Cosmology for the Curious

There’s a new college-level textbook out, Cosmology for the Curious, targeted at physics courses designed to explain basics of cosmology to non-physics majors. The authors are Delia Perlov and Alex Vilenkin. Back in 2006 Vilenkin published a popular book promoting the multiverse, Many Worlds in One, which I wrote about at the time, making the obvious comment that there was nothing like a testable experimental prediction to be found in the book. It seemed to me then that the physics community would never take seriously an inherently untestable theory, recognizing such a thing as pseudo-science. I thought that the only reason claims like those of Vilenkin were getting any attention was that they had some novelty. Surely after a few more years of attempts to extract a prediction of some sort led to nothing, the emptiness of this sort of idea would become clear to all and everyone would lose interest.

Eleven years later I’m as baffled by what has happened to the field of fundamental physics as I’m baffled by what has happened to democracy in the US. As all attempts to extract a testable prediction from the multiverse have failed, instead of going away, pseudo-science has become ever more dominant, with a hugely successful publicity campaign (including a lot of “Fake Physics”) overcoming scientific failure. Now this sort of thing is moving from speculative pop science to getting the status of accepted science, taught as such to undergraduates.

Many are worried about the status of science in our society, as it faces new challenges. I don’t see how the physics community is going to continue to have any credibility with the rest of society if it sits back and allows multiverse mania to enter the canon. Non-scientists taking science classes need to be taught about the importance of always asking: what would it take to show that this theory is wrong? how do I know this is science not ideology?

Any student who reads this textbook and looks for answers to these questions in it will find just two “tests” of the multiverse proposed:

  • Look for evidence of bubble collisions.
  • Believe this paper, and then if you find a black hole population with a certain kind of mass spectrum, that would be evidence for the multiverse.

Of course there is no evidence for bubble collisions or such a black hole population, but these are no-lose “tests”: no matter what you observe or don’t observe, the multiverse “theory” can only win, it can never lose. Is it really a good idea to teach courses telling college students that this is how science works?

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26 Responses to Cosmology for the Curious

  1. Chris Herzog says:

    Two bubbles found they had rainbows on their curves.
    They flickered out saying:
    “It was worth being a bubble, just to have held that rainbow thirty seconds.”

    –Carl Sandburg

  2. Hannes says:

    Peter, a little aside, there has been recent hints that CP violation occurs in neutrinos

    and commenters claim that this result might explain baroygenesis in the early universe. If that is the case, a further argument for physics beyond the standard model might be gone (you cited the article by Siegel in you blog, , where the failure of the standard model to explain baryogenesis is given as one of the reasons to go beyond the standard model). Could you comment on this, maybe in another post?

  3. Peter Woit says:

    The problem is that I don’t know much at all about baryogenesis models, so best to leave this question to bloggers who do.

  4. Dan Winslow says:

    It’s the power of instant, free mass communication, plus the seemingly ingrained predilection to hear what we want to believe rather than what is true. In both cases. The fact that ‘news’ is monetized by advertising makes it even worse. You can make money blathering about the multiverse, because it is cooler than not having one, and further means you can blather about anything since anything is possible. It’s a perfect setup.

  5. The Observer says:

    We live in an age of great bogosity. “We each have our own truth” is the mantra of the age. Objectivity cannot be expected to survive in such an atmosphere. Believe it or not, Karl Popper’s academic children began the “science is a cultural construct” movement in California a long time ago. Now, we hear the rumblings of direct attack on science and mathematics by their followers.

    It would be funny were it not so sad and so alarming.

  6. Peter Woit says:

    The Observer,
    I don’t think you can blame Popper, his academic children, or a “science is a cultural construct” movement for what is going on here. Those pushing the string landscape pseudo-science are at the heart of the academic establishment and it seems that their main motivation is simply that of being unwilling to admit to failure.

  7. Mozibur Ullah says:

    I blame both the internet and the media; personally, I’m not against speculation, so long at its labelled as such; I don’t think, however it’s a good idea to smuggle it into a book for undergraduates without qualification.

