Off to Oxford for the rest of the day to give a talk, which is apparently either a colloquial seminar or a seminal colloquium. I haven’t worked out which. Anyway, I thought I’d leave you with a wonderful bit of music by the genius that was György Ligeti. This piece, called Lontano, is one of the many works by this composer I have on my iPod so I’ll be listening to it again as the train speeds (?) through the snowy countryside taking me towards the dreaming spires..
Archive for November, 2010
There is a dish to hold the sea,
A brazier to contain the sun,
A compass for the galaxy,
A voice to wake the dead and done!
That minister of ministers,
Imagination, gathers up
The undiscovered Universe,
Like jewels in a jasper cup.
Its flame can mingle north and south;
Its accent with the thunder strive;
The ruddy sentence of its mouth
Can make the ancient dead alive.
The mart of power, the fount of will,
The form and mould of every star,
The source and bound of good and ill,
The key of all the things that are,
Imagination, new and strange
In every age, can turn the year;
Can shift the poles and lightly change
The mood of men, the world’s career.
by John Davidson (1857-1909)
A strange paper by Gurzadyan and Penrose hit the Arxiv a week or so ago. It seems to have generated quite a lot of reaction in the blogosphere and has now made it onto the BBC News, so I think it merits a comment.
The authors claim to have found evidence that supports Roger Penrose‘s conformal cyclic cosmology in the form of a series of (concentric) rings of unexpectedly low variance in the pattern of fluctuations in the cosmic microwave background seen by the Wilkinson Microwave Anisotropy Probe (WMAP). There’s no doubt that a real discovery of such signals in the WMAP data would point towards something radically different from the standard Big Bang cosmology.
I haven’t tried to reproduce Gurzadyan & Penrose’s result in detail, as I haven’t had time to look at it, and I’m not going to rule it out without doing a careful analysis myself. However, what I will say here is that I think you should take the statistical part of their analysis with a huge pinch of salt.
The authors report a hugely significant detection of their effect (they quote a “6-σ” result; in other words, the expected feature is expected to arise in the standard cosmological model with a probability of less than 10-7. The type of signal can be seen in their Figure 2, which I reproduce here:
Sorry they’re hard to read, but these show the variance measured on concentric rings (y-axis) of varying radius (x-axis) as seen in the WMAP W (94 Ghz) and V (54 Ghz) frequency channels (top two panels) compared with what is seen in a simulation with purely Gaussian fluctuations generated within the framework of the standard cosmological model (lower panel). The contrast looks superficially impressive, but there’s much less to it than meets the eye.
For a start, the separate WMAP W and V channels are not the same as the cosmic microwave background. There is a great deal of galactic foreground that has to be cleaned out of these maps before the pristine primordial radiation can be isolated. The fact similar patterns can be found in the BOOMERANG data by no means rules out a foreground contribution as a common explanation of anomalous variance. The authors have excluded the region at low galactic latitude (|b|<20°) in order to avoid the most heavily contaminated parts of the sky, but this is by no means guaranteed to eliminate foreground contributions entirely. Here is the all-sky WMAP W-band map for example:
Moreover, these maps also contain considerable systematic effects arising from the scanning strategy of the WMAP satellite. The most obvious of these is that the signal-to-noise varies across the sky, but there are others, such as the finite size of the beam of the WMAP telescope.
Neither galactic foregrounds nor correlated noise are present in the Gaussian simulation shown in the lower panel, and the authors do not say what kind of beam smoothing is used either. The comparison of WMAP single-channel data with simple Gaussian simulations is consequently deeply flawed and the significance level quoted for the result is certainly meaningless.
Having not looked looked at this in detail myself I’m not going to say that the authors’ conclusions are necessarily false, but I would be very surprised if an effect this large was real given the strenuous efforts so many people have made to probe the detailed statistics of the WMAP data; see, e.g., various items in my blog category on cosmic anomalies. Cosmologists have been wrong before, of course, but then so have even eminent physicists like Roger Penrose…
Another point that I’m not sure about at all is even if the rings of low variance are real – which I doubt – do they really provide evidence of a cyclic universe? It doesn’t seem obvious to me that the model Penrose advocates would actually produce a CMB sky that had such properties anyway.
Above all, I stress that this paper has not been subjected to proper peer review. If I were the referee I’d demand a much higher level of rigour in the analysis before I would allow it to be published in a scientific journal. Until the analysis is done satisfactorily, I suggest that serious students of cosmology shouldn’t get too excited by this result.
