The Skeptics Society & Skeptic magazine

Holzschnitt aus Camille Flammarion: L'Atmosphere - Météorologie Populaire. Paris 1888. Kolorierung : Heikenwaelder Hugo, Wien 1998. La version en noir & blanc connue est dans Camille Flammarion (1842-1925).- L'atmosphère : météorologie populaire, Hachette, Paris, 1888, p. 163 (

Trouble in the Multiverse

The boundary between science and mere scientific speculation can be elusive. Albert Einstein famously performed only thought experiments, but those mere ideas yielded counterintuitive predictions leading to experiments conclusively confirming his revolutionary theory. Other thought experiments imagined by Einstein and his colleagues meant to demonstrate the impossibility of quantum theory actually turned out to be conductible. When performed, those experiments refuted Einstein’s arguments and help confirm the quantum.

I think I can safely say that nobody understands quantum mechanics. —Richard Feynman

Recently, however, some much more troublesome (and troubling) ideas have been advanced by some astrophysicists and cosmologists: string theory and the multiverse. The motivation and justification of string theory is to bring order to the menagerie of subatomic particles. String theory posits that we live not in a four-dimensional universe of space-time (once a highly counterintuitive notion, but now firmly established) but in a universe of many more dimensions (10 or 11, at last count), most of which we ordinary humans fail to notice simply because we’re unable to move in or through them (and because they’re very, very small relative to the more familiar ones). The usual analogy is that of two-dimensional creatures living in a flatland—on a surface (either a plane extending infinitely in two dimensions or a bounded one such as the surface of a sphere)—who would be unable to perceive a third dimension (and perhaps even to conceive of it). With 10 or more spatial dimensions, we’re told, we can conceive of subatomic particles not as point-like entities but as string-like ones vibrating in modes that can account for the variety of particles actually observed. However, no testable predictions have yet been advanced to confirm or disprove the idea.

At several stages in the history of science, some theories and entities were posited only because they were useful, although many scientists working at the time doubted their physical reality. The heliocentric model of the solar system, for example, was initially accepted not as physically true but simply because its mathematics made it simpler to account for the apparent motion of the planets. Similarly, the atomic nucleus, the electron, and the photon were all at first considered useful concepts having no physical reality. It was sometimes not even clear that the theories could ever lead to experimentally testable predictions.

Of course, not all theories are successful, and not all hypothesized entities (for example, phlogiston and the élan vital) prove themselves to be real. As experiments (and, eventually, practical applications) proved the usefulness of some ideas, the concepts they embodied became accepted as part of physical reality. Right now, we’re at the familiar stage in which we can’t even conceive of a way to experimentally test the theory of hypermultidimensionality. However, if the history of science is any guide, scientists will eventually think of some observable implications and will perform the appropriate experiments. If the experiments succeed, the theory will become part of our scientific reality, and the previously paradoxical concepts will somehow become familiar and workable, even if not understandable; if those predictions fail, the theory will be rejected. However, if no one ever devises experimentally testable hypotheses, the theory will simply fade away as scientifically unproductive. (Or a competing theory without the extra dimensions will be devised that gives a better account of reality.)

The theory—or theories—of the multiverse, however, seems even more problematic than hypermultidimensionality. String theory hasn’t led to any testable predictions yet, but such predictions don’t seem to be intrinsically impossible. The notion of the multiverse, on the other hand, appears to be untestable in principle.

The notion of the multiverse, masquerading as scientific speculation, is equally entertaining and equally fictitious.

The notion that there can be more than one universe at first seems oxymoronic—after all, the word universe, with its prefix uni-, mean the whole of reality, all that exists. However, there is at least one striking parallel to this evolution of meaning: the word atom means, essentially, indivisible. Although we now know that what we still refer to as atoms are indeed further divisible and contain smaller entities, we now use the word to refer to the smallest unit of an element. Similarly, the word universe may be retained to point to its more-or-less original referent but with different implications: an entity that consists of everything that exists, of which there may be several.

Not all multiverses are created equal. One brand of multiverse, even if it may be untestable is, at least, scientifically unobjectionable. Our universe is currently understood to have originated in a Big Bang some 13.8 billion years ago. Given the limits of the speed of light, if some of the universe is already further away than 13.8 billion light-years (due to a period of hyperinflation), it is forever isolated from us. There may, then, be any number of island universes—initially parts of the same universe originating in a single Big Bang—each forever isolated from one another. Although this notion is in principle untestable, it appears at least consistent with our current understanding of reality.

