For oversized, spinning black holes, the singularity that a spacecraft would have to contend with would be very gentle. (Image credit: Shutterstock)
Getting to Know Wormholes
a conversation with physicists and mathematicians
click here for the BBC "In our Time" podcast
Melvyn Bragg and guests discuss the tantalising idea that there are shortcuts between distant galaxies, somewhere out there in the universe. The idea emerged in the context of Einstein's theories and the challenge has been not so much to prove their unlikely existence as to show why they ought to be impossible. The universe would have to folded back on itself in places, and there would have to be something to make the wormholes and then to keep them open. But is there anywhere in the vast universe like that? Could there be holes that we or more advanced civilisations might travel through, from one galaxy to another and, if not, why not?
With Toby Wiseman, Professor of Theoretical Physics at Imperial College London
Katy Clough, Senior Lecturer in Mathematics at Queen Mary, University of London
Andrew Pontzen Professor of Cosmology at Durham University
Producer: Simon Tillotson
With Toby Wiseman, Professor of Theoretical Physics at Imperial College London
Katy Clough, Senior Lecturer in Mathematics at Queen Mary, University of London
Andrew Pontzen Professor of Cosmology at Durham University
Producer: Simon Tillotson
Whitehead. Wormholes &
the Longing for Cosmic Connections
In physics, so we learn from the podcast above a wormhole is a hypothetical tunnel-like structure that connects two separate points in space-time, potentially allowing for faster-than-light travel between them. In theory, wormholes could connect distant parts of the universe, or even different universes, by providing a shortcut that bypasses the normal space-time distances. Wormholes are often visualized as a bridge or tunnel, where two mouths are connected by a throat.
The concept of a wormhole comes from solutions to Einstein's General Theory of Relativity, specifically the idea of an "Einstein-Rosen bridge." In general relativity, a wormhole could be formed by a distortion of space-time, where gravity bends space to create a tunnel. However, they are still purely theoretical, as no physical evidence of wormholes has been found, and they require exotic forms of matter—substances with negative energy density—to stay open long enough for anything to pass through them.
Wormholes are popular in science fiction because they offer a way to circumvent the enormous distances between stars and galaxies, making interstellar travel feasible within human timescales. However, creating or stabilizing a wormhole in reality would require technology and energy levels far beyond our current understanding and capabilities.
Interesting Propositions
In Process and Reality, Whitehead writes: "But in the real world it is more important that a proposition be interesting than that it be true. The importance of truth is, that it adds to interest" (p. 259). In physics and science fiction, Whitehead's maxim is illustrated by wormholes.
Wormholes, in physics, are hypothetical tunnels or shortcuts in space-time that could connect distant regions of the universe, and they come in different types such as traversable wormholes, Schwarzschild wormholes, and Einstein-Rosen bridges. They are interesting to physicists for mathematical reasons: they provide potential solutions to the equations of general relativity, offering insights into the fundamental nature of gravity, quantum mechanics, and the structure of the cosmos.
They are interesting to science fiction writers because, as noted above, they open up imaginative possibilities for storytelling—allowing characters to travel vast distances instantly, explore alternate dimensions, and confront the mysteries of the universe, thereby creating compelling narratives filled with wonder, adventure, and the unknown.
The Longing for Connection
From a Whiteheadian perspective, should they exist in actuality, they would make the universe even more connected, or at least connected in an especially unique way. Even if they do not exist, or they do exist but we can never know it, wormholes function as lures for feeling in the lives of theoretical physicists, science fiction writers, and their fans.
In any case, their attraction as possibilities tells us something important about human life itself: the longing for connection that is essential to our being—not only a connection with other actualities across the space-time spectrum but also a connection with the world of possibilities, with what "can be" and "might be," even if not. This longing for connection is a feeling, an aim, a desire. This desire includes an aim to understand, but also an aim to feel connected with something more than the private self. Whitehead would call it a "subjective aim." It is the drive that shapes what we do and who we become, propelling us toward new possibilities. In the context of wormholes, the subjective aim is not merely about traveling great distances but also about transcending the limitations of what we perceive as possible.
