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An Ungracious Nobel

Posted in The Universe and Stuff with tags , , , on October 25, 2020 by telescoper

Reinhard Genzel

You will no doubt recall the announcement a few weeks ago of the award of the 2020 Nobel Prize for Physics to Roger Penrose, Andrea Ghez and Reinhard Genzel.

Last week I saw an interview Professor Genzel to the German magazine Der Spiegel, which you can find here. I posted in on Facebook and was going to blog about it but I was busy and it slipped my mind. You can read the interview yourself and form your own opinion about it, but I found parts of it churlish and discourteous. You would think someone who had just won a Nobel prize would be a bit more gracious. Perhaps Genzel resents having to share it?

The first thing I found regrettable was the part about the work of the Event Horizon Telescope that I reported here last year:

Genzel: It was good that their image received a lot of attention. It is important to get people excited about research. And astronomy has a special role to play.

DER SPIEGEL: Are you trying to say that the image was good for attracting an audience, but wasn’t all that important from a scientific point of view?

Genzel: No, I wouldn’t say that. It is true, though, that such a beautiful, orange picture is enticing, even if it can’t be clearly interpreted. An open discussion is still ongoing among experts: Are we really sure of what we are looking at in this picture?

It is true that there are questions about how precisely to interpret the famous image, but did he really have to sound so dismissive? It seems to me that what follows  “No, I wouldn’t say that..” indicates that is precisely what he thinks.

I think of more importance though is what the interview reveals about his attitude to Andrea Ghez, with whom he shared half the prize. I’m not going to comment on the obvious falling out between the two. That kind of thing is regrettable but it does happen from time to time, and I don’t know enough about the background to attach any blame to either side. The question is, though, why would Genzel choose this moment to drag this all up? He seems to be going out of his way to imply that Andrea Ghez didn’t deserve her share of the prize.  Ypu would think someone who had just won a Nobel Prize would be a bit more gracious. And although he doesn’t say it explicitly there is more than a hint that he thinks Andrea Ghez only got her share because she is a woman.

Perhaps I’m reading too much into his words, but I know I’m not the only one to have been “disappointed” by these remarks. I’ve always supported the idea of the Physics Nobel Prize primarily on the grounds that it gets people talking about Physics, which this year’s announcement certainly has done. I just wish this particular interview had been more focussed on celebrating the science than on scoring points over his co-winner.

 

 

 

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R.I.P. James Randi (1928-2020)

Posted in LGBTQ+, The Universe and Stuff with tags , , , , on October 22, 2020 by telescoper

Yesterday I heard the sad news of the death, at the age of 92, of stage conjuror, humanist and famous debunker of charlatans, James Randi.  I guess quite a few of my readers won’t have heard of him, but he was a really interesting character. His real name was Randall James Hamilton Zwinge and he was born in Toronto. He was a professional magician (i.e. a conjuror) with the stage name “The Amazing Randi” who spent most of the last four decades debunking psychics and exposing fraudulent claims of the paranormal. Those of you out there old enough to remember the 1970s will recall the  “paranormalist”  Uri Geller being a household name for his numerous TV appearances bending spoons, stopping clocks and generally exhibiting supernatural powers. Randi exposed these as simple conjuring tricks, and got himself sued for his trouble.

There’s an interesting connection between the Uri Geller phenomenon and physics. In the 1970s, when Geller was at the height of his popularity, a physicist called John G. Taylor took great interest in him and the things that he appeared to be able to do. Professor of applied mathematics at King’s College, London, Taylor was (and remains) a very distinguished scientist and was the first to take the paranormal phenomena displayed by Geller seriously. When Uri Geller visited Britain in 1974, Taylor conducted scientific tests of Geller’s feats of metal bending using all the paraphernalia of modern science, including a Geiger counter. Taylor also experimented with some of the children and adults who claimed to manifest psychic abilities after seeing Uri Geller’s appearances on British television programs. Taylor’s interest in such phenomena was not only in its scientific validation, but also in investigation of the way in which such phenomena take place and the nature of the forces involved. He suggested the phenomena may be some low-frequency electromagnetic effect generated by human beings.

Through the 1970s Taylor was regarded as fully endorsing the paranormal metal bending of Uri Geller, but gradually has made more guarded statements; then in 1980 he largely retracted his support for Geller’s paranormal talents. In 1974 he wrote

The Geller effect—of metal-bending—is clearly not brought about by fraud. It is so exceptional it presents a crucial challenge to modern science and could even destroy the latter if no explanation became available.

Taylor then spent three years of careful investigation of such phenomena as psychokinesis, metal bending, and dowsing, but could not discover any reasonable scientific explanation or validation that satisfied him. He was particularly concerned to establish whether there is an electromagnetic basis for such phenomena. After failing to find this he did not believe that there was any other explanation that would suffice. Most of his experiments under laboratory conditions were negative; this left him in a skeptical position regarding the validity of claimed phenomena.

