The God Equation

When I was out for a bike ride yesterday I stopped by a large book store and looked to see if they had a copy of Michio Kaku’s new book The God Equation. They didn’t, but did have plenty of copies for sale of his various previous efforts to promote string theory, such as 1987’s Beyond Einstein, 1994’s Hyperspace and 2005’s Parallel Worlds. If someone interested in fundamental physics walks into a bookstore, and looks in the Science section for something to read written by a well-known physics professor, these books are what they’re likely to end up taking home and reading.

When I got back from the bike ride, several people had forwarded me a link to this story from the Guardian which gives a good idea of what’s likely in the book, claims like:

Well, string theory has also created a tremendous amount of interest, as well as a backlash. People say, well, where is the proof? Quite frankly we don’t have the proof, in the same way that Newton did not have the proof of his inverse square law back in 1666. Sometimes, the mathematics and the ideas are ahead of the concrete experimental data. That’s where the Large Hadron Collider comes into play…

The Standard Model is the theory of almost everything. It works spectacularly well but it’s one of the ugliest theories proposed so far. There’s this avalanche of experimental numbers you have to put in by hand. But in string theory the Standard Model just pops right out. With just a few assumptions you get the entire Standard Model. So the point here is that we need experimental proof and the LHC may give us hints of a deviation in the Standard Model and that’s where this post-LHC physics comes into play.

This is just complete and unadulterated bullshit, of exactly the same sort Kaku and a host of others well-credentialed physicists have been heavily and successfully promoting for the last 35 years. I started writing about this 20 years ago, and there have been some changes since then (for one thing, we have Sabine Hossenfelder). I’m still waiting though for any of the leading figures in the physics community responsible for the string-theory hype campaign to do anything at all to try and stop Kaku and the rest of the Fake Physics onslaught that they unleashed.

Usually with books like this, once I get a copy of the book I try and write here a careful review quoting the writer accurately and explaining the problems with what they’ve written, but this time I think I’ll pass on the grounds that this would be a waste of time.

The funny thing though is that I probably agree with Kaku far more than most people about the possibility of unification, although I wouldn’t use the terminology “God equation” to describe a unified theory. Unfortunately Kaku has done far more than most physicists to discredit the search for a better unified theory, through the endless nonsense he has put out about the subject in books like this. I do think we’ll find a better, more unified theory, and I even think I know a couple of the crucial equations, which, leaving God out of it, are:

Update: You can read the book’s introduction here. It seems that Kaku has conceptualized the book as a response to criticism of string theory. Near the end of the introduction, he assures us:

This book will hopefully give you a balanced, objective analysis of string theory’s breakthroughs and limitations.

This morning he’s on Morning Joe.

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32 Responses to The God Equation

  1. Dylan Mahoney says:

    What do those crucial equations represent, and where do they come from?

  2. Peter says:

    That Guardian quote makes me want to twist my own head off.

  3. David says:

    “Newton did not have the proof of his inverse square law back in 1666.”

    Newton computed the force required for an apple to fall as it did, for the moon to “fall” in its orbit around Earth, and for Haley’s comet to orbit as it did, and found the forces varied as the inverse square of the distance to Earth.

  4. Topologist Guy says:

    “The standard model pops right out.” Isn’t this simply false?

    The truth coming closest to this, I think, is that perturbative superstring theory on a flat 10D background reduces to a 10D supersymmetric quantum field theory at low energies (whose fields come from the low-energy excitations of the string). The project to get the specific 4D QFT that is the standard model, with its specific fields and numerical parameters, from a compactification of superstring theory has been a dream for decades and is farther than ever from being realized, with the enormous moduli space of possible string vacua. Of course we all already know this.

    So I think Michio Kaku is saying that superstring theory (on a flat background) reduces to *a* (10D) quantum field theory at low energies. It’s very disingenuous to precede this with a remark on how “ugly” the standard model is, precisely because of the apparently arbitrary assortment of fields and parameters (not because QFT itself is an ugly framework), which suggests that string theory reproduces these specific fields and parameters as a low-energy limit, which is simply untrue. Kaku’s statement really reduces to “you can recover a QFT as a low-energy limit of strings,” which is far less impressive.

  5. Peter Woit says:

    Dylan Mahoney,
    The first equation is the Dirac equation, and governs the behavior of matter fields. The second is the (anti)self-duality equation, which (especially from the twistor Penrose-Ward correspondence point of view) governs the behavior of gauge (force) fields.

  6. Peter Woit says:

    David/Topologist Guy,

    The serious question here is why Kaku makes obviously absurd claims and arguments (that the SM pops out of string theory, that the status of Newton’s law of gravitation when he came up with it was like the status of string theory). He’s clearly not operating according to any usual scientific principles. Ash Joglekar, see here
    says he understands Kaku not as a scientist, but as a fantasist and storyteller.

  7. Peter Orland says:


    Newton did not have to calculate anything new to get his law of gravitation. He just needed Kepler’s summary of Tycho’s observations.

