Today’s the day that over 60,000 school students across Ireland are receiving their Leaving Certificate Results. As always there will be joy for some, and disappointment for others. The headline news relating to these results is that a majority (68%) of grades have been scaled up to that the distribution matches last year’s outcomes. This has meant an uplift of marks by about 7.5% on average, with the biggest changes happening at the lower levels of grade.
This artificial boost is a consequence of the generous adjustments made during the pandemic and apparent wish by the Education Minister, Norma Foley, to ensure that this year’s students are treated “fairly” compared to last year’s. Of course this argument could be made for continuing to inflate grades next year too, and the year after that. Perhaps the Minister’s plan seems to be to keep the grades high until after the next General Election, after which it will be someone else’s job to treat students “unfairly”. Anyway, you might say that marks have been scaled to maintain a Norma Distribution…
One can’t blame the students, of course, but one of the effects of this scaling is that students will be coming into third-level education with grades that imply a greater level of achievement than they actually have reached. This is a particular problem with a subject like physics where we really need students to be comfortable with certain aspects of mathematics before they start their course. It has been clear that even students with very good grades at Higher level have considerable gaps in their knowledge. This looks set to continue, and we will just have to deal with it. This issue was compounded for a while because Leaving Certificate grades were produced so late that first-year students had to start university a week late, giving less time for the remedial teaching that many of them needed. At least this year we won’t have that problem, so can plan some activities early on in the new Semester.
Anyway, out of interest – probably mine rather than yours – I delved into the statistics of Leaving Certificate results going back six years for Mathematics (at Higher A and Ordinary B) level, Physics and Applied Mathematics which I fished out of the general numbers given here.
Here are the results in a table, with the columns denoting the grade (1=high) and the numbers are percentages:
You can seen that the percentage of students getting H1 in Mathematics has increased a bit to 12.6% after falling considerably from 18.1% in 2022 to 11.2% last year (2023); note the huge increase in H1 from 2020 to 2021 (8.6% to 15.1%). Another thing worth noting is that both Physics and Applied Mathematics have declined significantly in popularity since 2019 from 7210.
Now that the results are out there will be a busy time until next Wednesday (28th) when the CAO first round offers go out. That is when those students wanting to go to university find out if they made the grades and university departments find out how many new students (if any) they will have to teach in September.
P.S. When I was a little kid we used to call a “Certificate” a “Stiff Ticket”. I just thought you would like to know that.
Yesterday was the day that students in United Kingdom received this year’s A-level results. It seems the number of students getting the highest grades went up in England but down in Wales and Northern Ireland. That difference could be because of the timing of the transition from Covid-19 adjustments, with marks in Wales and Northern Ireland only returning to pre-pandemic levels this year; this may disadvantage applicants to universities this year, of course.
Another thing worth mentioning is that the number of students taking Physics A-level has increased by 12% this year, reversing a recent downward trend. In Physics, 31.5 per cent of students achieved the top grades. This was an increase from last year when 30.8 per cent were awarded an A or A*. That probably means that most students who applied to do Physics at university will get a place in their first-choice institution.
As always my advice to students who got disappointing results is
There’s always the clearing system and there’s every chance you can find a place somewhere good. If you’re reading this blog you might be interested in Physics and/or Astronomy so I’ll just mention that both Cardiff and Sussex have places in clearing and both are excellent choices.
At least you’ve got your results; students here in Ireland will have to wait next Friday (23rd August) to get to get theirs – not in the form of GCE A-levels, of course, but the School Leaving Certificate. I have been away all year so don’t know how admissions have been going for Maynooth but the intention seems to be to increase student numbers in any way possible despite the already huge student-staff ratio (the highest in Ireland) and lack of student accommodation. Anyway, Covid-19 adjustments are still in place in Ireland so the artificial inflation of Leaving Certificate grades will continue. It seems the Government doesn’t know how to get out of the system it has locked itself into and is intent on leaving it for the next Government to sort out.
