Month: August 2015

Praise the long time

An example of a simulation of an experiment to be done with the LHC
An example of a simulation of an experiment to be done with the LHC – © 1997 – 2015 CERN under licence CC-BY-SA-4.0.

On July 4, 2012, Atlas and cms experiments of the Large Hadron Collider (lhc) announced that they had identified the beh boson. This led to award 2013 Nobel Prize in Physics to François Englert and Peter Higgs. As I write this, LHC experiments are continuing, while it is rising in energy levels. On August 6, 2014, the space probe Rosetta joined comet 67P/Churyumov-Gerasimenko, dropping a module called Philae on it, among other experiments. This mission is at present still ongoing.

What is the common point between a particle physics experiment and a space science mission? They are both long time experiments: the first articles theorising the beh boson were published in 19641F. Englert and Brout, R., 1964. Broken symmetry and the mass of gauge vector mesons, Physical Review Letters, vol 13, n° 9,‎ pp 321 – 323. doi: 10.1103/PhysRevLett.13.321, available on line. 2P.W. Higgs, 1964. Broken symmetries and the masses of gauge bosons, Physical Review Letters, vol 13, n° 16,‎ pp 508 – 509. doi: 10.1103/PhysRevLett.13.508, available on line. and the design of the lhc began in 1994. Concerning the Rosetta mission, its starting point were in 1984 with the validation of the Horizon 2000 project.

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Notes

Notes
↑1 F. Englert and Brout, R., 1964. Broken symmetry and the mass of gauge vector mesons, Physical Review Letters, vol 13, n° 9,‎ pp 321 – 323. doi: 10.1103/PhysRevLett.13.321, available on line.
↑2 P.W. Higgs, 1964. Broken symmetries and the masses of gauge bosons, Physical Review Letters, vol 13, n° 16,‎ pp 508 – 509. doi: 10.1103/PhysRevLett.13.508, available on line.

How I extended Galileo’s work!

Spring tide in Wimereux
Spring tide in Wimereux (Pas-de-Calais, France) – photo by Marc Ryckaert under licence CC BY 3.0 via Wikimedia Commons.

I have already mentioned it: it is about time that I present the topics that I am interested in my work. As I have indicated on this site home page and as can be deduced from my resume, my areas of expertise are applied mathematics and theoretical computer science. My scope is physical oceanography. Specifically, I am reproducing ocean dynamics on computers.

However, though being a still evolving discipline, the study of ocean dynamics has a long history. The oldest references I have found were written during the antique times. The main topic on ocean dynamics they address is tide. I intend to present this story here. Much of the information you will find in the following comes from Bernard Simon’s La Marée océanique côtière1B. Simon, 2007. La Marée océanique côtière, collection “Synthèses”, Institut océanographique éditeur.. The following is an extract from the introduction of my Ph.D. thesis2Y. Le Bars, 2010. Modélisation de la dynamique océanique barotrope dans l’estuaire et le plateau amazoniens, Ph.D. thesis, Université de Toulouse III – Paul Sabatier.. This thesis focused on the development of an ocean model and its application to the estuary of the Amazon, so I do not claim to have achieved a definitive historical study: the following is a summary, albeit detailed, but with all the limitations of this exercise.

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Notes

Notes
↑1 B. Simon, 2007. La Marée océanique côtière, collection “Synthèses”, Institut océanographique éditeur.
↑2 Y. Le Bars, 2010. Modélisation de la dynamique océanique barotrope dans l’estuaire et le plateau amazoniens, Ph.D. thesis, Université de Toulouse III – Paul Sabatier.

Nights of the stars 2015

Apparent movements of stars around Polaris
Apparent movements of stars around Polaris – by Steve Ryan under licence CC BY-SA 2.0, via Wikimedia Commons.

From August 7 to 9, these are the Nights of the Stars. This August, several interesting phenomena will be observable. It takes place during a year rich in astronomical events, including Rosetta and New Horizons missions.

If you are in France, the French Association for Astronomy offers a list of events that take place this weekend in the territory. If you are in France these days, do not hesitate!