Autor: Alejandro Rivero

  It is not rocket science… until it is. Se me estaba haciendo difícil entender el efecto o maniobra Oberth, porque siempre pienso que las maniobras asistidas incluyen intercambio de momento, y precisamente la pagina de la wikipedia arranca con un aviso «not to be confused with gravity assist». Sin intercambio de momento, la variación…

A couple weeks ago, the account @iwontoffendyou twitted the following problem. It was presented as a «round 1» exercise for employee interviews. So the logical path is first to try to answer either analytical or numerically, and only after a good enough answer is produced one can step back and look are more fun details.…

Thinking about a major puzzle in the NCG approach to the standard model, I remember that sci.physics.research, via Baez’ weeks, was very fond of triality (in the way of Evans?) to justify why some dimensions allow supersymmetry. And this pivots over SO(8), for which I asked a couple of abusive questions in mathoverflow: Does ??(32)???8×?8…

This is another use of square roots in the spirit of the eighties… but a lot more recent, from Bjorken 2013. I have seen some recent variations in Berglund-Hubsch-Minic 2023. Actually I found this while looking for Hubsch’s textbook. They seem also to fanzy the idea of a Higgs with two vacuui, one of them…

Twitter going all-in in speculative physics, it is a good excuse to mention a friend’s blog that is echoing my -now some ten or fifteen years old- speculative ruminations. Basically it was the idea that string theory was right until, say, 1974… The papers at that time were still considering supersymmetry between mesons and fermions,…