Saturday, October 31, 2015

Bell's Inequlities and Memory: two stunning papers in Nature

Fig 1 from Hensen et al. a and b show the schematic setup
with a separate "ready" signal used to signal when 2 states
have been successfully entangled. e shows the separation.
Two pretty stunning papers in Nature.

The first "Loophole-free Bell inequality violation using electron spins separated by 1.3 kilometres" (Hensen et al) is a pretty strong test of what people have long suspected: that "local realism" in which the outcome of quantum measurements is pre-determined by some "hidden variables" is not compatible with special relativity and physical observations. Previous experiments had supported this but there were always some loopholes.

This is a lovely and ingenious experiment. But it is a great pity that they only ran 245 trials because it means that their result has a p-value of only 0.039. This is not remotely good enough for most of physics. The trials only took 18 days and it would presumably have been straightforward to run them for another couple of months which would have got the p-value well below 0.000001. It really needs to be replicated and I'm a bit surprised the referees didn't ask for this. (see PS).

The authors remark that: "Our observation of a statistically significant loophole-free Bell inequality violation thus indicates rejection of all local-realist theories that accept that the number generators produce a free random bit in a timely manner and that the outputs are final once recorded in the electronics. Strictly speaking, no Bell experiment can exclude all conceivable local-realist theories, because it is fundamentally impossible to prove when and where free random input bits and output values came into existence."

Fig 1 from Rajasethupathy et al.a-c show where the labelling
agents were injected and the images. d-g show the response
amplitudes and latencies, and h and i show the CA1 and
CA3 spiking. j shows no signal from the dentate neurons
The other paper I found particularly interesting was "Projections from neocortex mediate top-down control of memory retrieval" by Priyamvada Rajasethupathy and colleagues at Stanford, which sheds a fascinating light on the mechanisms of memory.  They report the discovery of a what they call "AC-CA projection" in mice [prefrontal cortex (predominantly anterior cingulate) to hippocampus (CA3 to CA1 region)].

They find that optogenetic manipulation of AC-CA projection can elicit contextual memory retrieval. They developed tools to observe cellular-resolution neural activity during memory retrieval in mice behaving in virtual-reality environments. They "found that learning drives the emergence of a sparse class of neurons in CA2/CA3 that are highly correlated with the local network and that lead synchronous population activity events; these neurons are then preferentially recruited by the AC–CA projection during memory retrieval. These findings reveal a sparsely implemented memory retrieval mechanism in the hippocampus that operates via direct top-down prefrontal input, with implications for the patterning and storage of salient memory representations."

Both papers are examples of really beautiful and innovative experimental techniques to address really deep questions that would once have been considered almost inaccessible to experiment, and are to be applauded. Though in both cases I wish the sample sizes had been higher (n=5 is uncomfortably low even if there is a p less than 0.01).

PS Prof Hanson has kindly emailed pointing out that this is a 2-Sigma result (they observe S =2.42 with a conventional calculated std of 0.20 and Bell's inequality would give S less than 2) and many physics papers report 2 or 3 sigma results. In addition he remarks that "there is no one in the field that has any doubt that this result will not be replicated (this is a sign that the a-priori probability that our null hypothesis was true is actually small)"  (this is what he wrote but of course he means "that this result will be replicated) All of which is fair enough as far as it goes. But:
  1. If it is only possible to get a 2 or 3 sigma result it may well be worth reporting, but when it is straightforward to get a more watertight result just by running the experiments a few more days it seems a pity not to do so. These additional experiments could have been run after the paper was submitted so as not to cause problems with the priority (it was accepted 40 days after submission).
  2.  There are enough examples in the history of science of results that do not agree with what everybody in the field thinks that it would still be great to be more certain.
He says that his team and others will certainly acquire more data in the future, so the p value should come down. Hopefully this will be reported in Nature as an addendum when the data are in: it would be good to have this as clear as the Higgs particle.

