5. Information Requires a Physical Medium
In the previous section, I demonstrated how absurd is the notion of information existing as an entity independent of everything else and being, by itself, more or less resistant to dissipation. In the current section, I will demonstrate that information—despite not referencing an entity of material existence per se—certainly requires a physical medium, without which it is incapable of existing. Given its relevance to my argument, I will begin by defining the term “information”.
Information designates, in the technical sense of the context of information theory, the surprise value of some content that reduces the amount of uncertainty that exists in some medium before the arrival of the informative content (Dawkins, 2004, p. 109; Adriaans, 2020). In other words, information designates the amount by which uncertainty or ignorance was reduced in some physical medium after it receives an informative message. Usually, what the content of the informative message does is transform the previously existing uncertainty into zero (i.e., into certainty) (Adriaans, 2020). To know the amount of information of a message, we just need to estimate what is the uncertainty or ignorance of the receiver of that message before receiving it and compare with the uncertainty or ignorance that persists in the receiver after receiving it (Dawkins, 2004, pp. 109, 112). In short, information describes the state of a physical system (whatever it may be), as well as the change that occurs in it when some event—say, the receipt of a message—causes an alteration in this state (Burgin and Mikkilineni, 2022).
Information can be represented, encoded, decoded, transmitted from one medium to another, copied, processed and measured (Shannon and Weaver, 1964, pp. 7-8; Dawkins, 2004, p. 111; Dawkins, 2015a, p. 22; Burgin and Mikkilineni, 2022). And in all these possibilities, a physical medium is essential. A fundamental property of information is that it, as I will discuss in more detail hereinafter, requires a physical medium to exist, to be conserved and to be transmitted. Information certainly does not exist as a metaphysical entity independent of the material medium. Even though the concept of information does not refer to an entity of material existence by itself (Anderson, 2010, p. 51; Burgin and Mikkilineni, 2022), this does not mean that it consists of a metaphysical entity, because, as I will demonstrate, it is inseparable from some physical medium. I will provide an example to help my explanation.
In electronic technology, information is stored in a sequence of zeros and ones—the so-called binary code. This is equivalent to saying that in any system based on binary code, each memory location (or memory address) can be either 0 or 1 (these two possible states can also be conceived as off and on) (Hawking, 1996, p. 188; Dawkins, 2015b, p. 163). If we compare a computer with, say, 500 gigabytes of memory capacity with one of 1000 gigabytes, the latter can store more information by enclosing a larger number of memory locations. In other words, the amount of information that any electronic device can store depends directly on the number of physical memory locations that it encloses (Dawkins, 2004, p. 110).
Before a computer’s memory interacts with an item (or system) to be stored, it is in a disordered state, as it encloses equal probabilities for both possibilities for each location—0 and 1. Once the memory interacts with a system to be stored, it is definitely in one state (0) or definitely in the other (1) (Hawking, 1996, p. 188). This implies that the memory has gone from a random (or disordered) state to a non-random (or ordered) state. Something relevant is that, for this to be possible (to go from randomness to non-randomness), energy is required. A specific memory location cannot be in the appropriate state of the system (according to the item to be stored) without an investment of energy (Hawking, 1996, pp. 188-189).
When the informative content of an item to be stored interacts with the computer memory, the previous uncertainty of each memory location is transformed into certainty after the arrival of the informative content. If an item occupies the equivalent of 172 memory locations, for it to be registered in the computer memory, each location of this series of 172 locations must be established in the corresponding state—definitely 0 or definitely 1. Trying to conceive of the information of a computer without referencing the physical medium (i.e., the memory locations) is impossible. When we talk about the information stored on a computer, we have to talk about the serial ordering corresponding to each specific item that is registered (whether in RAM or ROM memory, whether on a hard disk drive [HDD] or on a solid state drive [SSD]), with all their respective zeros and ones. (Random Access Memory [or RAM] is a memory in which information can be stored and read as much as you want. In turn, Read-Only Memory [or ROM] is a memory that, once information is stored, it can only be read. ROM memory, in contrast to RAM memory, makes it impossible to store new data if this has already happened. Indeed, it is possible to rewrite certain types of ROM memory through specialized processes, but that is not why they are produced.)
