Wednesday, 6 May 2015
Monday, 19 January 2015
After six years with the ATLAS experiment, in a variety of roles — most recently as a research assistant here at the University of Sydney — Dr Cuthbert has decided to call it a day. This morning, he begins his new career as a quant.
Good luck, Cameron. You'll be missed.
Friday, 21 November 2014
I was interviewed briefly on ABC's PM program yeterday, to cover this discovery, and LHC-related news more generally. A technical account of the work can be found in the paper LHCb submitted to Phys. Rev. Lett., which is available on the arXiv.
(What I've written simplifies things considerably: for example, these cascade-b's are negatively charged; there's also a matching set of neutral cascade-b's, each with an up quark in place of the down. And why are there three related states close in mass? As well as being an empirical observation, such patterns can be understood by considering the possible ways to combine quarks with various flavours and spins, taking into account the symmetry of the resulting wavefunction in each case. Readers with a considerable amount of university physics should be able to follow the PDG's discussion of the charmed baryons: baryons carrying one unit of “beauty” are an analogous case.)
Wednesday, 19 November 2014
Cosmic evolution may teach us how the good and the evil tendencies of man may have come about; but, in itself, it is incompetent to furnish any better reason why what we call good is preferable to what we call evil than we had before.As a claim about the limits of natural history, this is conventional enough. But the author may come as a surprise: Thomas Henry Huxley, in the second Romanes lecture, in Oxford, 1893. H/T Gertrude Himmelfarb, “Evolution and Ethics, Revisited,” The New Atlantis, Number 42, Spring 2014, pp. 81–87.
Tuesday, 14 January 2014
Friday, 19 April 2013
Monday, 6 August 2012
Given what was required to get from the top to the bottom of the atmosphere in one piece, it's a great relief.
Congratulations guys. Now we can all get back to work!
Sunday, 3 June 2012
The event was called “The Faith of a Physicist”, but we talked more about physics as such, in particular my own field (particle physics), and what it's like to be a physicist ... only then drawing the connections with my being a Christian, and having a degree in theology. So the talk is not itself a confession of faith. (There was some of that later in the day, but that's another story.) We covered a lot of good, scientific ground partly because the interviewer was my old friend Tim Patrick: a priest in the Anglican Diocese of Melbourne, but by training a geologist, with research experience in the field and the lab. After talking about physics itself we talked about its limits:
People ask ... what the limits of physics are. I don't know what the limits of physics are. I can tell you what the limits of my current experiments are, within a limited time horizon, but not really beyond that ... The questions that you can answer with physics are surprising if you don't have the scientific knowledge yourself, if that makes sense: you need to understand the field to have a sense for what the reach of the field is, and someone outside the field — you can't legislate it. Not just because it's an open enquiry, but because it's non-trivial: there's more things in heaven and earth than are dreamt of in my or your philosophy, and certainly in the philosophy of someone like you or me a hundred years ago. So you just have to run with it.We also covered the difficulty of interdisciplinary work, what the sciences and theology tell us about each other, a bit of 19th-century scientific history, the difference between scientific and cultural questions, ...
There were questions from the floor at the end of the interview, which for some reason have not made it onto the mp3 ... although my answers have. So that the answers might make more sense, I've done what I can to reconstruct the questions:
- at 28:22, the question was about divine action: what God's providence in natural (biological) history looks like physically, e.g. do I think God fiddles with DNA, or ...?
- at 29:58, a question about cosmology: what was happening before the Big Bang?
- at 31:06, a time-honoured question about the Second Law of Thermodynamics, and how it relates to the development of complexity in biology;
- at 33:21, are physicists mostly unbelievers?
- at 33:36, are metaphysical or religious motivations important in cosmology? in physics more generally? for me?
- at 35:31, are ideas about a “multiverse” well-grounded?
Monday, 22 August 2011
A fan of the US military writes in criticism of “support our troops” pieties:
The irony is that our soldiers are the last people who are likely to call themselves heroes and are apparently very uncomfortable with this kind of talk. The military understands itself as a group endeavor. As the West Point professor Elizabeth D. Samet recently noted, service members feel uneasy when strangers approach them to — as the well-meaning but oddly impersonal ritual goes — thank them for their service, thereby turning them into paradoxically anonymous celebrities. It was wrong to demonize our service members in Vietnam; to canonize them now is wrong as well. Both distortions make us forget that what they are are human beings...The change of tone in the coverage and discussion of Anzac Day, noticeable to anyone over a certain age, springs to mind as an Australian analogue, although the causes may be somewhat different.
An American radio host and author compares contemporary political debate to an auto-immune disease.
And my current nostalgia trip: Glycerine, the greatest hit of the band Bush. I have recently returned to an apartment complex where I was staying in late 1995, through 1996, and this song has been on my mind. Like many pop songs, it would not withstand too close an enquiry into the literal meaning of its lyrics, but as the distillation of a particular mood — masculine yearning, chastened by regret — it is superb. And in contrast to the posturing, braggarty tone of the songs in a male voice that followed it, it is unashamedly pretty. A female cover brings that out, although I do miss the surface roughness of the original:
I could have been easier on you,
I couldn't change though I wanted to.
Thursday, 18 August 2011
I'm quite impressed by this:
(1) This is the sort of long-distance thinking and investment that public institutions should sponsor, but the sponsorship that's foreseen here is modest and one-off: this money, together with some meetings to organise and incubate discussion among those interested, and amongst contenders for the funds. It seems as though they have got the level of public involvement right.
(2) They understand that one of the issues is to get past `“the giggle factor” associated with the subject'.
(3) The organisation, sociology, and ethics of the task is explicitly part of the agenda of study.
(4) They understand that we do not yet understand what the question is:
Then again, nobody is smart enough now to know what could come of the starship effort, Mr. Neyland pointed out. It would be naïve to think we even know the right questions to ask.
“If you had asked Einstein and Marconi in 1910 to define a worldwide communication system for the common man,” Mr. Neyland asked, “would he have come up with the iPhone?”
Tuesday, 20 July 2010
But just to keep me on my toes, here is his tribute to Fred Rogers, a mainstay of American children's television, of whom I was previously ignorant. It is hard to imagine someone with a more different sensibility.
The NYT's 2003 obituary for Fred Rogers offers more information.
Wednesday, 30 June 2010
Both experiments have presented preliminary results that hint at differences between matter and antimatter — specifically, kinds of differences that should not occur on our current understanding. And so there has been a certain amount of fuss.
Unlike the work mentioned in the previous post, which concerned mesons, the new results are from experiments on those most fascinating and frustrating of elementary particles, neutrinos. Complicating the interpretation is that there are anomalies in earlier MiniBooNE data which are still not understood.
If you're after a written version of the story, there is an article at PhysOrg.com.