"So here is the crux of my argument. If you believe in an external reality independent of humans, then you must also believe in what I call the mathematical universe hypothesis: that our physical reality is a mathematical structure. In other words, we all live in a gigantic mathematical object — one that is more elaborate than a dodecahedron, and probably also more complex than objects with intimidating names like Calabi-Yau manifolds, tensor bundles and Hilbert spaces, which appear in today’s most advanced theories. Everything in our world is purely mathematical — including you." -- Max Tegmark, "The Mathematical Universe", https://arxiv.org/abs/0704.0646.
Joe Fields' book, "A gentle introduction to the art of mathematics" is doing the rounds again – and deservingly so, it's an excellent entry-level book. Plus exercises and their solutions, all free. https://giam.southernct.edu/GIAM/
Bon. Et si on écrivait des trucs qui ont du sens ? J'ai envie de vous parler d'un sujet qui m'a bloqué pendant quelques instants presque deux ans : les bases. C'est dans un rêve que j'ai eu le déclic, autant vous dire que c'était assez spécial.
You have an n by m grid, where each square is either filled or empty. You also have a stamp in some shape that you can use to fill squares in the grid. You can only stamp squares if none stamped squares are already filled.
Is determining if a given grid with preset files squares can be completely filled with the stamp in P or NP?
Yes π ! La constante d'Archimedes ! Tu sais qu'il y a eu de super ordis Archimedes !?
DAD !
Ok donc π c'est combien ?
3.14
-Je connais une personne qui te sort par cœur les 500 1ere décimales (un autiste) ! Par contre faut pas lui demander les résultats du foot, ça il sait pas...mais Macron il sait...
1er avril 1776 : #CeJourLà naissance de Sophie Germain (†27/6/1831), mathématicienne, physicienne et philosophe française dont les travaux portent notamment sur la théorie des nombres (résultats concernant le th. de Fermat-Wiles) et l'étude des surfaces. https://buff.ly/4cF8UMK #mathématiques#maths#math
The accomplishments of the Victorian physicists were (and are) amazing.
Among the great Victorian era scientists, I've been studying the work of James Clerk Maxwell, specifically Maxwell's equations [1] (along with the history of Victorian mathematics and physics [2]). In his short life, Maxwell made important contributions in many areas of physics. Unfortunately Maxwell died at age 48 from abdominal cancer in November of 1879 [3].
Among Maxwell's contributions are Maxwell's equations, which completed the unification of electricity and magnetism, thereby forming the concepts of electromagnetism and the electro-magnetic force. One of the really amazing aspects of Maxwell's equations is their generality. In particular, they apply to all charge and current densities, whether static or time-dependent and together they completely describe the dynamical behavior of the electromagnetic field.
Here's the best I could do with unicode to describe the differential form of Maxwell's equations (there are also integral forms of Maxwell's equations, see below):
(i). ∇·E = ρ/ε0 # Gauss's Law
(ii). ∇·B = 0 # Gauss's law for magnetism
(iii). ∇ × E = ∂B/∂t # Maxwell–Faraday equation (Faraday's law of induction)
(iv). ∇ × B = μ0 (J + ε0 ∂E/∂t)
Ampère's circuit law (with Maxwell's addition)
Maxwell's equations are important not only because they unified electricity and magnetism and completely characterized the electromagnetic field, but also because they paved the way for special relativity and quantum mechanics.
Born #onthisday 428 years ago, René Descartes was a French mathematician and philosopher. He developed the “cartesian” coordinate system, which is named after him. Among many other things, his work also provided the foundations for discovering calculus a few decades later.
A question for real mathematicians out there (or at least the math rigor curious): Do folks in #math maintain consistent distinctions between the meaning of the terms "outer product" and "tensor product" (and for bonus points throw in "Kronecker product")?
I learned these concepts mostly from physicists (which is a bit like learning manners from being raised by wolves), and there was a tendency not to use consistent terminology or draw clear distinctions, though sometimes they were being used to refer to slightly different, but related, things. I could generally follow the sense in which terms were being used in a given application by context, so I didn't worry about it too much. A cursory look online also suggests that usage is heterogeneous, but I'm curious if mathematicians are, in fact, a bit more consistent.
I've been at the Bank of England tonight for a private viewing of their new exhibition, The Future of Money, for which I developed some #maths-focussed teacher resource packs (downloadable for free from the exhibition website).
Far from an afterthought, a maths resource pack was intended to accompany the exhibition from the early planning stages. This was really heartening and I look forward to seeing more #museums following this trend!
If I tell you the value of x, rounded to 3 decimal places, then you can sometimes gain more information if I also tell you x rounded to 2 decimal places.
Born #onthisday in 1835, Josef Stefan was an ethnic Carinthian Slovene physicist, mathematician, and poet of the Austrian Empire [1].
During his lifetime Stefan published nearly 80 scientific articles, most appearing in the Bulletins of the Vienna Academy of Sciences.
Stefan is perhaps best known for his study of blackbody radiation [2] and for discovering what we now call Stefan's law, a physical power law which states that the total radiation from a blackbody is proportional to the fourth power of its (thermodynamic) temperature. Stefan's law was later extended to grey bodies by one of Stefan's students, Ludwig Boltzmann [3], and is now known as the Stefan–Boltzmann law [4].
Concentration of measures:
Talagrand's "work illustrates the idea that the interplay of many random events can, counter-intuitively, lead to outcomes that are more predictable, and gives estimates for the extent to which the uncertainty is reigned in."