The much more problematic notion of a multiverse arises from a highly speculative interpretation of quantum mechanics. At that level, we’re told, the universe is in principle indeterminate. Certain properties of a subatomic particle (for example, whether the spin of a particle is up or down) have no reality—only relative probabilities—until a measurement is taken. One interpretation of quantum theory is that, at the moment of measurement the indeterminacy collapses and the spin is determined one way or the other.

However, another interpretation is not that a quantum collapse simply takes the one path or the other, but that the universe actually bifurcates at that moment, taking both paths at once, each in a separate universe cleaved from the original one, and henceforth and forever isolated from all others.

Not being able to understand one aspect of reality however is no justification for an entertaining but equally incomprehensible one.

It is awe-inspiring to imagine that a simple experiment in subatomic physics performed in our little corner of the universe could have such a powerful effect as to cleave it into two separate realities. Has the universe been innocently going along all this time without bifurcating until quantum physics was discovered and these experiments were performed? (This is not entirely without precedent: after all, no nuclear explosion ever occurred on Earth until scientists discovered how to set one off.) Does it all depend on a physicist daring to disturb the universe? Or is it that quantum collapse intrinsically causes universe bifurcation? Since there are an awful lot of particles in the universe (and, under some interpretations, all particles are quantum particles), they’re presumably collapsing all the time, leading to an awful lot of universes.

In some interpretations, quantum collapse eventually leads to all possible universes. We’re invited to imagine universes in which the asteroid that caused the extinction of the dinosaurs and so led to the evolution of Homo sapiens never hits Earth; in which Abraham Lincoln recovers from John Wilkes Booth’s bullet; in which Adolf Hitler was a successful painter and never becomes Führer; and of course a great many universes—in fact, almost all of them—in which nothing of interest to us happens at all. It’s like Borges’ near-infinite library of all possible books, The Library of Babel. Borges’ story, of course, is a thought experiment not meant to be taken literally. The notion of the multiverse, masquerading as scientific speculation, is equally entertaining and equally fictitious.

In its recent usage, the notion of the multiverse was motivated not by any compelling and inescapable implication of quantum mechanics itself but only by our difficulty making sense of it. This concept of the multiverse is entirely unlike, for example, the fact that light behaves sometimes like a wave and sometimes like a particle. We have been compelled to accept that duality as a demonstrated reality, even though it makes no intuitive sense. We don’t understand duality because we can think only in humanlevel terms: light isn’t really much like an ocean wave or a BB pellet—these are just the best we can do.

Skeptic 22.1 (cover)

This article appeared in Skeptic magazine 22.1 (2017).
Buy this issue

The multiverse, on the other hand, is an idea some people apparently believe makes intuitive sense—perhaps because it’s such a familiar and appealing staple of science fiction—but we’re not being forced to accept it by experimental results. We may be permanently at the stage in which we accept the mathematical accuracy and usefulness of the theory of quantum mechanics without ever being able to digest and accept its physical reality—all interpretations may forever seem counterintuitive and paradoxical. Not being able to understand one aspect of reality however is no justification for an entertaining but equally incomprehensible one. The wonder of the human mind is not that we can’t understand all of reality—it’s that we can understand any of it.

This limitless proliferation of universes seems to violate the laws of the conservation of matter and energy. Worse, it violates William of Ockham’s Razor: Entia non sunt multiplicanda praeter necessitate—that is, Entities should not be multiplied unnecessarily. Nor should universes be. END

About the Author

Peter Kassan, over the course of his long career in software, was a programer, a software technical writer, a manager of technical writers and programmers, and an executive at a software products company. He’s the author or co-author of several software patents. He’s been a skeptical observer of the pursuit of artificial intelligence for some time. His last piece for Skeptic was “I Am Not Living in a Computer Simulation, and Neither Are You,” in issue 21.4.

