BBC Horizon this week is running an episode How Small is the Universe? with a description that features the usual sort of hype about modern physics:
It is a journey where things don’t just become smaller but also a whole lot weirder. Scientists hope to catch a glimpse of miniature black holes, multiple dimensions and even parallel Universes. As they start to explore this wonderland, where nothing is quite what it seems, they may have to rewrite the fundamental laws of time and space.
Access to the video is restricted to IPs in the UK, so I can’t watch the thing, and should avoid being too critical. One of the two clips though advertises The landscape of String Theory and somehow I doubt that the clip explains why this is pseudo-science. Associated with the show is this article by Andy Parker of ATLAS, which gives the idea that ATLAS is looking for strings:
Strings can vibrate, and this allows us to explain all of the strange fundamental particles which we see as different vibrations of the strings – different notes from a cosmic violin.
So far, so simple – but to explain the particles we know about, the strings have to vibrate in lots of different ways.
Superstring Theory allows them to vibrate in a bizarre space with 11 dimensions – up, down, sideways, “crossways” and 7 other ways!
Experiments at the LHC are looking for evidence that you can move “crossways”. If we can, there could be whole universes, as big and marvellous as our own, sitting just down the road “crossways”.
No mention is made of the fact that the LHC has seen zero evidence for any such thing, or that few if any physicists ever thought there was any real chance it would.
The other experiment invoked is the MAGIC gamma ray telescope, presumably in the context of the search for Lorentz-violating dispersion of gamma rays from gamma ray bursters. This was discussed in an edition of This Week’s Hype from five year’s ago, which featured a Slashdot report that Gamma Ray Anomaly Could Test String Theory. At Scientific American, the story was Hints of a breakdown of relativity theory?, which was about this paper, and contained the news:
Another co-author, string theorist Dimitri Nanopoulos of Texas A&M, writes to me: “I am very excited about this, because as you know we suggested this effect about ten years ago and we have follow through with several analyses and/or improvement on theory. Notice that the 0.4 x 1018 GeV is the typical string scale!!!!”
Since 2007 there have been a series of much more sensitive results from Fermi ruling out the quantum gravity interpretation of the MAGIC observations (see e.g. here, here, here and here.)
Since I can’t watch the video, I don’t know what the BBC has to say about MAGIC’s results, in particular whether the show explains the story of the 2007 claims and how they were later shown not to have anything to do with space-time structure by the newer Fermi observations.
Update: I did just get a chance to watch the program. It was very well made, with the first half quite interesting, featuring the LHC and some atomic-physics scale experiments I would have loved to hear more about. About half-way through though, it started to go off the rails, with the usual kinds of problems. The extra dimensions at the LHC stuff made no mention of the fact that even string theorists see no good reason for them to show up at this scale, and the results to date confirm this. The Mike Green segment was pretty much pure string theory/multiverse hype. Reference to the “mind-boggling predictions” of string theory misses the main problem, that there are no predictions. In particular, no predictions about the gamma-ray dispersion MAGIC is looking for, which ended the show. The 5 second discrepancy described at the end in MAGIC 2005 observations I suspect has been shown to not be plausibly due to such dispersion by later Fermi results which went unmentioned.