Archive for Euclid

The MacGuffin of Euclid

Posted in Film, Literature, The Universe and Stuff with tags , , , , , on June 9, 2023 by telescoper

With the launch of the Euclid spacecraft due next month, and the last Euclid Consortium meeting before the launch coming up in just over a week, I thought I’d share another one of the nice little taster videos prepared by the European Space Agency:

The Euclid Mission has long been “sold” as a mission to probe the nature of Dark Energy in much the same way that the Large Hardon Collider was often portrayed as an experiment designed to find the Higgs boson. But as this video makes clear, testing theories of dark energy is just one of the tasks Euclid will undertake, and it may well be the case that in years to come the mission is remembered for something other than dark energy. On the other hand, big science like this needs big money, and making the specific case for a single big ticket item is an easier way to persuade funding agencies to cough up the dosh than for a general “let’s do a lot of things we’re sure we’ll fin something” approach. These thoughts triggered a memory of an old post of mine about Alfred Hitchcock so, with apologies for repeating something I have blogged about before, here’s an updated version.

Unpick the plot of any thriller or suspense movie and the chances are that somewhere within it you will find lurking at least one MacGuffin. This might be a tangible thing, such the eponymous sculpture of a Falcon in the archetypal noir classic The Maltese Falcon or it may be rather nebulous, like the “top secret plans” in Hitchcock’s The Thirty Nine Steps. Its true character may be never fully revealed, such as in the case of the glowing contents of the briefcase in Pulp Fiction , which is a classic example of the “undisclosed object” type of MacGuffin, or it may be scarily obvious, like a doomsday machine or some other “Big Dumb Object” you might find in a science fiction thriller. It may even not be a real thing at all. It could be an event or an idea or even something that doesn’t exist in any real sense at all, such the fictitious decoy character George Kaplan in North by Northwest. In fact North by North West is an example of a movie with more than one MacGuffin. Its convoluted plot involves espionage and the smuggling of what is only cursorily described as “government secrets”. These are the main MacGuffin; George Kaplan is a sort of sub-MacGuffin. But although this is behind the whole story, it is the emerging romance, accidental betrayal and frantic rescue involving the lead characters played by Cary Grant and Eve Marie Saint that really engages the characters and the audience as the film gathers pace. The MacGuffin is a trigger, but it soon fades into the background as other factors take over.

Whatever it is real or is not, the MacGuffin is the thing responsible for kick-starting the plot. It makes the characters embark upon the course of action they take as the tale begins to unfold. This plot device was particularly beloved by Alfred Hitchcock (who was responsible for introducing the word to the film industry). Hitchcock was however always at pains to ensure that the MacGuffin never played as an important a role in the mind of the audience as it did for the protagonists. As the plot twists and turns – as it usually does in such films – and its own momentum carries the story forward, the importance of the MacGuffin tends to fade, and by the end we have usually often forgotten all about it. Hitchcock’s movies rarely bother to explain their MacGuffin(s) in much detail and they often confuse the issue even further by mixing genuine MacGuffins with mere red herrings.

Here is the man himself explaining the concept at the beginning of this clip. (The rest of the interview is also enjoyable, convering such diverse topics as laxatives, ravens and nudity..)

There’s nothing particular new about the idea of a MacGuffin. I suppose the ultimate example is the Holy Grail in the tales of King Arthur and the Knights of the Round Table and, much more recently, the Da Vinci Code. The original Grail itself is basically a peg on which to hang a series of otherwise disconnected stories. It is barely mentioned once each individual story has started and, of course, is never found.

Physicists are fond of describing things as “The Holy Grail” of their subject, such as the Higgs Boson or gravitational waves. This always seemed to me to be an unfortunate description, as the Grail quest consumed a huge amount of resources in a predictably fruitless hunt for something whose significance could be seen to be dubious at the outset. The MacGuffin Effect nevertheless continues to reveal itself in science, although in different forms to those found in Hollywood.

