Best definition of the concept of emergence I have ever heard (Daniel Whiteson): "How is that we can cook chicken soup without knowing quantum field theory?"

I don't usually buy popular science books when they are about physics or math. I prefer some more technical explanations, perhaps not necessarily textbooks, but more technical. But I do exceptions, like this one. Almost all the popular physics books are […] [Original post on mathstodon.xyz]

I learnt some new stuff in Daniel and Kelly's Extraordinary Universe episode "Relativistic beaming". For instance, it's a mystery how super massive black holes in the center of galaxies form (it doesn't seem that they're the result of collapsing stars). And it's a mystery how they accumulated […]

I still don't understand why #python invented the "slice" operator when you already have the ":". It seems that slice is necessary for some uses, like an xarray you want from latitudes -10 to 10, where you'd do something like my_array.sel(latitude = slice(-10, 10)) Doing my_array […]

I met my ex girlfriend in the social dance tonight. I knew she was going to be there and the moments before I was really nervous, and also while dancing the first two songs. But after that I relaxed, not entirely, but I certainly relaxed. I even danced a couple of songs with her and talked a […]

Last thing happening in Spain now, with the crazy prices of houses and flats: ask for loan in a bank, then in another bank, then another... buy as many flats as possible and rent them, mostly to foreigners, with a higher purchasing power. The "human factor", as Graham Greene put it, plus […]

"We rise, we fall. We may rise by falling. Defeat shapes us. Our only wisdom is tragic, known too late, and only to the lost." Guy Davenport.

In my great delay watching series, I'm now with chapter 4 of Invasion. I'm not super seduced but I'll continue, for the moment.

50 years have passed since the death of Franco, the Spanish dictatorship. I've been watching a special program about it tonight. As the rest of countries, Spain is also suffering the wave of the far right, and 21% of the population think with Franco live was good or very good... so these […]

I bought a copy of "Explorations in Mathematical Physics", by Don Koks. It includes a wide variety of topics: random walks, discrete Fourier transform, geometric algebra, tensors (how not!), a bit of cosmology... Of course, it's not a treatise on any of these topics, and I think I know some of […]

Metzger also mentions a paper that showed that self-replicant probes could colonise *the entire universe* in about 1 billion years. I haven't found the reference, and I guess by the entire universe the article would refer to everything inside the cosmic horizon, but the numbers seem plausible […]

In his episode on October 2nd, the podcast "Daniel and Kelly's Extraordinary Universe" interviews Phil Metzger, who mentioned something curious, he thinks there will never be an upper limit of the demand of intelligence, so AI servers would eventually need to go to the space, and hopefully as […]

I heard the other day a relevant physicist who said that, although he has the maximum appreciation for Roger Penrose, the book "The Road to Reality" is not a good book. That its written apparently for Penrose himself and a few others, it is not well organized, introducing stuff to justify things […]

I learnt Differential Geometry for General Relativity, so we went directly to things like Riemann tensor, geodesics, parallel transport, and we skipped all the Gauss stuff: Gauss map, gaussian curvatures, etc. I would like to see a proof of Gauss Theorem Egregium with the machine I learnt, that […]

"My grandfather once told me that there were two kinds of people: those who do the work and those who take the credit. He told me to try to be in the first group; there was much less competition there." Indira Gandhi.

It's great to go back to pages in books that you folded or marked somehow in the past and read them again and discover immediately the reason why you marked them, and that it was a totally justifiable mark.

"These and other threats, including tariffs, sanctions and the revocation of diplomats’ U.S. visas, effectively killed the deal, according to the nine American, European and developing-nation diplomats directly involved in the negotiations. They spoke on the condition of anonymity out of fear of […]

We were taught a lot of new vocabulary in our German lessons the other day. Vocabulary that has to be memorised. The words are difficult (as usual in German) and they don't seem to have patterns, so techniques like the memory palace and similar can't mostly be used. Example where I have used a […]

TIL: philosopher John Searle has said, joking, that people who deny free will, when ordering at a restaurant, should say "just bring me whatever the laws of nature have determined I will get".

Question in Sean Carroll's last AMA episode: why didn't the universe, at the beginning, convert into a black hole if all the mass was in a point? Answer (paraphrased by me): General Relativity is time reversible. If you have a high density of matter, you can turn into a singularity in the […]

More than 2 months since the breakup and when I get a message from her I still got nervous and my heartbeat accelerates. When, I wonder, when will this be finally over?

This arrived yesterday. It seems an accessible text, that even a serious high school student could follow. It bridges part of the gap between differential geometry and map projections in geodesy.

The Canary Islands (where I live) have the worst quality of life of Spain. Meanwhile, our local politicians tell us that things are great because another record of tourists has been broken. La calidad de vida en Canarias sigue siendo la peor de España […]

"Dostoevsky gives me more than any scientist, more than Gauss!" Einstein, as told by his friend Alexander Moszkowski.

Still many ads in YouTube connecting without login, from desktop and with ad blockers. Does this happen to other people as well? I guess it depends on the length and type of the video.

