Guest blog by Dr Beni Yoshida, quantum information fellow at Caltech
The lessons we learned from the Ryu-Takayanagi formula, the firewall paradox, and the ER=EPR conjecture have convinced us that quantum information theory can become a powerful tool to sharpen our understanding of various problems in high-energy physics. But many of the concepts utilized so far rely on entanglement entropy and its generalizations, quantities developed by Von Neumann more than 60 years ago. We live in the 21st century. Why don’t we use more modern concepts, such as the theory of quantum error-correcting codes?
In a recent paper with Daniel Harlow, Fernando Pastawski and John Preskill, we have proposed a toy model of the AdS/CFT correspondence based on quantum error-correcting codes. Fernando has already written how this research project started after a fateful visit by Daniel to Caltech and John’s remarkable prediction in 1999. In this post, I hope to write an introduction which may serve as a reader’s guide to our paper, explaining why I’m so fascinated by the beauty of the toy model.
Guest blog by Dr Beni Yoshida, quantum information fellow at Caltech
I think that this 97-minute-long public lecture by David Gross at New York University hasn't been embedded on this blog yet:
It is not just another copy of a talk you have heard five times.
Two years ago, two Czech women (Antonie Chrástecká – the skinnier one – and Hana Humpálová) were going to spend 8 weeks in India. However, before they got there, they were kidnapped by a militant group in Balochistan, the largest province of Pakistan.
Czech government's negotiations with Pakistani authorities have been useless. After one such failed attempt, the Czech president Miloš Zeman told the Pakistani ambassador to Czechia that "your secret agency is worth a pile of cr*p. Can you explain to me how it's possible that two weeks after our compatriots were kidnapped, the governor of Balochistan was abducted as well?"
Ira Flatow's Science Friday belongs among the better or best science shows. Yesterday, he hosted some very interesting guests and the topic was interesting, too:
And if you have 30 spare minutes, you should click the orange-white "play" button above and listen to this segment.
I am not among those who would believe that rich people shouldn't be allowed to do politics. In fact, they may even do some of these activities at the same time. And Silvio Berlusconi's activities in Italy seemed borderline OK to me. But I am shocked by many people's selective inability to see the risks (and actual wrongdoings), especially in the case when the politicians are very rich entrepreneurs.
When talking about the post-Soviet realm, we often talk about "oligarchs". This word comes with some negative connotations. Some of them are unjustifiable signs of racism of a sort. When a wealthy Russian guy is doing the very same thing as his American or Italian colleagues, he may still be just an "oligarch" rather than a legitimate mogul or tycoon.
Well, sometimes the negative flavor may be justifiable. What is the difference between the "bad oligarchs" from the post-Soviet countries and the "good moguls" from the West? I think that the assumption is that the "oligarchs" are mixing their political and economical powers in ways that are not kosher and that abuse the poor existing standards when it comes to the enforcement of laws.
This blog post was written hours before it was revealed that co-pilot Andreas Lubitz appeared to want to 'destroy the plane': prosecutor, and is therefore obsolete (but my basic guess about the "suicidal act" was right)
My half-sister has been afraid of flying for many years. For two days, there is some evidence that she had a point.
The crash of Germanwings 9525 occurred 100 kilometers Northwest of Nice, and she's been living in Nice for many years. And yes, she has flown with Germanwings – a subsidiary of Lufthansa – in the past.
Unfortunately, due to a short circuit somewhere at the LHC, a small metallic piece will have to be removed – which takes a week (it's so slow because CERN employs LEGO men to do the job) – and the 2015 LHC physics run may be postponed by up to 5 weeks because of that.
Wolfram: You have the last week to buy Mathematica at a 25% discount (a "pi day" celebration; student edition). Edward Measure has already happily bought it.Meanwhile, ATLAS and CMS have flooded their web pages with new papers resulting from the 2012 run. In most of these papers, the Standard Model gets an "A".
I thought that the members of the European Parliament don't have the right to propose any laws but this rule must be inaccurate because today, the European Parliament will discuss the proposal by Mr Petr Šilar (Christian Democratic Union – Czechoslovak People's Party) and his brothers (these are not comrades) to abolish the constant switching from the winter time to summer time and back.
On Saturday-Sunday night, on March 29th, Europe is scheduled to switch to the summer time again: the period between 2 am and 3 am won't ever take place. Similarly, sometime in the Fall, for its big success, the 2 am through 3 am hour is repeated twice.
Recently, there have been lots of stories in the newspapers about genetic improvements of the humans, about mind control, and artificial organs that directly communicate with the brain etc. We have probably entered the era in which all these things have in principle been mastered and the gradual improvements of people's ability to "help" humans in similar ways have become an unavoidable scenario for the future.
