DIRAC Research Image Competition – The Winning Entries!

Posted in Art, The Universe and Stuff with tags , , , , , on November 9, 2022 by telescoper

DIRAC is a high-performance computing facility designed to serve the research community supported in the UK by the Science and Technology Facilities Council (STFC). Recently DIRAC ran a competition to select the best images produced using results obtained by this facility, and I was honoured to be asked to be one of the judges. Entries were divided into two Themes: Theme 1 (Particle and Nuclear Physics) and Theme 2 (Astronomy, Cosmology and Solar & Planetary Science) and scores were allocated by the judges based on visual impact and scientific interest. There were 41 entries altogether, all of a very high standard.

So, without further ado, I shall now show you the winning entries!

The winning image in Theme 1 was submitted by Ed Bennett and Biagio Lucini of Swansea University and called Let it (Wilson) flow. The description supplied by the creators reads:

A space-time slice of the topological charge density distribution of a 128 times 643 lattice field configuration (with periodic boundaries) from an ensemble of the SU(2) gauge theory with two flavours of Dirac fermion in the adjoint representation (also known as Minimal Walking Technicolor). Moving along the time direction from left to right, successive time-slices are also iterated using the gradient flow of the Wilson action, which removes the ultraviolet noise that would otherwise prevent computation of the configuration’s topological charge. This noise is clearly visible on the left, with the actual instantons (orange) and anti-instantons (blue) becoming visible at longer flow times to the right.

Here is the winning image for Theme 1:

Theme 1 winner: Let it (Wilson) flow by Ed Bennett and Biagio Lucini.

The winning entry of Theme 2 is entitled Immediate origin of the Moon as a post-impact satellite and was submitted by Jacob Kegerreis of Durham University who supplied the following description:

The Moon is thought to have formed following a giant impact, but the details are still hotly debated. New high-resolution simulations, like the one shown here, reveal that a Moon-like satellite can be immediately placed into a wide orbit around the Earth, in contrast with the traditional idea of later accretion from a debris disk. This opens up new possibilities for the Moon’s initial orbit and interior, which could help to solve mysteries like its tilted orbit, thin crust, and Earth-like isotopes. The 3D smoothed particle hydrodynamics (SPH) simulations were run using the SWIFT code on the DiRAC COSMA8 system with over 100 times higher resolution than the current standard. The SPH data from this mid-impact snapshot are rendered using Houdini and Redshift, with the colour, opacity, and emission controlled by the particle material, density, and internal energy.

Here is the winning image of Theme 2:

Theme 2 Winner: Immediate origin of the Moon as a post-impact satellite by Jacob Kegerreis

Congratulations to the winners!

It was a lot of fun being one of the judges for this competition and I learnt a lot about the science from the clever way in which many of the entries displayed their results. The field was very strong, and many more images were worthy of recognition, but we were only allowed to pick one winner from each Theme. I am however given to understand that it is planned to include the best of the rest alongside the winners in a 2023 calendar which will be distributed to the DIRAC user community.

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Playfair Again

Posted in Crosswords with tags , , , , on November 8, 2022 by telescoper

It’s been a while since I’ve blogged about my passion for crosswords, but this Sunday’s Azed puzzle in the Observer was in one of my favourite forms so I thought I’d mention it briefly here.

Azed is the pseudonym used by Jonathan Crowther who has been setting the Observer crossword since 1972; this week’s was number 1967. His  puzzles are usually standard cryptic crosswords which, though quite difficult as such things go, are nevertheless set in a fairly straightforward style. Every now and again, however,  he puts together a different type of puzzle that makes a different set of demands on the solver.  To be honest, I don’t always like these “funny” ones, as they sometimes seem to me to be contrived and inelegant, but this last one was a type I really like as it combines the normal cryptic crossword style with another interest of mine, namely codes and codebreaking.