Tuesday, October 27, 2015

Toby Spence and friends at Milton Court: Butterworth, Britten and Janacek

Julian, Toby, Lucy Waring, Emily Kyte and Claire Bournez
To Milton Court Concert Hall at the Guildhall School of Music and Drama for Toby Spence's wonderful recital, with Julian Milford accompanying.

They began with Butterworth's Six Songs from A Shropshire Lad of which I had previously heard two, and it was a real revelation what a sensitive composer Butterworth was: greatly helped by having two such superb interpreters who like Butterworth both studied at Oxford.

The poet of A Shropshire Lad, AE Housman, has been a figure in my imagination since my schooldays when I came across his "Fragment of a Greek Tragedy" with lines like:
But if you happen to be deaf and dumb
And do not understand a word I say,
Then wave your hand, to signify as much.
and this classic exchange:
Traveller: A shepherd's questioned mouth informed me that--
Chorus:    What? for I know not yet what you will say.*
Traveller: Nor will you ever, if you interrupt.
However Houseman was a very serious scholar and quite a deep poet. He failed his degree in Oxford, worked (like Einstein) as a clerk in the Patent Office, but established such a reputation as a private scholar that he became Professor of Latin at UCL and then at Cambridge!

Four songs by Britten followed, two somewhat mournful (O Waly, Waly and There's none to soothe) and then Toby announced "enough of this serious stuff" and produced two comic folk-songs set by Britten: The Crocodile which was a sailor's Tall Tale of being swallowed by an Enormous Crocodile (500 miles long, with a mouth 36 miles high) and a charming setting of Sally in our Alley.

The second half was Janacek's monumental The Diary of One Who Disappeared about a ploughman called Janicek who is seduced by and runs off with a gypsy girl called Zefka. There are 21 songs, mostly for the Tenor but some for a female trio and some for a Mezzo as Zefka.Claire Bournez, who sang Zefka, was striking in many respects: a lovely voice very well suited to the part, nice looking and with amazing long dark hair much commented on by the ladies afterwards.  Zefka's seduction technique is disarmingly simple:
Can it really be that I arouse such fear?
Sit here closer to me - must you keep your distance?
Or does my complexion alarm you?
I am not so dark as you might think;
Here, where the sun does not reach, I am quite a different colour!

Trio: She pulled back her blouse, revealing her breast
And all the blood in his body rushed to his head
The whole performance was a triumph, much applauded after the final tremendous song when Janicek finally leaves his village to live with Zefka and their son, though as Toby said no encore because how can you top that?

We had drinks afterwards and met some of Toby's delightful friends. A great evening. Catch anything by Toby of course - but look out also for Claire Bournez.

 * though I'd always remembered it as "Speak, for I know not what you are going to say!"

Sunday, October 25, 2015

Measure for Measure, and Agincourt

M4M Curtain call: Sarah Malin, John MacKay, Mathew Wynn, Ivanno
Jeremiah, Natalie Simpson, Romola Garai, Zubin Varla, Paul Ready,
Cath Whitfield,  Raphael Sowole, Tom Eden, Hammed Animashaun
Last night to Measure for Measure at the Young Vic, starring Romola Garai. It's a wonderful play, probably Shakespeare's most theological, all about Justice, Mercy, Truth, Hypocrisy and mis-perceptions.  There are the usual problems of setting the play in modern dress: at one point the Duke has his smart suit trousers clearly visible under his Friar's habit which makes the inability of his people to see the disguise absurd.

Possibly because many of them were film actors the cast were all miked which was also a bit of a pity. It was a strong cast with a fine ensemble and were many excellent performances: Garai was of course excellent as Isabella and I would single out Ivanno Jeremiah as her brother Claudio, John MacKay as Lucio, Tom Edden as Pompey and Sarah Malin in the minor role of Escalus (played as a female Civil Servant rather than "an ancient lord"). The entire play lasts just under 2 hours (no interval) and they have cut Mistress Overdone completely: she is referred to but doesn't appear.

