Archive for July, 2023

“First Light” Images from Euclid

Posted in Euclid, The Universe and Stuff with tags , , , , , on July 31, 2023 by telescoper

As I promised a couple of days ago, the “first light” images from the European Space Agency’s Euclid mission have now been released. You can find all the details here, but a summary is that these are “engineering” images, rather than part of the full survey to be undertaken by Euclid, and the commissioning of the instruments is not quite finished, but the telescope is now in focus and both instruments (the visual instrument, VIS, and the Near-Infrared Spectrometer & Photometer, NISP) are working well enough to show some preliminary results.

Anyway, here are the pictures released today, first from VIS:

Euclid early commissioning test images, showing an image by the VIS instrument (visible light). The full focal plane of VIS consisting of 36 detectors is shown on the left, and one detector in higher resolution on the right. Credits: © ESA/Euclid/Euclid Consortium/NASA, CC BY-SA 3.0 IGO

The next one is from NISP:

Euclid early commissioning test images, showing an image by the NISP instrument (near-infrared light). The full focal plane of NISP consisting of 16 detectors is shown on the left, and part of one detector in higher resolution on the right. Credits: © ESA/Euclid/Euclid Consortium/NASA, CC BY-SA 3.0 IGO

This final one, also from NISP, shows it working in grism mode, which allows the light from sources to be dispersed into a spectrum, enabling us to get much more information about the sources galaxies than a straightforward image would. The resulting images look a bit strange to the untrained eye – as the light from a point is spread out into a streak – but the result is wonderfully rich in information:

Euclid early commissioning test images, showing an image by the NISP instrument (near-infrared light), in its grism slitless spectroscopy mode. The full focal plane of NISP consists of 16 detectors, here a part of one detector is shown in full resolution. Credits: © ESA/Euclid/Euclid Consortium/NASA, CC BY-SA 3.0 IGO

For more information – and some higher-resolution images – see the official Euclid press release here.

For myself, I’d just say these images are absolutely amazing given that they were taken during the commissioning phase and the instruments aren’t fully tweaked yet. Over the next few weeks, there will be a performance verification phase which will tell us how good Euclid will be at meeting its science goals. But so far it’s all looking very good indeed. I’ve only ever seen simulations of what would come out and it’s very exciting to see what the real thing looks like!

Hats off to the brilliant instrumentation experts who not only designed and built the kit but who have been working so hard on the commissioning. They’ve done so much in the month that has passed since the launch!

P.S. You can find here a nice explainer of some of the instrumental artefacts you might have spotted in the images above.

From OJAp to AI

Posted in OJAp Papers with tags , on July 30, 2023 by telescoper

I was messing around with an AI “Art” generator and decided to use it to generate images to go with the latest four papers published at the Open Journal of Astrophysics, using the titles of these papers as prompts. The results are a mixture of strange and hilarious. I was only using the free version of the software which only allows 10 generations per day and there are lots of possible styles. I’m sure with more attempts one could get even more interesting outputs!

Anyway, if you click on each of the images below it should take you to an image of the overlay of the paper it is supposed to represent….

(This is a guest post by our Artificial Intelligence correspondent, A.I. Addio.)

Euclid has arrived…

Posted in Euclid, The Universe and Stuff with tags , , , on July 29, 2023 by telescoper

Here’s a little video update to accompany the news that, as of yesterday (28th July), the European Space Agency’s Euclid spacecraft has reached its orbit around L2, the second Lagrange Point of the Earth-Sun system:

More news is on the way. Commissioning of the instruments is now complete and the telescope is in focus. On Monday 31st July, ESA will release the first actual images from the Euclid telescope!

Stay tuned here.

Four New Publications at the Open Journal of Astrophysics

Posted in OJAp Papers, Open Access, The Universe and Stuff with tags , , , , , , , , , , , , , , , , on July 29, 2023 by telescoper

The rate of publication at the Open Journal of Astrophysics has now reached the point at which I think I’ll have to limit myself to weekly updates here rather than announcing every paper as it appears. We still announce individual papers on social media of course, meaning Mastodon, Facebook and the platform formerly known as Twitter…

This week we have published four papers which I now present to you here. These four take the count in Volume 6 (2023) up to 31 and the total published by OJAp up to 96. I speculated earlier this year that we might reach 100 before the end of 2023, now it looks certain we will reach the century mark as early as August! It is gratifying to see the range of papers published increasing, with all four of these in different categories.

In chronological order, the four papers published this week, with their overlays, are as follows. You can click on the images of the overlays to make them larger should you wish to do so.