About the image at the top

Universum by Heikenwaelder Hugo, Austria [CC BY-SA 2.5], via Wikimedia Commons is a colorized version of The Flammarion (by Anonymous [Public domain], via Wikimedia Commons) — a wood engraving by an unknown artist that first appeared in Camille Flammarion’s L’atmosphère: météorologie populaire (1888). The image depicts a man crawling under the edge of the sky (as if it were a solid hemisphere) to look at the mysterious Empyrean beyond. The caption underneath the engraving (not shown here) translates to “A medieval missionary tells that he has found the point where heaven and Earth meet…”

This article was published on February 21, 2018.


30 responses to “Trouble in the Multiverse”

  1. Mathew Goldstein says:

    The author of this article is writing about a topic that he has very Little understanding about. A multi-verse of one type or another are predictions of modern cosmology and the many worlds interpretation is a respectable, mainstream interpretation of quantum mechanics. When skepticism is defined as software engineers telling cosmologists that they are mistaken then that skepticism is one that presumes it knows more than the experts and that is presumptious and foolish.

  2. Jim says:

    I personally feel that the multiverse or many worlds interpretation is taking the easy way out. It has been very difficult to reconcile the concepts of QM. There are numerous interpretations of QM – – and it seems we should be concentrating on the ones that have the greatest chance of being testable. This way we can either find the correct interpretation by the one that passes the tests we devise or alternately we can eliminate interpretations that fail the tests we eventually devise reducing the pool of possibilities. If i understand it part of Fehnman’s interpretation is that the collapse of the wavefunction is therefore not a physical change to the system, just a change in our knowledge of it due to the second measurement. I like that idea.

    • Dr. Strangelove says:

      The interpretations of QM are philosophical not scientific. Each one explains the same observations and experiments. So you cannot decide which one is “true” It is a philosophical Truth that proponents of these interpretations are seeking. Much like it’s impossible to prove or disprove that all the physical laws are constantly being implemented by God like a puppet master behind the scene.

      Science can only say the physical laws are enough to explain the observations without the additional postulate of a puppet master. Similarly, QM is enough without the additional Truth offered by the various interpretations of QM

  3. Ed says:

    Really? You don’t know the difference between hypothesis, predictions and theory?
    Understanding science fundementals should be a prerequisite to getting an article accepted. .

  4. mjones78 says:

    I don’t believe in the multi-verse. Strangely, though, all my selves in all the other universes do. Weird.

    • Bob Pease says:

      That means that you have a chance of being correct. But this chance while non-zero is so close to zero that you would always lose any bet you made in your favor . However you also have a 10 percent chance of being right an infinite number of times in a row

      The aleph null idea also has a zero percent some universe and if this is one of them then ?????

      Actually Go ^ BRroncs = aleph semi-nulll but then maybe aleph-Bud equals Rockies instead

  5. Bertram M Brown OD says:

    There is no reason to assume that only one universe exists. In the last one hundred years, more information on universes, large and small. have been discovered. So many concepts set in stone have been shown to be inaccurate.

    If we assume that Einstein led to a new way of thinking about time, space, gravity and light, we can see that this was only the beginning of new discoveries.

    Einstein still made errors, because information was not known, which led to his Cosmological Constant. With Hubble finding multiple galaxies and that the universe was expanding, let to Einstein’s statement about his mistake. There is still a lack of knowledge about the universe(s) which was complicated by the discovery of accelerating universal expansion. Neither Einstein or Hubble knew this information. Therefore their theories do not include that as part of the theories

    This led to additional speculations including the concept of Dark Energy. a concept to explain the unknown without knowing if dark energy exists. Basically we know so little compared to what needs to be learned, so that many theories are just speculation and science fantasy. Future research will prove right or wrong all of these present day theories, including those stated by the most brilliant cosmologists.

    • Dr. Strangelove says:

      “There is no reason to assume that only one universe exists. ”

      Replace this sentence with: “There is no reason to assume that the universe is not created by God.”
      The rest of the sentences follow. Therefore? Theism is a reasonable position as one of the theories to be proven or falsified.

  6. Dr. Strangelove says:

    Peter Kassan,

    There are 3 types of multiverse:

    1. Bubble universes from eternal inflation
    Physicists cannot explain why the universe is ‘smooth’ so they invented inflation to smoothen the universe. The problem is the inflaton field is more inexplicable than the smooth universe because there is no evidence for it. They are good in math but poor in logic.