The interesting aspect of this particular puzzle, which is laid out on a normal crossword grid, is that it involves a type of code called a Playfair cipher. In fact, this particular scheme was invented by the scientist Charles Wheatstone whom most physicists will have heard of through “Wheatstone Bridge“. It was, however, subsequently popularized by Lord Playfair, whose name stuck rather than its real inventor’s. Stigler’s Law of Eponymy strikes again!

The Playfair scheme is built around the choice of a code word, which must have the special property that no letter occurs twice within it.  Other than that, and the fact that the more letters in the codeword the better the code, there aren’t any real constraints on the choice. The particular example used by Azed to illustrate how it works is ORANGESTICK.

The codeword is used to construct a Playfair square which is a 5×5 arrangement of letters involving the codeword first and then afterwards the rest of the alphabet not used in the codeword,  in alphabetical order. Obviously, there are 26 letters altogether and the square only holds 25 characters,  so we need to ditch one: the usual choice is to make I stand for both I and J, doing double duty, which rarely causes ambiguity in the deciphering process. The Playfair square formed from ORANGESTICK is thus

This square is then used as the basis of a literal digraph substitution cipher, as follows. To encode a word it must first be split into pairs of letters e.g. CR IT IC AL. Each pair is then seen as forming the diagonally opposite corners of a rectangle within the word square, the other two corner letters being the encoded form. Thus, in the example shown, CR gives SG (not GS, which RC would give).

Where a pair of letters appears in the same row or column in the word square, its encoded form is produced from the letters immediately to the right of or below each respectively. For the last letters in a row or column the first letters in the same row or column become the encoded forms. Thus IC is encoded as CE. When all the pairs are encoded, the word is joined up again, thus CRITICAL is encoded as SGCICEOP.

Obviously, to decipher encrypted text into plain one simply inverts the process as it is completely reversible.

The advantage of this over simpler methods of encipherment is that a given letter in the plain text is not always rendered as the same letter in the encrypted form: that depends on what other letter is next to it in the digraph. That means it isn’t cracked so easily using letter frequencies, as simple subsitution ciphers are.

Now, what does this have to do with a crossword? Well, in a Playfair puzzle like the one I’m talking about a certain number of answers – in the case of the latest Azed puzzle, eight – have to be encrypted before they will fit in the diagram. These “special” clues, however, are to the unencrypted form of the answer words. The codeword is not given, but must be deduced.

What one has to do, therefore, is to solve the clues for the unencrypted words, then solve all the other clues that intersect with them on the grid. Given a sufficient number of digraphs in both plain text and encrypted form one can infer the codeword and hence encrypt the remaining (unchecked) letters for the special answers.

It probably sounds very convoluted, but in this puzzle it isn’t so bad because the “special” clues are relatively straightforward which generates enough “cribs” in the form of letter-pairs in both plain and encrypted form. There aren’t enough pairs to deduce the codeword exactly – as not every letter in the codeword appears among the digraphs – but it helps knowing that it is an actual word rather than a jumble of letters. That, together with the rules for encryption using the  Playfair square, gives enough information to infer the codeword; the digraph PA which encrypts to AE is particularly useful in this case. In this case the codeword has 14 letters. I won’t tell you what it is because the competition is not yet closed!

What has to be done then is to use the codeword to complete the unchecked letters in the specials in their encrypted form. That bit is relatively straightforward but for the competition one also has to supply a “normal” cryptic clue for 9 down. That’s always the bit I find hardest!

 

 

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Neutrinos from NGC 1068

Posted in The Universe and Stuff with tags , , , , , on November 7, 2022 by telescoper

I’m a bit late onto this as I was rather busy last week, but I couldn’t resist passing on the news that the IceCube Neutrino Observatory has detected high-energy neutrinos (Tev) from the active galaxy NGC1068 (also known as Messier 77). The result is published in Science whence I stole this figure showing the concentration neutrinos correlated with the position of NGC1068, along with a couple of other sources.

The hotspot associated with NGC 1068 is the most intense feature observed on the whole sky. I won’t write any more because there are two videos about this discovery, the first a quick summary for general viewers:

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And the second is the full hour-long presentation as given last week.