Looking at the title of this paper you might be tempted to dismiss it on the grounds that warp drives are the stuff of science fiction (which they are), but this paper is really a rigorous technical study of the dynamical evolution and stability of spacetimes that violate the null energy condition, inspired by the idea of a warp drive. As soon as I announced this paper on social media it started to get attention. That will probably increase because there is now a press release to accompany the paper. I’ve taken the liberty of reproducing the text of the press release here:
–o–
Imagine a spaceship driven not by engines, but by compressing the spacetime in front of it. That’s the realm of science fiction, right? Well, not entirely. Physicists have been exploring the theoretical possibility of “warp drives” for decades, and a new study published in the Open Journal of Astrophysics takes things a step further – simulating the gravitational waves such a drive might emit if it broke down.
Warp drives are staples of science fiction, and in principle could propel spaceships faster than the speed of light. Unfortunately, there are many problems with constructing them in practice, such as the requirement for an exotic type of matter with negative energy. Other issues with the warp drive metric include the potential to use it to create closed time-like curves that violate causality and, from a more practical perspective, the difficulties for those in the ship in actually controlling and deactivating the bubble.
This new research is the result of a collaboration between specialists in gravitational physics at Queen Mary University of London, the University of Potsdam, the Max Planck Institute (MPI) for Gravitational Physics in Potsdam and Cardiff University. Whilst it doesn’t claim to have cracked the warp drive code, it explores the theoretical consequences of a warp drive “containment failure” using numerical simulations.
Dr Katy Clough of Queen Mary University of London, the first author of the study explains: “Even though warp drives are purely theoretical, they have a well-defined description in Einstein’s theory of General Relativity, and so numerical simulations allow us to explore the impact they might have on spacetime in the form of gravitational waves.”
Co-author Dr Sebastian Khan, from Cardiff University’s School of Physics and Astronomy, adds: “Miguel Alcubierre created the first warp drive solution during his PhD at Cardiff University in 1994, and subsequently worked at the MPI in Potsdam. So it’s only natural that we carry on the tradition of warp drive research in the era of gravitational wave astronomy .”
The results are fascinating. The collapsing warp drive generates a distinct burst of gravitational waves, a ripple in spacetime that could be detectable by gravitational wave detectors that normally target black hole and neutron star mergers. Unlike the chirps from merging astrophysical objects, this signal would be a short, high-frequency burst, and so current detectors wouldn’t pick it up. However, future higher-frequency instruments might, and although no such instruments have yet been funded, the technology to build them exists. This raises the possibility of using these signals to search for evidence of warp drive technology, even if we can’t build it ourselves.
Dr Khan cautions “In our study, the initial shape of the spacetime is the warp bubble described by Alcubierre. While we were able to demonstrate that an observable signal could in principle be found by future detectors, given the speculative nature of the work this isn’t sufficient to drive instrument development.”
The study also delves into the energy dynamics of the collapsing warp drive. The process emits a wave of negative energy matter, followed by alternating positive and negative waves. This complex dance results in a net increase in the overall energy of the system, and in principle could provide another signature of the collapse if the outgoing waves interacted with normal matter.
This research pushes the boundaries of our understanding of exotic spacetimes and gravitational waves. Prof Dietrich comments: “For me, the most important aspect of the study is the novelty of accurately modelling the dynamics of negative energy spacetimes, and the possibility of extending the techniques to physical situations that can help us better understand the evolution and origin of our universe, or the avoidance of singularities at the centre of black holes.”
Dr Clough adds: “It’s a reminder that theoretical ideas can push us to explore the universe in new ways. Even though we are sceptical about the likelihood of seeing anything, I do think it is sufficiently interesting to be worth looking!”
The researchers plan to investigate how the signal changes with different warp drive models and explore the collapse of bubbles travelling at speeds exceeding the speed of light itself. Warp speed may be a long way off, but the quest to understand the universe’s secrets continues, one simulated crash at a time.