It occurs to me that other cosmologists out there might have looked at this result in more detail than I have had time to. If so, please feel free to add your comments in the box…
IMPORTANT UPDATE: 7th December. Two papers have now appeared on the arXiv (here and here) which refute the Gurzadyan-Penrose claim. Apparently, the data behave as Gurzadyan and Penrose claim, but so do proper simulations. In otherwords, it’s the bottom panel of the figure that’s wrong.
ANOTHER UPDATE: 8th December. Gurzadyan and Penrose have responded with a two-page paper which makes so little sense I had better not comment at all.
Just a quick grouchy post about crosswords. The results of Azed No. 2006 “Spoonerisms” have been published. Once again, I drew a blank in the setting competition, although I did at least solve the puzzle correctly. This is one of Azed’s “funnies” in that the clues either contain a spoonerism in the definition part or indicate a spoonerism of the answer to be entered in the grid. You can find a full analysis of the clues and their solutions here.
Azed’s Spoonerism puzzles are apparently very popular with solvers. I found the puzzle mildly diverting, but I didn’t enjoy this one very much, as most of the spoonerisms were either very obvious or a bit dodgy. I don’t think MAO TOAST is a spoonerism of OUTMOST, for example; surely that would have to be something like TAO MOST?
Anyway, that’s not the origin of my gripe. The clue writing competition required a clue for the word “GROAN” incorporating a spoonerism in the definition. The winning clue, as judged by Azed, was the following:
See king crowned, grand on horse, organ playing some allegro anthems
The spoonerism here is “see king crowned” for “creaking sound” (i.e. the groan associated with a ship’s timbers, etc). However, in my opinion, the vowel sounds here simply don’t work: the “ee” in “see king” isn’t the same as the “ea” in “creaking”, and the stress pattern is different too – “see king” has evenly stressed syllables whereas “creaking” has a stress on the first syllable.
On top of the problematic spoonerism, this clue has no less than three cryptic indications – G+ROAN (grand on horse), an anagram of “ORGAN” indicated by “playing”, and a hidden word “some alleGRO AN thems”.
I quote Azed’s own opinion:
A good cryptic clue contains three elements:
1. a precise definition
2. a fair subsidiary indication
3. nothing else
It doesn’t say three subsidiary indications! I’ve noticed that the winning Azed competition clues often have multiple cryptic parts, so obviously Azed is more lenient than I would be. I just don’t like clues that hedge their bets. Three weak cryptic allusions aren’t as good as one clever one.
Just my opinion, of course…
For what it’s worth, my failed attempt at GROAN was
Seeking crowned King’s leg over one
I think “seeking” is better than “see king” for the reasons I described above, but I admit the cryptic part is questionable – King is “GR”, the apostrophe is short for “has”, and “leg over one” is O(A)N with leg referring to the cricketing expression.
Anyway, gripe over. I’ll get my coat.
Brightly the sun of summer shone,
Green fields and waving woods upon,
And soft winds wandered by;
Above, a sky of purest blue,
Around, bright flowers of loveliest hue,
Allured the gazer’s eye.
But what were all these charms to me,
When one sweet breath of memory
Came gently wafting by?
I closed my eyes against the day,
And called my willing soul away,
From earth, and air, and sky;
That I might simply fancy there
One little flower — a primrose fair,
Just opening into sight;
As in the days of infancy,
An opening primrose seemed to me
A source of strange delight.
Sweet Memory! ever smile on me;
Nature’s chief beauties spring from thee,
Oh, still thy tribute bring!
Still make the golden crocus shine
Among the flowers the most divine,
The glory of the spring.
Still in the wall-flower’s fragrance dwell;
And hover round the slight blue bell,
My childhood’s darling flower.
Smile on the little daisy still,
The buttercup’s bright goblet fill
With all thy former power.
For ever hang thy dreamy spell
Round mountain star and heather bell,
And do not pass away
From sparkling frost, or wreathed snow,
And whisper when the wild winds blow,
Or rippling waters play.
Is childhood, then, so all divine?
Or Memory, is the glory thine,
That haloes thus the past?
Not all divine; its pangs of grief,
(Although, perchance, their stay be brief,)
Are bitter while they last.
Nor is the glory all thine own,
For on our earliest joys alone
That holy light is cast.