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The Week(s) Ahead

Posted in Biographical, Education, Irish Language with tags , , on November 6, 2022 by telescoper

So here we are then. The study break is over. Tomorrow we resume teaching. Six weeks of the semester gone. Another six to go. I didn’t do half the things I meant to do last week but at least I’m not behind with teaching things. I should be able to cover everything I need to cover in the second half without having to speed up too much. That’s the hope anyway.

Over the weekend I’ve been thinking a bit about my social media strategy, if you can call it that. It seems Elon Musk has realized that Twitter isn’t worth a fraction of what he paid for it, and is worth even less now that advertisers are fleeing, so has decided to recoup at least some of his losses by giving priority to anyone who wants to pay $8 a month so they can broadcast whatever they like withouyt moderation. The famous “blue tick” will no longer even mean a verified user, just someone willing to pay to shout at everyone else. Musk is also in the process of sacking about half his workforce.

I’m not going to pay anything to the Chief Twit and don’t like the way Twitter is going anyway so I’ve decided that I will indeed move to Mastodon, which I quite like, and where you can find me here. I don’t have a huge Twitter following so migrating to Mastodon is no big deal for me. I see many thousands I know on Twitter and many more I don’t are doing likewise.

Posts from this blog are automatically sent to Twitter and I won’t stop doing that, but I won’t be logging on there much except from time to time to block anyone I see who has a blue tick on their profile…

Anyway, in other news, the forthcoming week also sees me resume my feeble attempts to learn the Irish language, so it’s possible I may be boring you all with updates over the next few weeks and months. You have been warned.

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Nocturne in Black and Gold

Posted in Art, Biographical with tags , , on November 5, 2022 by telescoper

`Only Connect’ – the epigraph of the novel Howard’s End by E.M. Forster – was a favourite phrase of one of my English teachers at school, and he invoked it whenever he set us one of his creative writing challenges. We were given two apparently disconnected things (usually news items), asked to think of a possible connection between them and write an story joining them together. From time to time when stuck for a topic for a blog post I’ve resorted to playing the same game.

In that vein: (a) I noticed a story last week about a painting by Piet Mondrian which has been hanging upside down for 75 years and (b) today is November 5th, Bonfire Night in the United Kingdom. The connection between these two things that sprang to my mind is this painting, Nocturne in Black and Gold – The Falling Rocket by James McNeill Whistler.

James Abbott McNeill Whistler, Nocturne in Black and Gold – the Falling Rocket, c1875, oil on panel, 60.3 × 46.7 cm (Detroit Institute of Arts)

This, the last in his wonderful series of paintings of night-time scenes, first displayed in 1877, is set in the Cremorne Gardens, which was a park in Chelsea, though in a manner typical of Whistler’s work of this period it is more a response to the location than a representation of it. The sombre colours – mainly green and blue, except for the grey smoke of the falling rocket and the gold flames and flashes of fireworks – are layered in such a way as to blur the situational context of the composition so that it’s no longer a purely figurative work. It’s certainly an enigmatic painting, but I think the arrangement of colours and textures is very well balanced as well as intriguing. It is historically important too, because it represents one of the first stirrings of modernism in art in England.

The compositional ambiguity is deliberate. The ghostly figures in the foreground are almost transparent. Are they even people? When asked this question himself, Whistler replied “They are just what you like”. Whistler is encouraging viewers of his work to construe their own meaning in, and interpretation of, what he put on the canvas. As an astrophysicist, the filamentary pattern of sparks reminds me of chains of distant galaxies. What does it remind you of?

Nocturne in Black and Gold is also famous for having been at the centre of a libel case. The influential art critic John Ruskin hated it and accused Whistler of “flinging a pot of paint in the public’s face”. Whistler sued for damages (though he couldn’t really afford to). He won the case against Ruskin, but the outcome was financially disastrous for him because he was awarded only one farthing in damages.