    I also recall reading that a few physicists on discovering QM, saying we need crazy counter-intuitive ideas to make sense of QM, maybe that’s set the stage for crazy ideas elsewhere, like in cosmology.

  8. Peter Woit says:

    Mozibur Ullah,
    I don’t think you can blame the internet/media for this one. We’re talking about a college course taught by a physicist whose views are now considered mainstream by many other physicists. This is a problem the physics community needs to face up to, not blame on others.

  9. Low Math, Meekly Interacting says:

    It’s a shame, really. I found the preview chapter on Newton’s laws quite enjoyable. Assuming the rest of well-established physics is covered in comparable style, I’d happily give the text a good read just for fun. There aren’t too many books out there that cover such material with this balance of rigor and accessibility. But with all the anthropic multiverse garbage larding the book’s final chapters, no thanks.

  10. Radioactive says:

    Is this so different from ‘String Theory for Undergraduates’? Have some faith in students to be able to notice bunk when they’re taught it.

  11. anon says:

    They never will change their mind, because they never have before. There were competent smart physicists from good universities looking for the luminiferous aether well into the 1930’s. If anyone’s noticed the people involved in these theories are starting to get quite old, they will eventually retire and new people with new idea’s will take their place.

  12. Peter Woit says:

    Why do you think non physics major students will recognize the multiverse as bunk, when IAS professors don’t?

    I don’t think it’s true that multiverse mania is just a disease of an older generation that will die out. Many of its proponents are not that old at all. It might even be that the older generation has more skeptics, people who were around when the field was healthy and can recognize the difference between an empty idea and one that works.

    The conventional argument that we’ll make progress by the old retiring and the young growing up with better ideas depends on those better ideas coming along. The really awful aspect of multiverse mania is that it’s a concerted attempt to get the young to give up and not even try to find an alternative.

  13. Don Murphy says:

    I conduct “Making Sense of Science” seminars to discuss contemporary advances in science. One seminar was on the multiverse, the purpose of which was to demonstrate that some “theories” are not testable and therefore not really theories. I presented the 11 or so “theories” Brian Greene puts forward in one of his books that he says all lead to the conclusion the multiverse must exist. Most of the seminar attendees understood that the multiverse is nothing more than pseudo-science. However, to my dismay, there were some who firmly believed that the multiverse confirmed their religious views on polytheism, and human beings being resurrected as gods to rule over multiple universes. A dangerous notion for so-called mainstream science to have spawned.

  14. G. S. says:

    One saving grace here is that the material taught in physics classes for non-majors is rarely absorbed by the students. The small amount that is absorbed is quickly forgotten after the post-finals beer binge and brain dump. The books get sold online or go in a box that gets stored in the least accessible spot in a parent’s garage. In ten years, 90% of the students who used this book for a college course won’t remember even having taken the class, let alone the material from it.

  15. neil says:

    IMO, interest in the multiverse persists among reputable physicists because it doesn’t violate any logic and offers the illusion of explaining the values of many physical constants (with the Anthropic principle) and fine tuning. It doesn’t of course, but absent a real explanation it is the only interesting game in town. It also offers the illusion of testability since practically any irregularity in the CMB can be claimed to be evidence of a neighboring bubble.

  16. Peter Woit says:

    Don Murphy,
    From another side, some atheists like to have the multiverse to use against theists making a fine-tuning argument for the existence of God. They don’t seem to realize that invoking an untestable theory to make such an argument puts them in a position indistinguishable from that they’re arguing against (relying on belief rather than scientific evidence).

  17. Jeffrey Wolynski says:

    The more you write about it, the more popular it becomes. You are feeding the flames. You know the rule about publicity? Even bad publicity is still publicity.

  18. R. Gates says:

    Your point about testability and predictions is a great one but actually, there may be some evidence for evidence for bubble collisions:

  19. The Observer says:

    Well, you are right that Popper’s academic children and the “science is a cultural construct” movement cannot really be the cause of this. They are too far separated as phenomena. It would be better had I put it that these separated phenomena have a common cause. That cause is the failure of belief in truth and the substitution of relativism.