In contrast to the endorsement in his first book, Superminds, he published a paper expressing his doubts in a paper in Nature (November 2, 1978) titled “Can Electromagnetism Account for Extra-sensory Phenomena?” He followed this with his book Science and the Supernatural (1980) in which he expressed complete skepticism about every aspect of the paranormal. In his final chapter he stated:

We have searched for the supernatural and not found it. In the main, only poor experimentation [including his own], shoddy theory, and human gullibility have been encountered.

Taylor’s investigation of the Geller effect is interesting because it shows that physics doesn’t have all the answers all the time, particularly not when the phenomena in question involve people. Physics research proceeds by assuming that Nature is not playing tricks, and that what can be measured must represent some sort of truth. This faith can be easily exploited by a charlatan. James Randi always argued that scientists aren’t the right people to detect tricks performed by people: this is best left to tricksters. There’s no reason to believe that a theoretical physicist – no matter how brilliant – can spot the way a clever deception is carried out. The best person to see that is a magician, someone like James Randi. Set a thief to catch a thief, and all that…

I wrote a blog post about James Randi about a decade ago because it was not until then, when he had reached the age of 81 that he revealed to the public that he was gay. I feel a bit sad that took him so long to step out of the closet, but I’m sure he was glad he made the decision. From wikipedia I learn that he married his partner José Alvarez in 2013. I hope their time together was happy, and send my condolences to José  on his loss.

Rest in peace, James Randi (1928-2020).

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A Question of Phosphine

Posted in Astrohype, The Universe and Stuff with tags , , , on October 21, 2020 by telescoper

Remember all the excitement last month about the claimed detection of phlogiston phosphine in the atmosphere of Venus?

Well, a wet blanket appears to have been thrown over it by a new paper on the arXiv by Snellen et al. Here is the abstract:

The conclusions are very clear, but the paper hasn’t been refereed yet. Let’s see what the authors of the original work have to say. For myself, I think a proper (i.e. Bayesian) analysis of the data is called for…

I should also mention in this context another paper on the arXiv from a few days ago, which uses a null detection to place an upper limit on the phosphine abundance.

Note that one of the authors of this second paper is Jane Greaves, who was on the original discovery paper.

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A Test of the Cosmological Principle using Quasars

Posted in The Universe and Stuff with tags , , , , on October 8, 2020 by telescoper

I’m not getting much time these days to even think about cosmology but Subir Sarkar drew my attention to an intriguing paper by his team so I thought I’d share it here. Here is the abstract and author list:

I find this an intriguing result because I’ve often wondered about the dipole anisotropy of the cosmic microwave background might not be exclusively kinematic in origin and whether they might also be a primordial contribution. The dipole (180°) variation corresponds to a ΔT/T of order 10-3, which a hundred times larger than the variation on any other angular scale. This is what it looks like:

This is usually interpreted as being due to the motion of the observer through a frame in which the cosmic microwave background is completely isotropic. A simple calculation then gives the speed of this motion using ΔT/T ≈ v/c. This motion is assumed to be generated by gravitational interaction with local density fluctuations rather than being due to anything truly cosmological (i.e. of primordial origin).

The features in the cosmic microwave background temperature pattern on smaller angular scales (the quadrupole, octopole, etc…) , which have ΔT/T of order 10-5 are different in that they are dominated by primordial density fluctuations. There should be a primordial dipole at some level, but the fact that these other harmonic modes have such low amplitudes and the assumption that the primordial dipole should be of the same order, combined with the fact that the CMB dipole does indeed roughly line up with the dipole expected to be generated by local inhomogeneities, has led to the widespread belief that this intrinsic dipole is negligible. This analysis suggests that it might not be.

What the authors have done is study the anisotropy of a large sample of quasars (going out to redshifts of order three) finding the dipole to be larger than that of the CMB. Note however that the sample does not cover the whole sky because of a mask to remove regions wherein AGN are hard to observe:

As well as the mask there are other possible systematics that might be at play, which I am sure will be interrogated when the paper is peer-reviewed which, as far as I know, is not yet the case.

P.S. I might just quibble a little bit about the last sentence of the abstract. We know that the Universe violates the cosmological principle even in the standard model: with scale-invariant perturbations there is no scale at which the Universe is completely homogeneous. The question is really how much and in what way it is violated. We seem to be happy with 10-5 but not with 10-3…

Update: On 23rd October Subir will be giving a talk about this an participating in a debate. For more details, see here.