First one up is “M-σ relations across cosmic time” by David Garofalo (1), Damian J. Christian (2), Chase Hames (1), Max North (3), Keegan Thottam (1) & Alisaie Eckelbarger (1). The author affiliations are: (1) Department of Physics, Kennesaw State University, USA; (2) Department of Physics and Astronomy, California State University, Northridge, USA; (3) Department of Information Systems, Kennesaw State University, USA. This is a discussion of the relationship between black hole mass and stellar velocity dispersion discovered in low redshift galaxies and its evolution with cosmic time. The paper was published on 25th July, is in the folder marked Astrophysics of Galaxies and can be found here.

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

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

The second paper to announce is “The fastest stars in the Galaxy” by Kareem El-Badry et al. (21 authors. This one is the fourth item in the folder marked Solar and Stellar Astrophysics and it reports the spectroscopic discovery of 6 new “runaway” stars, probably the surviving members of binary star systems in which one star exploded in a Type 1a supernova. The paper was published on 27th July 2023 and you can see the overlay here:

The accepted version of this paper can be found on the arXiv here.

The next paper is in the Earth and Planetary Astrophysics folder. It is in fact only the second paper we have published in that area. It is entitled “WHFast512: A symplectic N-body integrator for planetary systems optimized with AVX512 instructions” by Pejvak Javaheri & Hanno Rein (University of Toronto, Canada) and Daniel Tamayo (Harvey Mudd College, USA). This paper presents a fast direct N-body integrator for gravitational systems, and demonstrates it using a 40 Gyr integration of the Solar System.

Here is the overlay:

 

You can find the full text for this one on the arXiv here.

Last but by no means least, published yesterday (29th July), we have a paper that asks the question “Can Einstein (rings) surf Gravitational Waves?” by Leonardo Giani, Cullan Howlett and Tamara M. Davis of the University of Queensland, Australia. The primary classification for this one is Cosmology and Nongalactic Astrophysics and it discusses the possible effect(s) of gravitational waves on gravitational lensing observations.

 

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

Notes to Future Self

Posted in Biographical, The Universe and Stuff with tags , on July 28, 2023 by telescoper

Yesterday I was tidying up a bit and came across the old notebooks I used when I was a research student. As I suppose is the case with everyone else, there’s quite a lot in them that never went anywhere. If you can read the example above, about 3/4 of the way down the right-hand page I left a note saying “This is a pointless task”. I can’t remember if that referred to that particular integral or my research in general!

Some people who have seen this picture remarked on the size of my integral signs. That’s because I had to do quite a lot of integrals with complicated integrands, so I got into the habit of drawing big integral signs as a prelude to writing down what I assumed would be a horrible formula.

The way I worked in those days (1985-88) was to do a lot of rough scribblings on scrap paper. When I got to something I thought was promising I would write up a “neat” version in the notebook and throw away the workings. I know younger folks these days do most of their work on a screen but, as an old fogey, I still write a lot down on paper or on a blackboard. I didn’t have my own blackboard when I was a PhD student, but I did have plenty of notebooks – most of which I have kept. I think that I’ll always find an essential part of the mathematical thought process involves a pen or piece of chalk in my hand, moving around and guiding my brain.

Looking through these books I remember that I also wrote down ideas for follow-up projects. I managed to do very few of these, but some were done by other people elsewhere independently of me, so at least they were reasonable ideas!

No Second Troy, by W.B. Yeats

Posted in Poetry with tags , , on July 27, 2023 by telescoper

Why should I blame her that she filled my days
With misery, or that she would of late
Have taught to ignorant men most violent ways,
Or hurled the little streets upon the great,
Had they but courage equal to desire?
What could have made her peaceful with a mind
That nobleness made simple as a fire,
With beauty like a tightened bow, a kind
That is not natural in an age like this,
Being high and solitary and most stern?
Why, what could she have done, being what she is?
Was there another Troy for her to burn?

 

by William Butler Yeats (1865-1939)

R.I.P. Sinéad O’Connor (1966-2023)

Posted in Music, R.I.P. with tags , , on July 26, 2023 by telescoper

I just heard the truly awful news of the death at the age of 56 of Sinéad O’Connor. Words fail me, so here’s her classic Nothing Compares 2 U from 1990, when it was a worldwide hit.

There can’t be many pop videos done like this, entirely in close-up.

Incidentally I once saw Sinéad O’Connor in person, at the Zap Club in Brighton, when I literally bumped into her trying to get to the bar. When she turned around I was staggered to see such a beautiful face looking at me, although to be honest I did for a moment assume she was a boy. I was expecting an angry response to my clumsiness, but all I saw was an impish grin and those amazingly lovely eyes. That must have been in 1990 or earlier. Anyway, she was wearing the same leather jacket and cropped hair as in this picture, taken in 1988.