Peter Thomas (left) joined the University of Sussex as a lecturer in the Astronomy Centre in 1989 and remained there for his entire career. I know from my own time as Head of School that he was an excellent colleague. who made huge contributions to the University and indeed to his research discipline of cosmology.
Peter studied Mathematics at Cambridge University, graduating in 1983 and then did Part III (also known as the Certificate of Advanced Study) which he obtained in 1984. He stayed in Cambridge to do a PhD in the Institute of Astronomy under the supervision of Andy Fabian on Cooling Flows and Galaxy Formation, which he completed in 1987. He then spent a couple of years in Toronto as a Postdoctoral Fellow at the Canadian Institute for Theoretical Astrophysics (CITA) before taking up his lectureship at Sussex in 1989. His main research interests were in in the areas of galaxy formation, including numerical and semi-analytic models, and computer simulations of the formation of clusters of galaxies. He was a widely known and very highly respected researcher in the field of theoretical cosmology and extragalactic astrophysics.
I was a PDRA in the Astronomy Centre at Sussex when Peter joined in 1989; he was Professor in the Department of Physics & Astronomy when I returned there as Head of School of Mathematical and Physical Sciences in 2013, a position he himself subsequently held. He was a much-valued member of staff who made huge contributions to the Astronomy Centre, the Department of Physics & Astronomy, the School of Mathematical and Physical Sciences, and the University of Sussex as a whole. I also remember him as a colleague on various panels for PPARC and then STFC on which he served diligently.
Having known Peter for 35 years, and being of similar age, it was a shock to hear that he passed away. I understand that he had been suffering from cancer for over a year. I send my deepest condolences to his family, friends and colleagues. I understand that his funeral will be a private family affair, but there will be a more public occasion to celebrate his life at a later date.
I took my first degree in the Natural Sciences Tripos at the University of Cambridge. This involved doing a very general first year comprising four different elements that could be chosen flexibly. I quickly settled on Physics, Chemistry and Mathematics for Natural Sciences to reflect my A-level results but was struggling for the fourth. In the end I picked the one that seemed most like Physics, a course called Crystalline Materials. I didn’t like that at all, and wish I’d done some Biology instead – Biology of Cells and Biology of Organisms were both options – or even Geology, but I stuck with it for the first year.
Having to do such a wide range of subjects was very challenging. The timetable was densely packed and the pace was considerable. In the second year, however, I was able to focus on Mathematics and Physics and although it was still intense it was a bit more focussed. I ended up doing Theoretical Physics in my final year, including a theory project.
My best teacher at School, Dr Geoeff Swinden, was a chemist (he had a doctorate in organic chemistry from Oxford University) and when I went to Cambridge I fully expected to specialisze in Chemistry rather than Physics. I loved the curly arrows and all that. But two things changed. One was that I found the Physics content of the first year far more interesting – and the lecturers and tutors far more inspiring – than Chemistry, and the other was that my considerable ineptitude at practical work made me doubt that I had a future in a chemistry laboratory. And so it came to pass that I switched allegiance to Physics, a decision I am very glad I made.
(It was only towards the end of my degree that I started to take Astrophysics seriously as a possible specialism, but that’s another story…)
Anyway, when I turned up at Cambridge over 40 years ago to begin my course, and having Chemistry as a probable end point, I bought all the recommended text books, one of which was Physical Chemistry by P.W. Atkins. I found a picture (above) of the 1982 edition which may well be the one I bought (although I vaguely remember the one I had being in paperback). I thought it was a very good book, and it has gone into many subsequent editions. I also found the Physical part of Chemistry quite straightforward because it is basically Physics. I even got higher marks in Chemistry in the first year than I did in Physics but that didn’t alter my decision to drop Chemistry after the first year. When I did so, I followed tradition and sold my copy to a new undergraduate along with the other books relating to courses that I dropped.