As Zoe Svendsen points out in her short programme note, Measure for Measure is the only Shakespeare play to refer to the Bible in its title. In the Duke's first commission to Angelo he says:
Mortality and mercy in Vienna
Live in thy tongue and heart.
The dialogues between Isabella and Angelo are truly remarkable:
Your brother is a forfeit to the law
And you but waste your words.
                                                  Alas, alas!
Why, all the souls that were, were forfeit once,
And He that might the vantage best have took
Found out the remedy. How would you be
If He, which is the top of judgement, should
But judge you as you are.
"O it's excellent// to have a giant's strength, but it's tyrannous// to use it like a giant."

And of course when Angelo tells Isabella that if she denounced him, no-one would believe her "say what you can: my false o'erweighs your true" there are chilling modern resonances.

The moment when Isabella kneels to plead for the life of Angelo, despite thinking that he has effectively murdered her brother, is enormously moving, and was very well done indeed. It is the emotional and spiritual climax of the play. And indeed the only justification for the Duke's outrageous behaviour is that he really wants to find out whether Isabella is indeed as enormously virtuous as she is beautiful.

Svendsen makes much (as most moderns would) of the unsuitability of the marriages, but I don't think they would have seemed that way in the Shakespearian world. And the Duke is very clear that his love of Isabella depends on her consent and agreement.

Isabella and Marianna are of course variants of Elizabeth and Mary and it is perhaps no surprise that this was written for King James. Interesting also that we have names from two of Shakespeare's most popular plays: Claudio and Juliet.

Today is also the anniversary of the Battle of Agincourt. I'm reading Ian Mortimer's rather fascinating 1415: Henry V's Year of Glory and today I skipped to the account of the battle itself. I was invited to an Agincourt Dinner in the Guildhall but couldn't go due to a diary clash. A great pity!

Saturday, October 24, 2015

Churchill Dinner with Theresa May

Home Secretary and her "Great Predecessor"
To a "Churchill Dinner" on Thurs in the Cabinet War Rooms where the Guest of Honour was Theresa May. She spoke very well about the need to counter extremism and encourage inclusive and tolerant British Values.

David Starkey spoke before her and made some very interesting points about Magna Carta. He said that it was a failure and disaster in 1215 but he praised William Marshall to the skies, who re-issued the Charter in 1216 as an act of great statesmanship.

There was a delightful Churchill impersonator present and I was delighted to be able to introduce Theresa to her distinguished predecessor.

There is also an interesting Churchill Museum with a number of curious memorabilia and a lot of archive footage. I enjoyed the comment by Alanbrooke that the Cabinet War Rooms had every advantage as a war HQ save one - its close proximity to Winston. It was also fascinating to see the letter offering Churchill £20,000 to write the History of the English Speaking Peoples - to be completed by April 1939.

Monday, October 19, 2015

Frieda Hughes, Hamlet, Ariadne auf Naxos and other delights

So much happened not enough time to blog.

Last Tues we went to the Installation of David Wooton as Master of my Livery Company and met some delightful new people as well as many old friend.

Then on Weds to our brilliant friend Frieda Hughes' exhibition and launch of her book of poems "Alternative Values" which are accompanied and illustrated by a set of paintings.  These are truly amazing and I strongly recommend both the exhibition and the book. We went with two wonderful musician friends Toby Spence and Ruth Palmer and then had supper afterwards.

On Thurs we saw the live broadcast of Hamlet with Benedict Cumberbatch and on Fri took C and Daughter to the RoH production of the wonderful Ariadne Auf Naxos - where Jane Archibald was particularly exceptional as Zerbinetta in an overall very strong cast. I really love the brilliance of the conception and of the music, which is pretty much the wittiest and funniest thing written in  the 20th Century. It also speaks quite deeply about the real nature of music and the pretentiousness that we all have to a greater or lesser extent.

Sat saw us take a long weekend just by Bath in the delightful village of Freshford - and had a particularly inspiring sermon from a retired local government solicitor (and priest) in the Parish Church. He spoke very movingly and directly about how we are called to be servants and must not be concerned about our own "importance".