    2. Many-worlds interpretation of quantum mechanics
    Physicists invented universes with carbon copies of you just to avoid the collapse of the wavefunction of particles. But they created a bigger problem of violating conservation of mass-energy by creating trillions of universes out of nothing every time you wear your sunglasses and unwittingly split the wavefunction of photons by polarizing the sunlight.

    3. Landscape of string theory
    Physicists assert, without any basis, that our universe with intelligent life is highly improbable. To explain the existence of our universe, they invented infinite universes. Of course with infinite universes, anything possible is inevitable including intelligent life. The rebuttal to this is similar to Intelligent Design. What is asserted without evidence can be dismissed without evidence.

    I have a bizarre theory to explain these bizarre theories. Physicists are not that stupid. They invent bizarre theories so they can write papers and advance their career without actually doing science. Real science is hard because it requires empirical evidence. Indulging in fantasy is so much easier.

    • BillG says:

      I would qualify the multi-verse as a scientific question, yet not a scientific answer.
      Inflation and string theory is a unfinished scientific venture.

      • Dr. Strangelove says:

        Not all scientific ideas are equal. Some are good ideas, others are crap. Multiverse, inflation and strings are not good (by default they belong to the other category) Multiverse is not a question that arise from science. It’s a metaphysical speculation (Is Zeus Greek or Olympian?) Here are the scientific questions that do not necessarily lead to the multiverse:

        Why is the universe smooth and flat? Does a wavefunction really collapse? Is a wavefunction even real? Is our universe improbable? How can you infer a probability from one sample? (It’s nonsense or a random guess)

        The existence of the inflaton field cannot be proven because it disappeared long ago. It’s like a god who created the universe and then disappeared so it no longer exists. This is worse than theology. But you can still believe in inflation as a matter of faith.

        Nobody knows what equations to solve in string theory. If I tell you my theory revolutionizes modern physics and replaces the theory of relativity, quantum mechanics and the Standard Model but I don’t know its equations, much less if they are solvable. But you should believe it anyway because I hope one day I will discover them. That would be hilarious. But if I call it string theory, people praise it as the theory of everything.

        These theories are worse than wrong. As Wolfgang Pauli put it, they’re not even wrong!

  7. Barbara Harwood says:

    I have a speculation that I would like to throw into the discussion. I see the universe that we inhabit as the atomic world of a much larger universe, while the atomic world that we find so hard to grasp is the universe on a much smaller scale. This could stretch in both directions into infinity.
    As a child of about five or six I remember questioning the very existence of the universe by asking, “Why anything?” I never asked the question because I knew that nobody would understand the it, much less give me a satisfactory answer.

  8. Bob Pease says:

    There is a thin line betwwen the need for “Lay” enjoyment and participation
    The obvious again rules

    Scientists and philosophers have different way of thinking about their stuff than “lay” people

    The only thing thst works for me without provoking rage and gunfire is the simple reply

    “tell me more about that!! , and pass the BUD”

    Dr, Sidethink Hp.D

  9. Bert Brown says:

    More than 30 years in my manuscript “To The End of The Universe” (c) 1988, I discussed multiple universes and called the Megaverse. In 2010, I upgraded the manuscript adding additional information discovered after the original manuscript was written. An important in 1998 showed that the universe expansion was accelerating. From that cosmologist came up with the concept of Dark Energy. There is an alternative possibility as the cause. If there are multiple universes, then the acceleration would be caused by gravity. If this is accurate, then Dark Energy does not exist. In 2020, the James Webb Telescope will be launched. I am hoping that blue shifting objects will be discovered beyond where our universe could exist. If that happens, then multiple universes would exist separated by time or distance.

    On should not confuse this with Dark Matter which was proven to exist by both Fritz Zwicky and Vera Rubin. Unfortunate no one can tell you its composition.

  10. Richard says:

    The trouble comes from not clearly defining what one means by the word “universe” and using the word in different contexts. In statistics, for example, it means the group under study, but in metaphysics the word “universe” means the total of that which exists. Therefore, the notion that there can be more than one universe is impossible and significantly shortens the discussion.

  11. Jason says:

    It’s obvious that this theory was introduced by the spirit Jesus Christ.

    • RSH says:

      Hmmm. What would a “spirit” be made of? If a spirit exists, it has to be composed of/consist of something, right? If it’s not something, it’s nothing (that is, nonexistent).

