Archive for Milky Way

Nature tidbits [23 October 2025]

Posted in Books, Kids, pictures, Running, Travel, University life with tags , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , on November 27, 2025 by xi'an

In this October issue of nature, plenty of the “usual” topics, namely AI and Trump.2.0 wrecking balls, along with two cosmology entries that related to my trip to the early universe last week, and a pros-and-cons opposition about animal testing,

a discussion on the nature of the “little red dots” that have been recently observed and whose nature remains open, the most popular explanation (I was given during lunch) being black holes surrounded by gas (even though I cannot understand why the gas is not attracted by the black hole!) [and would have produced a more exciting cover!]

a review of the recent book Discordance: The Troubled History of the Hubble Constant by Jim Baggott, entitled Why we still don’t understand the Universe — even after a century of dispute! A review that regrets that more time is spent on the Hubble “constant” (which varies with time!) rather than more controversial issues like dark matter and dark energy (And strangely bemoans that the book is focussed on scientific developments, missing sociological ones. Duh?! (Bonus for a picture of suit-and-tie Edwin Hubble sitting at the centre of a telescope),

two entries on the well-being [or lack thereof] of PhD students, with nothing particularly surprising (eg, inclusivity and respect help!), and Brazil, Australia and Italy ranking top locations but in a comparative study that does not mention France (as often in international comparisons found in Nature) despite the place being in the top 10 countries delivering PhD degrees, not that I believe PhD students are particularly well-treated in French academia!, the (unexplained) surprise being Italy ranking so high given the close resemblance between the two countries (low stipends, shortage of postdoc and permanent positions, high teaching loads for the advisor, limited travel budgets),

a conference (purposedly) made of AI-written papers reviewed by AI referees, Agents4Science 2025, how universities are rushed into adapting to AI-fluent students, whose skills are changing, and the rise in fake authors produced by paper mills, with a limited range of acceptable solutions,

why Trump 2.0‘s blackmail on pharmaceutical companies is counter-productive and likely to slow down progress, and why his massive increase of highly qualified scientists is shooting (or nuking) USelf in the foot, given the huge proportion) of im/emigrated Nobel prize winners (for physics, chemistry, and medicine), along the (post-) Nobel prize in economics is a direct or indirect reply to this regression by awarding the Prize to economists who worked on the importance of creativity and science on growth (not very surprising at first look!)

Nature tidbits [30th October 2025]

Posted in Books, Kids, pictures, Running, Travel, University life with tags , , , , , , , , , , , , , , , , , , , , , , , , , , , , , on November 22, 2025 by xi'an

In this October issue of nature, items of interest (to me) [already highlighted in an emailed News Highlight]:

Google claim a significant ‘quantum advantage’ by quantum-echoes algorithms that they say is 13,000 faster than classical algorithms, but it is unclear from the nature article where and when their algorithms can be used, apparently missing to apply to realistic scientific applications… (Along with a paper on an “atom-array architecture that enables continuous operation with reloading rates of up to 30,000 initialized qubits per second while preserving coherence across a rearranged large-scale qubit array”.)

On the Trump vs. Science scene, a predicted drop in PhD admissions as an adaptation to (uncertain) Trump’s cuts, bans, visa restrictions, and other attempts at arm-bending and blackmailing  (And the novelty of me receiving applications from the US, a first!) Some U.S. departments have simply cancelled PhD admissions… But some universities have so far resisted the Orange pressure. Namely, the MIT, Brown University, (good old) Penn, UCLA, the University of Virginia (albeit agreeing to a deal), Dartmouth College, and the University of Arizona in Tucson. Vanderbilt has given in. (UT Austin and Harvard seem to be continuing the discussion with the Trump administration.) Meanwhile, China is zooming past! The issue also contains articles on how fundamental science discoveries have had hugely practical consequences, in case one need argue with a sceptic.

