Among this week’s physics highlights: physics loses one of its brightest stars; DARPA is interested in time crystals; and “black stars” or “gravastars” might totally be a thing that exists.
It’s been a year marked by loss thus far for the physics community. First Joe Polchinski died several weeks ago, and now Stephen Hawking has Died at 76. Tributes began rolling in immediately from around the world, including this touching remembrance by Sir Martin Rees. Physics Today posted a collection of tributes to Hawking, and the BBC collected his most memorable quotes. Sean Carroll was particularly busy. He wrote in the New York Times about Stephen Hawking’s Most Profound Gift to Physics: he gave us the biggest clues to how quantum gravity might work. For the Atlantic, he reminisced over an unusual experience picking up the renowned physicist from the airport. “Despite physical limitations, the late scientist had a singular, stubborn insistence on living life on his own terms.” He wrote a longish blog post about Hawking’s scientific legacy. And a few years ago, Sean told his story of how he first met Stephen Hawking in 2016 for Story Collider. And here’s my own offering at Quanta’s Abstractions blog: Why Stephen Hawking’s Black Hole Puzzle Keeps Puzzling. The renowned British physicist, who died today at 76, left behind a riddle that could eventually lead his successors to the theory of quantum gravity.
Related: A brief history of A Brief History of Time by Stephen Hawking: The late physicist’s editor, Peter Guzzardi, recalls his first meetings with Hawking and how his book became a bestseller. Also: To Boldly Transcend All Limits: The Visionary Legacy of Stephen Hawking. He was not only a top scientist, but also a great science writer and a visionary thinker interested in space exploration and colonization, Artificial Intelligence (AI), and the long-term future of our species. Bonus: At Popular Science, Rachel Feltman pondered her brief encounter with the famous physicist: “what do you even say to Stephen Hawking while you’re eating meatballs together?” And i09 remembered Stephen Hawking’s Most Delightful Pop Culture Cameos. My personal favorite was not included: an amusing short (produced for Caltech’s One Enchanted Evening celebration in 2016) facing off against actor Paul Rudd in a game of quantum chess:
Hawking’s passing also marked Albert Einstein’s birthday, and the traditional celebration of Pi Day. Wired‘s Rhett Allain advised, This Pi Day, Calculate the Value of Pi for Yourself: You just have to add up all the rectangles. He also re-upped his 2017 post on How to calculate Pi on a random walk. Related: Pi is the key to a beautiful, impossible formula that shows math is scarily perfect. Also: Why is pi here? And why is it squared? A most beautiful solution to the Basel problem, using light. And of course, the day brought out the usual slightly grumpy calls for a more mathematically accurate alternative: Forget Pi Day. We should be celebrating Tau Day. (When Tau Day is celebrated with its own dessert (like having pie for Pi Day, maybe this curmudgeonly crusade will gain some traction.)
DARPA Is Funding Time Crystal Research. “Time crystals, systems of atoms that maintain a periodic ticking behavior in the presence of an added electromagnetic pulse, have now piqued the interest of one well-funded government agency: the Department of Defense.”
Rinsing is Key to Removing Stains. Experiments show that rinsing clothes after washing can create imbalances in detergent concentration that pulls dirt out of the fabric.
Why the Tiny Weight of Empty Space Is Such a Huge Mystery. The amount of energy infusing empty space seems too small to explain without a multiverse. But physicists have at least one alternative left to explore.
Watch the High-Flying Physics of a Plant’s Exploding Fruits. When it’s time for the hairyflower wild petunia to pass its genes to the next generation, it does it with a bang.
A new and more flexible neutron interferometer design relies on the moiré effect, in which two periodic patterns are combined to give a longer-period pattern.
Google thinks it’s close to “quantum supremacy.” Here’s what that really means. “You’ll struggle to find any [researcher] who likes the term `quantum supremacy’ … It’s very catchy, but it’s a bit confusing and oversells what quantum computers will be able to do.”
