A periodic backup of my mobile phone yesterday - mainly pictures and videos - was the occasion to give a look back at things I did and places I visited in 2014, for business and leisure. I thought it would be fun to share some of those pictures with you, with sparse comments. I know, Facebook does this for you automatically, but what does Facebook know of what is meaningful and what isn't ? So here we go.
The first pic was taken at Beaubourg, in Paris - it is a sculpture I absolutely love: "The king plays with the queen" by Max Ernst.
Still in Paris (for a vacation at the beginning of January), the grandiose interior of the Opera de Paris...
Each January, I scamper out of the basement and talk to folks during MIT's Independent Activities Period. The Alumni Association is the sponsor (no one from the physics or math department is inviting me).
This morning I woke up at 6AM, had a shower and breakfast, dressed up, and rushed out in the cold of the fading night to catch a train to Mestre, where my car was parked. From there I drove due north for two hours, to a place in the mountains called Pieve di Cadore. A comfortable ride in normal weather, but this morning the weather was horrible, with an insisting water bombing from above which slowly turned to heavy sleet as I gained altitude. The drive was very unnerving as my car is old and not well equipped for these winter conditions - hydroplaning was frequent. But I made it.
In 1973, during a symposium to celebrate the 500th birthday of Copernicus, Brandon Carter, a post-doctoral researcher in astrophysics at the University of Cambridge, tweaked his audience by stating that humanity did indeed hold a special place in the Universe - the exact opposite of what scientists from Copernicus on have said.
Since then, it has gone in and out of fashion, and the Anthropic Principle, as it was called, was most recently embraced in some M-Theory flavors of string theory.
The CMS Collaboration at the LHC collider has recently measured a non-negligible rate for the fraction of Higgs boson decays into muon-tau pairs, as I reported in this article last summer. The observation is not statistically significant enough to cause an earthquake in the world of high-energy physics, and sceptics like myself just raised a gram of eyebrows at the announcement - oh yeah, just another 2-sigma effect. However, the matter becomes more interesting if there is a theoretical model which allows for the observed effect, AND if the model is not entirely crazy.
There is no more important universal problem in the Standard Model of elementary particles than the problem of mass and mixing flavor hierarchies.
The mainstream theoretical approach for treating it is to probe different group-symmetry flavor models. For decades, this math approach has not led to established flavor theory.
Is seems reasonable at this time to view flavor concept as related to new physics fundamental paradigm that should be firstly approached by simple means of semi-empirical phenomenology as exampled by physics history of e.g. quantum mechanics (Plank, Einstein, De-Broglie, Rutherford, Bohr, ...).
Neutrinos almost never interact, 10,000,000,000,000 neutrinos pass through your hand every second but fewer than one actually makes contact with any of the atoms inside us.
When neutrinos do interact with another particle, it happens at very close distances and involves a high-momentum transfer. Mostly. Physicists have found evidence that these tiny particles might be involved in a weird reaction, even for neutrinos. A paper in Physical Review Letters shows that neutrinos sometimes can also interact with a nucleus but leave it basically untouched - inflicting no more than a "glancing blow" - resulting in a particle being created out of a vacuum.
Apologizing for the silence of last week, due not so much to Christmas holidays but to my working around the clock to write a grant proposal, I wish to show you today a graph which describes very well the complexities of modern day frontier theoretical calculations. That graph is the collection of some of the Feynman diagrams that have to be calculated in order to evaluate a property of the electron called its "anomalous magnetic moment".
Frozen cold but not the way beyond absolute zero. Flickr/kriimurohelisedsilmad , CC BY-NC-SA
By Tapio Simula, Monash University