As a less urgent issue, some researchers at Institut Pasteur in Paris identified new diseases that did not help Napoléon’s Grande Armée as it retreated from Moscow, from the DNA of 13 soldiers buried in Lithuania. (With nature failing to give credit to the painter Adolph Northen for his famous “Napoleon’s retreat from Moscow” illustrating the story, attributed to the researchers in the paper!)

In this period of ERC announcements of their grantees, an analysis of the two-digit rise in applications. Unsurprising, given the international context. Along with a decrease in funding due to a lack of adjustment against inflation since 2007. (Incidentally, I found out this week that Torsten Elßin—at the Max Planck Institute for Astrophysics—I visited once had been selected for a Synergy grant on a 3D Milky Way Atlas. Along another cosmology Synergy grant at MPA on the Epoch of Reionization.)

A runner’s must-read that starts with the statement “the human body has a ‘metabolic ceiling’ that even the most extreme athletes cannot surpass”. Which would be 2.4 times the basal metabolic rate (BMR) for extended periods—by which the authors mean 30 weeks and over!, not a half-marathon. Not so exciting a paper in the end.

As predicted by the cover, a Royal Society meeting acknowledging the AI language models killed Turing’ test and questioning the next one. Since assessing the capacities and limitations of novel AIs and AGIs sounds more relevant and societally important. To wit, “;the Turing test of the future should question whether an AI is safe, reliable and provides meaningful benefit, he said, and should also ask who bears the cost of that benefit”. (As discussed in the book review of The Means of Prediction: How AI Really Works (and Who Benefits) by Maximilian Kasy, in the same volume. And yet another paper on AI biases.)

not summiting Volcan Osorno

Posted in Mountains, pictures, Running, Travel with tags , , , , , , , , , , , , , , on October 31, 2022 by xi'an

While in Puerto Varas for BNP13, I tried to summit the nearby Orsono volcano (2652m) but it did not work out… Indeed, Huella Andina, the guiding company, chose to postpone the climb by two consecutive days for fear of snowfall (which did not materialise) and ended up choosing the windiest day of the week. In the meanwhile, Zhu Yichen had joined me and we all three were at the start of the trail (at about 1000m) at the earliest, starting hiking by 4:30 under a magnificent Southern night sky on top of us, with a rich Milky Way. And the Southern X. Obviously all by ourselves. The wind was strong then but quite bearable and the trail of powdery ash quite smooth till we reached a small hut to put crampons and add one more layer, around 1600m.

When we started again the wind had strengthened with the incoming dawn, rising to a point where we could hardly stand up to it, and our guide eventually decided to turn back, as it was only to get worse in the remaining 600m to the top, confirming the earlier prediction of 70km/hour winds… Yichin was of the same opinion and hence we reluctantly turned back down to the bottom of the slope, with the wind mostly on our back and a pleasant steady gradient descent. (Although my tights are still sensitive three days after the climb!) Surprisingly I was not feeling particularly cold (and with the right face protection my nose was not close to frozen, which happened on Monte Rosa in 2016). Even after seeing my best North Face mitt been blown away within a second of loosing grip of it! (Anyone with a spare left hand down mitt?! Because it had to be the left hand, of course!)

Obviously, this was quite disappointing as I had planned the climb for weeks, brought all the layers to face a potential -20⁰ windchill, was in good enough shape, did not feel any altitude effect, and we did not even reach the glacier. It was most frustrating as the summiting attempt would have worked so nicely in either one of the previous two days, but these are the rules of the mountaineering game, especially in an oceanic climate as in Southern Chile. And with narrow windows as those allowed by attending a one week conference. At least we were back to the BNP conference in time for the morning coffee break! I wish the conference participants hoping to summit later had better luck.

where will stars be in 10⁶ years?

Posted in Kids, pictures, Travel with tags , , , , , , on December 4, 2020 by xi'an

black holes capture Nobel

Posted in Statistics, Travel, University life with tags , , , , , , , on October 7, 2020 by xi'an