The other day I traveled with Kalliopi and our two newborns to Padova from Lulea. After six full months in Lapland - a full autumn and winter, in fact - I needed to get back to my original office, and take care of other business at what has become my second home now. Meanwhile, travel has become considerably more complicated for me: traveling with two infants is no easy matter.

Although I have long retired from serious chess tournaments (they take too much time, a luxury I do not have anymore - even more so now that I have two infants to help grow!), I insist playing online blitz on chess.com, with alternating fortunes. My elo rating hovers in the 2200-2300 range, signalling that I still have my wits around me (I figure it is a very good way to keep a watch on my mental capabilities: if Alzheimer lurks, I will spot it early). 

These days I am putting the finishing touches on a hybrid algorithm that optimizes a system (a gamma-ray observatory) by combining reinforcement-learning with gradient descent. Although I published an optimization strategy for that application already, I am going back to it to demonstrate a case where the simultaneous optimization of hardware and software is necessary, for a paper on co-design I am writing with several colleagues.
In the course of the software development, I ran into a simple but still interesting statistical issue I had not paid attention to until now. So I thought I could share it with you here.

Strange how time goes by. And strange I would say that, since I know time does not flow, it is just our perception of one of the spacetime coordinates of our block universe... 
The thing is, on February 5 I will turn 60. An important date for anybody - I could say a milestone. First of all, let me say that we give for granted all the days of our life we got to live, but in truth we did not know it from the start we would make it far. I do feel rather young still, but I am very well aware that there are heaps of ways I could have ended my life earlier. Accidents, but also naturally occurring sickness.

I recently listened again to Richard Feynman explaining why the flowing of time is probably an illusion. In modern physics time is just a coordinate, on the same footing as space, and the universe can be described as a four-dimensional object — a spacetime block. In that view, nothing really “flows”. All events simply are, laid out in a 4D structure. What we experience as the passage of time is tied instead to the arrow of entropy: the fact that we move through a sequence of states ordered by increasing disorder, and that memory itself is asymmetric.

Today I was saddened to hear of the passing of Hans Jensen, a physicist and former colleague in the CDF experiment at Fermilab. There is an obituary page here with nice pics and a bio if you want detail on his interesting, accomplished life. Here I thought I would remember him by pasting an excerpt of my 2016 book, "Anomaly! Collider Physics and the Quest for New Phenomena at Fermilab", where he is featured. The topic of the anecdote is the data collection for the top quark search. The date is December 1992.
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