The demonstration began on the afternoon of May 21, 1946, at a secret laboratory tucked into a canyon some three miles from Los Alamos, New Mexico, the birthplace of the atom bomb. Louis Slotin, a Canadian physicist, was showing his colleagues how to bring the exposed core of a nuclear weapon nearly to the point of criticality, a tricky operation known as “tickling the dragon’s tail.” - The Demon Core and the Strange Death of Louis Slotin
"Although it will seem remedial to mention this, all Breakout-style games have at least three things in common – each contains paddles, balls, and target objects for the balls to hit." -- Lego Bricktopia level designer, Mark Nelson, shares his vast of knowledge of Breakout-style games (previously 1, 2) in Breaking Down Breakout: System And Level Design For Breakout-style Games. [more inside]
Henri Bergson was one of the most celebrated philosophers of the early 20th century, and his very public conflict with Albert Einstein over "the nature of time" was considered the reason that Einstein's 1921 Nobel Prize was NOT awarded specifically for his Theory of Relativity. Ouch.
Tim Blais, aka A Capella Science [of Rolling in the Higgs and Bohemian Gravity] sings in reverse about the physics of "Entropic Time." "Stars explode and leaves turn brown and fall /That's thermodynamics' second Law /But from a deep view /That doesn't need to be true /Time symmetry precludes entropic time." [more inside]
Physics Fun is an Instagram account with short videos of physics, math and science 'toys.' An accompanying blog looks at some in more detail.
Gravitational Waves Exist: The Inside Story of How Scientists Finally Found Them. The New York Times also has a writeup.
Signs of Modern Astronomy Seen in Ancient Babylon - "Scientists have found a small clay tablet with markings indicating that a sort of precalculus technique was used to track Jupiter's motion in the night sky." [more inside]
Published in 1913, a best-seller in the 1930s and long out of print, Physics for Entertainment was translated from Russian into many languages and influenced science students around the world ... In the foreword, the book’s author describes the contents as “conundrums, brain-teasers, entertaining anecdotes, and unexpected comparisons,” adding, “I have quoted extensively from Jules Verne, H. G. Wells, Mark Twain and other writers, because, besides providing entertainment, the fantastic experiments these writers describe may well serve as instructive illustrations at physics classes.”
Illustrations, diagrams, and animations, many of maths and physics concepts, created for Wikipedia by Lucas Vieira Barbosa.
Let’s draw Feynman diagrams! (Part 1 of 20) You do not need to know any fancy-schmancy math or physics to do this! That’s right. I know a lot of people are intimidated by physics: don’t be! Today there will be no equations, just non-threatening squiggly lines. Even school children can learn how to draw Feynman diagrams (and, I hope, some cool science). Particle physics: fun for the whole family.
A man who draws pictures for the computer explains the space doctor's big idea about time and space using only simple words. [more inside]
Nima Arkani-Hamed is championing a campaign to build the world's largest particle collider - "Two years ago, he agreed to become the inaugural director of the new Center for Future High Energy Physics in Beijing. He has since visited China 18 times, campaigning for the construction of a machine of unprecedented scale: a circular particle collider up to 60 miles in circumference, or nearly four times as big around as Europe's Large Hadron Collider (LHC). Nicknamed the 'Great Collider', and estimated to cost roughly $10 billion over 30 years, it would succeed the LHC as the new center of the physics universe. According to Arkani-Hamed and those who agree with him, this 100-trillion-electron-volt (TeV) collider would slam subatomic particles together hard enough to either find the particles that the LHC could not muster or rule them out, rescuing or killing the naturalness principle and propelling physicists toward one of two radically different pictures: that of a knowable universe, or an unknowable multiverse." [more inside]
A series of 55 animated vintage book graphics by Henning M. Lederer
Maybe Jesus could walk on water, but anybody can walk on this non-Newtonian fluid (SLYT)
The 2015 Nobel Prize in Physics Takaaki Kajita of Japan and Arthur B. McDonald of Canada share the 2015 Nobel Prize in Physics for their work in neutrino oscillations ("metamorphosis in neutrinos" in the press release), in which neutrinos switch flavors as it propagates through space. The finding has a large impact on the standard model, as it requires neutrinos to have non-zero mass.