    Science has always been a phenomenon dependent on experience. I believe that it was called “speculative science” long before it was called “natural philosophy”, long before Galileo, and that was exactly right, because induction is speculative. But, from the bottom side the relativists about truth have attacked truth and want to mold science as being something that, as a “cultural construct”, they can reconstruct as they see fit. Does that not sound like exactly the same thing as, from the top, those in love with untestable visions of their own seeking to make it legitimate to “extend” science into a subject no longer dependent on experiment but something in which being “the only game in town”, for example (in their own opinions), makes it desirable to call the creations of their own minds, divorced from experience, “science”. They may be brilliant, but they have gone relativist on the ancient understanding of speculative science as something based, not on pure creativity, but experience.

    Is this not, really, exactly the same phenomenon played out from below and from above.

    I think that science is in danger of being crushed by a pincer movement between the relativists below, who are in the process of forming up for a politically powerful attack on science, and the relativists above, who want to reconstruct science to suit their own varius relativist redefinitions of science.

    Another way to put this is: We have gone crazy.

    You are doing really great and important work, but you sound a little discouraged. I would like to encourage you by suggesting strongly that you hang in there and remain the beacon of sense that you have been for many years now.

    We need you.

  20. Peter Woit says:

    R. Gates,
    These bogus claims are just endless, I’ve wasted far too much of my time trying to debunk them here over the years, now think that’s just hopeless. It’s always the same thing:

    1. Scientific paper with no evidence at all for a bubble collision
    2. Press release from university mentioning “possible evidence for multiverse”
    3. Loads of press stories like the one you link to.

    Everyone involved in this bullshit should just be ashamed of themselves.

    Looking back, I think one reason I didn’t mention this particular example on the blog is that others have done so, see

  21. Peter Woit says:

    Some more related to the last comment:

    I wish more physicists/cosmologists/astronomers would start to do what Peter Coles did in that case. It really is part of the job of anyone in those fields who cares about the public understanding of their science.

    One reason I wish this would happen is that I’m sick and tired of wasting my time on this, doing a job others should be doing. In addition, note that the reason I found the Coles blog entry was that it is linked as a trackback to the arxiv paper that started this. Trackbacks to any of my blog entries are banned by the arxiv. Historically one of the main reasons for this is that I seem to have upset Joe Polchinski by a blog entry criticizing a Bousso/Polchinski article promoting the multiverse. He then went on a campaign to ensure that my blog entries criticizing multiverse papers would never show up as links at the arXiv. So, best when others deal with this.

  22. Jeff says:

    The Atlantic has an interesting article ( discussing the way in which American society in general–across political, religious, and ethnic lines–has elevated personal fantasy over objective reality as “the truth”. It describes both how origins of this shift can trace back to left-leaning academia as well as elements in mainstream left politics (though this is not a “both-sider” article; it clearly draws out that regarding actual party leaders, platforms, and propaganda, the American right is far deeper into fantasy than the centrist/left).

    But while reading the article, I kept thinking back to this blog, and this post in particular. The article touches on domains and personality types where magically thinking hasn’t taken hold: physical/empirical sciences, rationalists, the a-religious/a-spiritual. Sadly, I think the author overestimates how immune even those areas are to magical thinking.

  23. Peter Woit says:

    Re previous comment:

    It seems that the arXiv has changed its policy and is now allowing trackbacks to my blog entries. No idea what changed or when this happened, seems to have been within the past few months.

  24. Peter Coles says:

    Thanks for your comments about my post at `In The Dark’.

    Sadly it would be full-time job keeping up with all the misleading cosmological hype going around so I’ve let quite a few other papers slip!

  25. AcademicLurker says:

    No idea what changed or when this happened, seems to have been within the past few months.

    The arxiv had their big user survey recently. Maybe there was a significant pro-Woit vote…

  26. Shantanu says:

    Academiclurker and Peter,
    FWIW, that’s exactly one of the feedbacks I gave to arxiv readers.

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