Yesterday I found out that Peter Atkins has decided to make one of his books available to download. The book concerned is however not the compendious tome I bought, but a shorter summary called Concepts in Physical Chemistry, which was published in 1995. This is no doubt a very useful text for beginning Chemistry students so I thought I’d pass on this information. You can download it here, although you have to do it chapter by chapter in PDF files.
P.S. Chemistry in Spanish is ‘Química’. Since Physics and Chemistry share the same building in the University of Barcelona, where I am currently working, I frequently walk past rooms with doors marked ‘Quim’ (but I have never taken the opportunity to enter one).
I was intrigued to see this graphic accompanying an article about hurling. Notice that the left hand side shows the field equations of Einstein’s General Theory of Relativity and some expressions to do with quantum mechanics. Hurling is indeed an extraordinary – and extraordinarily fast – sport but is the article implying that classical physics is inadequate to describe it? Perhaps it is implying that through hurling we will at last arrive at a Theory of Everything?
Here’s another video in the Cosmology Talks series curated by Shaun Hotchkiss. This one very timely after yesterday’s announcement. Here is the description on the YouTube page:
The Dark Energy Spectroscopic Instrument (DESI) has produced cosmological constraints! And it is living up to its name. Two researchers from DESI, Seshadri Nadathur and Andreu Font-Ribera, tell us about DESI’s measurements of the Baryon Acoustic Oscillations (BAO) released today. These results use one full year of DESI data and are the first cosmological constraints from the telescope that have been released. Mostly, it is what you might expect: tighter constraints. However, in the realm of the equation of state of dark energy, they find, even with BAO alone, that there is a hint of evidence for evolving dark energy. When they combine their data with CMB and Supernovae, who both also find small hints of evolving dark energy on their own, the evidence for dark energy not being a cosmological constant jumps as high as 3.9σ with one combination of the datasets. It seems there still is “concordance cosmology”, it’s just not ΛCDM for these datasets. The fact that all three probes are tentatively favouring this is intriguing, as it makes it unlikely to be due to systematic errors in one measurement pipeline.
My own take is that the results are very interesting but I think we need to know a lot more about possible systematics before jumping to conclusions about time-varying dark energy. Am I getting conservative in my old age? These results from DESI do of course further underline the motivation for Euclid (another Stage IV survey), which may have an even better capability to identify departures from the standard model.
P.S. Here’s a nice graphic showing the cosmic web showing revealed by the DESI survey:
Here’s an interestingly different talk in the series of Cosmology Talks curated by Shaun Hotchkiss. The speaker, Sylvia Wenmackers, is a philosopher of science. According to the blurb on Youtube:
Her focus is probability and she has worked on a few theories that aim to extend and modify the standard axioms of probability in order to tackle paradoxes related to infinite spaces. In particular there is a paradox of the “infinite fair lottery” where within standard probability it seems impossible to write down a “fair” probability function on the integers. If you give the integers any non-zero probability, the total probability of all integers is unbounded, so the function is not normalisable. If you give the integers zero probability, the total probability of all integers is also zero. No other option seems viable for a fair distribution. This paradox arises in a number of places within cosmology, especially in the context of eternal inflation and a possible multiverse of big bangs bubbling off. If every bubble is to be treated fairly, and there will ultimately be an unbounded number of them, how do we assign probability? The proposed solutions involve hyper-real numbers, such as infinitesimals and infinities with different relative sizes, (reflecting how quickly things converge or diverge respectively). The multiverse has other problems, and other areas of cosmology where this issue arises also have their own problems (e.g. the initial conditions of inflation); however this could very well be part of the way towards fixing the cosmological multiverse.
The paper referred to in the presentation can be found here. There is a lot to digest in this thought-provoking talk, from the starting point on Kolmogorov’s axioms to the application to the multiverse, but this video gives me an excuse to repeat my thoughts on infinities in cosmology.
