Imagine a circular wheel rolling, without skidding, on a flat, horizontal surface. The #locus of any given point on its #circumference is called a #cycloid. It is a #periodic#curve with #period over the #circle's circumference and has #cusps whenever the point is in contact with the surface (the two sides of the curve are tangentially vertical at that point).
Interestingly, it is also the curve that solves the #Brachistochrone problem, which means that starting at a cusp on the inverted curve (maximum height), a frictionless ball will roll under uniform gravity in minimum time from the start to any other point on the curve, even beating the straight line path.
How quantum physics could 'revolutionise everything'
Growing up on a farm in Australia, Liam Hall was a mechanic "getting greasy, scraped knuckles", but in recent years his career has taken a more technical turn.
He's now the head of quantum biotechnology at CSIRO, Australia's national science agency.
Seeking Ultimates: An Intuitive Guide to Physics, Second Edition by Peter T. Landsberg, 2020
Takes us on a journey that explores the limits of our scientific knowledge, emphasizing the gaps that are left. The book starts with everyday concepts such as temperature, and proceeds to energy, the Periodic Table, and then to more advanced ideas.
#VideoGames#GameEngines#Physics#SImulation: "A key part of many game engines is the physics engine, which mathematically models everything we’ve learned about the physical world. A strong wind can be simulated using velocity. An animated bubble might take into account surface tension. Last year, Epic released Lego Fortnite, a family-friendly mode in which players can build—and destroy with dynamite—their own Lego constructions. The game is cartoonish, but its mechanics are grounded in reality. “When the building falls, everybody knows what that’s supposed to look like,” Saxs Persson, an executive at Epic, told me. “It looks good because they got the mass right.
They got the collision volumes right. They got the gravity right. They got friction, which is really hard. They got wind, terrain. All of it has to be perfect.” Even the precise tension of pulling Legos apart, a common muscle memory, has been simulated. “It’s all math,” he said.
Yet certain things remain hard to simulate. There are multiple types of water renderers—an ocean demands a kind of simulation different from that of a river or a swimming pool—but buoyancy is challenging, as are waves and currents."
Weird #plumbing issue. In warm weather, our toilet and drains sound hollow, gurgles, etc, when flushing or draining, like when the tub is drained. In the cold months, it is fine. Last year we had the system snaked 100%. No clogs–been an issue since we bought house in 2019.
I am thinking the warm weather, wind, etc is causing negative air pressure through the main roof plumbing vent
「 Einstein's "model of gravity has been essential for everything from theorizing the Big Bang to photographing black holes," said lead author and Waterloo mathematical physics graduate Robin Wen in a statement about the research. "But when we try to understand gravity on a cosmic scale, at the scale of galaxy clusters and beyond, we encounter apparent inconsistencies with the predictions of general relativity." 」
I've just discovered (should be Sir) Roy Kerr (https://en.wikipedia.org/wiki/Roy_Kerr) , #NewZealand mathematician famous for his solution for rotating black holes published a paper last month which showed #singularities do not have to exist in a #BlackHole, at least not how the 2020 Nobel prize winner Sir Roger Penrose described. For #Physics this is a huge deal. For #NewZealand media it wasn't worth a mention. But, here is a description of what he's done if you are game. https://flip.it/iwDh4a
If you've worked with Godot to make 3D games you probably had trouble getting your characters behave reliably. If you were working on a movement-based game for any amount of time, you've probably felt the pain.
Even though the Navier–Stokes equations are deterministic, it seems that you cannot make predictions beyond a fixed time horizon, no matter how small the initial uncertainty. #physics#fluidmechanics
Swiss mathematician Johann Jakob Balmer was born #OTD in 1825.
Balmer is most renowned for his discovery of the Balmer series, a formula used to predict the wavelengths of visible light emitted by hydrogen. In 1885, he was interested in the spectral lines of hydrogen observed in the sun's spectrum. He then proposed an empirical formula to predict the wavelengths of the visible lines of the hydrogen spectrum.
The usual approach to detecting dark matter is to search for particles with a specific range of masses. The hope is that even if we see nothing, we'll at least know more about what dark matter is not.
Physicists at Fermilab have now released the first data from a different type of detector, one that looks for dark matter over a much wider range at lower sensitivity.
Result: still no dark matter, but a larger swathe of parameter space ruled out.
#OTD in 1905. Albert Einstein completes his doctoral thesis at the University of Zurich.
Titled "Eine neue Bestimmung der Moleküldimensionen", he calculated the size of sugar molecules in solution and from this a value for the Avogadro constant. It is related to his work on Brownian motion, published in the same year, and supported the atomic hypothesis, which was still controversial among leading physicists at the time.
J. J. Thomson of the Cavendish Laboratory announces his discovery of the electron as a subatomic particle, over 1,800 times smaller than a proton (in the atomic nucleus), at a lecture at the Royal Institution in London.
Thomson showed that cathode rays were composed of previously unknown negatively charged particles (now called electrons), which he calculated must have bodies much smaller than atoms and a very large charge-to-mass ratio.
Why the physics of particles might be on the verge of a revolution, how black holes evaporate, and when relativity inspires young minds. It’s “Phreaky Physics,” on Big Picture Science.
French mathematician and physicist Henri Poincaré was born #OTD in 1854.
He is considered one of the founders of the field of topology. He was among the first to present the Lorentz transformations, part of the groundwork for Albert Einstein’s theory of special relativity. Poincaré also studied the behavior of planetary orbits and contributed to the three-body problem in celestial mechanics, exploring the stability and motion of celestial bodies.
New publication: "Climate of a cave laboratory representative for rock art caves in the Vézère area (south-west France)"
Leye Cave (Dordogne, France) is a laboratory cave in the Vézère area, a region that contains some of the most famous rock art caves in the world such as Lascaux, Font-de-Gaume and Combarelles, and is listed as Human World Heritage by UNESCO. Leye Cave was selected because it is representative of paint... #Physics#SocialSciencehttps://doi.org/10.5038/1827-806X.52.2.2442