It was a big year. Fermilab discovered possible evidence of new physics with the muon G-2 experiment. Physicists created a time crystal, a new phase of matter that appears to violate one of nature’s most cherished laws. And we got a glimpse of an enormous pair of bubbles towering over the Milky Way. Read the articles in full at Quanta: https://www.quantamagazine.org/the-year-in-physics-20211222/
Quanta Magazine is an editorially independent publication supported by the Simons Foundation.
A new study finds the magnetic field generated by a tsunami can be detected a few minutes earlier than changes in sea level and could improve warnings of these giant waves.
Tsunamis generate magnetic fields as they move conductive seawater through the Earth’s magnetic field. Researchers previously predicted that the tsunami’s magnetic field would arrive before a change in sea level, but they lacked simultaneous measurements of magnetics and sea level that are necessary to demonstrate the phenomenon.
The new study provides real-world evidence for using tsunamis’ magnetic fields to predict the height of tsunami waves using data from two real events—a 2009 tsunami in Samoa and a 2010 tsunami in Chile—that have both sets of necessary data. The new study was published in AGU’s Journal of Geophysical Research: Solid Earth, which focuses on the physics and chemistry of the solid Earth.
Syngas is an important feedstock for modern chemical industries and can be directly used as fuel. Carbon monoxide (CO) is its main component. Direct conversion of widespread renewable biomass resources into CO can help to achieve sustainable development.
Conventionally, bio-syngas is mainly produced through thermal-chemical processes such as pyrolysis, steam reforming or aqueous reforming, which require high temperature and consume a lot of energy.
Recently, a research team led by Prof. Wang Feng from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences, in collaboration with Prof. Wang Min from Dalian University of Technology, developed a new method to directly convert bio-polyols into CO.
Posted in physics | Leave a Comment on Time dilation
In physics and relativity, time dilation is the difference in the elapsed time as measured by two clocks. It is either due to a relative velocity between them (special relativistic “kinetic” time dilation) or to a difference in gravitational potential between their locations (general relativistic gravitational time dilation). When unspecified, “time dilation” usually refers to the effect due to velocity.
After compensating for varying signal delays due to the changing distance between an observer and a moving clock (i.e. Doppler effect), the observer will measure the moving clock as ticking slower than a clock that is at rest in the observer’s own reference frame. In addition, a clock that is close to a massive body (and which therefore is at lower gravitational potential) will record less elapsed time than a clock situated further from the said massive body (and which is at a higher gravitational potential).
These predictions of the theory of relativity have been repeatedly confirmed by experiment, and they are of practical concern, for instance in the operation of satellite navigation systems such as GPS and Galileo.[1] Time dilation has also been the subject of science fiction works.
The empirical fact of short winter days and long winter nights has been known essentially forever, and has driven enormous amounts of human activity including the construction of monuments like the passage tomb at Newgrange that I keep banging on about in previous posts about timekeeping. The correct explanation of the phenomenon has only been understood for around 400 years, dating back to Johannes Kepler’s description of the orbits of the planets.
The change in the relative length of days and nights is due to a combination of the motion of the Earth about the Sun, and the rotation of the Earth on its axis. Specifically, it happens because the Earth’s axis is tilted by about 23 degrees relative to the axis of its orbit. And because angular momentum is conserved, that axis stays pointing in the same direction through the whole orbit, in the same way that a gyroscope on a gimbal mount will remain pointed in the same direction in space as it’s moved around.
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The bus that takes my 10-year-old to school picks him up at around 7:23 am, but he usually starts fidgeting loudly a good ten minutes before that, so he and I will go outside to wait. In recent weeks, between grumbles about particular classes or the recess monitor who won’t let him go outside in shorts and a T-shirt in 40-degree (F) weather, he’s been asking “Why is it so dark?” The answer, of course, is “astrophysics,” but with a side order of theology and politics.
This Tuesday, December 21, is the winter solstice in the Northern Hemisphere, meaning it’s the shortest day of the year. It’s not the earliest sunset (that was a couple of weeks ago) or the latest sunrise (that’s in early January), but it’s the day with the fewest hours between sunrise and sunset.
A new scientific study says the universe may actually change its own laws of physics to achieve stability and evolution, called “The Autodidactic Universe.”
Physicists are translating commonsense principles into strict mathematical constraints for how our universe must have behaved at the beginning of time.
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It turns out that “nothing” is one of the most interesting somethings in all of physics. Signup for your free trial to The Great Courses Plus here: http://ow.ly/OOOp30beNyt.
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At this point, the paper mingles cosmology, or the study of the universe and its origins, with biology. “We ask whether there might be a mechanism woven into the fabric of the natural world, by means of which the universe could learn its laws,” the authors write. In other words, a universal law might transcend all scientific fields. That means that the laws of physics, as we know them, could be subject to higher-order laws of the universe that control them—and that we can’t even comprehend.
“Exploring links between fields is crucial because knowledge is not fundamentally compartmentalized,” says Bruce Bassett, professor at the University of Cape Town’s Department of Mathematics and head of the Cosmology Group at the African Institute of Mathematical Sciences in South Africa. We humans are simply narrow-minded. “We segment and compress knowledge into biology, and physics, and sociology because of our limited brains, and the cost of that segmentation and compression is that we easily miss the commonalities and hidden universality between branches of human knowledge.”
The months-long project demonstrates the physics behind the CPUs we take for granted.
Computer chips have become so tiny and complex that it’s sometimes hard to remember that there are real physical principles behind them. They aren’t just a bunch of ever-increasing numbers. For a practical (well, virtual) example, check out the latest version of a computer processor built exclusively inside the Minecraft game engine.
Minecraft builder “Sammyuri” spent seven months building what they call the Chungus 2, an enormously complex computer processor that exists virtually inside the Minecraft game engine. This project isn’t the first time a computer processor has been virtually rebuilt inside Minecraft, but the Chungus 2 (Computation Humongous Unconventional Number and Graphics Unit) might very well be the largest and most complex, simulating an 8-bit processor with a one hertz clock speed and 256 bytes of RAM.
Minecraft processors use the physics engine of the game to recreate the structure of real processors on a macro scale, with materials including redstone dust, torches, repeaters, pistons, levers, and other simple machines. For a little perspective, each “block” inside the game is one virtual meter on each side, so recreating this build in the real world would make it approximately the size of a skyscraper or cruise ship.
