KREUZADER (Posts tagged physics)

1.5M ratings
277k ratings

See, that’s what the app is perfect for.

Sounds perfect Wahhhh, I don’t wanna
Bell’s theorem for temporal order Time has a fundamentally different character in quantum mechanics and in general relativity. In quantum theory events unfold in a fixed order while in general relativity temporal order is influenced by the...

Bell’s theorem for temporal order

Time has a fundamentally different character in quantum mechanics and in general relativity. In quantum theory events unfold in a fixed order while in general relativity temporal order is influenced by the distribution of matter. When matter requires a quantum description, temporal order is expected to become non-classical—a scenario beyond the scope of current theories. Here we provide a direct description of such a scenario. We consider a thought experiment with a massive body in a spatial superposition and show how it leads to entanglement of temporal orders between time-like events. This entanglement enables accomplishing a task, violation of a Bell inequality, that is impossible under local classical temporal order; it means that temporal order cannot be described by any pre-defined local variables. A classical notion of a causal structure is therefore untenable in any framework compatible with the basic principles of quantum mechanics and classical general relativity.

Source: nature.com
physics
scientists labor to open a doom portal to hell: Physicists Peer Inside a Fireball of Quantum Matter A gold wedding band will melt at around 1,000 degrees Celsius and vaporize at about 2,800 degrees, but these changes are just the beginning of what...

scientists labor to open a doom portal to hell:

Physicists Peer Inside a Fireball of Quantum Matter

A gold wedding band will melt at around 1,000 degrees Celsius and vaporize at about 2,800 degrees, but these changes are just the beginning of what can happen to matter. Crank up the temperature to trillions of degrees, and particles deep inside the atoms start to shift into new, non-atomic configurations. Physicists seek to map out these exotic states — which probably occurred during the Big Bang, and are believed to arise in neutron star collisions and powerful cosmic ray impacts — for the insight they provide into the cosmos’s most intense moments.Now an experiment in Germany called the High Acceptance DiElectron Spectrometer (HADES) has put a new point on that map.

Source: quantamagazine.org
doom physics
Scientists are searching for a mirror universe. It could be sitting right in front of you. At Oak Ridge National Laboratory in eastern Tennessee, physicist Leah Broussard is trying to open a portal to a parallel universe. She calls it an...

Scientists are searching for a mirror universe. It could be sitting right in front of you.

At Oak Ridge National Laboratory in eastern Tennessee, physicist Leah Broussard is trying to open a portal to a parallel universe.

She calls it an “oscillation” that would lead her to “mirror matter,” but the idea is fundamentally the same. In a series of experiments she plans to run at Oak Ridge this summer, Broussard will send a beam of subatomic particles down a 50-foot tunnel, past a powerful magnet and into an impenetrable wall. If the setup is just right — and if the universe cooperates — some of those particles will transform into mirror-image versions of themselves, allowing them to tunnel right through the wall. And if that happens, Broussard will have uncovered the first evidence of a mirror world right alongside our own.

Source: nbcnews.com
physics
Quantum Leaps, Long Assumed to Be Instantaneous, Take Time When quantum mechanics was first developed a century ago as a theory for understanding the atomic-scale world, one of its key concepts was so radical, bold and counter-intuitive that it...

Quantum Leaps, Long Assumed to Be Instantaneous, Take Time

When quantum mechanics was first developed a century ago as a theory for understanding the atomic-scale world, one of its key concepts was so radical, bold and counter-intuitive that it passed into popular language: the “quantum leap.” Purists might object that the common habit of applying this term to a big change misses the point that jumps between two quantum states are typically tiny, which is precisely why they weren’t noticed sooner. But the real point is that they’re sudden. So sudden, in fact, that many of the pioneers of quantum mechanics assumed they were instantaneous.

A new experiment shows that they aren’t. By making a kind of high-speed movie of a quantum leap, the work reveals that the process is as gradual as the melting of a snowman in the sun. “If we can measure a quantum jump fast and efficiently enough,” said Michel Devoret of Yale University, “it is actually a continuous process.” The study, which was led by Zlatko Minev, a graduate student in Devoret’s lab, was published on Monday in Nature.

