oce 🐆

I try to contribute to things getting better, with sourced information, OC and polite rational skepticism.
Disagreeing with a point ≠ supporting the opposite side, I support rationality.
Let’s discuss to make things better sustainably.
Always happy to question our beliefs.

  • 13 Posts
  • 17 Comments
Joined 2 years ago
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Cake day: July 7th, 2023

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  • Ajuster l’offre et la demande d’électricité à quelques pouillemes prés en temps réel pour éviter que le système s’écroule est un défi technique énorme pour tous les pays, même développés (le Texas a régulièrement des problèmes par exemple). Il y a normalement pas mal de sécurités pour absorber les déséquilibres, mais il y a eu des défaillances en chaîne la-dessus. Le renouvelable a probablement joué un rôle parce qu’il démultiplie les sources et donc rend le système d’équilibre plus compliqué. Mais il a suffisamment d’autres avantages qui compensent la complexité additionnel. Je pense qu’il n’y a que les populistes anti renouvelable qui trouveront dans cet incident un argument contre les renouvelables en général. Le problème était probablement dans la maintenance des systèmes qui sécurisent l’équilibrage.






  • I was surprised so I did the computation just to resolve the disk of Betelgeuse at 550 nm, and I found a telescope of 2.8 m, that’s definitely already doable. We already have 8 m in one piece and 10 m segmented, JWST is 6.5 m segmented. The ELT is planned to be 39 m for 2028. So this star is closer and bigger than I thought.

    And these are the images we have from one of the top imaging instrument SPHERE on the VLT in 2019. It’s precise enough to show the change of shape due to its variable star type.


  • It would be the size of the telescope’s diffraction artifacts probably. Meaning the shape you see on the picture is not related to the size of the star but only to the physical limits of the optical instrument. This diffraction pattern is proportional to the color your looking at and inversely proportional to the size of the telescope primary mirror. The bigger the telescope primary mirror, the smaller the diffraction pattern and the more chance you have that this artifact will not completely hide the object you are looking at. I didn’t do the math, but I guess to image the actual disk of Betelgeuse, the size of the telescope you need is probably still science fiction, even with interferometry.