The Large Hadron Collider (LHC), switched on to the accompaniment of great fanfares a few years ago, provides a nice example of how the MacGuffin actually works pretty much backwards in the world of Big Science. To the public, the LHC was built to detect the Higgs Boson, a hypothetical beastie introduced to account for the masses of other particles. If it exists the high-energy collisions engineered by LHC should (and did) reveal its presence. The Higgs Boson is thus the LHC’s own MacGuffin. Or at least it would be if it were really the reason why LHC has been built. In fact there are dozens of experiments at CERN and many of them have very different motivations from the quest for the Higgs, such as evidence for supersymmetry.

Particle physicists are not daft, however, and they realized that the public and, perhaps more importantly, government funding agencies need to have a really big hook to hang such a big bag of money on. Hence the emergence of the Higgs as a sort of master MacGuffin, concocted specifically for public consumption, which is much more effective politically than the plethora of mini-MacGuffins which, to be honest, would be a fairer description of the real state of affairs.

While particle physicists might pretend to be doing cosmology, we astrophysicists have to contend with MacGuffins of our own. One of the most important discoveries we have made about the Universe in the last decade is that its expansion seems to be accelerating. Since gravity usually tugs on things and makes them slow down, the only explanation that we’ve thought of for this perverse situation is that there is something out there in empty space that pushes rather than pulls. This has various possible names, but Dark Energy is probably the most popular, adding an appropriately noirish edge to this particular MacGuffin. It has even taken over in prominence from its much older relative, Dark Matter, although that one is still very much around.

We have very little idea what Dark Energy is, where it comes from, or how it relates to other forms of energy with which we are more familiar, so observational astronomers have jumped in with various grandiose strategies to find out more about it. This has spawned a booming industry in surveys of the distant Universe, all aimed ostensibly at unravelling the mystery of the Dark Energy. It seems that to get any funding at all for cosmology these days you have to sprinkle the phrase “Dark Energy” liberally throughout your grant applications.

The old-fashioned “observational” way of doing astronomy – by looking at things hard enough and long enough until something exciting appears (which it does with surprising regularity) – has been replaced by a more “experimental” approach, more like that of the LHC. We can no longer do deep surveys of galaxies to find out what’s out there. We have to do it “to constrain models of Dark Energy”. This is just one example of the (not entirely positive) influence that particle physics has had on astronomy in recent times.

Whatever the motivation for doing these projects now, they will undoubtedly lead to many new discoveries, so I’m not for one minute arguing that the case for, e.g, the Euclid mission is misguided. I’m just saying that in my opinion there will never be a real solution of the Dark Energy problem until it is understood much better at a conceptual level, and that will probably mean major revisions of our theories of both gravity and matter. I venture to speculate that in twenty years or so people will look back on the obsession with Dark Energy with some amusement, as our theoretical language will have moved on sufficiently to make it seem irrelevant.  That’s how it goes with MacGuffins. In the end, even the Maltese Falcon turned out  to be a fake, but what an adventure it was along the way!

The Euclid Launch Kit!

Posted in The Universe and Stuff with tags , , , , , on May 17, 2023 by telescoper

As the launch of the European Space Agency’s Euclid mission approaches, though we don’t know official launch date yet, the associated publicity machines are ramping up for the big occasion. The latest bit of merch is the Euclid Launch Kit.

Sadly, this does not allow you to build your own Falcon 9 launcher which is what I inferred from the name. What it is is an interactive PDF file that allows you to navigate around and learn things about the satellite, its orbit, its instruments and the science case. I think it’s pretty good. You can download it here. It’s over 100 MB though, so beware if you have a very slow connection.

To whet your appetite, here some graphics extracted from the launch kit. You can click on the tiles to make them bigger.

The two science images relate to weak gravitational lensing and baryon acoustic oscillations; for more details you can click on the relevant links.

Euclid’s Cosmic Mystery Contest!

Posted in The Universe and Stuff with tags , on May 9, 2023 by telescoper

I just saw the announcement of this competition and thought I’d share it here to encourage people to enter:

The winner gets a trip to European Space Operations Centre (ESOC) in Darmstadt which will be Mission Control for Euclid, which will be launched from Florida in July.

You can find out more about the competition, including the rules and instructions on how to enter, here.

Here are some suggestions:

You could choose to bake a cake, cross stitch, design a fabric, paint, draw, dance or anything else that comes to mind that symbolizes these proportions 5-25-70 and helps others understand just how much of the Universe we know and don’t know.