Prehensions as Forms of Connection
Whitehead speaks of the activity of being connected as "prehension." Prehensions are the fundamental feelings by which we are connected to other things—people, events, ideas. Through prehensions, the world becomes part of us. Wormholes, whether real or imagined, are prehensive possibilities. As possibilities, they symbolize a connection that brings distant parts of the universe into an intimate relationship.
When we think about wormholes, their imaginative potential becomes part of what Whitehead calls our subjective immediacy—our "real internal constitution." This way of being—where possibilities, no matter how speculative, affect our inner reality—shows how even imagined constructs like wormholes enrich our experience and highlight our relational existence.
Wormholes, then, are much more than hypothetical constructs in physics; they represent our inherent drive to expand, connect, and bring new possibilities into our subjective experience. They tell us about the curiosity, the longing, and the relational desire that defines human life, echoing Whitehead’s insight that the true value of an idea is not limited to its verifiability, but lies in its ability to evoke wonder and enrich our ongoing journey of becoming.
The concept of a wormhole comes from solutions to Einstein's General Theory of Relativity, specifically the idea of an "Einstein-Rosen bridge." In general relativity, a wormhole could be formed by a distortion of space-time, where gravity bends space to create a tunnel. However, they are still purely theoretical, as no physical evidence of wormholes has been found, and they require exotic forms of matter—substances with negative energy density—to stay open long enough for anything to pass through them.
Wormholes are popular in science fiction because they offer a way to circumvent the enormous distances between stars and galaxies, making interstellar travel feasible within human timescales. However, creating or stabilizing a wormhole in reality would require technology and energy levels far beyond our current understanding and capabilities.
Interesting Propositions
In Process and Reality, Whitehead writes: "But in the real world it is more important that a proposition be interesting than that it be true. The importance of truth is, that it adds to interest" (p. 259). In physics and science fiction, Whitehead's maxim is illustrated by wormholes.
Wormholes, in physics, are hypothetical tunnels or shortcuts in space-time that could connect distant regions of the universe, and they come in different types such as traversable wormholes, Schwarzschild wormholes, and Einstein-Rosen bridges. They are interesting to physicists for mathematical reasons: they provide potential solutions to the equations of general relativity, offering insights into the fundamental nature of gravity, quantum mechanics, and the structure of the cosmos.
They are interesting to science fiction writers because, as noted above, they open up imaginative possibilities for storytelling—allowing characters to travel vast distances instantly, explore alternate dimensions, and confront the mysteries of the universe, thereby creating compelling narratives filled with wonder, adventure, and the unknown.
The Longing for Connection
From a Whiteheadian perspective, should they exist in actuality, they would make the universe even more connected, or at least connected in an especially unique way. Even if they do not exist, or they do exist but we can never know it, wormholes function as lures for feeling in the lives of theoretical physicists, science fiction writers, and their fans.
In any case, their attraction as possibilities tells us something important about human life itself: the longing for connection that is essential to our being—not only a connection with other actualities across the space-time spectrum but also a connection with the world of possibilities, with what "can be" and "might be," even if not. This longing for connection is a feeling, an aim, a desire. This desire includes an aim to understand, but also an aim to feel connected with something more than the private self. Whitehead would call it a "subjective aim." It is the drive that shapes what we do and who we become, propelling us toward new possibilities. In the context of wormholes, the subjective aim is not merely about traveling great distances but also about transcending the limitations of what we perceive as possible.
Prehensions as Forms of Connection
Whitehead speaks of the activity of being connected as "prehension." Prehensions are the fundamental feelings by which we are connected to other things—people, events, ideas. Through prehensions, the world becomes part of us. Wormholes, whether real or imagined, are prehensive possibilities. As possibilities, they symbolize a connection that brings distant parts of the universe into an intimate relationship.
When we think about wormholes, their imaginative potential becomes part of what Whitehead calls our subjective immediacy—our "real internal constitution." This way of being—where possibilities, no matter how speculative, affect our inner reality—shows how even imagined constructs like wormholes enrich our experience and highlight our relational existence.
Wormholes, then, are much more than hypothetical constructs in physics; they represent our inherent drive to expand, connect, and bring new possibilities into our subjective experience. They tell us about the curiosity, the longing, and the relational desire that defines human life, echoing Whitehead’s insight that the true value of an idea is not limited to its verifiability, but lies in its ability to evoke wonder and enrich our ongoing journey of becoming.