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Astronomy Look-alikes No. 101

Posted in Astronomy Lookalikes, Television, The Universe and Stuff with tags , , , , , on October 6, 2020 by telescoper

One winner of the 2020 Nobel Prize for Physics, Roger Penrose, is based in Oxford where he also plays Chief Superintendent Bright in the popular TV detective series Endeavour…

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The 2020 Nobel Prize for Physics

Posted in The Universe and Stuff with tags , , , on October 6, 2020 by telescoper

I don’t know about you but I was a bit surprised by this year’s announcement of the Physics Nobel Prize but that’s largely because it went to something cosmic last year and not because I disapprove in any way. Roger Penrose’s work in the 1960s on the black hole singularity theorems is rightly famous and the observational discovery of the supermassive black hole in the centre of the Milky Way is also more than worthy of recognition.

Congratulations to Roger Penrose, Reinhard Genzel and Andrea Ghez!

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New Publication at the Open Journal of Astrophysics!

Posted in OJAp Papers, Open Access, The Universe and Stuff with tags , , , , , , on October 2, 2020 by telescoper

Time to announce another new paper in the Open Journal of Astrophysics. The latest publication is by Amy Louca and Elena Sellentin, both of the Sterrewacht Leiden in the The Netherlands, and is entitled The impact of signal-to-noise, redshift, and angular range on the bias of weak lensing 2-point functions. This is another one for the Cosmology and Nongalactic Astrophysics folder.

Here is a screen grab of the overlay:

You can click on the image to make it larger should you wish to do so. You can find the arXiv version of the paper here.

We actually published this one a few days ago but there was a slight delay registering the metadata and also I was very busy, so this post is a little late. With this paper, we have published as many papers so far in 2020 as we did in 2019 so with several more in the pipeline this looks like being our busiest year

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17 Postdoctoral Positions in Astronomy all at the same Institution!

Posted in The Universe and Stuff with tags , , on October 1, 2020 by telescoper

I know how difficult it is for budding astronomers to find postdoctoral positions, so when I saw that there are no fewer than 17 such positions have become available at the same time at the same institution – Instituto de Astrofísica de Canarias (IAC) on Tenerife (Spain) – I couldn’t resist sharing. Postdoc positions are a bit like buses: you can wait ages for one,  and then seventeen come along all at the same time!

Below you will find links these positions, most of which have deadlines at the end of October (except one with has 15th October, and one at the end of November). Applicants must have their PhD by the time of the application deadline.

The Galaxias 2020 post is in Johan Knapen’s group, and can be to work on deep imaging from LSST.

You will see that 12 of the 17 positions are for 4-year ‘Advanced Fellow’ positions, several of which are in the area of formation and evolution of galaxies. Other areas are Solar physics, exoplanets, stellar and interstellar physics, Milky Way and Local Group, and cosmology & astroparticles.

Other galaxies-related positions are the HARMONI and the ‘Estallidos’ ones; EUROCC is for supercomputing support.

– 12 contratos PS-2020-040 Advanced -Fellows SO 2020 (deadline: 31/10/20)
https://www.iac.es/en/employment/doce-contratos-postdoctorales-advanced-fellows-so-2020twelve-postdoctoral-contracts-advanced-fellows-so-2020-ps

– 1 contrato PS-2020-041 Galaxias 2020 (deadline: 31/10/20)
https://www.iac.es/en/employment/un-contrato-postdoctoral-galaxias-2020one-postdoctoral-contract-galaxias-2020-ps-2020-041

– 1 contrato PS-2020-043 HARMONI 2020 (deadline: 31/10/20)
https://www.iac.es/en/employment/un-contrato-postdoctoral-harmoni-2020one-postdoctoral-contract-harmoni-2020-ps-2020-043

– 1 contrato PS-2020-044 Astroparticulas-MAGIC 2020 (deadline 30/11/20)
https://www.iac.es/en/employment/un-contrato-postdoctoral-astroparticulas-magicone-postdoctoral-contract-astroparticulas-magic-2020-ps-2020-044

– 1 contrato PS-2020-045) EUROCC 2020 (deadline: 31/10/20)
https://www.iac.es/en/employment/un-contrato-postdoctoral-eurocc-2020one-postdoctoral-contract-eurocc-2020-ps-2020-045

– 1 contrato PS-2020-049 Estallidos 2020 (deadline: 15/10/20)
https://www.iac.es/en/employment/un-contrato-postdoctoral-estallidos-2020one-postdoctoral-contract-estallidos-2020-ps-2020-049

 

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Memories of My First Paper

Posted in Biographical, The Universe and Stuff with tags , on September 28, 2020 by telescoper

The death of John Barrow reminded me of a post I did some years ago about my first ever publication, which was published on 15th September 1986 while I was doing my DPhil at Sussex under John’s supervision. I’m mentioning
it hereby way of a postscript to yesterday’s piece.

Here is the front page:

mnras_paper

This was before the days of arXiv so there isn’t a copy on the preprint server, but you can access the whole article here on NASA/ADS.