Anyway, the connection with the Mondrian story is that Whistler’s case was done no favours when this painting was brought into the courtroom during the Whistler v Ruskin case, as it was was presented for viewing upside down…

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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 November 4, 2022 by telescoper

It’s time once again for me to announce new paper at the Open Journal of Astrophysics. The new paper, published last week, is the 15th paper in Volume 5 (2022) and the 63rd in all. The latest publication is entitled “Two-photon amplitude interferometry for precision astrometry” and the authors are Paul Stankus, Andrei Nomerotski and Anže Slosar of Brookhaven National Laboratory (USA) and Stephen Vintskevich (Moscow Institute of Physics & Technology, Russia).

The paper presents a new method for doing interferometry with quantum-mechanically entangled photons and is thus is in the folder marked Instrumentation and Methods for Astrophysics. I don’t know much about this area – and there are many whose baseline opinion is that interferometry is a bit of a fringe topic that is rather complex perhaps needs more visibility in the current phase of its development  (geddit?) – but the physics looks fascinating to me. Amplitude interferometry should be contrasted with the intensity interferometry method of Hanbury Brown and Twiss which I remember learning about as an undergraduate.

Anyway, here is a screen grab of the overlay which includes the  abstract:

You can click on the image to make it larger should you wish to do so. The full image used in the overlay is this:

 

You can find the officially accepted version of the paper on the arXiv here.

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Is Astronomy the worst for Bullying and Harassment?

Posted in Harassment Bullying etc on November 3, 2022 by telescoper

I don’t mind admitting that I’m deeply depressed about all these stories of bullying and sexual harassment in Astronomy that have surfaced recently, and I’m sure there are many more that haven’t yet come to light. I’ve experienced some toxic behaviour in my time but nothing on the scale of what has emerged recently.

I wonder whether all this means that Astronomy is worse than other areas of academia or whether everywhere else is just as bad?

I put up a totally unscientific Twitter poll to see what my readers think. Please feel free to let me know your opinion:

https://twitter.com/telescoper/status/1588187399968153602

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Guest Post: The Bullying of Hannelore

Posted in Harassment Bullying etc on November 2, 2022 by telescoper

I am publishing this guest post from someone who works in Astronomy in a UK University. The author is anonymous (though I know who it is), the Department is not identified (though I know what it is) and all the names have been changed (for the reason that there is an ongoing legal case). Despite these restrictions, in the wake of the Tim de Zeeuw scandal, and others, I think these stories should be told.

The Bullying of Hannelore

I am an Astronomy Professor at a UK University. In June last year, I witnessed acts of bullying by my Head of Department against a junior administrative assistant on a fixed-term contract.

The administrative assistant — her name is Hannelore — was assigned to help me with the Examinations, in the time of COVID.  She was in a visibly wretched condition, weeping uncontrollably on zoom calls. I am sure Hannelore hated appearing in such a dejected and tearful state on zoom with someone she barely knew. She was a proud woman once, but it had all gone. 

She told me a harrowing story of sustained bullying by my Head of Department, culminating in an (illegal) dismissal notice from my University at the end of the academic year.

By the end of the Examinations, Hannelore was not sleeping. I remember going to bed after zooming one evening, and wondering what to do, who to contact, whether Hannelore would be alive the next day. I remember being relieved on checking email the next morning that there were messages from her through the night. She may not have slept, but at least Hannelore was still alive. 

What to do? Till then, I had been very friendly with my Head of Department, a (superficially) genial and charming man. We had written research papers together. By contrast, I hardly knew Hannelore. 

My University regularly pumps out tweets about breaking the silence around bullying and harassment. It has compulsory ‘active by-standing’ online courses for us all to attend. My University has ‘Dignity at Work’ representatives and ‘Well-being Advocates’ in every department. It has multiple Equality, Diversity & Inclusion committees to protect, amongst other things, the interests of women. It trumpets its ‘people strategy’ and ‘people action plan’. 

