It seems that a couple of the authors of the recent Cosmic Controversy letter (discussed here) are going on a campaign to embarrass the 29 physicists who were convinced to sign their letter. Andrei Linde has gone to Lubos Motl’s blog to thank him for his blog entry which lauded Linde as having eaten from the biblical tree of knowledge and which denounced his critics as imbeciles. To deal with Linde and his claims, Ijjas, Steinhardt and Loeb have added a new webpage to their website called Fact Checking. It lists the four “predictions” of inflation claimed to agree with experiment by Linde et al. and gives four references to papers published by Linde touting different “predictions” for the same quantities, predictions not agreeing with experiment.
This month’s Scientific American has a remarkable cover story, The Quantum Multiverse from one of the other four letter authors, Yasunori Nomura. I’ve seen some fairly bizarre stories about fundamental physics in Scientific American over the years, but this one sets a new standard for outrageous nonsense, and I’m wondering whether it too may cause some of the 29 co-signers of the letter co-authored by Nomura to question the wisdom of joining with him and Linde. Nomura is well known for a definite prediction based on the multiverse: in 2009 he co-authored a paper claiming that the multiverse predicted the Higgs mass would be 141 GeV +/- 2 GeV. This played a major role in the film Particle Fever. That three years later the Higgs was discovered at 125 GeV seems to have had no effect on his multiverse enthusiasm.
The new SciAm cover story is not about anything new, but is based on a 6 year old paper by Nomura discussed here. At the time I wrote about this “I’m having trouble making sense of any of these papers” and quoted Lubos’s evaluation: “They’re on crack”. Nothing I’ve seen about this over the past six years seems to me to make any sense at all, including the new SciAm cover story, which just seems even more content-free and meaningless than previous efforts to explain this “multiverse interpretation of quantum mechanics”. On the obvious question: how would you test this, Nomura just has this to say:
Evidence so far indicates that the cosmos is flat, but experiments studying how distant light bends as it travels through the cosmos are likely to improve measures of the curvature of our universe by about two orders of magnitude in the next few decades. If these experiments find any amount of negative curvature, they will support the multiverse concept because, although such curvature is technically possible in a single universe, it is implausible there. Specifically, a discovery supports the quantum multiverse picture described here because it can naturally lead to curvature large enough to be detected, whereas the traditional inflationary picture of the multiverse tends to produce negative curvature many orders of magnitude smaller than we can hope to measure.
This paragraph manages to put together three different misleading and unsupported claims:
- “If these experiments find any amount of negative curvature, they will support the multiverse concept because, although such curvature is technically possible in a single universe, it is implausible there.” This is just nonsense.
- “the traditional inflationary picture of the multiverse tends to produce negative curvature many orders of magnitude smaller than we can hope to measure”. What is the inflationary multiverse “prediction” for negative curvature? As far as I can tell it’s compatible with pretty much any level we might observe.
- “the quantum multiverse picture described here because it can naturally lead to curvature large enough to be detected.” I can’t find anywhere a calculation of the negative curvature expected by the “quantum multiverse picture”, and I don’t believe any such calculation is possible.
Given some of the outrageous hype I’ve seen in recent years in respectable publications, it’s gotten rather hard to shock me with this sort of thing, but I do find this Scientific American cover story shocking.
Update: For some reason this was not mentioned in the SciAm article, but the paper justifying Nomura’s claims about negative curvature is here.
Update: A modest proposal: Given the situation, I think someone needs to write a letter to SciAm complaining about the Nomura article and get leaders of the community to sign in support of it. They could start gathering signatures by writing to the 29 signers of the earlier letter. If these people were willing to object to the Steinhardt et al. article, they should be willing to object to the far worse Nomura article.