The ability to jump forward and backwards in time has long fascinated science fiction writers and physicists alike. So is it really possible to travel into the past and the future?
Category: physics – Page 159
Scientists discover that sperm can ‘defy the laws of physics’
Sperm can “defy the laws of physics”, according to new research.
The laws of motion have helped us to comprehend the behaviours of the natural world for centuries, but sperm appears to go against one of the laws set down by Isaac Newton.
Kenta Ishimoto and his fellow mathematical scientists from Kyoto University have revealed new research which suggests that sperm actually display qualities which don’t follow Newton’s third law of motion.
Princeton astrophysicist helps find record-smashing black hole born in the universe’s infancy
An international team of astrophysicists including Princeton’s Andy Goulding has discovered the most distant supermassive black hole ever found, using two NASA space telescopes: the Chandra X-ray Observatory (Chandra) and the James Webb Space Telescope (JWST).
The black hole, which is an estimated 10 to 100 million times more massive than our sun, is 13.2 billion light-years away in the galaxy UHZ-1, which means the telescopes are peering back in time to when the universe was “extremely young,” Goulding said — only about 450 million years old.
“This is one of the most dramatic discoveries to come out of the James Webb Space Telescope” and the discovery of the most distant growing supermassive black hole known, said Michael Strauss, professor and chair of astrophysical sciences at Princeton, who discussed the findings with the researchers but was not part of the research team. “Indeed, it completely smashes the old record.”
A new theory linking evolution and physics has scientists baffled—but is it solving a problem that doesn’t exist?
In October, a paper titled “Assembly theory explains and quantifies selection and evolution” appeared in the journal Nature. The authors—a team led by Lee Cronin at the University of Glasgow and Sara Walker at Arizona State University—claim their theory is an “interface between physics and biology” which explains how complex biological forms can evolve.
The paper provoked strong responses. On the one hand were headlines like “Bold New ” Theory of Everything’ Could Unite Physics And Evolution”
On the other were reactions from scientists. One evolutionary biologist tweeted after multiple reads I still have absolutely no idea what [this paper] is doing. Another said I read the paper and I feel more confused […] I think reading that paper has made me forget my own name.
New Synthetic Superatomic Material is “World’s Best Semiconductor”
Researchers at Columbia University have created a superatomic material that’s being lauded as the “world’s best semiconductor.” Through a surprising twist of physics, it’s expected to allow processing (switching) speeds in the femtosecond scale. Here’s why it will most likely be a piece of the semiconductors puzzle, not its final shape.
How Einstein’s Daydream of Light Created Relativity
Einstein’s fascination with light, considered quirky at the time, would lead him down the path to a brand new theory of physics.
Living half a century before Einstein, a Scotsman, James Clerk Maxwell, revealed a powerful unification and universalization of nature, taking the disparate sciences of electricity and magnetism and merging them into one communion. It was a titanic tour-de-force that compressed decades of tangled experimental results and hazy theoretical insights into a tidy set of four equations that govern a wealth of phenomena. And through Maxwell’s efforts was born a second great force of nature, electromagnetism, which describes, again in a mere four equations, everything from static shocks, the invisible power of magnets, the flow of electricity, and even radiation – that is, light – itself.
At the time Einstein’s fascination with electromagnetism was considered unfashionable. While electromagnetism is now a cornerstone of every young physicist’s education, in the early 20th century it was seen as nothing more than an interesting bit of theoretical physics, but really something that those more aligned in engineering should study deeply. Though Einstein was no engineer, as a youth his mind burned with a simple thought experiment: what would happen if you could ride a bicycle so quickly that you raced beside a beam of light? What would the light look like from the privileged perspective?
MIT Physicists Transform Pencil Lead Into Electronic “Gold”
Isolate thin flakes that can be tuned to exhibit three important properties.
MIT is an acronym for the Massachusetts Institute of Technology. It is a prestigious private research university in Cambridge, Massachusetts that was founded in 1861. It is organized into five Schools: architecture and planning; engineering; humanities, arts, and social sciences; management; and science. MIT’s impact includes many scientific breakthroughs and technological advances. Their stated goal is to make a better world through education, research, and innovation.
Civilizations Could Use Gravitational Lenses to Transmit Power From Star to Star
In 1916, famed theoretical physicist Albert Einstein put the finishing touches on his Theory of General Relativity, a geometric theory for how gravity alters the curvature of spacetime. The revolutionary theory remains foundational to our models of how the Universe formed and evolved. One of the many things GR predicted was what is known as gravitational lenses, where objects with massive gravitational fields will distort and magnify light coming from more distant objects. Astronomers have used lenses to conduct deep-field observations and see farther into space.
In recent years, scientists like Claudio Maccone and Slava Turyshev have explored how using our Sun as a Solar Gravity Lens (SGL) could have tremendous applications for astronomy and the Search for Extratterstiral Intelligence (SETI). Two notable examples include studying exoplanets in extreme detail or creating an interstellar communication network (a “galactic internet”). In a recent paper, Turyshev proposes how advanced civilizations could use SGLs to transmit power from star to star – a possibility that could have significant implications in our search for technosignatures.
The preprint of Turyshev’s paper, “Gravitational lensing for interstellar power transmission,” recently appeared online and is being reviewed for publication. Slava G. Turyshev is a research scientist with the Structure of the Universe Research Group at NASA’s Jet Propulsion Laboratory. This group is engaged in a wide range of research topics associated with the evolution of the Universe from the Big Bang to the present day. This includes the formation of the first stars and galaxies, the role of Dark Matter and Dark Energy in the formation of large-scale cosmic structures, and the accelerating expansion of the cosmos Universe (respectively).
Physicists turn pencil lead into metaphorical ‘gold’
MIT physicists and colleagues have metaphorically turned graphite, or pencil lead, into gold by isolating five ultrathin flakes stacked in a specific order. The resulting material can then be tuned to exhibit three important properties never before seen in natural graphite.
“It is kind of like one-stop shopping,” says Long Ju, an assistant professor in the MIT Department of Physics and leader of the work, which is reported in the Nature Nanotechnology. “In this case, we never realized that all of these interesting things are embedded in graphite.”
Further, he says, “It is very rare to find materials that can host this many properties.”
Vacuum in optical cavity can change material’s magnetic state without laser excitation
Researchers in Germany and the U.S. have produced the first theoretical demonstration that the magnetic state of an atomically thin material, α-RuCl3, can be controlled solely by placing it into an optical cavity. Crucially, the cavity vacuum fluctuations alone are sufficient to change the material’s magnetic order from a zigzag antiferromagnet into a ferromagnet. The team’s work has been published in npj Computational Materials.
A recent theme in material physics research has been the use of intense laser light to modify the properties of magnetic materials. By carefully engineering the laser light’s properties, researchers have been able to drastically modify the electrical conductivity and optical properties of different materials.
However, this requires continuous stimulation by high-intensity lasers and is associated with some practical problems, mainly that it is difficult to stop the material from heating up. Researchers are therefore looking for ways to gain similar control over materials using light, but without employing intense lasers.