But, when I told others about the bullying of Hannelore, they were not interested. The Departmental ‘Well-being Advocate’ thought it was someone else’s problem. The Chair of the Departmental EDI Committee declined to intervene and repeatedly acted to protect the abuser. No-one wanted to believe that bullying on this scale was actually taking place, right under their noses, in my University.

So, I blew the whistle. I covertly recorded what was going on and made a witness statement to my University. By now, news of this distressing scandal had begun to reach the top. Senior managers were taking the decisions.

My University was aghast at what had happened.

Not at the bullying. At the covert recording.

And then my genial and charming Head of Department wielded his knife. I had always known that there was a streak of cunning and malice beneath the jokey bluster. My Head of Department said that it was all the other way round.  I had been harassing him. I had been deliberately causing stress and anxiety to Hannelore, so as to trap him and smear him as a bully.

At first, I thought this was some kind of sick joke. Surely no-one would believe such a far-fetched and improbable story. It was like Boris Johnson saying he was the victim and complaining that other people were bullying him by going on and on about lockdown parties.

I was wrong.  My University thought the allegations against me were so serious that they warranted an immediate investigation. It has an excellent, detailed and well-constructed grievance policy, which it proudly publishes on the web. The first step is that the accuser produces some evidence in support of any allegation. But, senior managers decided that my Head of Department’s allegations were too grave to warrant asking for any evidence. There was no need to be hampered by a well-constructed grievance policy. An investigation into my activities by an external and highly-paid barrister was commissioned to probe the extent of my wrong-doing.

My University’s investigation into me continues to this day, 15 months later. I have been forced to hire lawyers to defend myself (at my expense).

Hannelore did not kill herself. Some inner core of doggedness somehow pulled her through the darkness. The bullying has abated, though not stopped. Her insecure job was reluctantly returned to her. Hannelore was withdrawn and almost catatonic for many months afterwards. She still cannot talk easily about what happened to her. She is too frightened to complain formally to my University. She has been receiving counselling (at her expense).

The genial and charming Head of Department continues to hold sway with the top-level managers who run my University. He still enjoys exercising power over people, especially ones he dislikes. 

And I … I have learnt some very ugly things about my University. Things I would rather not have discovered. 

I have learnt that the current power and methods of my University’s management directly contradict the values my University purports to have. They are abusive of basic trust, integrity and decency. I have learnt that many of my departmental colleagues are ready to look the other way, if it involves challenging a powerful man who controls promotion or resources.

I have learnt that my University prefers sloganizing to action, prefers tweeting about ‘people strategies’ to safeguarding.  I have learnt what it is like to be a female member of staff on an insecure contract. As a male Professor with a good salary and tenure, I had the resources to hire lawyers to defend myself against my University. The Hannelores stand no chance.

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Astronomical Apocalypse Look-alike

Posted in Astronomy Lookalikes, Film, The Universe and Stuff with tags , , on November 1, 2022 by telescoper

I know it’s a bit late for Hallowe’en but have you noticed the similarity between the physical manifestation of the apocalyptic Sumerian deity Gozer as seen in the film Ghostbusters (left) and the pattern of dark coronal holes recently observed by NASA in the Sun’s atmosphere (right)? I wonder if, by any chance, they might be related?

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Hallowe’en in the Dark once more

Posted in Biographical, Film, Music with tags , , on October 31, 2022 by telescoper

So we have arrived at October 31st, Hallowe’en or, in pagan terms, Samhain. This, a cross-quarter day – roughly halfway between the Autumnal Equinox and the Winter Solstice – represents the start of winter (“the dark half of the year“) in the Celtic calendar. As it turns out I didn’t get any trick-or-treaters this evening. I think the torrential rain put the dampeners on any such adventures, and I could scarcely hear the fireworks for the sound of the rain stotting down on my roof.

Despite my own reservations about Hallowe’en, I’ve decided to resurrect the following little video which seems to be appropriate for the occasion. It’s made of bits of old horror B-movies but the music – by Bobby “Boris” Pickett and the Crypt-kickers is actually the second 7″ single I ever bought, way back in 1973…

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