Could the Weirdness of Quantum Physics Produce a New Kind of Star? Related: Black Hole Pretenders Could Really Be Bizarre Quantum Stars. New research reveals a possible mechanism allowing “black stars” and “gravastars” to exist.
Mystery of neutrino masses may be explained by dark matter force. “Two of the most mysterious and elusive particles in the cosmos, neutrinos and dark matter, might be tied together by a weak force that permeates galaxies and give neutrinos mass.”
The Magic (and Math) of Skating on Thin Ice without Falling In. Congelation ice, unlike “snow ice,” grows slowly downward from the surface of a calm lake in a vertical, column-like fashion with horizontal interlocking grains.
There’s a stunning Northern Lights-like celestial phenomenon that’s officially named “Steve.”
How Einstein Lost His Bearings. By 1913, Einstein had nearly completed general relativity. But a simple mistake set him on a tortured, two-year reconsideration of his theory. Today, mathematicians still grapple with the issues he confronted.
X-Ray Imaging uncovers hidden ancient text in medieval manuscript. An international, multidisciplinary team is using X-rays from SLAC to reveal the hidden text of a medical manuscript by the ancient Greek doctor Galen that was written on parchment in the 6th century and scraped off and overwritten with religious text in the 11th century. [Image: University of Manchester/SLAC National Accelerator Laboratory]
Newer Horizons: Scientists Pitch Pluto Probe as a Unique Deep-Space Telescope.
Welcome to the Center of the Universe. For the men and women who use the Deep Space Network to talk to the heavens, failure is not an option.
Colliding neutron stars prove equality before the law of gravity: The neutron star explosion confirmed the equivalence principle: gravitational waves and light travelled 130 million years and arrived at virtually the same time.
Astronomers have spotted a nearly naked black hole fleeing the scene of a close encounter, but, like a badly written romcom, a merger sometime in the future is inevitable.
Chemistry bots collude on Twitter to speed up their experiments. Communicating on social media has allowed a pair of robots to conduct chemistry experiments together and get faster results.
In honor of the release of the film version of A Wrinkle in Time: “[I]n our world, tesseracts don’t exist outside of geometry. But they do have a corollary in theoretical physics called a wormhole: a passage that connects two distant points in spacetime.”
The Physics of the Speeder Chase in ‘Solo: A Star Wars Story’: How do you pull off a banking turn if there’s no road to bank off?
A low-cost experiment to visualise the Fourier series: video analysis of a real plucked coiled spring.
Embroidering Electronics into the Next Generation of “Smart” Fabrics. Unlike today’s wearables, new fabrics promise to come with antennas and batteries that are flexible and washable.
Acoustical Analysis of Shouting Into the Wind: The physics of shouting into the wind are now slightly better plumbed.
LHC exhibit expands beyond the visual: The touring Tactile Collider event explores new ways to access Large Hadron Collider science through touch, sound and live interaction. Related: Global Physics Photowalk 2018: Eighteen physics facilities will give photographers a behind-the-scenes look at science.
Carl Sagan on the Enchantment of Chemistry, with Stunning Illustrations by Artist Vivian Torrence.
How Army Ants Employ Innate Algorithms to Build Bridges With Their Own Bodies To Allow for Crossing.
“Artist Thomas Blanchard is no stranger to fluid dynamics. His previous short films focused on mixtures of oil and paint, but in Dance Dance, flowers are front and center.”
Why Do Some Predictions Succeed & Others Fail? Watch The PBS Show Predictions By The Numbers, which analyzes probabilities.
OK Go explains the incredible math behind their “The One Moment” music video.
Finally, here’s a lovely video exploring The Physics of Pole Dancing–a subject near and dear to my heart. (See also my 2016 Gizmodo article on the simple physics of pole dancing, and a 2013 post from Wired‘s Rhett Allain exploring the physics of rigid body equilibrium as it pertains to pole dancing.)