Source: quantamagazine.org
physics quantum physics
Seeing the quantum “As individual particles of light, photons belong to the world of quantum mechanics – a place that can seem totally unlike the Universe we know. Physics professors tell students with a straight face that an electron can be in two...

Seeing the quantum

As individual particles of light, photons belong to the world of quantum mechanics – a place that can seem totally unlike the Universe we know. Physics professors tell students with a straight face that an electron can be in two places at once (quantum superposition), or that a measurement on one photon can instantly affect another, far-away photon with no physical connection (quantum entanglement). Maybe we accept these incredible ideas so casually because we usually don’t have to integrate them into our daily existence. An electron can be in two places at once; a soccer ball cannot.

But photons are quantum particles that human beings can, in fact, directly perceive. Experiments with single photons could force the quantum world to become visible, and we don’t have to wait around – several tests are possible with today’s technology. The eye is a unique biological measurement device, and deploying it opens up exciting areas of research where we truly don’t know what we might find. Studying what we see when photons are in a superposition state could contribute to our understanding of the boundary between the quantum and classical worlds, while a human observer might even participate in a test of the strangest consequences of quantum entanglement.

Source: aeon.co
physics
Dark Matter Strikes Back at the Galactic Center “ Statistical evidence has previously suggested that the Galactic Center GeV Excess (GCE) originates largely from point sources, and not from annihilating dark matter. We examine the impact of unmodeled...

Dark Matter Strikes Back at the Galactic Center

 Statistical evidence has previously suggested that the Galactic Center GeV Excess (GCE) originates largely from point sources, and not from annihilating dark matter. We examine the impact of unmodeled source populations on identifying the true origin of the GCE using non-Poissonian template fitting (NPTF) methods. In a proof-of-principle example with simulated data, we discover that unmodeled sources in the Fermi Bubbles can lead to a dark matter signal being misattributed to point sources by the NPTF. We discover striking behavior consistent with a mismodeling effect in the real Fermi data, finding that large artificial injected dark matter signals are completely misattributed to point sources. Consequently, we conclude that dark matter may provide a dominant contribution to the GCE after all.
Source: arxiv.org
dark matter astronomy physics astrophysics
Dark-matter detector observes exotic nuclear decay “ Electron capture and two-neutrino double electron capture. a, An iodine-124 atom can decay with a half-life of 4.2 days to an atom of tellurium-124, through a process called electron capture. The...

Dark-matter detector observes exotic nuclear decay

Electron capture and two-neutrino double electron capture. a, An iodine-124 atom can decay with a half-life of 4.2 days to an atom of tellurium-124, through a process called electron capture. The nucleus of the iodine-124 atom captures an electron from the electron shells that surround it. A proton (circled) in the nucleus is converted into a neutron, and a neutrino is emitted. b, A xenon-124 atom cannot decay by electron capture, because of the law of energy conservation. However, it can decay with an extremely long half-life to a tellurium-124 atom, through a process known as two-neutrino double electron capture. The xenon-124 nucleus captures two electrons from the surrounding electron shells, which results in the conversion of two protons (circled) into neutrons, and the emission of two neutrinos. The XENON Collaboration2 has measured the half-life of this process to be 1.8 × 1022 years — about one trillion times the age of the Universe.

Source: nature.com
physics
Have Dark Forces Been Messing With the Cosmos? “Long, long ago, when the universe was only about 100,000 years old — a buzzing, expanding mass of particles and radiation — a strange new energy field switched on. That energy suffused space with a kind...

Have Dark Forces Been Messing With the Cosmos?

Long, long ago, when the universe was only about 100,000 years old — a buzzing, expanding mass of particles and radiation — a strange new energy field switched on. That energy suffused space with a kind of cosmic antigravity, delivering a not-so-gentle boost to the expansion of the universe.