Back then, the time of the AIDS crisis, Sinéad O’Connor stood up for LGBTQ+ rights. She sang at Pride when it was far from fashionable to do so, and participated in the Red Hot and Blue album, which featured a wide range of artists doing covers of Cole Porter songs. I’ve always loved her satirical take on You So Something To Me, in which she is done up to resemble Veronica Lake:

Life had often been a struggle for Sinéad – she suffered from mental health problems and had to endure the loss of her son just 18 months ago – but she was a uniquely talented artist who enriched many lives. I just hope she knew how much she was loved by so many people.

R.I.P. Sinéad O’Connor (1966-2023).

R.I.P. Charles W. Misner (1932-2023)

Posted in R.I.P., Uncategorized with tags , , , on July 26, 2023 by telescoper
Charles Misner, pictured in 2016. (Picture credit: Maia Zewert)

Earlier this year I wrote a blog post pointing out that the classic textbook Gravitation by Misner, Thorne and Wheeler (above) is 50 years old this year. MTW (as it is usually known) was first published in 1973, and has has now been reprinted 24 times.

I was therefore saddened to learn that the eminent theoretical physicist Charles W. Misner, the first author of this famous tome, passed away a couple of days ago, on 24th July 2023, at the age of 91. A full obituary of Prof. Misner can be found here.

Rest in peace, Charles W. Misner (1932-2023)

The First Room-Temperature Superconductor?

Posted in The Universe and Stuff with tags , , , on July 25, 2023 by telescoper

This is outside my usual areas, but there’s a new paper on arXiv which, if verified, could be extremely important. It’s called The First Room-Temperature Ambient-Pressure Superconductor and it is written by three scientists based in Korea. High temperature superconductivity has been, er, a hot topic for some years. One must be cautious because (as far as I am aware) the article has not yet been refereed, but is this a breakthrough?

Here is the abstract:

It seems to me that 400K is a bit hot for a room, but the point is that the material behaves as a superconductor (i.e. zero resistivity) for T < Tc so cooler rooms would do! The current definition of “high temperature” is Tc > 77K which is much lower than the Tc = 400 K stated here.

Here’s part of a figure from the paper showing (right) the material LK-99 and its structure (left):

I’m not an expert, but it looks like the material involved is neither particularly expensive nor particularly complicated so it should be relatively easy to determine whether these results are reproducible.

Comments from experts are welcome!

Something more than Night…

Posted in Literature with tags on July 24, 2023 by telescoper

Yesterday (23rd July) was the birthday of the late great American crime novelist Raymond Chandler, who was born on that day in 1888. A reminder of this factoid appeared on one of my social media feeds last night, along with this memorable quote:

The streets were dark with something more than night.

I assumed this came from one of his novels, perhaps The Big Sleep or Farewell My Lovely, but it is actually from an essay which serves as an introduction to a collection of four short novels, Trouble Is My Business, Finger Man, Goldfish, and Red Wind when they were published in a single volume in 1950. Since this is now in the public domain, as indeed are all his novels and stories, I thought I’d share the essay here, as it is a good description of the rise of the “hard-boiled” style of American crime fiction, exemplified by Chandler himself, Dashiell Hammett and others, as it compares with the more “refined” murder mysteries of, say, Agatha Christie. It’s a very perceptive piece, enhanced by Chandlers sharp wit and tight prose.

–o–

Some literary antiquarian of a rather special type may one day think it worth while to run through the files of the pulp detective magazines which flourished during the late twenties and early thirties, and determine just how and when and by what steps the popular mystery story shed its refined good manners and went native. He will need sharp eyes and an open mind. Pulp paper never dreamed of posterity and most of it must be a dirty brown color by now. And it takes a very open mind indeed to look beyond the unnecessarily gaudy covers, trashy titles and barely acceptable advertisements and recognize the authentic power of a kind of writing that, even at its most mannered and artificial, made most of the fiction of the time taste like a cup of lukewarm consommé at a spinsterish tearoom.

I don’t think this power was entirely a matter of violence, although far too many people got killed in these stories and their passing was celebrated with a rather too loving attention to detail. It certainly was not a matter of fine writing, since any attempt at that would have been ruthlessly blue-penciled by the editorial staff. Nor was it because of any great originality of plot or character. Most of the plots were rather ordinary and most of the characters rather primitive types of people. Possibly it was the smell of fear which these stories managed to generate. Their characters lived in a world gone wrong, a world in which, long before the atom bomb, civilization had created the machinery for its own destruction, and was learning to use it with all the moronic delight of a gangster trying out his first machine gun. The law was something to be manipulated for profit and power. The streets were dark with something more than night. The mystery story grew hard and cynical about motive and character, but it was not cynical about the effects it tried to produce nor about its technique of producing them. A few unusual critics recognized this at the time, which was all one had any right to expect. The average critic never recognizes an achievement when it happens. He explains it after it has become respectable.

The emotional basis of the standard detective story was and had always been that murder will out and justice will be done. Its technical basis was the relative insignificance of everything except the final denouement. What led up to that was more or less passagework. The denouement would justify everything. The technical basis of the Black Mask type of story on the other hand was that the scene outranked the plot, in the sense that a good plot was one which made good scenes. The ideal mystery was one you would read if the end was missing. We who tried to write it had the same point of view as the film makers. When I first went to work in Hollywood a very intelligent producer told me that you couldn’t make a successful motion picture from a mystery story, because the whole point was a disclosure that took a few seconds of screen time while the audience was reaching for its hat. He was wrong, but only because he was thinking of the wrong kind of mystery.

As to the emotional basis of the hard-boiled story, obviously it does not believe that murder will out and justice will be done—unless some very determined individual makes it his business to see that justice is done. The stories were about the men who made that happen. They were apt to be hard men, and what they did, whether they were called police officers, private detectives or newspaper men, was hard, dangerous work. It was work they could always get. There was plenty of it lying around. There still is. Undoubtedly the stories about them had a fantastic element. Such things happened, but not so rapidly, nor to so close-knit a group of people, nor within so narrow a frame of logic. This was inevitable because the demand was for constant action; if you stopped to think you were lost. When in doubt have a man come through a door with a gun in his hand. This could get to be pretty silly, but somehow it didn’t seem to matter. A writer who is afraid to overreach himself is as useless as a general who is afraid to be wrong.

As I look back on my stories it would be absurd if I did not wish they had been better. But if they had been much better they would not have been published. If the formula had been a little less rigid, more of the writing of that time might have survived. Some of us tried pretty hard to break out of the formula, but we usually got caught and sent back. To exceed the limits of a formula without destroying it is the dream of every magazine writer who is not a hopeless hack. There are things in my stories which I might like to change or leave out altogether. To do this may look simple, but if you try, you find you cannot do it at all. You will only destroy what is good without having any noticeable effect on what is bad. You cannot recapture the mood, the state of innocence, much less the animal gusto you had when you had very little else. Everything a writer learns about the art or craft of fiction takes just a little away from his need or desire to write at all. In the end he knows all the tricks and has nothing to say.

As for the literary quality of these exhibits, I am entitled to assume from the imprint of a distinguished publisher that I need not be sickeningly humble. As a writer I have never been able to take myself with that enormous earnestness which is one of the trying characteristics of the craft. And I have been fortunate to escape what has been called “that form of snobbery which can accept the Literature of Entertainment in the Past, but only the Literature of Enlightenment in the Present.” Between the one-syllable humors of the comic strip and the anemic subtleties of the litterateurs there is a wide stretch of country, in which the mystery story may or may not be an important landmark. There are those who hate it in all its forms. There are those who like it when it is about nice people (“that charming Mrs. Jones, whoever would have thought she would cut off her husband’s head with a meat saw? Such a handsome man, too!”). There are those who think violence and sadism interchangeable terms, and those who regard detective fiction as subliterary on no better grounds than that it does not habitually get itself jammed up with subordinate clauses, tricky punctuation and hypothetical subjunctives. There are those who read it only when they are tired or sick, and, from the number of mystery novels they consume, they must be tired and sick most of the time. There are the aficionados of deduction and the aficionados of sex who can’t get it into their hot little heads that the fictional detective is a catalyst, not a Casanova. The former demand a ground plan of Greythorpe Manor, showing the study, the gun room, the main hall and staircase and the passage to that grim little room where the butler polishes the Georgian silver, thin-lipped and silent, hearing the murmur of doom. The latter think the shortest distance between two points is from a blonde to a bed.

No writer can please them all, no writer should try. The stories in this book certainly had no thought of being able to please anyone ten or fifteen years after they were written. The mystery story is a kind of writing that need not dwell in the shadow of the past and owes little if any allegiance to the cult of the classics. It is a good deal more than unlikely that any writer now living will produce a better historical novel than Henry Esmond, a better tale of children than The Golden Age, a sharper social vignette than Madame Bovary, a more graceful and elegant evocation than The Spoils of Poynton, a wider and richer canvas than War and Peace or The Brothers Karamazov. But to devise a more plausible mystery than The Hound of the Baskervilles or The Purloined Letter should not be too difficult. Nowadays it would be rather more difficult not to. There are no “classics” of crime and detection. Not one. Within its frame of reference, which is the only way it should be judged, a classic is a piece of writing which exhausts the possibilities of its form and can hardly be surpassed. No story or novel of mystery has done that yet. Few have come close. Which is one of the principal reasons why otherwise reasonable people continue to assault the citadel.