Archive for munroes

Glenshee [jatp]

Posted in Mountains, pictures, Running, Travel with tags , , , , , , , , on June 26, 2018 by xi'an

paradise island

Posted in Mountains, pictures, Travel with tags , , , , , , , on August 14, 2017 by xi'an

As should be obvious from the pictures posted here in the past days, I have been away on vacations on the Scottish island of Skye, part of the Inner Hebrides. This is a place that had stood very high in my dream vacation places, mostly because of the mountain range that stands at the bottom of the island, called the Cuillins. There are 13 Munroes (tops above 3,000 feet) in that range and its entire traverse takes a very long day, including several belays. As I was there for a family vacation, we [alas!] only went up the easiest group, made of Sgùrr nan Gillean, Am Basteir, and Bruach na Frìthe, and did not climb Sgùrr nan Gillean. This was a fairly easy hike with a 900m differential, the only difficulty being in route finding. Which was made harder than needed by me first confusing a group of three hills with these Cuillins for the first third of the hike! And relating to instructions in our guidebook that covered the opposite side of the mountains. It was however a most pleasant walk, quite dry by Scottish standards (where it is often hard to separate water and soil) and with sun part of the way (it actually did not start to rain until the final half-hour). And not too many people on the path.
The other days saw easier walks at lower elevations, from a grassy and pleasant route to the top of MacLeod’s North Table [with terrific views of Western Skye and the Outer Hebrides], to a tour of the Gresornish peninsula under a pouring rain but with an amazing light (and an exciting crossing of a definitely web bog where even sheep did not do]. Overall, this was a great week in a secluded location, keeping mostly away from the few tourist traps [except for a trip to the Isle of Skye Brewery and to the compulsory Neist Point lighthouse] and I hope I can get back there one day. Although other Northern paradise islands like Mull, Harris, and the Faeroe are also beguiling..!
An unsolved puzzle about this visit to Skye is that, while there are sheep all over the island, which makes spotting any form of wildlife but midges impossible!, lamb meat is curiously absent from restaurant menus [except from the offal parts used in haggis]. The few persons we asked seemed perplexed by our question and had no convincing explanation to this absence!

Glen Coe Salomon SkyRace [sept. 16-18, 2016]

Posted in Mountains, pictures, Running, Travel with tags , , , , , , , , on February 14, 2016 by xi'an

After pondering a (little) while about whether or not joining the Skyline Scotland races, I decided to register for the Ring of Steall skyrace! It is a 25km trail run starting from Kinlochleven and going over the five Munroes of the Ring of Steall facing Ben Nevis, as well as down to Glen Nevis in the middle. Not as impressive as the Glen Coe skyrace the day after, with its 52km and 4600m positive differential!

I climbed this ridge in Winter with Jérôme Accardo (twice) and Peter Green (once), in the most beautiful day I ever had when mountaineering in Scotland. The route should be easier in September with (hopefully!) no ice or snow… although one never knows!

BunneinBeag, Ring of Steall, February 2003, with J. Accardo and P. Green, the most exhilarating and sunniest Scottish day ever!

Glencoe skyline: my dream race!

Posted in Mountains, pictures, Running, Travel with tags , , , , , , , , , , on September 26, 2015 by xi'an

I came upon the news by mere chance: the first Salomon Glencoe skyline mountain race took place last month, on Aug. 22, in one of my favourite mountaineering spots, the Valley of Glencoe. I have hiked and climbed in this valley six or seven times, and “bagged” seven of the nine local Munroes, mostly in Winter conditions. The race includes all of them in a 53km route with a 4,256m total ascent (and descent!), with a scramble of Buachaille Etive Mor via the classic Curved Ridge route and the west-to-east traverse of the Aonach Eagach. Absolutely awesome!

The winners completed the route in 7:36 for Joe Symmons and 7:44 for Emelie Forsberg, with the last runner finishing in 14 hours. I really wish I could enter this race but the organisers screen quite thoroughly entrances based on past experience, insisting on previous mountain races, and so this must remain a dream..!

from top of Stob Choire down towards northern plateau, Glencoe, Apr. 21, 2012

computational methods for statistical mechanics [day #1]

Posted in Mountains, pictures, Running, Statistics, Travel, University life with tags , , , , , , , , , , , , on June 4, 2014 by xi'an

Arthur Seat, Edinburgh, Sep. 7, 2011

The first talks of the day at this ICMS workshop [“at the interface between mathematical statistics and molecular simulation”] were actually lectures introducing molecular simulation to statisticians by Michael Allen from Warwick and computational statistics to physicists by Omiros Papaspiliopoulos. Allen’s lecture was quite pedagogical, even though I had to quiz wikipedia for physics terms and notions. Like a force being the gradient of a potential function. He gave a physical meaning to Langevin’ equation. As well as references from the Journal of Chemical Physics that were more recent than 1953. He mentioned alternatives to Langevin’s equation too and I idly wondered at the possibility of using those alternatives as other tools for improved MCMC simulation. Although introducing friction may not be the most promising way to speed up the thing… He later introduced what statisticians call Langevin’ algorithm (MALA) as smart Monte Carlo (Rossky et al., …1978!!!). Recovering Hamiltonian and hybrid Monte Carlo algorithms as a fusion of molecular dynamics, Verlet algorithm, and Metropolis acceptance step! As well as reminding us of the physics roots of umbrella sampling and the Wang-Landau algorithm.

Omiros Papaspiliopoulos also gave a very pedagogical entry to the convergence of MCMC samplers which focussed on the L² approach to convergence. This reminded me of the very first papers published on the convergence of the Gibbs sampler, like the 1990 1992 JCGS paper by Schervish and Carlin. Or the 1991 1996 Annals of Statistics by Amit. (Funny that I located both papers much earlier than when they actually appeared!) One surprising fact was that the convergence of all reversible  ergodic kernels is necessarily geometric. There is no classification of kernels in this topology, the only ranking being through the respective spectral gaps. A good refresher for most of the audience, statisticians included.

The following talks of Day 1 were by Christophe Andrieu, who kept with the spirit of a highly pedagogical entry, covering particle filters, SMC, particle Gibbs and pseudo-marginals, and who hit the right tone I think given the heterogeneous audience. And by Ben Leimkuhler about particle simulation for very large molecular structures. Closing the day by focussing on Langevin dynamics. What I understood from the talk was an improved entry into the resolution of some SPDEs. Gaining two orders when compared with Euler-Marayama.  But missed the meaning of the friction coefficient γ converging to infinity in the title…