Wormholes and Whitehead's
Categories of Existence
Whitehead's categories of existence, as presented in his work Process and Reality, offer a framework for understanding the different kinds of entities that make up our experience and the world around us, including wormholes. As a hypothetical structure it is, for physicists and for science fiction writers (and their fans) a proposition functioning as a lure for feeling. There are, says Whitehead, eight categories of existence.
- Actual Entities: The fundamental units of reality, also known as "occasions of experience." They are the primary building blocks of the universe, representing moments of experience or events rather than static substances. Actual entities are characterized by their internal process of becoming and their relationships with other entities.
- Prehensions: The basic relational activities through which an actual entity experiences and responds to other entities. Prehensions can be either positive, where aspects of another entity are taken into account, or negative, where aspects are excluded. Prehensions reflect how actual entities are interconnected and influence one another.
- Nexus (or Nexūs): A collection of interrelated actual entities that form a specific pattern or grouping. A nexus is a set of entities that are "objectively united" in a particular way, indicating the relational aspect of existence and the formation of larger structures from individual actual entities.
- Eternal Objects: These are abstract or pure potentialities, akin to Platonic forms, that provide qualities and patterns which can be realized in the process of becoming of actual entities. Eternal objects can be thought of as pure possibilities—qualities like colors, shapes, and emotions—that influence how actual entities take shape but do not exist in themselves as concrete entities. They are of two kinds: eternal objects of the objective species which are embodied or actualized in objective space-time relations, and those of the subjective species which are embodies or actualized in the subjective side of reality: the subjective forms (see below).
- Propositions: Propositions are potential patterns of relationships between eternal objects and actual entities. They represent possible ways that eternal objects could be realized in the world; they are "impure potentials" that involve a contrast between what is purely potential and what is actual, functioning as "lures for feeling." Propositions help actual entities envision possibilities, providing a creative function that helps guide the process of becoming.
- Subjective Forms: These refer to how an actual entity feels or experiences its prehensions. The subjective form is the particular way in which an actual entity interprets or internalizes the influence of other entities, shaping its own internal state of experience. Subjective forms include emotions such as attraction and repulsion, which influence how an entity responds to other entities and events. These emotions shape the overall tone of an entity's experience, giving richness and qualitative depth to its interactions.
- Contrasts: Whitehead uses the idea of contrasts to describe how various elements within an experience (like prehensions or eternal objects) interact with and define one another through differentiation. This is important for understanding how complexity and novelty arise in the process of becoming.
- Multiplicities: Multiplicities have not unity of their own. They are collections of actual entities understood as disjunctions: that is, as different from one another and with no evidently shared property. This is how they differ from nexūs.
At face value, wormholes are propositions: lures for feeling and understanding. As propositions, they embody a contrast between the world as we know it and the world as it might be. Imagining wormholes is itself a form of prehension—a prehension of possibilities—that enriches imaginative experience, enhancing the subjective forms of those who conceive of them. The imaginers—human beings, in this case—are actual entities or, more precisely, a series of concrescing subjects extending from birth (and perhaps before) to death (and perhaps after). Each concrescence "prehends" the entire universe, integrating a multiplicity into the momentary unity of a single experience. Felt potentials, such as wormholes, are among the "many" that "become one" in the immediacy of each moment, even if they do not exist as actualities. In doing so, they reveal a world of pure potentialities, some mathematical and others emotional, that is real in its own right, even if not actual. Thus, wormholes, as conceived by physicists and science fiction writers, instantiate these categories in unique ways, adding to a sense of human adventure. We are rightly glad that they exist, even if only as possibilities—whether or not we ever actually travel to distant galaxies. They remind us how deeply connected we long to be.
