When two hands touch, there is a sensuality of the flesh, an exchange of warmth, a feeling of pressure, of presence, a proximity of otherness that brings the other nearly as close as oneself. Perhaps closer. And if the two hands belong to one person, might this not enliven an uncanny sense of the otherness of the self, a literal holding oneself at a distance in the sensation of contact, the greeting of the stranger within? So much happens in a touch: an infinity of others—other beings, other spaces, other times—are aroused.
When two hands touch, how close are they? What is the measure of closeness? Which disciplinary knowledge formations, political parties, religious and cultural traditions, infectious disease authorities, immigration officials, and policy makers do not have a stake in, if not a measured answer to, this question? When touch is at issue, nearly everyone’s hair stands on end. I can barely touch on even a few aspects of touch here, at most offering the barest suggestion of what it might mean to approach, to dare to come in contact with, this infinite finitude. Many voices speak here in the interstices, a cacophony of always already reiteratively intra-acting stories. These are entangled tales. Each is diffractively threaded through and enfolded in the other. Is that not in the nature of touching? Is touching not by its very nature always already an involution, invitation, invisitation, wanted or unwanted, of the stranger within?
Electric Fields & Yearnings: Attraction and Repulsion: Touching on Touch
Touch, for a physicist, is but an electromagnetic interaction.
A common explanation for the physics of touching is that one thing it does not involve is . . . well, touching. That is, there is no actual contact involved. You may think you are touching a coffee mug when you are about to raise it to your mouth, but your hand is not actually touching the mug. Sure, you can feel the smooth surface of the mug’s exterior right where your fingers come into contact with it (or seem to), but what you are actually sensing is the electromagnetic repulsion between the electrons of the atoms that make up your fingers and those that make up the mug. Electrons are tiny negatively charged particles that surround the nuclei of atoms, and having the same charges they repel one another, much like powerful little magnets. As you decrease the distance between them the repulsive force increases. Try as you might, you cannot bring two electrons into direct contact with each other.
The reason the desk feels solid, or the cat’s coat feels soft, or we can (even) hold coffee cups and one another’s hands, is an effect of electromagnetic repulsion. All we really ever feel is the electromagnetic force, not the other whose touch we seek. Atoms are mostly empty space, and electrons, which lie at the farthest reaches of an atom, hinting at its perimeter, cannot bear direct contact. Electromagnetic repulsion: negatively charged particles communicating at a distance push each other away. That is the tale physics usually tells about touching. Repulsion at the core of attraction. See how far that story gets you with lovers. No wonder the romantic poets had had enough.
The quantum theory of touching is radically different from the classical explanation. Actually, it is radically queer, as we will see.
Quantum Field Theory: A Virtual Introduction
Quantum field theory allows for something radically new in the history of Western physics: the transience of matter’s existence. No longer suspended in eternity, matter is born, lives, and dies. But even more than that, there is a radical deconstruction of identity and of the equation of matter with essence in ways that transcend even the profound un/doings of (nonrelativistic) quantum mechanics. Quantum field theory is a call, an alluring murmur from the insensible within the sensible to radically rework the nature of being and time. The insights of quantum field theory are crucial, but the philosophical terrain is rugged, slippery, and mostly unexplored. The question is: How to proceed with exquisite care? We will need to be in and of the science, no way around it. Unfortunately, in the limited spacetime I have here I can only lightly touch, really just barely graze, the surface.
Quantum field theory differs from classical physics not only in its formalism but in its ontology. Classical physics inherits a Democretean ontology—only particles and the void—with one additional element: fields. Particles, fields, and the void are three separate elements in classical physics, whereas they are intra-related – indeed, co-constitutive – elements in quantum field theory.
For one thing, there is a correspondence between particles and fields: in particular, particles are quanta of the corresponding fields. For example, what in Newtonian physics is an external force, such as the electromagnetic force or the gravitational force, is rethought in terms of fields, the electromagnetic field and the gravitational field, respectively. In QFT, the particle or quantum of the electromagnetic field is a photon, the quantum of a gravitational field is a graviton. And furthermore, things we normally think of as particles are quanta of their respective fields: for example, the electron is a quantum of the electron field, and so on.
Another feature is that the void is far from vacuous, and something very profound happens to the relationship between particles and the void. I will continue to explain how this relationship is radically rethought in what follows. For now, I simply note, pace Democritus, that particles no longer take their place in the void; rather, they are constitutively entangled with it.
