Today I heard* Monday's edition of BBC Radio 4's programme called "In Our Time". This one was about the Graviton. You may recall me talking about this series before, back when I'd heard the one about Magnetism. My thoughts are roughly the same as before. A good and worthy (and very welcome) discussion of physics, but rather poorly executed overall. This is because the message got rather muddled. It started rather well, but it just kept going around the same tight circle, more or less, repeating the same tired stuff about the incompatibility of current gravitation theory (General Relativity) and everything else that the universe does, which is quantum mechanical at the core. The graviton arises as a key and natural idea about how to understand quantum gravity (at least from a particle physicist's perspective). This is worth saying once or twice, maybe thrice, rather clearly, but then I think that's enough in a forty minute programme when you want to cover a lot of ground. But they kept coming back to it, like a broken record.
One of the other problems I've found it that the host, Melvin Bragg, interrupts the speakers rather a lot and makes a mess of some of their explanations in doing so, sometimes trying out a poor analogy of his own that he believes might do the trick to explain something. I suspect that there might be a producer yelling "abort! abort!" in his headphones whenever a guest is beginning to sound a little too specialist and then Melvin Bragg tries to turn the conversations elsewhere, or "soften" the words a bit. This had the unfortunate effect of allowing misleading (and sometimes just plain wrong and/or silly) things to hang there, and even become real and re-enter the conversation. The guests, being obscure academics like all of us, appear to suffer from that problem of being so clearly pleased to be asked on to a primetime show like this that they don't insist on being allowed to correct the inadvertent silliness, perhaps because they're worried they'll never be asked again. (We are all media tarts at heart, so I can see this being a factor, even if not consciously). I don't really know why for sure (that was just a guess), but it seems to happen anyway. For example, have a listen to the program and try to spot when one of the guests valiantly attempts to explain what spin is. He's about to trot out your favourite analogy which is innacurate, but an acceptable representation of some key attributes when you don't have more time (you know...top spinning on axis, etc), when Bragg interrupts with something or other about fairgrounds and things, and the next thing you know, spin is candyfloss. Amazingly, nobody tries to clear this up. And it emerges again later: supersymmetry is some way of changing the candyfloss from one type to another. (...huh?)
I don't know (as research colleagues) any of the people (Roger Cashmore, Jim Al-Khalili, Sheila Rowan) who were the guests and I am sure that they are fine people and good at what they do. They explained what they do rather well in fact (e.g. Sheila Rowan talked quite a bit about gravity waves, and quite interestingly and informatively too). But none of them, as far as I could tell from what they said, had much firsthand knowledge about what is actually going on in research involving gravitons, per se. This is the same weakness I pointed out about the Magnetism show last time. As a result, there were all sorts of simply alarmingly incautious statements (such as how the LHC might discover the gravitino and then this would prove that there were gravitons, as well as solve the dark matter problem. (....huh?! that assumes rather a lot, no...?) [update: or how we might produce gravitons directly at the LHC, and see them from missing energy signatures]) which were a bit embarrasing to hear [update: embarrassing largely because of the degree of overstatement about what the LHC can most likely do....unless we are really lucky....there is a wealth of dark matter candidates besides something like the gravitino, and we'll probably need another accelerator to sort out the details....]. The usual over-blown claims about string theory were bandied about, with nothing beyond, say, 1995's duality revolution mentioned as having any input (positive or negative) to the prospects for physics. The conflation with gravity wave research and graviton research (both interesting fields) was rather annoying, but I am pleased to say that all of the guests made important points to separate the two, once the host took a step back and let them talk.
Despite all that, I must say that it is nice (and welcome) to hear that the programme makers still have a commitment to discussing ideas from physics right along side other ideas from other fields. It was a bit like sitting in on a pub conversation, and being pleasantly surprised to hear what they were talking about. This is healthy. There was some good banter (such as Bragg giving Rowan a hard time about the fact that she keeps binging up rubber sheets every time she is going to try to explain something) and this was also good to hear mixed in with the other stuff.
I can only hope that the show's producers will invite guests who not only have the historical persepective, but also guests who are actively doing research in the topic too. It lends a better balance to the proceedings and is a better resource to those learning about the topic afresh. This could make "In Our Time" into a truly great programme. Right now it keeps missing the mark, and being only "pretty good, considering", at least in the area of science, for the reasons that I mentioned here and in the other post.
-cvj
*Thanks for mentioning it, Ed Copeland!
