If scientists could measure the oscillations of just one energized cesium atom, they’d be able to keep perfect time, but they can’t due to a weird phenomenon called the standard quantum limit.
Instead, they have to measure thousands of atoms at once and then average out the results for atomic clocks, which leads to a just slightly imprecise second.
Now, MIT researchers have found a way to create a more precise atomic clock by exploiting another weird quantum phenomenon: entanglement.
For 15 years, scientists have been baffled by the mysterious way water flows through the tiny passages of carbon nanotubes—pipes with walls that can be just one atom thick. The streams have confounded all theories of fluid dynamics; paradoxically, fluid passes more easily through narrower nanotubes, and in all nanotubes it moves with almost no friction. What friction there is has also defied explanation.
In an unprecedented mashup of fluid dynamics and quantum mechanics, researchers report in a new theoretical study published February 2 in Nature that they finally have an answer: ‘quantum friction.’
The proposed explanation is the first indication of quantum effects at the boundary of a solid and a liquid, says study lead author Nikita Kavokine, a research fellow at the Flatiron Institute’s Center for Computational Quantum Physics (CCQ) in New York City.
Dubbed the “Quark,” the motor weighs just 63 pounds.
Koenigsegg is also marketing an EV drive unit made up of two Quark motors, plus its small-but-powerful inverter, and small low-ratio planetary gearsets at each output shaft. The unit is called the “Terrier,” and serves up 670 hp and 811 lb-ft in a package that weighs just 187 pounds, and which offers torque vectoring across an axle. A Terrier can be bolted directly to a car’s monocoque as well.
More information on the Terrier unit is forthcoming, and presumably, it will be featured on future Koenigsegg products. As ever, the numbers are deeply impressive and entirely unsurprising from the innovative Swedish firm.
Researchers from the University of Illinois developed GPU-accelerated software to simulate a cell that metabolizes and grows like a living cell.
Every living cell contains its own bustling microcosm, with thousands of components responsible for energy production, protein building, gene transcription and more.
Scientists at the University of Illinois at Urbana-Champaign have built a 3D simulation that replicates these physical and chemical characteristics at a particle scale — creating a fully dynamic model that mimics the behavior of a living cell.
Published in the journal Cell, the project simulates a living minimal cell, which contains a pared-down set of genes essential for the cell’s survival, function and replication. The model uses NVIDIA GPUs to simulate 7,000 genetic information processes over a 20-minute span of the cell cycle – making it what the scientists believe is the longest, most complex cell simulation to date.
That is not to say that the advantage has been proven yet. The quantum algorithm developed by IBM performed comparably to classical methods on the limited quantum processors that exist today – but those systems are still in their very early stages.
And with only a small number of qubits, today’s quantum computers are not capable of carrying out computations that are useful. They also remain crippled by the fragility of qubits, which are highly sensitive to environmental changes and are still prone to errors.
Rather, IBM and CERN are banking on future improvements in quantum hardware to demonstrate tangibly, and not only theoretically, that quantum algorithms have an advantage.
We’ve been trying for a long time to make a tiny Sun on Earth, one that would sustainably produce energy by nuclear fusion of hydrogen or similar atoms. Come to think of it, I’d like one for my basement.
Fusion requires quite a bit of heat to get going, but once it does, it starts producing its own heat. If you can keep that system contained so it doesn’t expand too much or allow too much heat to escape, further fusion happens. If it reaches a point where self-heating becomes the primary driver of fusion, you have yourself a “burning plasma”.
The actual Sun has a pretty easy time sustaining fusion because of the crushing gravity at its center, but we Earthlings need to be a bit more creative to achieve that here at home (because we don’t have any 4-nonillion pound weights handy). The burning plasma, indeed a tiny star, is one of the key milestones on the path to usable nuclear fusion. Until now, no one had ever made such a thing.
“It is what I would call a dippy process,” Richard Feynman later wrote. “Having to resort to such hocus-pocus has prevented us from proving that the theory of quantum electrodynamics is mathematically self-consistent.”
Justification came decades later from a seemingly unrelated branch of physics. Researchers studying magnetization discovered that renormalization wasn’t about infinities at all. Instead, it spoke to the universe’s separation into kingdoms of independent sizes, a perspective that guides many corners of physics today.
Renormalization, writes David Tong, a theorist at the University of Cambridge, is “arguably the single most important advance in theoretical physics in the past 50 years.”
If a particle has no mass, how can it exist?
Scientists think that, under some circumstances, dark matter could generate powerful enough gravitational waves for equipment like LIGO to detect.
Four physicists share their journeys through academia into industry and offer words of wisdom for those considering making a similar move.