Most of us – whether scientists or not – have an uncomfortable time coping with the concept of infinity. Physicists have had a particularly difficult relationship with the notion of boundlessness, as various kinds of pesky infinities keep cropping up in calculations. In most cases this this symptomatic of deficiencies in the theoretical foundations of the subject. Think of the ‘ultraviolet catastrophe‘ of classical statistical mechanics, in which the electromagnetic radiation produced by a black body at a finite temperature is calculated to be infinitely intense at infinitely short wavelengths; this signalled the failure of classical statistical mechanics and ushered in the era of quantum mechanics about a hundred years ago. Quantum field theories have other forms of pathological behaviour, with mathematical components of the theory tending to run out of control to infinity unless they are healed using the technique of renormalization. The general theory of relativity predicts that singularities in which physical properties become infinite occur in the centre of black holes and in the Big Bang that kicked our Universe into existence. But even these are regarded as indications that we are missing a piece of the puzzle, rather than implying that somehow infinity is a part of nature itself.
The exception to this rule is the field of cosmology. Somehow it seems natural at least to consider the possibility that our cosmos might be infinite, either in extent or duration, or both, or perhaps even be a multiverse comprising an infinite collection of sub-universes. If the Universe is defined as everything that exists, why should it necessarily be finite? Why should there be some underlying principle that restricts it to a size our human brains can cope with?
On the other hand, there are cosmologists who won’t allow infinity into their view of the Universe. A prominent example is George Ellis, a strong critic of the multiverse idea in particular, who frequently quotes David Hilbert
The final result then is: nowhere is the infinite realized; it is neither present in nature nor admissible as a foundation in our rational thinking—a remarkable harmony between being and thought
But to every Hilbert there’s an equal and opposite Leibniz
I am so in favor of the actual infinite that instead of admitting that Nature abhors it, as is commonly said, I hold that Nature makes frequent use of it everywhere, in order to show more effectively the perfections of its Author.
You see that it’s an argument with quite a long pedigree!
Many years ago I attended a lecture by Alex Vilenkin, entitled The Principle of Mediocrity. This was a talk based on some ideas from his book Many Worlds in One: The Search for Other Universes, in which he discusses some of the consequences of the so-called eternal inflation scenario, which leads to a variation of the multiverse idea in which the universe comprises an infinite collection of causally-disconnected “bubbles” with different laws of low-energy physics applying in each. Indeed, in Vilenkin’s vision, all possible configurations of all possible things are realised somewhere in this ensemble of mini-universes.
One of the features of this scenario is that it brings the anthropic principle into play as a potential “explanation” for the apparent fine-tuning of our Universe that enables life to be sustained within it. We can only live in a domain wherein the laws of physics are compatible with life so it should be no surprise that’s what we find. There is an infinity of dead universes, but we don’t live there.
I’m not going to go on about the anthropic principle here, although it’s a subject that’s quite fun to write or, better still, give a talk about, especially if you enjoy winding people up! What I did want to say mention, though, is that Vilenkin correctly pointed out that three ingredients are needed to make this work:
An infinite ensemble of realizations
A discretizer
A randomizer
Item 2 involves some sort of principle that ensures that the number of possible states of the system we’re talking about is not infinite. A very simple example from quantum physics might be the two spin states of an electron, up (↑) or down(↓). No “in-between” states are allowed, according to our tried-and-tested theories of quantum physics, so the state space is discrete. In the more general context required for cosmology, the states are the allowed “laws of physics” ( i.e. possible false vacuum configurations). The space of possible states is very much larger here, of course, and the theory that makes it discrete much less secure. In string theory, the number of false vacua is estimated at 10500. That’s certainly a very big number, but it’s not infinite so will do the job needed.