No matter how information is represented—bits, spin (a quantum property intrinsic to a subatomic particle), charge, holes in a punched card (a rigid type of paper that stores digital data due to the presence or absence of holes, made in specific locations) or electrical impulses transmitted by neurons—it is always linked to a physical medium (Landauer, 1996). And no matter if we are talking about storing information on a computer or on any other medium, energy is essential for both storing information (of any type) on a physical medium and expressing it (Nelson and Cox, 2013, p. 20; Hawking, 1996, pp. 188-189). The absence of energy would imply the inevitable dissipation of information—which is the same as saying that it would go from an ordered state to a disordered state, devoid of meaning (Nelson and Cox, 2013, p. 20). In other words, as a result of its non-randomness, conserving information is energetically costly and goes against the much more probable scenario of its dissipation (Pal and Pal, 1991; Duncan and Semura, 2007; Knight, 2009, pp. 558-559; Nelson and Cox, 2013, p. 23). In short, for the previous uncertainty (i.e., the disorder) of a system to be converted into certainty (i.e., into order), the use of energy is a requirement (Hawking, 1996, pp. 188-189; Knight, 2009, p. 559; Atkins and Jones, 2010, p. 288).
Rolf William Landauer (1927-1999) was a physicist who dedicated his career to establishing the physical principles of information. He is famous for an article titled “Information is Physical” (1991), in which he argued that discarding a bit of information in a computational process inevitably causes an increase in entropy (what became known as the “Landauer’s principle”). Landauer was a scientist who contributed substantially to establishing information as something vulnerable to the laws of physics. In the article titled “The physical nature of information”, Landauer (1996) argued that, since information does not exist as something abstract (or, as we could also say, metaphysical), but rather as something always intrinsically associated with a physical representation, this implies that information is vulnerable to the laws of physics.
Despite having argued in favor of information as something that requires a physical representation, Landauer (1967, 1976, 1982, 1984, 1986, 1991, 1996, 1999) never stated, in any of his articles in which he discusses information, that the reason for this is due to the equivalence between mass and energy. Henceforth, I will demonstrate that it is possible to corroborate, by means of the equivalence between mass and energy, Landauer’s conclusion that information requires a physical medium and is subject to the laws of physics. Energy being necessary for information to exist and be conserved has relevant implications for the question of whether information can or cannot exist devoid of a physical medium. This is what I will discuss now.
As I said before, information requires energy (Hawking, 1996, p. 195; Knight, 2009, pp. 558-559; Nelson and Cox, 2013, p. 20; Schrödinger, 2013, p. 73; Huang et al., 2015; Hawking, 2018, p. 112). And as postulated by Einstein’s famous equation—E = mc2 (where “E” represents energy, “m” mass, and “c” the speed of light)—, mass and energy are equivalent. This implies that energy has mass and vice versa (Einstein, 1905b; Hawking, 1996, p. 137; Hawking, 2018, p. 112). In Einstein’s words: “The mass of a body is a measure of its energy-content; if the energy changes … the mass changes in the same sense” (1905a). Using other words, the equivalence between mass and energy means that stating that any mass has an energy associated with it is equivalent to stating that any energy has a mass associated with it.
It is unnecessary to delve into the physical concept of mass. What matters for my discussion is that mass is a property inherent to matter, or, in other words, mass is the amount of matter that a body contains (Hawking, 2001, p. 205; Hawking, 2018, p. 29). Therefore, since mass and energy are equivalent and information requires energy, this implies that information requires mass (i.e., a physical medium). My argument can be summarized as follows:
Premise 1: Information requires energy.
Premise 2: Mass and energy are equivalent.
Conclusion: Information requires mass (i.e., matter).
The way the above argument is structured constitutes the basic structure that composes a deductively valid argument, whose conclusion is a logical consequence of the premises used (Goldstein et al., 2007, pp. 46-47; Walton, 2008, p. 138). What defines a deductively valid argument (or simply valid argument) is the logical impossibility of a false conclusion being generated from the foundation in true premises—this is what it means to affirm that the conclusion logically follows from the premises (Goldstein et al., 2007, pp. 16, 45-46; Walton, 2008, p. 138). The result of a valid argument will never be an argument that leads true premises to a false conclusion; if the premises used in a valid argument are true, its conclusion must necessarily be true (Goldstein et al., 2007, p. 46; Walton, 2008, p. 143). In other words, what defines a deductively valid argument is the fact that it encloses the attribute of incontestability; whenever its premises are true, it is absolutely certain that its conclusion will also be true (Walton, 2008, p. 143). To ensure the legitimacy of a deductively valid argument, just ensure that the premises used are true; if they are, then we will be facing an argument that is both valid and legitimate (Goldstein et al., 2007, p. 16).