With such a ray, no spell of thine
Can make our later pleasures shine,
Though long ago they passed.
by Anne Brontë (1820-1849)
Up early this morning, cold notwithstanding, to take part in an all-day workshop on Public Attitudes to Science conducted by the market-research organization IPSOS-Mori on behalf of the Department for Business Innovation and Skills (BIS) I can’t really say much about what happened since it’s an ongoing research project, but it was very interesting and particularly nice to talk to the participants (who were aged 18-24). My role was as a “science expert” so my job was to explain a bit about how the kind of science I do actually works in practice, compared with what they thought before the event.
On the way home I had to find my way back through the crowded streets of Cardiff. Today was the last day of the autumn rugby internationals, and Wales were playing New Zealand at home. There was a fantastic atmosphere in the city, as always on match days, although the combination of a rather boisterous rugby crowd with large numbers of Christmas shoppers did slow down my journey home. The game just ended, Wales 25 New Zealand 37; not as one-sided as many feared and a much better spectacle than last week’s awful match against Fiji.
I took a few pictures of Bute Park on my way to the event this morning. It looked very beautiful, but it wasn’t half cold early on. I doubt if there’ll be much rugby played on the sports fields for a while, because the ground is frozen solid at the moment!
I don’t mind admitting that I’m a bit down today. Being stuck at home with a fever and sore throat, and with mounting backlog of things to do isn’t helping my mood. On top of that I’ve got a general sense of depression about the future.
On the one hand there’s the prospect of huge increases in tuition fees for students, the motivation for many demonstrations all around the country (including an occupation here at Cardiff). I have to admit I’m firmly on the side of the students. It seems to me that what is happening is that whereas we used to finance our national gluttony by borrowing on over-valued property prices, we’ve now decided to borrow instead from the young, forcing them to pay for what we got for free instead of paying for it ourselves; it’s no wonder they’re angry. Call me old-fashioned, but I think universities should be funded out of general taxation. How many universities, and what courses, are different questions and I suspect I differ from the younger generation on the answers.
The other depressing thing relates to the other side of academic life, research. The tide of managerialism looks like sweeping away every last vestige of true originality in scientific research, in a drive for greater “efficiency”. I’ve already blogged about how the Science & Technology Facilities Council (STFC) is introducing a new system for grants which will make it impossible for individual researchers with good ideas to get money to start new research projects. Now it seems the Engineering and Physical Sciences Research Council (EPSRC) is going to go down the same road. It looks likely that in future only large-scale, low-risk research done in big consortia will be funded. Bandwagons are in; creativity is out.
Improving “efficiency” sounds like a good idea, but efficiency of what? These plans may reduce the cost of administering research grants, but they won’t do anything to increase the rate of scientific progress. Still, scientific progress can’t be entered easily on a spreadsheet so I suppose in this day and age that means it doesn’t matter.
I found the following in a story in this weeks Times Higher,
A spokeswoman for the Science and Technology Facilities Council also cited stability and flexibility as the main rationales for merging its grants programmes into one “consolidated grant”, a move announced earlier this month.
It looks like STFC has seconded someone from the Ministry of Truth. The change to STFC’s grant system is in fact driven by two factors. One is to save money, which is what they’ve been told to do so no criticism there. The other is that the costly fiasco that is the new RCUK Shared Services Centre was so badly conceived that it has a grant system that is unable to adminster 5-year rolling grants of the type we have been used to having in astronomy. On top of that, research grants will last only 3 years (as opposed to the previous 5-year duration). There’s a typically Orwellian inversion going on in our spokesperson’s comment: for “stability and flexibility”, read “instability and inflexibility”.
We’re not children. We all know that times are tough, but we could do with a bit less spin and a bit more honesty from the people
ruining running British science. Still, I’m sure the resident spin doctors at STFC are “efficient”, and these days that’s all that matters.
The following excerpt from Wordsworth’s The Excursion pretty much sums it up.
Life’s autumn past, I stand on winter’s verge;
And daily lose what I desire to keep:
Yet rather would I instantly decline
To the traditionary sympathies
Of a most rustic ignorance, and take
A fearful apprehension from the owl
Or death-watch: and as readily rejoice,
If two auspicious magpies crossed my way;–
To this would rather bend than see and hear
The repetitions wearisome of sense,
Where soul is dead, and feeling hath no place;
Where knowledge, ill begun in cold remark
On outward things, with formal inference ends;
Or, if the mind turn inward, she recoils
At once–or, not recoiling, is perplexed–
Lost in a gloom of uninspired research;
Meanwhile, the heart within the heart, the seat
Where peace and happy consciousness should dwell,
On its own axis restlessly revolving,
Seeks, yet can nowhere find, the light of truth.