Let’s begin with the question of the void. Nothingness. The absence of matter. The blank page. Utter silence. No thing, no thought, no awareness, complete ontological insensibility.
Shall we utter some words about nothingness? What is there to say? How to begin? How can anything be said about nothing without violating its very nature, perhaps even its conditions of possibility? Isn’t any utterance about nothingness always already a performative breach of that which one means to address? Have we not already said too much simply in pronouncing its name?
Classically speaking, the void is that which is devoid of matter, that which literally doesn’t matter.
When it comes to the quantum vacuum, as with all quantum phenomena, ontological indeterminacy (not epistemological uncertainty) is at the heart of (the) matter . . . and no matter. Indeed, is it not rather the very nature of existence that is at issue, or rather nonexistence, or rather the conditions of im/possibilities for non/existence? . . . Or maybe that’s the very question the vacuum keeps asking itself. Maybe the ongoing questioning of itself is what generates, or rather is, the structure of nothingness. The vacuum is no doubt doing its own experiments with non/being. In/determinacy is not the state of a thing, but an unending dynamism. The play of in/determinacy accounts for the un/doings of no/thingness.
From the point of view of classical physics, the vacuum has no matter and no energy. But the quantum principle of ontological indeterminacy calls the existence of such a zero-energy, zero-matter state into question, or rather, makes it into a question with no decidable answer. Not a settled matter, or rather, no matter. And if the energy of the vacuum is not determinately zero, it isn’t determinately empty. In fact, this indeterminacy is responsible not only for the void not being nothing (while not being something), but it may in fact be the source of all that is, a womb that births existence. Birth and death are not the sole prerogative of the animate world. “Inanimate” beings also have finite lives. “Particles can be born and particles can die,” explains one physicist. In fact, “it is a matter of birth, life, and death that requires the development of a new subject in physics, that of quantum field theory. . . . Quantum field theory is a response to the ephemeral nature of life.”
According to QFT, the vacuum can’t be determinately nothing because the indeterminacy principle allows for “fluctuations” of the quantum vacuum: that is, some kind of changes of the state of nothingness. How can we understand “vacuum fluctuations”?
Let’s consider a very simple example of a field: an infinite drumhead. If the drumhead is not vibrating, then it is completely flat and has the same value everywhere— let’s call this the zero value, corresponding to no displacement. If a drummer now taps the drumhead, it vibrates, and waves of energy flow outward from where it is tapped.
Thus far we have a classical field theory, with a perfectly still drumhead representing the classical vacuum (or zero-energy state), and a vibrating drumhead representing a nonzero-energy state. Now we add quantum physics.
Quantizing the field means that only certain discrete vibrational states exist. (If you’re not used to thinking about different vibrational modes of a drum, it may be easier to visualize a stringed instrument with only a discrete set of standing waves, or harmonics, possible.) Now we add special relativity, in particular, the insight that matter and energy are equivalent (E = mc2). Since vibrations of the field carry energy, and only a discrete set of energy states can exist, and a mass value can be assigned to each energy state, then we can see that a field vibrating at a particular frequency or energy is equivalent to the existence of particles of matter with a particular mass. This correspondence between quantum particles and quantized fields is the cornerstone of QFT.
Now let’s return to our question: what is a vacuum fluctuation? Using the drum example, the quantum vacuum would correspond to a state where the average value of the displacements is zero everywhere, that is, there’s no drummer tapping the drum. And yet the stillness of the drumhead is not assured, or rather, there is no determinate fact of the matter as to whether or not the drumhead is perfectly still, even in the absence of all external disturbances, including drumming.
The vacuum is a speaking silence: a quiet cacophony of different frequencies, pitches, tempos, melodies, noises, pentatonic scales, cries, blasts, sirens, sighs, syncopations, quarter tones, allegros, ragas, bebops, hiphops, whimpers, whines, screams, are threaded through the silence, ready to erupt, but simultaneously crosscut by a disruption, dissipating, dispersing the would-be sound into non/being, an indeterminate symphony of voices.
In other words, vacuum fluctuations are the indeterminate vibrations of the vacuum or zero-energy state. Putting this point in the complementary language of particles rather than fields, we can understand vacuum fluctuations in terms of the existence of virtual particles: virtual particles are quanta of the vacuum fluctuations. That is, virtual particles are quantized indeterminacies-in-action.
