@wrog@mastodon.murkworks.net2026-01-08 15:31:41
I decided it was time for another go at explaining Special Relativity.
I remain annoyed at how few people really get it, even amongst avid SF consumers, who have gotten entirely too accustomed to generations of SF writers papering over the FTL issues with technobabble, 'cause we need that galactic empire, don'tcha know.
The idea is to do this with basic geometry you knew or could have learned about in 6th grade plus a bit of algebra (up to Pythagorean Theorem, which I *d…
@deprogrammaticaipsum@mas.to2025-11-02 19:57:24
"Dr. Charles Misner, who passed away in 2023 at the age of 91, was a professor of physics at the University of Maryland from 1963 to 2000, and a renowned expert in General Relativity. He was the recipient of the Albert Einstein medal in 2015, and was the co-author of “Gravitation”, one of the best-selling books in the subject of General Relativity, featuring none other than Kip Thorne on the cover."
@arXiv_physicsgenph_bot@mastoxiv.page2025-11-12 08:11:59
Physics is simple only when analyzed locally
Matteo Luca Ruggiero
https://arxiv.org/abs/2511.07447 https://arxiv.org/pdf/2511.07447 https://arxiv.org/html/2511.07447
arXiv:2511.07447v1 Announce Type: new
Abstract: The definition of a reference frame in General Relativity is achieved through the construction of a congruence of time-like world-lines. In this framework, splitting techniques enable us to express physical phenomena in analogy with Special Relativity, thereby realizing the local description in terms of Minkowski spacetime in accordance with the equivalence principle. This approach holds promise for elucidating the foundational principles of relativistic gravitational physics, as it illustrates how its 4-dimensional mathematical model manifests in practical measurement processes conducted in both space and time. In addition, we show how, within this framework, the Newtonian gravitational force naturally emerges as an effect of the non-geodesic path of the reference frame.
toXiv_bot_toot
@emd@cosocial.ca2025-12-09 14:21:35
Nothing hurts my head more than reading about time. https://mastodon.social/@h4ckernews/115688679152089280
@patrikja@functional.cafe2025-12-07 21:21:27
X-mas comes early this year: the ICFP 2025 talks are now on YouTube.
You can catch my talk on "Domain-specific tensor languages" below. We explore implementing tensor calculus in #Haskell, supporting both Einstein notation and Penrose diagrams to model things like General Relativity and black holes. 🕳️🚀
My talk:
@karlauerbach@sfba.social2025-12-03 02:40:50
Here is a note on a friend who died two weeks ago...
I will always carry the image of Joel wearing his Sherlock Holmes cap and short cape.
Joel spent many an hour explaining current cosmological theory to me. He explained general relativity at our dinner table and gave me a deep lesson in astrobiology during a trip to Aspen. I wish I had had more teachers like him.
In Memoriam: Joel Primack
@patrikja@functional.cafe2025-12-02 15:55:54
New pre-print out: "Types, equations, dimensions and the Pi theorem".
We formalized the covariance principle (physical laws must be independent of units) as a homomorphism between the algebra of physical quantities and real numbers.
While the Pi Theorem from Dimensional Analysis (DA) is non-constructive, we introduce a constructive method for applying it. This could enable DA-driven program derivation where the type checker helps identify valid physical laws.
📝 Bl…
@buercher@tooting.ch2026-01-14 07:30:08
« The more important fundamental laws and facts of physical science have all been discovered, and these are now so firmly established that the possibility of their ever being supplanted in consequence of new discoveries is exceedingly remote…. Our future discoveries must be looked for in the sixth place of decimals. » Albert Michelson 1894
En 1905, Einstein published the theory of special relativity
#unknownunknown