-matter substance contains information.
    – Cort Ammon
    Commented Apr 28, 2022 at 23:21
  • how is the approach you choose relevant to what really happens? Of course if you assume there is immaterial information in the first place it's "very reasonable" to reach this same conclusion, yet the reasoning is totally flawed. But whatever "approach" you chose, what exemple of information not ingrained in a physical body can you give? How many minds have you demonstrably interacted with that weren't associated with a brain?
    – armand
    Commented Apr 29, 2022 at 0:10
  • @armand I am operating under the open world assumption(OWA) for this answer. Just because I cannot prove that there is immaterial information does not mean I can assume there is no immaterial information. From the word choice I am seeing you use, I'm getting the impression that you are discussing the topic from the perspective of a particular Closed World Assumption(CWA). As you have noticed, you can always reduce statements made with OWA to any particular...
    – Cort Ammon
    Commented Apr 29, 2022 at 15:43
  • ... CWA system you choose, simply by asserting all missing information as false. Of course, this is known to have many tricky challenges if you don't have universal agreement as how to apply it. It is clear from your words that you have a particular heuristic that you are applying, one which is quite common and is recognized to not only be consistent with physicalism, but in fact I believe is the definition of a physicalist approach. Thus, your assumptions can reduce my entire answer to only the second paragraph, as that is the only reading that fits those assumptions.
    – Cort Ammon
    Commented Apr 29, 2022 at 15:47

Shannon information (entropy, actually) is an abstract concept that applies first and foremost to strings over an alphabet of symbols. In that sense, it is nonphysical (I would prefer to call it abstract, in the sense of abstracting from the real world onto simpler models of the world).

Curiously, it turns out that defining entropy still makes sense more generally in statistical mechanics and it looks pretty much the same as Shannon entropy. Read more on Wikipedia. This has implications about the physicality of information (even abstract information). Since any abstract information needs to be represented physically, it turns out, for example, that erasing (abstract) information from a physical medium takes a minimum amount of energy to perform. (Landauer's principle)

This is important, because it means you can do things like argue about algorithms (in particular cryptographical ones where entropy matters) in terms of minimum energy expenditure instead of runtime (or abstract complexity), and arrive at things like:


As a starting point, we will consider that each elementary operation implies a minimal expense of energy; Landauer's principle sets that limit at 0.0178 eV, which is 2.85×10^-21 J. On the other hand, the total mass of the Solar system, if converted in its entirety to energy, would yield about 1.8×10^47 J (actually that's what you would get from the mass of the Sun, according to this page, but the Sun takes the Lion's share of the total mass of the Solar system). This implies a hard limit of about 6.32×10^68 elementary computations, which is about 2^225.2. (I think this computation was already presented by Schneier in "Applied Cryptography".)

The whole answer is worth a read and the comments, too.

I think that makes information pretty physical, even if the original definition by Shannon is abstract.

  • Shannon information is the inverse of entropy. And Shannon channels aren't limited to strings over alphabets.
    – CriglCragl
    Commented Dec 20, 2021 at 17:51

Information itself is not physical. It is neither matter nor energy.

Information is the configuration (order, shape) of physical matter or energy.

A book is a physical object. The story it contains is information encoded in the shapes and the order of printed characters.

A broadcast radio wave is physical energy. The program you receive is information encoded in the shape of the radio wave.


Genetic information is a product of a mind.

Information is purposeful - it conveys knowledge about or prescribes something meaningful, such as data, function, concept, or process
It is prescriptive - it prescribes biological functions
It prescribes organismal features, such as organs, their arrangement in a body plan, and their relationship to each other
It prescribes the regulation of information expression in time (4th dimension of genetic information) to maintain and operate an organism
It possesses a code system which is the alphabet of it's language system
It possesses linguistics properties - phonetics, semantics, punctuation, syntax, and grammar
    Language is physically represented by symbols
    Symbolism is non-material - symbols represent objects, processes, or concepts which are external to themselves
    The application of meaning to a symbol and interpretation of meaning from a symbol is a mental process, not a material process
    Minds apply meaning to matter, not the other way around
    It is illogical to apply mental properties to matter 
Information is a non-material entity
Once information has been created it may be encoded upon a medium. The information is created first and encoded upon a medium afterward. The medium upon which information is encoded does not precede the creation of the information.
Information is not bound to whatever medium upon which it is encoded - information does not change when encoded upon various mediums and it is conveyed without relocation of any portion of the medium upon which it is encoded
Information cannot be physically measured because it has no physical dimensions or mass - the concept of measuring one pound or one meter of information is nonsensical.
    Example: The information in a book can be copied onto any other medium without the information changing in any way and without relocation of the material medium upon which it is encoded:
    Reading a book: If information and minds were both physical, it would be impossible to receive (read) the information in a book without relocating the material of the book into the brain of the reader.
    Reading a printed message to another person: If information and minds were both physical, it would be impossible to convey (read aloud) the information in a book without relocating the material of the book into the brain of the listener.
    Speaking to an audience: If information and minds were both physical, it would be impossible to share information with an audience without relocating the material of the provider's brain to the brains of the each member of the audience. 