    Kepler’s first law (a planetary orbit is an ellipse, with the sun at one focus) and Kepler’s second (equal areas) law, together imply an inverse square relationship of acceleration towards the sun. Then Kepler’s third law enforces that $GM_{\odot}$ is the same for each planet. I don’t know if Newton discovered the gravitational force law this way, but that would be my guess (a historian would know better).

  8. Kaku drives me up a wall. Time and again, he deliberately erases or obscures the line between science and complete bs speculation, presents all of this on TV or in print without qualification, and acts like that’s fine because it gets people interested in science.

  9. Michael Weiss says:

    Newton’s theory coherently and quantitatively retrodicted key observations (Kepler’s laws, Tycho rich database of astronomical observations) and in turn predicted a vast body of further observations. (Indeed, the precision of the classical predictions enabled future rigorous testing of GR. The Lamb shift was also quantitative and precise, enabling the development and testing of QED.)

    Given experimental constraints, it is not credible to equate the Newtonian paradigm with the status or sociology of String Theory, however brilliant the mathematics and however elegant its continuing impact in condensed-matter physics.

  10. Amitabh Lath says:

    Strings are one of those concepts that have become accepted by repetition. I have had to correct generation-Z/alpha members of my extended family from proclaiming to their grade-school science class that their “…uncle works at the LHC which is a powerful microscope that can make out strings inside quarks inside protons inside atoms…”

  11. Sabine says:

    Thanks for the link.

    As Douglas mentions above, lots of people trying to excuse this by claiming it’s okay because it “gets people interested in science”. What they forget to mention though is that the people who actually get interested in science by things like this figure out very quickly that they’ve been sold vacuous quackery and end up being cynical nay-sayers and general science skeptics.

    It’s an interesting question why the Guardian would run factually incorrect scientific statements like this. Suppose the topic hadn’t been string theory but climate change. Would they have printed utter nonsense just because it might “get people interested in science”? Certainly not. Why not? Because it’s irresponsible.

    I suppose when it comes to string theory they believe it doesn’t really matter whether what you say about it is right or wrong. I think that’s incredibly short-sighted though. Because research in the foundations of physics is a long-term investment into new technologies. I wish the Guardian editors would think a little more about what they run on their pages, or at least add an explanation for the reader for how to gauge the scientific credibility of Kaku’s statements.

  12. Julien says:

    I think you can write to the guardian and they may publish your letter. See the links at

    Also, Katharine Viner is editor-in-chief and the page above tells you how to build her email address from her name.

  13. Low Math, Meekly Interacting says:

    “…in the same way that Newton did not have the proof of his inverse square law back in 1666.”

    Seriously, WTF is this about? I’m not being facetious. I have to believe there’s some point being made here that is obscured by an outrageous level of omission. Like maybe he’s thinking of the fact that Newton had no mechanism to explain the inverse square law, like maybe instantaneous action at a distance, which made Newton himself uncomfortable, begged for further insight. Or something. My ever-dwindling faith in humanity increasingly depends on such generous rationalizations.

  14. Peter Woit says:

    I don’t think a letter would be worth the effort. If they did publish such a letter no one would see it.

    It would be great if somebody would contact the Guardian and ask them to issue a correction, to appear on the same page as the bogus claims by Kaku. Also good to get them to be aware they need to do some basic fact-checking before publishing claims like Kaku’s. In particular his claim that Isaac Newton’s discoveries were at the time untestable speculation should have set off red flags for any author or editor who had taken even a high school class in physics.

    In general, this phenomenon of the huge amount of public misunderstanding of string theory should be addressed. I’ve done my part, string theorists themselves should take some responsibility for the mess that their proponents have created and do something about it.

  15. Ash Jogalekar says:

    “Unfortunately Kaku has done far more than most physicists to discredit the search for a better unified theory.”

    Although I agree that Kaku often says nonsense that’s highly misleading, I think professional physicists pushing string theory have done far more harm to “discredit the search for a better unified theory” than Kaku ever did.

  16. I could be wrong, but a quick look at Google scholar suggests that Kaku hasn’t published anything academic in many years, and there is nothing on the arxiv after 1999. I have no issue with people shifting gears into popularization, but to have pretensions of being an active scientist when not publishing for over two decades is too much.

  17. maciej says:

    While many Kaku’s statements are clearly exaggerated, I think it is only for the PR of his books or PR of himself. Unfortunately this is how the “sales” work. Kaku has not been publishing scientific papers for years. He has became a sales man of his books, so I would not care much for his claims and I don’t think scientists do.

    Also, look at his textbooks on QFT or String Theoy/M-theory. Do you see those out-of-touch claims there? Not at all. Actually these books are rather well written. This shows that his exaggerated claims are only for the public. You may still not like it, but I don’t think it is creating any more harm for the scientific community i.e. there would be still hype about ST even if Kaku was not known to the public.

