Thinking more and more seriously that I should create a "Tutorials in Physics" journal that doesn't publish new research, but tutorials on advanced but relatively settled topics, aimed at first year PhD students who need an introduction to the topic. #Physics#AcademicChatter
Coordinated Lunar Time will help people fly around, land and do science on the moon.
Time passes on the moon at a different speed than it does on earth (58.7 millionths of a second faster each day than on Earth) because relativistic physics wants to, or just does, confuse us (and space-time be like that).
Niels Bohr publishes the first paper of the trilogy "On the constitution of atoms and molecules" in The London, Edinburgh, and Dublin Philosophical Magazine and Journal of Science. This trilogy provides a comprehensive review of the origin and content of Bohr's atomic history. In a longer perspective, Bohr's quantum atom of 1913 gave rise to the later Heisenberg-Schrödinger quantum mechanics and all its relevant consequences.
"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.
British chemist and physicist William Crookes died #OTD in 1919.
He was a pioneer of vacuum tubes, inventing the Crookes tube which was made in 1875. This was a foundational discovery that eventually changed the whole of chemistry and physics. His experiments with cathode rays laid the groundwork for the discovery of the electron by J.J. Thomson. He is credited with discovering the element thallium, announced in 1861, with the help of spectroscopy.
The main thing that bothers me about "3 Body Problem" so far is the suggestion that if lots of science experiments started having weird results suddenly, physicists would be all "well, science is broken, might as well pack it in", as opposed to "whoa, this is amazing, we need more funding to study this phenomenon!".
So, I'm thinking about the intermediate axis theorem and how it applies to ballistics and projectile behavior in a zero atmosphere, zero gravity environment.
Bows and crossbows could be interesting self-defense choices in such an environment because they wouldn't have to deal with the overheating issues of traditional firearms. But I'm wondering if those long, cylindrical projectiles would begin to tumble before striking their target.
”To the extent that nature is imagined as a mere machine, and mind is imagined as this external observer upon that machine, … we're going to have a merely external view of something that also has an inside. And if we can't include the contributions at the causal level of that interiority, then we're only goding to be understanding nature in terms of finished form, and we're going to lack an understanding of nature as a process of formation. And we can understand the mineral world, the inorganic physical world, decently well just as a bunch of finished forms. It's why math works so well in physics, but to try to understand the living world—whether single cells or plants or animals or human beings—just as a collection of finished forms, obeying fixed laws, doesn't work. So until we can cultivate this other way of knowing, and see how we can participate in the the formative process, I think we're going to be locked into a very limited form of science, that's not only limited in the sense of not letting us fully understand how nature works, but it's limited in the sense that through its technological applications we're actually destroying the world.”
—Matthew Segall https://youtu.be/UoHTxPPWcCY?feature=shared&t=4329 #matthewsegall#science#mathematics#physics#nature#life
It’s now thought that they could illuminate fundamental questions in #physics, settle questions about #Einstein’s theories, & even help explain the #universe.
…In recent yrs, the amt of data that scientists have discovered about black holes has grown exponentially.
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.
Hund is particularly known for his work on the electronic structure of molecules & the application of quantum mechanics to chemical bonding. He formulated the "Hund's rules," which describe the arrangement of electrons in atomic orbitals, particularly in the context of molecular orbital theory. He also made contributions to the understanding of the behavior of atoms & molecules in magnetic fields, as well as to the theory of spectra.
We went to a talk yesterday evening by Prof Brian Cox, physicist and cosmologist.
The presentation was on the origins of the universe, life and everything ; it covered the theory and mathematics of black holes and the space-time continuum. Very heady stuff, very well done, and with a lot of excellent effects and photos from space telescopes.
Despite being impressed I came away wondering two things:
What is the point of these branches of science? It's fascinating and clever but what does it achieve?
Secondly, it's seems more descriptive of the universe than anything else - so is it really about science? Is it closer to philosophy or art-through-technology than practical science?
I doubt I'm the first sceptic in the room, but it's not an area that I've been challenged to think about before.
MARWAN, the #Moroccan#Research & #Education#Network, recently welcomed a significant #connectivity upgrade from Rabat to London, where it peers with the GÉANT network with onward traffic to other R&E networks around the world.
Astrophysicist believes he's cracked the code for time travel (www.earth.com)
After years of research, Professor Mallett claims to have finally developed the revolutionary equation for time travel.