      Perhaps you’re joking or being sarcastic. If so, as the comedian said, never mind…

  12. Richard Harkness says:

    From the article: “Certain properties of a subatomic particle (for example, whether the spin of a particle is up or down) have no reality—only relative probabilities—until a measurement is taken.”

    Rather than “until a measurement is taken,” as stated above, I think it might be more accurate to say: “until an interaction with ANY macro-world object…”
    Such objects might be atoms and larger “objects.” It could be that, without quantum uncertainty at the micro-world level, our macro-world could not have come into existence.

  13. Herb says:

    As J. B. S. Haldane famously said, “The Universe is not only queerer than we suppose, but queerer than we CAN suppose.”

    This is an excellent post. It explains, in simple terms, the dilemma astrophysicists and quantum physicists have in trying to explain the universe. But the author left out two recently discovered fields: Dark Energy and Dark Matter. And since those two together are said to comprise 95% or so of the universe, then they have to become part of the hunt for a “unified field theory.” For the most part, then, we’ve been trying to explain our observations of only 5% of the “visible” universe.

    I know it frustrates the quantum physicists that explaining the weird behavior of quantum mechanics is counter-institutive and contrary to common sense. The astrophysicists are similarly perplexed. In that regard, my concern with science is that it is limited by the fact that it is carried out by human beings. There must be, to the extent possible, an objective science that has, literally, universal application – testable, falsifiable. Science therefore has developed and is continuing to develop the tools and intellectual concepts that humans can use to better understand the universe in all of its aspects. Meanwhile, the universe just rocks along. It has no secrets, no mysteries. Those are our problems to try and solve, and do so the only way we can – anthropically.

    • George says:

      Dark Matter and Dark Energy are more of the same thing as String Theory. Interesting and necessary descriptions of phenomena we don’t yet understand. So far as I know, there has been no test that proves the actual existence of either. The fact that they “explain” something that we do not understand does not mean that they actually exist.

  14. ACW says:

    The implications of the fictitious multiverse for science fiction haven’t entirely been thought through, either. If there are an infinite number of possible alternative universes, then Captain Kirk accomplishes effectively nothing by saving or not saving Edith Keeler in the one particular universe in which this specific version of his consciousness happens to exist. He hasn’t changed history; if anything, all he’s done is to shift his subjective consciousness from one version of the multiverse to the next. It effectively does away with free will as well, which if nothing else should make Sam Harris happy, since he’s always been antsy with the concept of free will anyway. (Sam Harris doesn’t recognize he’s making a simple error out of philosophy 101, on a par with the college sophomore who suddenly realizes he can never prove his subjective perception of ‘red’ is the same as someone else’s – “maybe if I could be inside your skull, what I see as ‘red’ would be ‘blue’!” – or that you can never directly see your own face, or all the similar profundities that teenagers exclaim ‘wow’ over after a bowl of good hash. ;) ) I suspect the hypothesis of the multiverse as a scientific reality is best left to the experts, and folks like me can just concentrate on making the most of our tiny little subjective eyeblink of life in our universe. Cheers!

  15. RJS says:

    The multiverse is not an ad hoc, speculative guess introduced from outside of theory. It’s a prediction from at least one version of cosmological inflation theory. And there have be several proposed methods to test this prediction by more detailed study of the cosmic microwave background radiation.

    This situation is similar to the prediction of the existence of the Higgs particle in 1964. Additional symmetry-breaking terms (the Higgs mechanism) were added to the Lagrangian of the electroweak theory to account for the known masses and the short ranges of the weak nuclear force particles (W and Z weak gauge bosons). The success of this modification gave additional credence to the existence of a Higgs field with its associated particle (the Higgs boson). The Higgs was discovered in 2012 at CERN.

    • Ken Farnsworth says:

      You misunderstand. You are referring to the idea that the Big Bang was either recycling from a prior universe, or that universes big-bang into existence from the collision of nearby “branes.” This is a cosmological-based hypothesis.
      This article, on the other hand, is referring to a quantum mechanics-based hypothesis that every time there is a decision, both (or more) outcomes are realized, albeit in separate, newly created universes. This is indeed speculative, and probably doesn’t deserve the label “hypothesis.” It has nothing to do with big bangs or cosmology.