Item 3 requires a process that realizes every possible configuration across the ensemble in a “random” fashion. The word “random” is a bit problematic for me because I don’t really know what it’s supposed to mean. It’s a word that far too many scientists are content to hide behind, in my opinion. In this context, however, “random” really means that the assigning of states to elements in the ensemble must be ergodic, meaning that it must visit the entire state space with some probability. This is the kind of process that’s needed if an infinite collection of monkeys is indeed to type the (large but finite) complete works of shakespeare. It’s not enough that there be an infinite number and that the works of shakespeare be finite. The process of typing must also be ergodic.
Now it’s by no means obvious that monkeys would type ergodically. If, for example, they always hit two adjoining keys at the same time then the process would not be ergodic. Likewise it is by no means clear to me that the process of realizing the ensemble is ergodic. In fact I’m not even sure that there’s any process at all that “realizes” the string landscape. There’s a long and dangerous road from the (hypothetical) ensembles that exist even in standard quantum field theory to an actually existing “random” collection of observed things…
More generally, the mere fact that a mathematical solution of an equation can be derived does not mean that that equation describes anything that actually exists in nature. In this respect I agree with Alfred North Whitehead:
There is no more common error than to assume that, because prolonged and accurate mathematical calculations have been made, the application of the result to some fact of nature is absolutely certain.
It’s a quote I think some string theorists might benefit from reading!
Items 1, 2 and 3 are all needed to ensure that each particular configuration of the system is actually realized in nature. If we had an infinite number of realizations but with either infinite number of possible configurations or a non-ergodic selection mechanism then there’s no guarantee each possibility would actually happen. The success of this explanation consequently rests on quite stringent assumptions.
I’m a sceptic about this whole scheme for many reasons. First, I’m uncomfortable with infinity – that’s what you get for working with George Ellis, I guess. Second, and more importantly, I don’t understand string theory and am in any case unsure of the ontological status of the string landscape. Finally, although a large number of prominent cosmologists have waved their hands with commendable vigour, I have never seen anything even approaching a rigorous proof that eternal inflation does lead to realized infinity of false vacua. If such a thing exists, I’d really like to hear about it!
I can’t speak about the American Institute of Physics or the American Physical Society but in the context of the Institute of Physics – of which I am a Fellow and in whose house magazine the article appears – I draw your attention to the last sentence of the above excerpt which contains a commitment to “invest funds generated from publishing back into research” (my emphasis).
Really? The IOP invests in research? That’s news to me. How do I apply for a grant? Will they fund my next PhD student?
The IOP invests its funds in many things – many of them worthy – but it does not spend a significant part of the vast income it generates from its publishing house on research. The claim that it does is just dishonest. There’s point in mincing words.
This is an important distinction, particularly so that publishing in most IOP journals now requires the payment of a hefty Article Processing Charge (APC; Artificial Profit Charge would be more apt) which often has to be paid for out of research grants. Previously the revenue of IOP Publishing was appropriated from library budgets through subscriptions, so physicists were less aware of just how much the IOP was raking in. Now that researchers are having to find the funds themselves from research grants it has become more obvious that the IOP is actually a drain on research funds, not a source of them. The APC is a levy on research, designed to generate funds for other things. I think this model is indefensible. What gives the IOP the right to impose charges that far exceed the cost of disseminating scientific results in order to appropriate funds for its other activities?
Moreover, even if the IOP did fund research, what benefit would that be to a researcher in Spain, South Korea or Singapore or indeed anywhere outside the UK and Ireland?
The slogan for the initiative described in the article is “Purpose-led Publishing”. That reminds me of an old saying from systems theory: the Purpose Of a System Is What it Does (POSIWID). What the system does in this case is to raise funds for the IOP. That’s its purpose. Everything else is just marketing spiel.
The claim that IOP Publishing does not make a profit is disingenuous too. It does make a substantial profit. The only difference between it and the likes of Elsevier is where the profits go. A true not-for-profit publisher would charge only at the level to cover the costs of publication. The Purpose that should be leading Publishing in physics is the dissemination of scientific results, not the generation of revenue for sundry other things.