Atop the twin spires of the Andromeda and Milky Way Galaxies the eerie call-and-response of bagpipe players echoed across the valley. I watched four siblings race one another up to the top of the Multiverse's spire as their mother, standing at the base, tried to maneuver a cell phone around the fifth child strapped to her chest.-The Duke, the Landscape Architect and the World's Most Ambitious Attempt to Bring the Cosmos to Earth by Alina Simone is an article about the Crawick Multiverse in Dumfriesshire, Scotland, and its designer, landscape architect Charles Jencks. The garden is designed to represent modern cosmological theories.
Dr. Prescod-Weinstein talks about her inspiration, teaching herself what she needed to know, how she keeps balance in her life, and being one of 89 black women with a physics Ph.D., and the only theoretical physicist. [more inside]
Explore the deepest mysteries at the frontier of fundamental physics, and the most promising ideas put forth to solve them. A map of the frontier of fundamental physics built by interactive developer Emily Fuhrman.
“In 1999, two Canadian astrophysicists, Stéphane Dumas and Yvan Dutil, composed and sent a message into space. The message was composed of twenty-three pages of bitmapped data, and was sent from the RT-70 radio telescope in Yevpatoria, Ukraine, as part of a set of messages called Cosmic Call.” [more inside]
Science "explains things" in various ways. You can start with initial conditions, and apply laws of motion (classical kinematics). Or you can predict things via evolving probabilities (quantum mechanics). Or you can find emergent laws (thermodynamics). Or ... - There are many different modes of explanation. Recently, David Deutsch invented a new one: Constructor Theory. [more inside]
The Last True Know-It-All reviews Andrew Smith's biography of Thomas Young - "The Last Man Who Knew Everything (including hieroglyphs). Was Young The Smartest Person Ever? [more inside]
The Singular Mind of Terry Tao - "Imagine, he said, that someone awfully clever could construct a machine out of pure water. It would be built not of rods and gears but from a pattern of interacting currents." (via) [more inside]
Princeton researchers have discovered a long-theorized, never-observed variety of massless (quasi)-particle called the Weyl fermion. Exciting things to come maybe! (Bat-signal: expert.) [more inside]
French magician and juggler Antoine Terrieux created a series of remarkably self-sustaining sculptures using different arrangements of hair dryers, and has also incorporated them in funny ways in his stage performance. He also plays with a diabolo in ways that seem to defy gravity. [via]
At Robert Krulwich's NPR science blog, a couple of reflections on nothingness: Building Me and 2 Ways To Think About Nothing.
Rumble roar clatter. Does what it says, etc. Home page of the creator, Jelle Bakker, the Marble Master. [more inside]
While you were out, your childminders have been entertaining your offspring with dry ice experiments. You're that sort of parent, with those sorts of friends. On your return, you discover that this has gone down very well with junior, and that there's some solid CO2 left over. What could be better than to continue the science fun in the morning? All you have to do is keep the stuff cool overnight. Simple enough? Perhaps not. (Previously)
Here's a neat browser toy where you can play with gravitation interaction and make planetary orbits...or horribly destabilize them.
Calculating the Speed of Light Using a Microwave and PEEPS (or other melty things) from National Geographic's Education Blog and NPR's Skunk Bear videos (showing some history of calculating the speed of light... with peeps as historical scientists, of course)
Frank Wilczek: Physics in 100 Years [pdf] - "Here I indulge in wide-ranging speculations on the shape of physics, and technology closely related to physics, over the next one hundred years. Themes include the many faces of unification, the re-imagining of quantum theory, and new forms of engineering on small, intermediate, and large scales." [more inside]
Twirl an upside-down soda glass and toss it down a tabletop (somewhat like the hero in the video game Tapper), and the glass will pull off in a direction opposite of the spin. Spin a granite curling stone and throw it down the ice, however, and it will travel in the same direction as the spin. Video blog SmarterEveryDay looks at physics theories that try to figure out why this counterintuitive result happens.
Rainworks are positive messages and art that only appear when it rains. Peregrine Church watched a video showing off the properties of superhydrophobic coatings and got an idea uniquely suited to his environment: famously rainy Seattle.* Using a spray-on coating, he did a stencil at a bus stop. It's invisible in dry weather, but as rain hits it and the wet concrete darkens, the writing and art becomes clear. Since then, more have been added: tentacles, hopscotch grids, environmental messages, lily pads, and more. [more inside]
Scientists at the École Polytechnique Fédérale de Lausanne have captured "The first ever photograph of light as both a particle and wave" (images of the photo and the microscope in right hand column) using "EPFL’s ultrafast energy-filtered transmission electron microscope – one of the two in the world." The EPFL's explanatory video: Two-in-one photography: Light as wave and particle. Reference: Simultaneous observation of the quantization and the interference pattern of a plasmonic near-field. Nature Communications.