All right. I know it’s a shitty little paper. But you have to start somewhere!

I’m particularly sad that, looking back, it reads as if I meant to be very critical of the Kaiser (1984) paper that inspired it. I still think that was a brilliant paper because it was based on a very original idea that proved to be enormously influential. The only point I was really making was that a full calculation of the size of the effect Nick Kaiser had correctly identified was actually quite hard, and his simple approximation was of limited quantitative usefulness. The idea was most definitely right, however.

I was just a year into my PhD  DPhil when this paper came out, and it wasn’t actually on what was meant to be the subject of my thesis work (which was the cosmic microwave background), although the material was related.

This paper provides two excellent illustrations of what a good supervisor John was. I was a bit stuck with the project that John had assigned me and eventually admitted to him that I was having problems getting anywhere. I thought he’d assume I was useless and suggest that someone else should supervise me. But no. He said he realised it was a hard problem and sometimes it’s good to think about something else when you’re stuck. So he asked me to look at cluster clustering for a bit. I told him what I found and he said I should write this up as a paper, which I did. Most importantly however the trick I used in simplifying the calculations in this paper turned out to be applicable to the first problem, hotspots in the cosmic microwave background, which led a success in the project and to my second paper. We were both delighted that everything turned out well with that original project.

My original draft of this first paper had John Barrow’s name on it, but he removed his name from the draft (as well as making a huge number of improvements to the text). At the time I assumed that he took his name off because he didn’t want to be associated with such an insignificant paper, but I later realized he was just being generous. It was very good for me to have a sole-author paper very early on. I’ve taken that lesson to heart and have never insisted – unlike some supervisors – in putting my name on my students’ work.

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R.I.P. John D Barrow (1952-2020)

Posted in Biographical, The Universe and Stuff with tags on September 27, 2020 by telescoper

My heart is filled with sorrow as I find myself having to pass on some very sad news. I have just heard of the death, yesterday, at the age of 67, of esteemed physicist, mathematician, author and polymath John Barrow. With his passing, one of cosmology’s brightest lights has gone out.

John Barrow was my thesis supervisor. Words can’t express how much I owe him for his advice and encouragement not only during my graduate studies but also throughout the 35 years that have elapsed since I started my career, as a research student at Sussex University.

John had an extraordinary mind that combined immense mathematical gifts with an encyclopedic knowledge of all kinds of literature and a wonderful flair for writing. He wrote dozens of books and a theatre play as well as hundreds of scientific articles. He was a whirlwind of ideas who had an uncanny knack of finding clever ways to crack previously unsolved problems. That he was happy to share these ideas with his students is a credit to his intellectual generosity. He inspired dozens of researchers early in their careers and continued to inspire them when they became not so young.

On a personal level, John was rather reserved and, despite his being a talented and confident public speaker, I always felt he was a rather shy person. He was a committed Christian and a regular churchgoer though he didn’t talk much about his private religious beliefs in the Department.

It is also interesting that, despite writing a number of superb popular books, giving public lectures and being a regular guest on radio programmes he steadfastly refused to appear on television. He just didn’t want to become a TV celebrity, though I suspect that if he did he would have been rather good at it.

Although I didn’t see as much of him in recent years as I would have liked, John was a member of the RAS Club which gave me the opportunity to see and talk to him fairly frequently. I always found him a very agreeable dining companion. We usually discussed sport on such occasions rather than science, actually. John was a talented middle-distance runner in his younger days and he gave me a lot of advice about training, etc, when I started running marathons. We also shared an interest in football – at which he was rather good, having had a trial for Chelsea Juniors – and we played together quite a few times in Sussex days. I remember him as a quality midfielder with a terrific engine, though he was not a natural goalscorer.

John also had a very dry and sometimes lugubrious sense of humour. I remember sending him a congratulatory email in 2003 when I found out he had been made a Fellow of the Royal Society. He replied thanking me but pointing out his joy at having been elected was tempered by the fact that the first official communication he got from Carlton House was a rather substantial bill for the subscription and a form on which to enter details to be used in an obituary.

It was through the RAS Club that I first heard, about a year ago that John was suffering from cancer. For a time he responded well to treatment but a few weeks ago I heard that his condition had deteriorated to the extent that only palliative care was possible. That news came as a shock as he always seemed so healthy and ageless that one imagined him to be indestructible. Today’s news was not unexpected but still distressing. The end came more quickly than we imagined but at least he was at home among his loved ones when he passed away.

I send heartfelt condolences to Elisabeth and the rest of John’s family, and friends and colleagues at Cambridge and elsewhere.

UPDATE: An obituary of John, written by Michael Rown-Robinson, is now available online on the Guardian website.

Rest in peace, Professor John D Barrow FRS (1952-2020).

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