Once you have created your creation you have to put an image or a video of it on social media. For more ideas see here.

P.S. The Universe’s vital statistics of 5-25-70 would seem to present quite a challenge if someone were to design an outfit!

Euclid Launch Window Update!

Posted in The Universe and Stuff with tags on April 26, 2023 by telescoper

(The Euclid spacecraft will be launched via SpaceX on a Falcon 9 rocket from Cape Canaveral in July 2023, but no further details are publicly available right now.)

Euclid in a Nutshell

Posted in Literature, The Universe and Stuff with tags , , , , on February 21, 2023 by telescoper

O God, I could be bounded in a nut shell and count
myself a king of infinite space…

Hamlet, Act 2, Scene II.

It Hamlet rather than Euclid who said those words, but they came into my mind when I saw the latest nice video about the Euclid Mission from the European Space Agency, entitled Euclid in a Nutshell. It’s a quick one-minute summary of of what the mission is for and what it will do:

The text with the video reads:

ESA’s Euclid mission is designed to explore the composition and evolution of the dark Universe. The space telescope will create a great map of the large-scale structure of the Universe across space and time by observing billions of galaxies out to 10 billion light-years, across more than a third of the sky. Euclid will explore how the Universe has expanded and how structure has formed over cosmic history, revealing more about the role of gravity and the nature of dark energy and dark matter.

Euclid is a fully European mission, built and operated by ESA, with contributions from NASA. The Euclid Consortium – consisting of more than 2000 scientists from 300 institutes in 13 European countries, the US, Canada and Japan – provided the scientific instruments and scientific data analysis. ESA selected Thales Alenia Space as prime contractor for the construction of the satellite and its Service Module, with Airbus Defence and Space chosen to develop the Payload Module, including the telescope. NASA provided the near-infrared detectors of the NISP instrument.

A Backronym for Euclid?

Posted in The Universe and Stuff, Poetry, mathematics with tags , , , , on February 13, 2023 by telescoper
The Euclid Satellite

As a fully paid-up member of the Campaign for the Rejection of Acronymic Practices I was pleased to see the top brass in the Euclid Consortium issue instructions that encourage authors to limit their use of acronyms in official technical documents. Acronyms are widely used in the names of astronomical instruments and surveys. Take BOOMERanG (Balloon Observations Of Millimetric Extragalactic Radiation And Geophysics) and HIPPARCOS (HIgh Precision PARallax COllecting Satellite) to name just two. A much longer list can be found here.

I’m very pleased that the name of the European Space Agency’s Euclid mission is not an acronym. It is actually named after Euclid the Greek mathematician widely regarded as the father of geometry. Quite a few people who have asked me have been surprised that Euclid is not an acronym so I thought it might be fun to challenge my readers – both of them – to construct an appropriate backronym i.e. an acronym formed by expanding the name Euclid into the words of a phrase describing the Euclid mission. The best I’ve seen so far is:

Exploring the Universe with Cosmic Lensing to Identify Dark energy

But Euclid doesn’t just use Cosmic Lensing so I don’t think it’s entirely satisfactory. Anyway, your suggestions are welcome via the box below.

While you’re thinking, here is the best poetic description I have found (from Edna St Vincent Millay):

Euclid alone has looked on Beauty bare. 
Let all who prate of Beauty hold their peace,
And lay them prone upon the earth and cease
To ponder on themselves, the while they stare
At nothing, intricately drawn nowhere
In shapes of shifting lineage...

New Publication at the Open Journal of Astrophysics

Posted in OJAp Papers, Open Access, The Universe and Stuff with tags , , , , , on February 8, 2023 by telescoper

We’re on a bit of a roll at the Open Journal of Astrophysics and it’s time to announce yet another paper. We actually published this one yesterday (7th February 2023), which makes it two in two days. I don’t think we’ll keep up that rate but we have seen a big increase in submissions recently and these are working their way through the system very nicely. We aim to publish accepted papers within a day of the revised version appearing on arXiv.