Given that my argument is based on demonstrably true premises, its conclusion (information requires a material medium) is necessarily true. This argument establishes that information is something intimately related to some physical medium. Information simply does not exist without a physical medium. This decisively refutes the theory of information as something independent of a material medium, making it too absurd to deserve serious consideration.
We can think of information based on an analogy with the attribute of rigidity. Rigidity does not exist as a metaphysical entity, devoid of a physical medium. There is no immaterial essence of rigidity wandering around in some abstract space (whatever that place is) just waiting for the opportunity to manifest itself in some material medium. Rigidity is a property enclosed by matter (considered with the appropriate arrangements of molecules or atoms for the manifestation of such property), which is equivalent to saying that it is inseparable from it. The attribute of rigidity does not exist in the absence of matter. So it is with information. Information—despite not being something material in itself—requires a material medium to exist. Information is a property that a physical medium can enclose. There is another relevant analogy. Let us think of the noun “hole”. This term serves to designate any type of opening or orifice existing in a body. No hole exists as an abstract entity, independent of matter, but rather as part of a material body. A hole refers to the absence of matter in some part of a material body and, for this reason, it is inseparable from it. Despite not being something material in itself, a hole requires a physical medium to exist.
Of course, some essentialist could still argue that, since it is possible to transmit information from a book to our mind, from a computer or cell phone to our mind, or from one mind to another, this inevitably refutes the notion that information requires a physical medium. And that, therefore, it certainly exists as something metaphysical. In reality, it does not refute it, and I will demonstrate why hereinafter.
We, sentient beings, can share information with each other in various ways (e.g., through speech, writing, and gestures—whether in person or by digital means, such as videos and texts on the internet). Although in some cases it may seem (to an essentialist) that information exists devoid of a physical medium (such as in the exchange of information from one mind to another), it is enough to analyze more closely to realize that, in fact, there is nothing metaphysical in the transfer of information. Let us analyze the case of transmitting information from one mind to another through speech. In this case, one brain acts as the emitter of information and the other acts as the receiver of it. I will focus first on the emitter.
To transmit information to someone through speech, the emitter of that information has to generate vocal sounds, which will be intercepted by the receiver. The voice is produced by means of disturbances—due to the vibrations of the vocal folds—in the air coming from the lungs (Zhang, 2016). When exhaled from the lungs, the air moves to the pharynx, where the vocal folds are located. In them, there is an anatomical structure called glottis, which consists of the space between the two vocal folds. The glottis is like a door; it can be open, closed or semi-open. When open (as when we breathe), no sound is produced. For the voice to be produced, the opening of the glottis has to be closed or reduced (Zhang, 2016). When a stream of air is directed to the vocal folds, the pressure exerted on the lower part of the glottis increases. As soon as the subglottic pressure exceeds a pressure threshold, the vocal folds vibrate (or, in other words, are excited) (Zhang, 2016). The vibrations disturb the immediately surrounding air molecules, causing them to disturb their neighboring molecules, and so on until the wave dies out. The intensity of a wave is reduced proportionally to the square of the distance from its point of origin. This implies that a sound silences quickly as the distance to its source increases (the inverse square law, however, does not apply to sounds produced in closed environments). This is how sound is propagated through air (Knight, 2009, pp. 616, 621; Dawkins, 2015b, p. 37).
Sound consists of a mechanical wave. One of the defining characteristics of mechanical waves is that they require a physical medium to propagate (which is why there is no sound in space) (Knight, 2009, p. 603). Propagation medium is the term used to designate the physical substance through which the wave propagates. For example, the propagation medium of a wave formed in water consists of the water itself (Knight, 2009, p. 603). Any propagation medium must have the characteristic of elasticity. This means that a propagation medium must be able to return to its equilibrium state after being disturbed or displaced—due to some force (Knight, 2009, p. 603). In the case of water, for example, gravity is the force responsible for restoring its surface to its equilibrium state after it has been displaced (from the point of impact of, say, a stone falling on a portion of water) due to the wave that passed through it (Knight, 2009, pp. 603-604). The disturbance or displacement that characterizes a mechanical wave consists of an ordered movement of the atoms or molecules of the medium through which it propagates, which contrasts with the random atomic or molecular movements related to thermal energy (Knight, 2009, p. 604).