For example, this video shows an artificial arm that has been trained to behave almost as good as the real one (it has earned 70% of the "score" of Nature's prototype) after brachial plexus injury. See The Lancet article by Prof Oskar Aszman et al. (Vienna) and a Gizmag review of the work plus Google News.
Some muscles have been transplanted, and the artificial limb has been added on top of that. Impulses from the transplanted muscles are being read and evaluated – after weeks of training exercises that may be analogous to the machine learning strategies at Kaggle.com – and the people ultimately learn how to control the new metallic organ while the limb learns to listen.
Last night, I was reading the Sunday edition of Frankfurter Allgemeine Zeitung where the first seemingly trustworthy estimate of the day when Greece runs out of cash has appeared. See Deutsche Welle for a new story in English.
A statue of the Greek government
The European Commission – a body that is supposed to be the government of the European Union – has some folks in Athens and they should know something about the amount of cash in the Greek government coffers and about the daily inflows and outflows.
The last day when Tsipras' boys will boast liquidity should be April 8th. On the following day, Greece is supposed to make a half-a-billion-dollar repayment and that should already be too much for their financial abilities unless they will receive some new aid. Interestingly enough, Tsipras will visit Moscow on April 8th so it can't be excluded that Russia will provide Greece with cash just hours before the otherwise predictable default.
For three months, clairvoyants, psychics, and fortune tellers in Prague – and Czechia – have had the opportunity to win $4,000 in a very easy way. Just arrive to the Nový Smíchov mall, paranormally look through the safe box over there, see what's inside (or be a prophet or soothsayer and predict the objects that would be written in this blog post), and write the correct answer – "a toothbrush, a [restaurant] bill, and a walnut [marble would be tolerated]" – to a web form.
Socialite, sponsor, and trader Václav Dejčmar (who co-hosted my black hole talk in Prague-Barrandov in January) contributed the money and the toothbrush. Leoš Kyša, the vice-chairman of Sisyphus (the Czech counterpart of CSICOP; the name is chosen because the fight against paranormal beliefs looks like a fight against windmills) added the bill, and Jakub Kroulík from Deceitful Players (falesni-hraci.cz), a gang of playful skeptics who have learned to do everything that psychics can do, added the walnut.
You know, many psychics and fortune tellers have to work hard and get $10 from one client. You need to repeat it many times to earn $4,000. So the safe box could be handy.
None of the seemingly strong anomalies reported by the LHCb collaboration has been recognized as a survivor but many people believe that similar events are not being overlooked by TRF and they rely on this blog as a source, so I must give you a short report about a new bold announcement by LHCb.
20 March 2015: \(B^0\to K^*\mu^+\mu^-\): new analysis confirms old puzzle (LHCb CERN website)In July 2013, TRF readers were told about the 3.7 excess in these muon decays of B-mesons.
The complete 2011-2012 data, which was just 3 inverse femtobarns because we talk about LHCb (perhaps I should remind you that it is a "cheaper" LHC detector that focuses on bottom quarks and therefore on CP-violation and flavor violation), have been analyzed. The absolute strength of the signal has decreased but so did the noise so the significance level remained at 3.7 sigma!
Sadly, the Czech newspapers informed us about the death of Prof Petr Vopěnka, a prominent Czech mathematician whom I knew in person (as a student).
Incidentally, in recent years, he was affiliated with the regional university here in Pilsen but I never met him here; he mostly used the affiliation to write some mostly historical books, and he wrote many books.
As Google Scholar tells you, he wrote some papers that were famous, relatively to what was usual in Czechoslovakia.
A large percentage of the people and the "mainstream media" have all kinds of crazy opinions, often combined with downright hostility towards science in general and modern theoretical physics in particular. Supersymmetry has been a frequent target of numerous outlets in recent years.
But the 2015 LHC run is getting started and it's an exciting time – surely not a good time for bitterness – and one sometimes finds newspapers that turn out to be great surprises. Today, I need to celebrate the story
It also honestly states that there's no direct experimental sign of SUSY yet, and that the LHC may change this situation soon or not.
If you're somewhere in Europe, expect the partial solar eclipse sometime between 9 am (the Moon will first bite into the "2 o'clock" place of the solar disk) and noon local time (the Moon will leave the Sun at the place "9 o'clock" or so). For example, Czechia will see the eclipse to peak around 10:47 am Prague Winter Time when about 75% of the area of the solar disk will be hidden by the Moon (France will peak at 80% etc.) and the remaining Sun will be U-shaped (the shadow will be close to "noon" of the solar disk).
Today's solar eclipse will also be a total one in a thin strip going mostly through the Atlantic ocean, on the Eastern side from the Greenland and then towards the North Pole (a coincidence).