Physics World has reported that "US physicist Val Fitch, who shared the 1980 Nobel Prize for Physics with James Cronin, died on 5 February at the age of 91. Fitch and Cronin were awarded the prize for the discovery in 1964 that subatomic particles called K-mesons violate a fundamental law in physics known as CP symmetry, allowing physicists to make an absolute distinction between matter and antimatter." Fitch's passing was noted in Princeton University News, and an extended obituary appeared in the Washington Post.
Follow the realtime path of a photon leaving the surface of our Sun
The equations on the blackboard may be the problem. Mathematics, the language of science, may have misled the scientists. “The idea,” says physicist Lee Smolin, “that the truth about nature can be wrestled from pure thought through mathematics is overdone… The idea that mathematics is prophetic and that mathematical structure and beauty are a clue to how nature ultimately works is just wrong.” [more inside]
If you had to knock over a 100 pound domino with a domino that is 5mm high and 1mm thick (and weighs a few ounces), how would you do it? Give it some thought, perhaps discuss it over a beer, and then enjoy an interesting physics demonstration here.
This idea that nature is inherently probabilistic — that particles have no hard properties, only likelihoods, until they are observed — is directly implied by the standard equations of quantum mechanics. But now a set of surprising experiments with fluids has revived old skepticism about that worldview. The bizarre results are fueling interest in an almost forgotten version of quantum mechanics, one that never gave up the idea of a single, concrete reality.
The experiments involve an oil droplet that bounces along the surface of a liquid. The droplet gently sloshes the liquid with every bounce. At the same time, ripples from past bounces affect its course. The droplet’s interaction with its own ripples, which form what’s known as a pilot wave, causes it to exhibit behaviors previously thought to be peculiar to elementary particles — including behaviors seen as evidence that these particles are spread through space like waves, without any specific location, until they are measured.
Particles at the quantum scale seem to do things that human-scale objects do not do. They can tunnel through barriers, spontaneously arise or annihilate, and occupy discrete energy levels. This new body of research reveals that oil droplets, when guided by pilot waves, also exhibit these quantum-like features.
Detcord burns extremely quickly. One of the finest applications of high speed photography I've ever seen. Merry Christmas! [more inside]
The list to follow is offered purely in a spirit of fun and education, and is not intended to be definitive. It concerns only the most basic physics concepts, and nothing electronic. No answers are offered. [more inside]
In this paper, we examine a first-year torque and angular acceleration problem to address a possible use of the forelimbs of Tyrannosaurus rex. A 1/40th-scale model is brought to the classroom to introduce the students to the quandary: given that the forelimbs of T. rex were too short to reach its mouth, what function did the forelimbs serve? This issue crosses several scientific disciplines including paleontology, ecology, and physics, making it a great starting point for thinking “outside the box..." Lipkin and Carpenter have suggested that the forelimbs were used to hold a struggling victim (which had not been dispatched with the first bite) while the final, lethal bite was applied. If that is the case, then the forelimbs must be capable of large angular accelerations α in order to grab the animal attempting to escape. The concepts of the typical first-year physics course are sufficient to test this hypothesis... Naturally, student love solving any problem related to Tyrannosaurus rex.
In a Multiverse, What Are the Odds? "Testing the multiverse hypothesis requires measuring whether our universe is statistically typical among the infinite variety of universes. But infinity does a number on statistics." (previously) [more inside]
At the Far Ends of a New Universal Law
The law appeared in full form two decades later, when the mathematicians Craig Tracy and Harold Widom proved that the critical point in the kind of model May used was the peak of a statistical distribution. Then, in 1999, Jinho Baik, Percy Deift and Kurt Johansson discovered that the same statistical distribution also describes variations in sequences of shuffled integers — a completely unrelated mathematical abstraction. Soon the distribution appeared in models of the wriggling perimeter of a bacterial colony and other kinds of random growth. Before long, it was showing up all over physics and mathematics. “The big question was why,” said Satya Majumdar, a statistical physicist at the University of Paris-Sud. “Why does it pop up everywhere?”