I've heard that a spin 1 particle that mediates an interaction (like a photon) has the property that equal changes repel and different changes attract. And that's why you can immediately discard the graviton as a spin 1 particle (in theory, it's a spin 2). I heard this from an authorised voice […]

In the episode "What came before the Big Bang?" (podcast "Daniel and Kelly's Extraordinary Universe") Daniel and Kelly interview Phil Halper, author and cosmologist. He tells about an important scientific meeting in Copenhagen where a lot of the thorny questions of physics were asked to an […]

TIL: we have many books from Aristotle. It may seem that we have a huge part of what he wrote, but experts estimate that around half of his total production is lost.

I managed to watch 30 minutes of a YouTube video. I mean 30 minutes entangled with 30 interruptions for commercials.

The renowned critic Harold Bloom said that the three more important writers of the XXth century were Marcel Proust, James Joyce, and Franz Kafka. Other experts have emitted their opinion, but I think, as an amateur, that I agree with Bloom. I would even go further. In my opinion, Kafka is the […]

The wonders? that could be hidden in Stephen Hawking's (and others) floppy disks. A digital dark age? The people rescuing forgotten knowledge trapped on old floppy disks https://www.bbc.com/future/article/20251009-rescuing-knowledge-trapped-on-old-floppy-disks

When my mother was correcting exams and she saw the same mistake over and over again, sometimes she had to go to the dictionary because she began to doubt herself. I went to a dancing lesson. It finished at 22.00. I'm among the youngest. Once it finished, colleagues at least 15 years older than […]

László Krasznahorkai's (current Nobel in Literature) book "Herscht 07769" has more than 400 pages in the English translation... and just one sentence!! The book is a concatenation of subordinate clauses. Proust's style of very long sentences of one or even two pages has been taken to the maximum […]

I went to a class about this library. It's an incredibly powerful tool that, if everything goes well, will be the standard python library for meteorology and hydrology (at least for some time). It's still in development, so many things like regridding data are still not entirely finished. But […]

TIL: the quote "the meaning of life" is supposed to have existed since antiquity. But it doesn't appear in the writings of Plato, Aristotle, Epictetus, Seneca, Augustine, Aquinas, Descartes, Hume, or Kant. The first reference appears in a satirical work by Thomas Carlyle in the XIX century […]

Something I don't understand (among many, many other things) is why you need inflation to solve the horizon problem in cosmology (the fact that all the universe seems to have the same temperature everywhere). It is said that with just the Big Bang, there are points that are causally […]

The gossip said that Alexander Dumas, father, use other people to write parts of his books. As far as I know this was never proved. But a friend told me a funny anecdote (that probably never happened). Dumas father asked to his son: "Son, have you read my last book?" "I did, father, and you?"

One of my weird questions is if every law of physics that we are typically taught in vectorial form can be written with differential forms. I know they can be written in tensorial form. But probably not with differential forms. For instance, in Einstein equations, you have the energy-momentum […]

"Life as Narrative" is a way of thinking about your life in linear terms, from born to death, telling yourself a linear story. It has been encouraged by many people, including highly respected authors and philosophers such as Oliver Sacks, Paul Ricoeur, and Daniel Dennet. Even Marcus Aurelius […]

László Krasznahorkai, Nobel in Literature. I know him and knew he was among the favourites, but I haven't read anything by him. I have heard he's a difficult author. I hope to read something by him soon. Or at least try it.😅

I tooted some weeks ago that I think the author who will win the Nobel in Literature tomorrow would be the Romanian Mircea Cărtărescu, but that I would be unpredictable (as the Swedish academics sometimes are) and vote for the Portuguese Antonio Lobo Antunes. Let's see tomorrow how wrong I am.

I don't know if I should familiarise myself with rasterio or go to the more efficient (but less pythonic) GDAL.

I've been using jax lately to compute jacobians to transform vectors between 2 coordinate systems. It took me some time learning how to vectorize (jax.vmap) to do many operations, perhaps due to its functional? thinking I'm not used to. But once that was surpassed, I have to say that jax is a […]

Author Alphonse Daudet on his physical suffering (he had syphilis): "Illness should be treated as an unwanted guest, to whom no special attention is accorded; daily life should continue as normally as possible. I don't believe I will get better, and nor does Charcot [his doctor]. Yet I always […]

I'm finishing a book on geometrical tensor calculus, and in the last chapter there's sophisticated stuff like the exterior covariant derivative and similar. Some laws of physics that are typically taught without this formalism are shown in this formalism, but there's much material in few pages […]

TIL: about Ed Emshwiller, graphic artist of the 50s, 60s and 70s, who draw lots of illustrations in science fiction. He was also interested in experimental cinema.

A cartoon from my new book, 'Physics for Cats'. Out next week: www.tomgauld.com

It has arrived!!

Some people risk their lives to help others. They're an inspiration. Thanks to the Freedom Flotilla.

What ebooks stores do you recommend? I have a Kindle, but I want to avoid Amazon. I can buy an EPUB and later convert to Kindle via Amazon itself.