I have avoided publishing in IOP journals for many years because I think the approach of IOP Publishing is unethical. Now I have decided that I no longer wish to be associated with the IOP in any way. I have paid the subscription for 2024 but when that lapses I won’t renew it. Enough is enough.
At the annual AAS Meeting in New Orleans last week there was an announcement of a result that made headlines in the media (see, e.g., here and here). There is also a press release from the University of Central Lancashire.
Here is a video of the press conference:
I was busy last week so didn’t have time to read the details so refrained from commenting on this issue at the time of the announcement. Now that I am back in circulation, I have time to read the details, but unfortunately was unable to find even a preprint describing this “discovery”. The press conference doesn’t contain much detail either so it’s impossible to say anything much about the significance of the result, which is claimed (without explanation) to be 5.2σ (after “doing some statistics”). I see the “Big Ring” now has its own wikipedia page, the only references on which are to press reports, not peer-reviewed scientific papers or even preprints.
So is this structure “so big it challenges our understanding of the universe”?
The Big Ring (blue) and another large structure (red)Spot the Ring in the actual data
Based on the available information it is impossible to say. The large-scale structure of the Universe comprises a complex network of walls and filaments known as the cosmic web which I have written about numerous times on this blog. This structure is so vast and complicated that it is very easy to find strange shapes in it but very hard to determine whether or not they indicate anything other than an over-active imagination.
To assess the significance of the Big Ring or other structures in a proper scientific fashion, one has to calculate how probable that structure is given a model. We have a standard model that can be used for this purpose, but to simulate very structures is not straightforward because it requires a lot of computing power even to simulate just the mass distribution. In this case one also has to understand how to embed Magnesium absorption too, something which may turn out to trace the mass in a very biased way. Moreover, one has to simulate the observational selection process too, so one is doing a fair comparison between observations and predictions.
I have seen no evidence that this has been done in this case. When it is, I’ll comment on the details. I’m not optimistic however, as the description given in the media accounts contains numerous falsehoods. For example, quoting the lead author:
The Cosmological Principle assumes that the part of the universe we can see is viewed as a ‘fair sample’ of what we expect the rest of the universe to be like. We expect matter to be evenly distributed everywhere in space when we view the universe on a large scale, so there should be no noticeable irregularities above a certain size.
This just isn’t correct. The standard cosmology has fluctuations on all scales. Although the fluctuation amplitude decreases with scale, there is no scale at which the Universe is completely smooth. See the discussion, for example, here. We can see correlations on very large angular scales in the cosmic microwave background which would be absent if the Universe were completely smooth on those scales. The observed structure is about 400 Mpc in size, which does not seem to be to be particularly impressive.
I suspect that the 5.2σ figure mentioned above comes from some sort of comparison between the observed structure and a completely uniform background, in which case it is meaningless.
My main comment on this episode is that I think it’s very poor practice to go hunting headlines when there isn’t even a preprint describing the results. That’s not the sort of thing PhD supervisors should be allowing their PhD students to do. As I have mentioned before on this blog, there is an increasing tendency for university press offices to see themselves entirely as marketing agencies instead of informing and/or educating the public. Press releases about scientific research nowadays rarely make any attempt at accuracy – they are just designed to get the institution concerned into the headlines. In other words, research is just a marketing tool.
In the long run, this kind of media circus, driven by hype rather than science, does nobody any good.
P.S. I was going to joke that ring-like structures can be easily explained by circular reasoning, but decided not to.
The views presented here are personal and not necessarily those of my employer (or anyone else for that matter).
Feel free to comment on any of the posts on this blog but comments may be moderated; anonymous comments and any considered by me to be vexatious and/or abusive and/or defamatory will not be accepted. I do not necessarily endorse, support, sanction, encourage, verify or agree with the opinions or statements of any information or other content in the comments on this site and do not in any way guarantee their accuracy or reliability.
In the Dark 