The vacuum is an animate dynamism of the indeterminacy of non/being. It is a no-thingness: neither nothing nor something, the vacuum is an excitedly exuberant exploration of virtuality; where virtual particles—whose identifying characteristic is indeterminacy—are having a field day performing experiments in being and time. That is, virtuality is a kind of thought experiment the world performs. Virtual particles do not traffic in a metaphysics of presence. They do not exist in space and time. They are ghostly non/existences that teeter on the edge of the infinitely fine blade between being and nonbeing. Admittedly, virtuality is difficult to grasp. Indeed, this is its very nature.
Quantum Field Theory: A Touchy Subject
When it comes to quantum field theory, it is not difficult to find trouble — epistemological trouble, ontological trouble, a troubling of kinds, of identities, of the nature of touching and self-touching, of being and time, to name a few. It is not so much that trouble is around every corner; according to quantum field theory, it inhabits us and we inhabit it, or rather, trouble inhabits everything and nothing — matter and the void.
How does quantum field theory understand the nature of matter? Let us start with the electron, one of the simplest particles — a point particle — a particle devoid of structure. Even the simplest bit of matter causes all kinds of difficulties for quantum field theory. For, as a result of time-being indeterminacy, the electron does not exist as an isolated particle but is always already inseparable from the wild activities of the vacuum. In other words, the electron is always (already) intra-acting with the virtual particles of the vacuum in all possible ways. For example, the electron will emit a virtual photon and then reabsorb it. This possibility is understood as the electron electromagnetically intra-acting with itself. Part of what an electron is, is its self-energy intra-action. But the self-energy intra-action is not a process that happens in isolation either. All kinds of more involved things can and do occur in this frothy virtual soup of indeterminacy that we ironically think of as a state of pure emptiness. For example, in addition to the electron exchanging a virtual photon with itself – that is, touching itself – it is possible for the virtual photon to enjoy other intra-actions with itself: for example, the virtual photon can metamorphose/transition — change its very identity. It can transform into a virtual electron-positron pair, that subsequently annihilate each other and morph back into a single virtual photon before it is reabsorbed by the electron. (A positron is the electron’s antiparticle — it has the same mass but the opposite charge and goes backward in time, an expression of the fact that even the very direction of time is indeterminate.) And so on. This “and so on” is shorthand for an infinite set of possibilities involving every possible kind of intra-action with every possible kind of virtual particle it can intra-act with. That is, there is a virtual exploration of every possibility. And this infinite set of possibilities, or infinite sum of histories, entails a particle touching itself, and the particle that transmits the touch transforming itself, and then that touching touching itself, and transforming, and touching other particles that make up the vacuum, and so on, ad infinitum. (Not everything is possible given a particular intra-action, but an infinite number of possibilities exist.) Every level of touch, then, is itself touched by all possible others. Particle self-intra-actions entail particle transitions from one kind to another in a radical undoing of kinds — queer/ trans*formations. Hence self-touching is an encounter with the infinite alterity of the self. Matter is an enfolding, an involution, it cannot help touching itself, and in this self-touching it comes in contact with the infinite alterity that it is. Polymorphous perversity raised to an infinite power: talk about a queer/trans* intimacy!
What is being called into question here is the very nature of the “self,” and in terms of not just being but also time. That is, in an important sense, the self is dispersed/diffracted through time and being. Commenting specifically on the electron’s self-energy intra-action, the physicist Richard Feynman, who won a Nobel prize for his contributions to developing QFT, expressed horror at the electron’s monstrous nature and its perverse ways of engaging with the world: “Instead of going directly from one point to another, the electron goes along for a while and suddenly emits a photon; then (horrors!) it absorbs its own photon. Perhaps there’s something ‘immoral’ about that, but the electron does it!”
This self-energy/self-touching term has also been labeled a perversion of the theory because the calculation of the self-energy contribution is infinite, which is an unacceptable answer to any question about the nature of the electron (such as what is its mass or charge?). Apparently, touching oneself, or being touched by oneself — the ambiguity/undecidability/indeterminacy may itself be the key to the trouble — is not simply troubling but a moral violation, the very source of all the trouble.
The “problem” of self-touching, especially self-touching the other, is a perversity of quantum field theory that goes far deeper than we can touch on here. The gist of it is this: this perversity that is at the root of an unwanted infinity, that threatens the very possibility of calculability, gets “renormalized” (obviously — should we expect anything less?!).
