Archive for the ‘physics’ category: Page 81
Jul 16, 2022
Knots in the resonator: Elegant math in humble physics
Posted by Saúl Morales Rodriguéz in categories: mathematics, mobile phones, physics
At the heart of every resonator—be it a cello, a gravitational wave detector, or the antenna in your cell phone—there is a beautiful bit of mathematics that has been heretofore unacknowledged.
Yale physicists Jack Harris and Nicholas Read know this because they started finding knots in their data.
In a new study in the journal Nature, Harris, Read, and their co-authors describe a previously unknown characteristic of resonators. A resonator is any object that vibrates only at a specific set of frequencies. They are ubiquitous in sensors, electronics, musical instruments, and other devices, where they are used to produce, amplify, or detect vibrations at specific frequencies.
Jul 14, 2022
Photonic fractals open a new area of topological physics
Posted by Jose Ruben Rodriguez Fuentes in category: physics
Jul 13, 2022
Aquatic carnivorous plants with ultra-fast traps studied
Posted by Quinn Sena in category: physics
Circa 2010
How do Utricularia, aquatic carnivorous plants commonly found in marshes, manage to capture their preys in less than a millisecond? A team of French physicists from the Laboratoire Interdisciplinaire de Physique has identified the ingenious mechanical process that enables the plant to ensnare any small, a little too curious aquatic animals that venture too closely. It is the reversal of its curvature and the release of the associated elastic energy that make it the fastest known aquatic trap in the world. These results are published on 16 February 2011 on the website of the journal Proceedings of the Royal Society of London B.
Utricularia are carnivorous plants that capture small prey with remarkable suction traps. Utricularia are rootless plants formed of very thin, forked leaves on which wineskin-shaped traps, just a few millimeters in size, are attached. Only the flowers, standing on long stems, stick out of the water. The traps are underwater. When an aquatic animal (water fleas, cyclops, daphnia or small mosquito larvae) touches its sensitive hairs, the trap sucks it in, in a fraction of a second, along with water, which is then drained through its walls.
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Jul 13, 2022
DeepMind AI learns simple physics like a baby
Posted by Dan Kummer in categories: physics, robotics/AI
Inspired by research into how infants learn, computer scientists have created a program that can pick up simple physical rules about the behaviour of objects — and express surprise when they seem to violate those rules. The results were published on 11 July in Nature Human Behaviour1.
Developmental psychologists test how babies understand the motion of objects by tracking their gaze. When shown a video of, for example, a ball that suddenly disappears, the children express surprise, which researchers quantify by measuring how long the infants stare in a particular direction.
Luis Piloto, a computer scientist at Google-owned company DeepMind in London, and his collaborators wanted to develop a similar test for artificial intelligence (AI). The team trained a neural network — a software system that learns by spotting patterns in large amounts of data — with animated videos of simple objects such as cubes and balls.
Jul 12, 2022
What If Physics IS NOT Describing Reality?
Posted by Dan Breeden in categories: physics, space
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Jul 12, 2022
DeepMind AI learns physics
Posted by Jose Ruben Rodriguez Fuentes in categories: information science, physics, robotics/AI
An algorithm created by AI firm DeepMind can distinguish between videos in which objects obey the laws of physics and ones where they don’t.
Jul 11, 2022
Enter the General Relativity Rabbit Hole: Unraveling Space, Time and the Fourth Dimension
Posted by Dan Breeden in categories: physics, space
Piecing together our universe’s most paradoxical and confusing, yet elegant and shatterproof, theory.
Jul 10, 2022
Peter Tse — What Makes Brains Conscious?
Posted by Alan Jurisson in categories: chemistry, mathematics, neuroscience, physics
Everything we know, think and feel—everything!—comes from our brains. But consciousness, our private sense of inner awareness, remains a mystery. Brain activities—spiking of neuronal impulses, sloshing of neurochemicals—are not at all the same thing as sights, sounds, smells, emotions. How on earth can our inner experiences be explained in physical terms?
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Jul 10, 2022
Dark matter: Our review suggests it’s time to ditch it in favor of a new theory of gravity
Posted by Ken Otwell in categories: cosmology, physics
We can model the motions of planets in the Solar System quite accurately using Newton’s laws of physics. But in the early 1970s, scientists noticed that this didn’t work for disk galaxies —stars at their outer edges, far from the gravitational force of all the matter at their center—were moving much faster than Newton’s theory predicted.
This made physicists propose that an invisible substance called “dark matter” was providing extra gravitational pull, causing the stars to speed up—a theory that’s become hugely popular. However, in a recent review my colleagues and I suggest that observations across a vast range of scales are much better explained in an alternative theory of gravity proposed by Israeli physicist Mordehai Milgrom in 1982 called Milgromian dynamics or Mond —requiring no invisible matter.
Mond’s main postulate is that when gravity becomes very weak, as occurs at the edge of galaxies, it starts behaving differently from Newtonian physics. In this way, it is possible to explain why stars, planets and gas in the outskirts of over 150 galaxies rotate faster than expected based on just their visible mass. But Mond doesn’t merely explain such rotation curves, in many cases, it predicts them.