    In my opinion, the real damage comes from known and active researches in ST who still make similar unsupported claims.

  18. Jim Eadon says:

    True story. Yesterday (before reading this post) I asked a famous String Theorist for how String Theory connected with testable physics. He answered that the testable predictions of String Theory are “Super Symmetry” and the “Hagedorn tower of particles”.
    Perhaps dissatisfied with his own reply, he then simply deleted his (Twitter) tweet, and blocked me.
    That exchange with a String Theorist (I’ll not mention his name, but he’s high-profile) told me more convincingly even than critics that the String Theory HEP programme has not gone well…
    Interestingly, he also said that you did not need to test String Theory to see whether it is correct, because “it *is* the laws of physics”

  19. Peter Woit says:

    Maciej/Jim Eadon,
    Kaku is an extreme case, but the problem of misleading/exaggerated claims for string theory is a widespread one.

  20. Robinson says:

    I am not a physicist, just an interested reader. It’s funny you mention his books being very visible. I have a copy of Hyperspace, purchased in just such a manner as you describe. Kaku is charismatic (like Brian Greene) and has been in many TV shows like Horizon (BBC), which give him name recognition with us hoi polloi.

    I cannot really comment on the content.

  21. Ted Rogers says:

    He was also interviewed about the book by Michael Shermer:

    It is very long, but still seems like something of a missed opportunity for a skeptic.

  22. Peter Woit says:

    Ted Rogers,

    I took a quick look at the transcript. Shermer is supposedly a professional skeptic, but when he asks Kaku for experimental evidence of string theory, he seems all right with a response about strings vibrating in 11 dimensions and the mind of god. Inviting Kaku on and then seemingly taking the attitude that “this guy is a reputable scientist, so whatever he says must make sense”, he’s not exactly an advertisement for his brand of skepticism.

  23. Ted Rogers says:


    Yes, that was my reaction. Very frustrating.

  24. Bernhard says:

    Kaku should stick to writing about the future (he’s a fantasist, as someone said), since his books on this are quite entertaining (whether one believes his predictions is not the point), and I think he’s rather careful interviewing people outside his own area of expertise.

    In all his books, it is always when he talks about string theory that I have to roll my eyes. He has excellent technical knowledge (which is the reason he continues to get a “pass”), there is no excuse to write some much BS about the Standard Model popping out of string theory no matter what amount of simplification he wants to get behind in order to have the excuse. This is technically so wrong that no amount of simplification justifies writing it.

  25. Peter Woit says:

    Took a closer look at the transcript of the Shermer interview. When pressed about testability he lists three ways to test string theory:

    1. String theory predicts dark matter, will see this at next generation post-LHC collider.
    2. LISA will see gravitational waves from the big bang predicted by string theory
    3. Measurements of the gravitational force inverse square law “in your living room” will see deviations predicted by string theory.

    Utter horseshit.

    Shermer’s reaction: “You always blow my mind with these things.”

  26. Peter Woit says:

    One fun thing about the Shermer interview:
    Around 19:47 he refers to a book called “Not Even Wrong” that came out a decade or so ago and criticizes string theory as untestable, he thinks authored by a guy named “Witten”.

  27. >he thinks authored by a guy named “Witten”.

    who thinks? I presume you mean Shermer, since surely Kaku wouldn’t make that mistake.

  28. Peter Woit says:

    Yes, it’s Shermer who thinks this.

  29. Amitabh Lath says:

    If you got kicked off the fnal muon g-2 webinar, it is on youtube.

  30. Bernhard says:

    “he thinks authored by a guy named “Witten”.”

    I can’t stop laughing about this…

  31. Patrick Dennis, MD says:

    David, Peter O. — The story goes that Robert Hooke and Edmund Halley were trying to work out the nature of gravity. The best guess was that it varied inversely as the square of the distance, but they were frustrated that they could not show that such a force would lead to elliptical orbits. So one (Halley, I think) asked Newton what kind of orbit would result from an inverse-square gravity, and Newton immediately answered, “an ellipse.” He said he had already proved it, but did not have the proof immediately at hand. When he eventually showed it to his colleagues in the form of a brief manuscript, they realized that he was on to something very big indeed, and it was at their urging that the off-the-cuff calculation emerged years later as Principia.

  32. David says:

    Why had he worked out the equation of the orbit? Because he had already thought about the force law of gravitation.

    “ After dinner, the weather being warm, we went into the garden and drank thea, under the shade of some apple trees…he told me, he was just in the same situation, as when formerly, the notion of gravitation came into his mind. It was occasion’d by the fall of an apple, as he sat in contemplative mood. Why should that apple always descend perpendicularly to the ground, thought he to himself…” from Memoirs of Sir Isaac Newton’s Life by William Stukeley, 1752

    Stukely got the story straight from Sir Isaac. Newton worked out that the force on the moon was the same as the force on the apple, diminished by the square of the ratio of the distances. That, combined with his fluxions, was enough for him to work out the orbit as a conic section.

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