Reading List for Wormholes
offered by BBC's In Our Time
Jim Al-Khalili, Black Holes, Wormholes and Time Machines (Taylor & Francis, 1999)
Andrew Pontzen, The Universe in a Box: Simulations and the Quest to Code the Cosmos (Riverhead Books, 2023)
Claudia de Rham, The Beauty of Falling: A Life in Pursuit of Gravity (Princeton University Press, 2024)
Carl Sagan, Contact (Simon and Schuster, 1985)
Kip Thorne, Black Holes & Time Warps: Einstein's Outrageous Legacy (W. W. Norton & Company, 1994)
Kip Thorne, Science of Interstellar (W. W. Norton & Company, 2014)
Matt Visser, Lorentzian Wormholes: From Einstein to Hawking (American Institute of Physics Melville, NY, 1996)
Three Types of Groupings of Actual Entities
Multiplicities, Nexūs and Societies
In Whitehead's Process and Reality, "nexus," "societies," and "multiplicities" are distinct but interrelated concepts within his philosophy of organism, all referring to various ways in which actual entities relate to one another. Here is a breakdown of how they differ:
1. Nexus
A nexus (plural: nexūs) is any grouping or network of actual entities that are related by their prehensions, meaning their processes of feeling or interacting with each other. It refers to the general idea of actual entities being connected through their relational activities. A nexus is a set of entities that are interrelated in a way that forms a definable pattern, but without the specific type of structure or order seen in societies.
Key points about nexus:
2. Society
A society is a specific kind of nexus characterized by enduring patterns and stability across time. In a society, actual entities inherit a common defining characteristic, forming a stable structure that persists and reproduces itself. Societies are essentially nexūs with an additional organizing principle that provides continuity and identity over time.
Key points about societies:
3. Multiplicity
A multiplicity is a more abstract concept that refers to any group or collection of entities without implying any particular kind of relational order or interconnection. A multiplicity lacks the structured interconnectedness of a nexus or the cohesive unity of a society.
Key points about multiplicities:
Summary of Differences
In short, multiplicities are the broadest type of grouping, nexūs involve relational networks, and societies are nexūs with a stable, self-replicating structure.
1. Nexus
A nexus (plural: nexūs) is any grouping or network of actual entities that are related by their prehensions, meaning their processes of feeling or interacting with each other. It refers to the general idea of actual entities being connected through their relational activities. A nexus is a set of entities that are interrelated in a way that forms a definable pattern, but without the specific type of structure or order seen in societies.
Key points about nexus:
- It can be heterogeneous—made up of entities that are not necessarily similar.
- Nexūs can be either temporary or enduring, depending on the kinds of interactions between the entities.
- It represents a network of relations, where the emphasis is on the process of relationality rather than any particular enduring pattern.
2. Society
A society is a specific kind of nexus characterized by enduring patterns and stability across time. In a society, actual entities inherit a common defining characteristic, forming a stable structure that persists and reproduces itself. Societies are essentially nexūs with an additional organizing principle that provides continuity and identity over time.
Key points about societies:
- A society requires a common element of form—an organizing principle that individual members inherit from the past, ensuring continuity.
- Societies can endure over time because the actual entities within the society perpetuate a common characteristic or form that allows for stability and reproduction.
- Examples of societies include biological organisms, atoms, and social groups where the individual entities (e.g., cells, particles, people) participate in an ongoing collective identity.
3. Multiplicity
A multiplicity is a more abstract concept that refers to any group or collection of entities without implying any particular kind of relational order or interconnection. A multiplicity lacks the structured interconnectedness of a nexus or the cohesive unity of a society.
Key points about multiplicities:
- A multiplicity is just a grouping of entities, not necessarily involving prehensive relations.
- It does not imply any pattern of internal relations like nexūs do.
- Unlike societies, multiplicities have no organizing principle that provides continuity or coherence over time. They are simply aggregates.
Summary of Differences
- Nexus: A grouping of actual entities defined by the fact that they are interrelated through prehensions; has relational complexity but does not necessarily have an enduring or common form.
- Society: A specific kind of nexus that exhibits an enduring pattern and a common element of form, allowing for stability and continuity over time.
- Multiplicity: A collection of entities without inherent relational structure or interconnection; does not imply the relational organization of nexūs or the continuity of societies. The universe, supplying initial data for a given actual entity or concrescing subject, is a multiplicity.
In short, multiplicities are the broadest type of grouping, nexūs involve relational networks, and societies are nexūs with a stable, self-replicating structure.