      • RJS says:

        You are referring in your article to Hugh Everett’s “Many Worlds” hypothesis that dates to the mid 1950s. And yes that’s one interpretation of the measurement problem in quantum mechanics.

        “Multiverse” refers to certain cosmological theories that arose after Alan Guth proposed the inflationary universe model in the early 1980s.

        Terminology is important when discussing these things.

  16. Dr. Patrick Buick says:

    I live by M.S.’s Believing Brain. It’s all I have–I believe.

    I am a skeptic, but believe in two concepts:

    1. Cause and affect.
    Nothing happens without a cause-known or unknown.

    2. Constant change. Nothing stays the same.
    A second is not always a second.

    3. All knowledge is uncertain. Oh, #3.

  17. Bad Boy Scientist says:

    I really, really enjoyed this article. I hope we see more discussions along these lines. I teach (Astronomy & Physics) and to my non-STEM students I like to explain the notions of the multiverse – there are several – and then point out, as our author does, that these are speculations, not theories and not even hypotheses (which must provide testable predictions).
    But that is OK. It is OK for scientists to speculate on these things because many theories trace their origins back to some speculation.
    I also point out that many of the explanations found in Astronomy texts are somewhere between speculation and well-tested theories. We teach them because they are our best understanding today. But the thrilling thing about Astronomy is as our instruments get better we test these ideas better and better.
    One last point I make to my Astro classes: we learn three models of gravity: Galileo’s, Newton’s and Einstein’s. They are quite different explanations of gravity but all give sufficiently good answers within their realm (that’s why we still teach all 3 to physicists). This should make us careful of thinking that any one of them describes the fundamental reality of gravity – just because we can make very accurate predictions using a curved-spacetime model doesn’t mean that Nature is doing it that way.

    Again. Excellent article!!

    • Dr. Strangelove says:

      The fundamental reality of gravity is metaphysics. In the language of philosophy, metaphysics deals with the nature of reality. Epistemology is what can be learned about reality, not what reality is. That’s metaphysics. Science is epistemology. It is a method of inquiry. Physics deals only with what can be observed. The unobservable is either metaphysics or math.

      Metaphysicist: How many angels can dance on the head of a pin?
      Physicist: It doesn’t matter. We can’t see the angels.
      Mathematician: Certainly infinite! My Angel Probability Theorem proves that the sum of this infinite convergent series is exactly one.

  18. Tzindaro says:

    I do not accept most of the theories of modern science.

    For example, I think the luminiferous ether exists, the energy of the sun comes from the surrounding space, not from internal fusion, spontaneous generation is real and evolution is not, there is a vital force that animates living organisms distinct from biochemistry or the known energies of physics, telepathy, touch-healing, and mind control via telepathic hypnosis are realities, many species of invisible animals are living among us undetected, and I am not yet decided about phlogiston but it is certainly possible.

    I also think there is no such thing as the age of the earth; it has just always been here, the fossil record shows many species that started to form, then were aborted and never actually came into existence, new species do not usually come from ancestors; they just happen, but modern apes are descended from humans within the last 5,000 years, radioactivity did not exist until less than 6,000 years ago, and many other things that most scientists think are not true.

    And before you dismiss me as a religious fundamentalist of some sort, let me state that I am a militant atheist and have zero respect for the mythology of any religion. I just think we are still living in the Dark Ages and eventually. most of the theories of today will be disproven.

    • ACW says:

      I think you need to adjust the strap on your tinfoil hat. It appears the transmissions from Mars are still getting through.

    • lcs says:

      So in other words, you have no excuse for being absolutely wrong about everything you just stated.

This site uses Akismet to reduce spam. Learn how Akismet processes your comment data. Comments are closed 45 days after an article is published.

Skeptic Magazine App on iPhone


Whether at home or on the go, the SKEPTIC App is the easiest way to read your favorite articles. Within the app, users can purchase the current issue and back issues. Download the app today and get a 30-day free trial subscription.

Download the Skeptic Magazine App for iOS, available on the App Store
Download the Skeptic Magazine App for Android, available on Google Play
SKEPTIC • 3938 State St., Suite 101, Santa Barbara, CA, 93105-3114 • 1-805-576-9396 • Copyright © 1992–2024. All rights reserved • Privacy Policy