10 Laws of Nature Regarding Information which verify that creation is true and evolution is false: The following is a transcript of Dr. Werner Gitt from his book, "In the Beginning Was Information".


Anything material, such as physical/chemical processes, cannot create something non-material
Information is a non-material fundamental entity and not a property of matter
Information requires a material medium for storage and transmission
Information cannot arise from statistical processes
There can be no information without a code - no thought or idea can be shared without a code
All codes result from an intentional choice and agreement between sender and recipient
The determination of meaning for and from a set of symbols is a mental process that requires intelligence
There can be no new information without an intelligent, purposeful sender
Any given chain of information can be traced back to an intelligent source
Information comprises the non-material foundation for all:
    technological systems
    works of art
    biological systems 


Since the DNA code of all life is clearly within the definition domain of information, we conclude that there must be a sender
Since the density and complexity of the DNA encoded information is billions of times greater than man's present technology, we conclude that the sender must be supremely intelligent
Since the sender must have
    encoded (stored) the information into the DNA molecules,
    constructed the molecular biomachines required for the encoding, decoding, and synthesizing process and,
    designed all the features for the original life forms, 

We conclude the sender must be purposeful and supremely powerful,

Since information is a non-material fundamental entity and cannot originate from material quantities, we conclude that the sender must have a non-material component
Since information is a non-material fundamental entity and cannot originate from material quantities, and since information also originates from man, we conclude man's nature must have a non-material component (spirit)
Since information is a non-material entity, we conclude that the assumption "the universe is comprised solely of mass and energy" is false.
    biological information originates only from an intelligent sender and,
    all theories of chemical and biological evolution require that information must originate solely from mass and energy alone (without a sender), we conclude that all theories or concepts of biological evolution are false. 

Anyone who disagrees with these laws and conclusions must falsify them by demonstrating the initial origin of information from purely material sources. Therefore, the laws of nature about information have,

refuted the assumption of scientific materialism and the theories of chemical and biological evolution
all philosophies or theories based on the assumption of scientific materialism including chemical and biological evolution are falsified by the laws of nature about information. 
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    Your formatting makes this very difficult to read.
    – CriglCragl
    Commented Dec 20, 2021 at 18:20

What do you mean by non-physical? What fundamentally can that even mean. I suggest it is an incoherent category, or at best a way of grouping and abstracting physical things to compare them, which intrinsically involves physical things.

"A miracle is a violation of the laws of nature; and as a firm and unalterable experience has established these laws, the proof against a miracle, from the very nature of the fact, is as entire as any argument from experience can possibly be imagined." - Hume, in On Miracles

And whatever new regularity is revealed, becomes a new part of the regularities of nature. Whatever is scientifically verified, becomes part of science.

"I ask you please to tell me how the soul of a human being (it being only a thinking substance) can determine the bodily spirits, in order to bring about voluntary actions. For it seems that all determination of movement happens through the impulsion of the thing moved, by the manner in which it is pushed by that which moves it, or else by the particular qualities and shape of the surface of the latter. Physical contact is required for the first two conditions, extension for the third. You entirely exclude the one [extension—i.e., spatial dimensions] from the notion you have of the soul, and the other [physical contact] appears to me incompatible with an immaterial thing." - Elizabeth of Bohemia in letters to Descartes

Because it takes being physical, to generate physical changes.

The resolution of the challenge of Maxwell's Demon to the law of net increasing entropy in an isolated system, echoes Elizabeth of Bohemia's challenge which has not been satisfactorily answered by substance dualists. Information is physical, and Shannon entropy grounds that. The reason there is a misconception about this I would contend, is substrate independence, that being able to represent complex states in different specific media shows independence from a specific instantiation, but not from physical instantiation itself. There are also issues around the meaning of causality that mislead, discussed here: Is the idea of a causal chain physical (or even scientific)?

The modern scientific worldview consists of two types of properties. Energy, like momentum. And informational, like position, and entropy. That makes the scientific model property dualist, and though there are clear links like angular momentum relating to that of the universe as a whole, and entropy resulting in energy diffusing, these two categories cannot yet be fully merged into one 'language' of description. Discussed here: Is the idea that "Everything is energy" even coherent?

The expectation historically was that informational properties were only secondary relational properties of the fundamental substance (then mass, later unified with energy). But informational properties are increasingly being understood as in the more fundamental language, eg symmetries, and that as being key to unifying General Relativity's information speed limits, and Quantum Field Theory's understanding of information flow. Chiribella's Purification Principle, Marletto & Deutsch's Constructor Theory, t'Hooft's cellular automaton interpretation of QM, and Rovelli et al's Loop Quantum Gravity, all make this shift from geometry to information (space from state-space).

Even mathematics doesn't exist independently of manifestations, but is a language (set of abstractions that are efficiently substrate independent) based on drawing out regularities in symmetry operations (ie number lines as continuous symmetries).

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