The latest paper is the 6th paper in Volume 6 (2023) as well as the 71st in all. This one is another one for the folder marked Cosmology and Nongalactic Astrophysics. The title is “Almanac: Weak Lensing power spectra and map inference on the masked sphere”. The nub of the problem addressed by this paper is that the usual statistical analysis of data presented in projection on the sky involves spherical harmonics, which are orthogonal functions on the celestial sphere, but when the sky is not completely covered (i.e. part of it is masked), these functions are not orthogonal on what remains.

The authors of this paper are Arthur Loureiro (University of Edinburgh, UK), Lorne Whiteway (University College London, UK), Elena Selentin (Leiden University, NL), Javier Silva Lafaurie (Leiden University, NL), Andrew Jaffe (Imperial College London, UK) and Alan Heavens (Imperial College London, UK)

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


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.

How Euclid will scan the sky

Posted in The Universe and Stuff with tags , , , , , on February 7, 2023 by telescoper

A missive from Euclid High Command arrived yesterday confirming that ESA’s Euclid mission would be launched by SpaceX on a Falcon 9 rocket on a date between July 1st and July 30 (2023). It will soon be time to start getting nervous!

I also noticed that another video has appeared on the Euclid public website showing how the satellite will work. It’s not a traditional general-purpose observatory on which different users bid for time to observe different objects (as is the case for JWST, for example) but a dedicated mission that will compile a systematic survey with very specific science goals.

Euclid scans across the sky using a ‘step-and-stare’ method, combining separate measurements to form the largest cosmological survey ever conducted in the visible and near-infrared. Each time Euclid ‘stares’, its telescope points to a position in the sky, performing imaging and spectroscopic measurements on an area of approximately 0.5 deg² around this position. After each stare, the telescope steps to a new position.

This way the instruments will scan over a total of around 35% of the sky. This is the largest area over which one can guarantee a a complete detection of the galaxies necessary for Euclid’s cosmological studies. The rest of the sky is dominated by the high density of bright stars in our galaxy, and by the dust in the plane of our Solar System, both of which get in the way of the cosmology observations.

I hope this clarifies the situation.

The Euclid Public Website

Posted in The Universe and Stuff with tags , , , , , on February 2, 2023 by telescoper

With the European Space Agency’s Euclid mission now scheduled for launch in the 3rd Quarter of 2023 a lot of work has been put in recently in developing the Euclid mission’s public website. For those of you not in the know, there is a summary on the new website:

ESA’s Euclid mission is designed to explore the composition and evolution of the dark Universe. The space telescope will create a great map of the large-scale structure of the Universe across space and time by observing billions of galaxies out to 10 billion light-years, across more than a third of the sky. Euclid will explore how the Universe has expanded and how structure has formed over cosmic history, revealing more about the role of gravity and the nature of dark energy and dark matter.

The public website is can be found here. Check it out. Many more stories, pictures and videos will be added over the forthcoming weeks but in the mean time here is a taster animated movie that shows various elements of the Euclid spacecraft, including the telescope, payload module and solar panels.

Even more information about the science to be done with Euclid can be found on the Euclid Consortium website, which is being revamped ahead of the launch.

SpaceX launch confirmed for Euclid

Posted in Biographical, The Universe and Stuff with tags , , , on December 15, 2022 by telescoper

I’m a bit fragile today. I don’t know why, but it may be connected with our Departmental Christmas partylast night. I’m glad I didn’t have too much to drink. Ahem.

Anyway, in my current condition I only have time for a short post to pass on the news that I today saw official confirmation that, negotiations having been successfully completed, the European Space Agency’s Euclid mission will indeed be launched by SpaceX, on a Falcon 9 rocket.

Various working meetings have been scheduled to start next week between ESA, SpaceX and Thales Alenia Space – Italia (TAS-I, who constructed the vehicle). The launch period is confirmed to be somewhere in the 3rd Quarter of 2023 and may even be as early as 1st July 2023. The actual launch window of one month will be agreed on the 1st of February.

Now there will be intense activity preparing the Euclid vehicle for launch as well as readying the Ground Segment – the bit that collects and processes the data.

The 2023 Annual Euclid Consortium Meeting, scheduled to be in Copenhagen in from 19th to 23rd June will be the last such meeting before the launch. I am very much looking forward to attending it.