The term “thermal energy” denotes the kinetic and potential energy enclosed by the molecules or atoms of a given physical system as they move (when in the gaseous state) or as they vibrate (when in the solid state) (Knight, 2009, p. 485). Kinetic energy refers to the energy due to motion and potential energy refers to the energy due to the interaction between two different bodies and that depends on the position that a given body occupies. When a system is “hot”, this means that it encloses more thermal energy than a system that is “cold” (Knight, 2009, p. 485).
In the example of transmitting information from one mind to another through speech, the air is the physical medium through which the information is transmitted from the emitter’s mind to the receiver’s mind. But not only the air acts as a physical medium of transmission. The body-brain system—both of the emitter and of the receiver—is a crucial part of this information flow. After all, the information leaves one brain to reach the other. For this to happen, the emitter’s brain sends commands to the body to produce specific vocal sounds. In turn, the receiver’s brain receives the information from the vocal sounds through a specialized sensory “portal”—the ear (Damasio, 2012, p. 100). This is another way of saying that the information necessarily has to go through the nervous system of both bodies. This information flow is only possible due to an important aspect of body-brain communication: it operates in both directions. From the brain to the body and from the body to the brain (Damasio, 2012, p. 100).
Before proceeding, I have to make a brief digression. It is obvious that the brain belongs to the body. However, the reason why it is convenient to designate it a position of exclusivity (as I did with the expression “body-brain”) is due to the fact that the brain has the ability to communicate—through electrochemical signaling—with any other part of the body. And not only that. These other parts of the body, all of them, also communicate with the brain (Damasio, 2012, p. 98). Any signals from the external environment have to cross the body’s boundary—starting from the sensory portals—to be able to enter the brain (Damasio, 2012, p. 97). It is the body of the organism that interacts with the immediately surrounding external environment, whose changes caused in the body as a consequence of the interaction are mapped (i.e., recorded) in the brain. The only way for the brain to obtain information about the external environment is through the body, from its surface (Damasio, 2012, p. 97).
The patterns mapped in the central nervous system (i.e., in the brain) generate what we, sentient creatures, happen to call pleasures, pains, visions, sounds, touches, tastes, smells or, in short, images (Damasio, 2012, p. 74). It is important to point out that the expression “mental image” (which should be understood as equivalent to the terms “map” and “neural pattern”) does not refer only to visual neural patterns, but to any type of sensory pattern formed in the central nervous system (Damasio, 2012, pp. 68-69, 72). An example of this are the mental images of sounds. It is about them that I will discuss henceforth.
When we produce vocal sounds to transmit information to a receiver, sound waves propagate through the air until they reach their ear (one of the sensory portals) (Knight, 2009, p. 602). The neural mapping of a sound begins in the ear, in a structure called cochlea. The cochlea receives the sound energy and transduces it into electrical impulses—the language of the nervous system—, which are then directed to the central nervous system (Damasio, 2012, p. 72; Kandel et al., 2013, p. 654). The term “transduction” designates the process by which a specific type of energy (e.g., photons [in the case of light]; pressure waves [in the case of sounds]; chemical, mechanical and thermal stimuli [in the case of pain]) is received by a specialized receptor for that type and then converted into an electrical impulse (Kandel et al., 2013, pp. 458, 460).
The cochlea’s conical structure is filled with hair cells—receptor cells specialized in transducing a specific type of energy: pressure waves (or mechanical waves). They are the ones that transduce the mechanical information of sound into electrical signals. An important characteristic of hair cells is that they respond to specific sound frequencies. Each hair cell has its own characteristic frequency (Damasio, 2012, p. 73; Kandel et al., 2013, p. 669). This is how we perceive different sounds. Our perception of sound depends on its frequency. Distinct frequencies (caused by the vibration of some object) are interpreted by our brain as different sounds (Damasio, 2012, p. 73; Kandel et al., 2013, p. 455). In this context, the term “frequency” denotes the number of complete oscillations that occur in a specific period—usually per second (Hawking, 2001, p. 204). In the International System of Units (SI), frequency is measured in hertz (Hz). Saying that the frequency of a sound wave is 45 Hz means that the wave oscillates (or vibrates) 45 times per second. In other words, the frequency of a wave refers to the number of times it was generated per unit of time.