Just back so apologies for not having posted much in the meantime!

Sunday, October 11, 2015

Conservative Conference and Hector MacLean

Ovation for Cameron on inequality
Went to my first ever Conservative Conference in Manchester which was fascinating. Mostly un-bloggable but some points I can mention.

I did see Cameron and again shook him by the hand to congratulate him. I had to leave before his speech but I saw it on YouTube and it was magnificent and inspiring. He got his first standing ovation when he called for the Party to act to deal with inequality!

The quality of some of the women MPs in the 2010 and 2015 intake is staggering.
  • I was very fortunate to sit next to Penny Mordaunt at a dinner (whose brilliant Loyal Address speech is the best I've ever heard)
  • Nicky Morgan is a very good egg indeed - the first of the female 2010 intake to reach the Cabinet. It was interesting speaking to a senior NUT official who said how much they like her because she really listens and respects teachers!
  • Lucy Fraser - a QC before she was an MP - is very impressive indeed.
  • Nicola Blackwood is outstanding, a very able Chair of the Science and Technology Select Committee. More than holds her own in a room full of FRSs one of whom has a Nobel Prize, and she'd only 35!
  • Rebecca Pow was also most impressive.
Last night attended a 25th wedding anniversary celebration of two dear friends, held at the Middle Temple. C wore her wonderful dress by Hector MacLean. Get one if you can!

Sunday, October 04, 2015

Werther and Tallis

Two wonderful musical evenings - blogged in haste!

On Friday we saw our friend Carolyn Dobbin in the ETO's excellent production of Werther. This was the first date at the RCM but there are plenty of others. In addition to Carolyn I'd single out Lauren Zolezzi and Michael Druiett but the whole cast was strong. Catch it if you can!

Then on Sat to an amazing choral concert in Cambridge at OLEM - the highlight being Tallis's 40 part Motet!  The excellent programme note* begins: "Tallis's famous 40-part motet is the greatest musical product of its time in England, and would have been the wonder of its age - had his contemporaries known of its existence."

Apparently there is an anecdote that Tallis composed it in response to a ducal challenge for an English composer to respond to Alessandro Strigio's two (related) 40-part works. "The work remained completely unknown until James I presented Nonsuch Palace to his heir, Prince Henry, and the score was discovered in the library.

The concert was conducted by Robert Hollingworth one of the masters of Renaissance conducting and the founder of I Fagiolini.  I'm told that there was a slight muddle in Choirs 7 and 8 at one point but I certainly didn't notice and the whole effect was magnificent! Though as will be seen below, I had a family interest.

* The programme note was by Son, who was in the choir along with Daughter-in-Law and Younger Grandson!

Saturday, October 03, 2015

Supermoon, Kayak and Cornwall

Back from trips to Cornwall and Milan.

To Cornwall to see my mother for her birthday. We sad to learn on Sunday that Rev Canon Julia Wilkinson had died on Sat. May she rest in peace and rise in GLORY!

It was a pretty flat calm so I went out in a kayak and after a trial run the previous day checked with the lifeguard whether he thought it would be OK to go to the Quies and back - rocks that have always been near the horizon and which I have visited by Kayak 5 times before. "Go for it mate, great conditions" he said, forgetting (as I had done) that the Supermoon's supertides meant that the tiderace there was really spectacular.  If you look closely at the 2nd picture you can see how white the water is between the rocks.

As I came close I could hear the tiderace and was conscious that this was a bit of a "situation" but when I tried to go diagonally across it between the tiny rock (barely visible) and its tall neighbour the tide flipped me over and I was capsized at sea in a tiderace. Fortunately I kept my oar and my head and got back on, but I then found I was unable to make progress against the tiderace. I was planning to wait when lifeguards came out in a RIB and offered to tow me through the current to the other side - which I was happy to accept. Got back in time to do 3 Capsize Practice, which I should have done before I went out!

The supermoon was indeed spectacular, the more so since I could, at least in theory, have been killed by it!