How does this happen? Physicists conjectured that there are two different kinds of infinities/perversions involved in this case: one that has to do with self-touching and another that has to do with nakedness. That is, in addition to the infinity related to self-touching, there is an infinity associated with the “bare” point particle, that is, with the metaphysical assumption we started with that there is only an electron — the “undressed,” “bare” electron — and the void, each separate from the other. Renormalization is the systematic cancellation of infinities: an intervention based on the idea that the subtraction of (different size) infinities can be a finite quantity. Perversion eliminating perversion. The cancellation idea is this: the infinity of the “bare” point particle cancels the infinity associated with the “cloud” of virtual particles; in this way, the “bare” point particle is “dressed” by the vacuum contribution (that is, the cloud of virtual particles). The “dressed” electron — the electron in drag — that is, the physical electron, is thereby renormalized, that is, made “normal” (finite). (I am using technical language here!) Renormalization is the mathematical handling/taming of these infinities. That is, the infinities are “subtracted” from one another, yielding a finite answer. Mathematically speaking, this is a tour de force. Conceptually, it is a queer theorist’s delight. It shows that all of matter, matter in its “essence” (of course, that is precisely what is being troubled here), is a massive overlaying of perversities: an infinity of infinities.
To summarize, quantum field theory radically deconstructs the ontology of classical physics. The starting point ontology of particles and the void — a foundational reductionist essentialism — is undone by quantum field theory. According to QFT, perversity and monstrosity lie at the core of being — or rather, it is threaded through it. All touching entails an infinite alterity, so that touching the other is touching all others, including the “self,” and touching the “self” entails touching the stranger within. Even the smallest bits of matter are an unfathomable multitude. Each “individual” always already includes all possible intra-actions with “itself” through all possible virtual others, including those (and itself) that are noncontemporaneous with itself. That is, every finite being is always already threaded through with an infinite alterity diffracted through being and time. Indeterminacy is an un/doing of identity that unsettles the very foundations of non/being.
Electrons, for example, are inherently chimeras—cross-species cross-kind mixtures—made of virtual configurations/reconfigurings of disparate kinds of beings dispersed across space and time in an undoing of kind, being/becoming, absence/presence, here/there, now/then. So much for natural essence. The electron — a point particle without structure — is a patchwork of kinds sutured together in uncanny configurations. Trying out new appendages made of various particle-antiparticle pairs, producing and absorbing differences of every possible kind in a radical undoing of “kind” as essential difference: its identity is the undoing of identity. Its very nature is unnatural, not given, not fixed, but forever transitioning and transforming itself. Electrons (re)birth themselves in their engagement with all others, not as an act of self-birthing, but in an ongoing re-creating, that is, an un/doing of itself. Electrons are always already untimely. It is not that electrons sometimes engage in such perverse explorations: these experiments in intra-active trans-material performativity are what an electron is.
Ontological indeterminacy, a radical openness, an infinity of possibilities, is at the core of mattering. How strange that indeterminacy, in its infinite openness, is the condition for the possibility of all structures in their dynamically reconfiguring in/stabilities. Matter in its iterative materialization is a dynamic play of in/determinacy. Matter is never a settled matter. It is always already radically open. Closure cannot be secured when the conditions of im/possibilities and lived indeterminacies are integral, not supplementary, to what matter is. In an important sense, in a breathtakingly intimate sense, touching, sensing, is what matter does, or rather, what matter is: matter is condensations of responses to the desires/desirings to be in touch, a collective responsiveness/responsivity.
Each bit of matter is constituted in response-ability; each is constituted as responsible for the other, as being in touch with the other. Matter is a matter of untimely and uncanny intimacy, condensations of being and times.
This piece draws on selections from three published works:
K. Barad. 2012. What is the Measure of Nothingness? Infinity, Virtuality, Justice / Was ist das Maß des Nichts? Unendlichkeit, Virtualität, Gerechtigkeit, dOCUMENTA (13): 100 Notes – 100 Thoughts / 100 Notizen – 100 Gedanken | Book Nº099 (English & German edition, 2012).
K. Barad. 2012. “On Touching – The Inhuman That Therefore I Am,” in differences: A Journal of Feminist Cultural Studies, Special Issue “Feminist Theory Out of Science”, Vol. 23, No. 3, pp. 206-223.
K. Barad. 2015. “TransMaterialities: Trans*/Matter/Realities and Queer Political Imaginings,” GLQ, Special Issue on “Queer Inhumanisms,” edited by Mel Chen & Dana Luciano, 21:2-3, 387-422.
This talk was originally delivered as an invited Lecture, “On Touching the Stranger Within: The Alterity that Therefore I Am” for “Hold Me Now. Feel and Touch in an Unread World Symposium,” curated by Jack Halberstam, Stedelijk Museum, Amsterdam, March 24, 2018.