Another key factor in the example of transmitting information from one mind to another through speech is the steps of encoding and decoding the informative message. The reason both brains can share mutually intelligible information is because, in our hypothetical example, they both speak the same language. Obviously, the emitter encodes an informative message based on a certain language (English, say). For the message to make sense to the receiver, it has to be decoded by him. This is only possible if the receiver has been literate in the same language as the emitter. This is another way of saying that they both have to share the same code. If a message is encoded in English and the receiver is unable to decode that linguistic code (for being, for example, literate in Chinese), he will be unable to decode the message upon receiving it. In other words, for someone to decode a received message, he must have the same code that was used to encode that message.
To conclude this example of transmitting information from one mind to another through speech, we still need to analyze language and its processing. And, just like the other aspects of this example, none of them have anything metaphysical. Regarding linguistic processing, the brain is the organ responsible for performing it. More specifically, numerous regions of the cerebral cortex—such as Broca’s area, Wernicke’s area, basal ganglia, auditory cortex and specific sectors of the insular cortex—are involved in the task of linguistic processing (Kandel et al., 2013, pp. 1354, 1364; Oh et al., 2014). Language, in turn, is based on an arbitrary association of certain sounds with certain meanings. This is how we can write or speak about anything (Kandel et al., 2013, p. 1354). What makes language remarkably distinct from other modes of communication is its main attribute: the capacity to combine a finite set of sounds in practically infinite ways. Each language has its own set of sounds; what we call phonemes. Phonemes, in turn, are used to form morphemes and words (Kandel et al., 2013, p. 1354). A morpheme is the smallest linguistic unit with meaning, and is best represented by prefixes and suffixes. For example, in English, the prefix un (which signals a negation) can be added to an adjective to indicate an opposition to the meaning of the term without the prefix (e.g., unhappy) (Kandel et al., 2013, p. 1354). Each language has its own set of rules that establish how phonemes are combined to constitute morphemes (Kandel et al., 2013, p. 1354).
As I demonstrated throughout the previous paragraphs, each step of transmitting information from one mind to another through speech depends on physical factors, from the information that leaves the emitter to the information that reaches the receiver and is decoded by him. Therefore, there is nothing metaphysical in this information transfer. And this also applies to any situation in which information is transmitted from a mind to some medium (physical or digital) or vice versa.
The words I am using to bring these ideas to you were first formed, however briefly and sketchily, as auditory, visual, or somatosensory images of phonemes and morphemes, before I implemented them on the page in their written version. Likewise, the written words, now printed [or displayed on a screen] before your eyes, are first processed by you as verbal images (visual images of written language) before their action on the brain promotes the evocation of yet other images, of a nonverbal kind. The nonverbal kinds of images are those that help you display mentally the concepts that correspond to words. (Damasio, 2012, pp. 74-75, author’s emphasis)
Briefly, whatever type of information transfer we analyze, we will inevitably find that information is based on some physical medium. The implication of this is that information is subject to the laws of physics. However, I must point out that stating that information requires a physical medium is not equivalent to stating that it is something material by itself. What I argued in the current article is that information requires a physical medium to exist and to be preserved (in case it already exists). Saying that information is not something material by itself but requires a physical medium may seem somewhat paradoxical. This, however, is no more paradoxical than understanding that, despite colors not existing as something material by themselves, they—like information, rigidity, and holes—do not exist without being intrinsically associated with something material. (In the case of colors, we have to consider the role of the brain in their perception. Distinct frequencies of electromagnetic waves, within a specific range, are perceived as distinct colors. However, there is nothing intrinsically chromatic in the frequencies of the waves. Colors are a creation of the brain—in association with physical objects—and do not exist outside of it.)
Now that I have demonstrated the reductio ad absurdum of the solution to the problem of mutational protection that is based on an a priori protection, and that information requires a physical medium, it is time to engage in the discussion of mutational protection as an a posteriori consequence of whatever phenomenon is responsible for it. Once we have ruled out that mutational protection could be due to an intrinsic property of the information itself, or to the existence of a mechanism based on deliberation, what remains is for this phenomenon to occur as a consequence of the gene expression. After all, if mutational protection is not due to the information itself, and neither to the existence of a mechanism based on deliberation, what could explain it but the frequency of the gene expression? Therefore, what we have to investigate is why mutational protection is due to the frequency of gene expression. This is the topic of the section henceforth.