Physics Week in Review: June 9, 2018
Top quarks and Higgs in the same collisions, a superfluid time quasicrystal, and using atomic clocks to test relativity are among this week's physics highlights.
One Quadrillion LHC Collisions Lead to a Rare Discovery. Related: The perfect couple: Physicists see top quarks and Higgs bosons emanating from the same collisions in new results from the Large Hadron Collider.
Dark Matter Undetectable in Gravitational Waves: Calculations show that dark matter affects the propagation of gravitational waves but at a level far below the sensitivity of current detectors. Related: What Is Dark Matter and Why Hasn't Anyone Found It Yet? An excellent explainer by Gizmodo's Ryan Mandelbaum.
Could dark matter atoms explain a recent observation? Maybe, "a tiny fraction of dark matter has a charge, allowing it to interact with regular matter during the time between the Big Bang and formation of the Cosmic Microwave Background."
The LHC has found that the Higgs boson works perfectly in accordance with the Standard Model of Particle Physics' predictions. That's a problem because it leaves us without clues to dark matter and other mysteries.
Magnetic helium makes superfluid time crystal. "I've hit the jackpot with a time quasicrystal that is also a time supersolid. If that makes no sense to you, don't worry, it doesn't make sense to me either."
Finally, scientists have found intriguing organic molecules on Mars. "A variety of organic compounds were discovered by NASA's Curiosity rover, which heated the Martian rocks to 500 Celsius to release the chemicals." Related: Curiosity rover sees seasonal Mars methane swing. Methane on the Red Planet waxes and wanes with the seasons - another clue in the search for life.
Physicists Used Atomic Clocks To Test Einstein's Theory of Relativity in a 14-Year Experiment. Related: These Physicists Watched a Clock Tick for 14 Years Straight to test Einstein's theory of general relativity. Also: Einstein's general relativity says experiments should come out the same way, no matter where they are in space and time. A new NIST experiment backs that up, using Earth itself as the lab.
Peering at atomic structures with no more than pencil and paper. Who would guess that cracking the mystery of how infinitesimally small atoms arrange themselves at the edges of crystals in advanced materials could be as simple as one, two, three?
Training a neural network in phase-change memory beats GPUs. "a brain is remarkably energy-efficient, in part because it combines memory, communications, and processing in a single execution unit, the neuron. A brain also has lots of them, which lets it handle lots of tasks in parallel."
Plasma is a state of matter, like liquid or gas, that is fatal to bacteria, so a new wearable plasma patch is being tested to dress wounds.
A new theory behind how splashing drops break up. "the physics of the rim formation and breakup has been difficult to unravel. But a new paper offers some exciting insight into this unsteady process." [Image: Y. Wang et al.; via MIT News]
Honey Bees Are the First Insect Known to Grasp the Concept of Zero. By giving bees visual math quizzes, scientists discovered that these insects know a null set when they see one.
The Quirkier Uses of Graphene: The versatile carbon material can be used in everything from hair dye to running shoes.
Questioning Assumptions: Have Binary Stars Been Tricking us into Overestimating the Age of Clusters?
The 25% Revolution--How Big Does a Minority Have to Be to Reshape Society? A committed few can influence the many and sweep away social conventions, new research shows. See also my 2015 essay for BOOM California about how it takes a phase transition to change a mind.
Physics Face-off: The Momentum Principle vs. Newton's 2nd Law. Which method is better? It's complicated.
There Are No Laws of Physics. There's Only the Landscape. Scientists seek a single description of reality. But modern physics allows for many different descriptions, many equivalent to one another, connected through a vast landscape of mathematical possibility.
How to email a cat. "To celebrate the launch of New York's pneumatic-tube network, a tortoiseshell cat was sent a mile uptown" See also my 2011 Scientific American blog post about the history of vacuum physics and pneumatic tubes:
There's an "Inverse Piano" in Your Head: A Kavli Prize-winning scientist details the magic of transforming vibrations into sound in the inner ear.
Surprise! Jupiter's Lightning Looks a Lot Like Earth's. Data from NASA's Juno spacecraft reveals thunderbolts around the giant planet's stormy poles.
Is there really a Planet Nine? Or just a swarm of small, icy worlds?
In "Liquid Calligraphy," artist Rus Khasanov's letters dissolve once he draws them.
Is nature continuous or discrete? How the atomist error was born. "The answer to the central question at the heart of modern science, 'Is nature continuous or discrete?' is as radical as it is simple."
Basketball Physics: Why Is That Ball Spinning? "Putting backspin on a shot "softens" the bounce, by reducing the horizontal velocity of the ball after the rebound."
The Hairy Ball Theorem revisited - a newer, shorter, proof. "This is famously stated as "you can't comb a hairy ball flat without creating a cowlick " It can also be written as, "Every smooth vector field on a sphere has a singular point."
If Fairy Tales Were Graphs, eg Hansel and Gretel and Path Marking Mechanisms.
Why 350F is the magic number for baking. "Baking is all about setting off a chain of reactions called the Maillard reaction. To get the right result, you need to balance the rate at which moisture is lost and browning occurs."
Dianna Cowern, aka YouTube's Physics Girl, recruited skateboarding legend Rodney Mullen and a couple of friends with a high-speed camera for this look at the physics of skateboarding.
BBC News went to the IAEA's labs at Seibersdorf near Vienna to find out how they inspect the world's nuclear sites.
"One of the great challenges in fluid dynamics is understanding how order gives way to chaos. Initially smooth and laminar flows often become disordered and turbulent. This video explores that transition in a new way using sound."
Finally check out Sean Carroll, my personal Time Lord, on how meaning is created, by us, within the natural world: