Archive for nuclear weapons elimination day

Nature squeakbits [26 February 2026]

Posted in Books, pictures, Running, Travel with tags , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , on April 16, 2026 by xi'an

In this issue of Nature, uncovering the fundamental (and Ig-Nobel worth) reason why basketball shoes are squeaking, the reason being a shockwave travelling through the sole!, two tribunes against nuclear testing and “must & should” towards a successor to the START treaty… While we should ask & act for a global and if not unilateral nuclear disarmament! This alas coïncides with France announcing the increase of its nuclear arsenal and the extension of its “umbrella” to several EU countries…

And another coverage of the deplorable Trump administration dismantling the biodefense and pandemic preparedness branches of the US NIAID, presumably a late under-the-belt jab at the national institute Anthony Fauci directed for 38 years. Meaning one of the forefronts for pandemic research and vaccine development has been dismantled. Plus the US EPA revoking the 2009 statement that climate change is endangering the US population and removing greenhouse-gas emission rules. In tune with the Drill, baby, drill! motto of the Trump supporters more interested in their short-term profits than in the long-term (no-)future of the country. Paradoxically sitting in the same issue as a comment calling for a policy-making assessment of avoidable climate-change risks. Illustrated by London’s drownin’ below

And a summary of their conclusions from 23 of the 27 members (from 27 countries) of the Scientific Advisory Group for the Origin of Novel Pathogens for the WHO. After 3.5 years of debate on the origin of COVID-19! Four hypotheses are examined and other hoaxes and conspiracies are debunked.

Another political entry about the EU and its Horizon Europe programme (that is funding my ERC Synergy grant) baring (researchers from) Chinese research organisations from applying for its grants in sensitive methodologies, in order to prevent “the undesired transfer of IP”. Following similar and earlier actions in the US with the (newspeak!) China Initiative launched by Trump 1.0 that turned into a witch hunt.

An exciting 228 metres of rock and mud providing a window on the past 23 million year weather. Obtained from the West Antarctica Ice Sheet.

of first importance

Posted in Books, Kids, Statistics, University life with tags , , , , , , , , , , , , , on June 14, 2022 by xi'an

My PhD student Charly Andral came with the question of the birthdate of importance sampling. I was under the impression that it had been created at the same time as the plain Monte Carlo method, being essentially the same thing since

\int_{\mathfrak X} h(x)f(x)\,\text dx = \int_{\mathfrak X} h(x)\frac{f(x)}{g(x)}g(x)\,\text dx

hence due to von Neumann or Ulam, but he could not find a reference earlier than a 1949 proceeding publication by Hermann Kahn in a seminar on scientific computation run by IBM. Despite writing a series of Monte Carlo papers in the late 1940’s and 1950’s, Kahn is not well-known in these circles (although mentioned in Fishman’s book), while being popular to some extent for his theorisation of nuclear war escalation and deterence. (I wonder if the concept is developed in some of his earlier 1948 papers. In a 1951 paper with Goertzel, a footnote signals than the approach was called quota sampling in their earlier papers. Charly has actually traced the earliest proposal as being Kahn’s, in a 14 June 1949 RAND preprint, beating Goertzel’s Oak Ridge National Laboratory preprint on quota sampling and importance functions by five days.)

(As a further marginalia, Kahn wrote with T.E. Harris an earlier preprint on Monte Carlo methods in April 1949, the same Harris as in Harris recurrence.)

total elimination of nuclear weapons

Posted in Statistics with tags , , , , on September 26, 2021 by xi'an