Then, after another 100,000 years or so, the new field simply winked off, leaving no trace other than a speeded-up universe.

So goes the strange-sounding story being promulgated by a handful of astronomers from Johns Hopkins University. In a bold and speculative leap into the past, the team has posited the existence of this field to explain an astronomical puzzle: the universe seems to be expanding faster than it should be.

Source: The New York Times
cosmology physics astronomy
Light–matter entanglement creates Schrödinger-cat states “Researchers at the Max Planck Institute for Quantum Optics in Garching, Germany, have succeeded in creating Schrödinger-cat states using a single rubidium-87 atom in an optical cavity to...

Light–matter entanglement creates Schrödinger-cat states

Researchers at the Max Planck Institute for Quantum Optics in Garching, Germany, have succeeded in creating Schrödinger-cat states using a single rubidium-87 atom in an optical cavity to control a propagating light pulse. The feat could help advance the field of quantum state engineering with possible applications in quantum networks and quantum computing.

In 1935 physicist Erwin Schrödinger devised his famous thought experiment involving a cat that could, surprisingly, be both dead and alive at the same time. In his gedanken, the decay of a radioactive atom triggers a mechanism (the breaking of a vial containing a poisonous gas) that kills the cat. However, since the decay of the radioactive atom is a completely random and quantum phenomenon, we cannot know the moment at which the cat dies. Mathematically, the feline is in an entangled superposition of quantum states – known as the “Schrödinger-cat” state.

Source: physicsworld.com
physics quantum physics
NIST Atomic Clocks Now Keep Time Well Enough to Improve Models of Earth “Experimental atomic clocks at the National Institute of Standards and Technology (NIST) have achieved three new performance records, now ticking precisely enough to not only...

NIST Atomic Clocks Now Keep Time Well Enough to Improve Models of Earth

Experimental atomic clocks at the National Institute of Standards and Technology (NIST) have achieved three new performance records, now ticking precisely enough to not only improve timekeeping and navigation, but also detect faint signals from gravity, the early universe and perhaps even dark matter.

The clocks each trap a thousand ytterbium atoms in optical lattices, grids made of laser beams. The atoms tick by vibrating or switching between two energy levels. By comparing two independent clocks, NIST physicists achieved record performance in three important measures: systematic uncertainty, stability and reproducibility.

[…]

Einstein’s theory of relativity predicts that an atomic clock’s ticking, that is, the frequency of the atoms’ vibrations, is reduced—shifted toward the red end of the electromagnetic spectrum—when observed in stronger gravity. That is, time passes more slowly at lower elevations.

While these so-called redshifts degrade a clock’s timekeeping, this same sensitivity can be turned on its head to exquisitely measure gravity. Super-sensitive clocks can map the gravitational distortion of space-time more precisely than ever. Applications include relativistic geodesy, which measures the Earth’s gravitational shape, and detecting signals from the early universe such as gravitational waves and perhaps even as-yet-unexplained dark matter.

NIST’s ytterbium clocks now exceed the conventional capability to measure the geoid, or the shape of the Earth based on tidal gauge surveys of sea level. Comparisons of such clocks located far apart such as on different continents could resolve geodetic measurements to within 1 centimeter, better than the current state of the art of several centimeters.

Source: nist.gov
physics
Successful second round of experiments with Wendelstein 7-X “ The experiments conducted from July until November at the Wendelstein 7-X fusion device at the Max Planck Institute for Plasma Physics (IPP) in Greifswald have achieved higher values for...

Successful second round of experiments with Wendelstein 7-X

The experiments conducted from July until November at the Wendelstein 7-X fusion device at the Max Planck Institute for Plasma Physics (IPP) in Greifswald have achieved higher values for the density and the energy content of the plasma and long discharge times of up to 100 seconds – record results for devices of the stellarator type. Meanwhile, the next round of the step-by-step upgrading of Wendelstein 7-X has begun. It is to equip the device for greater heating power and longer discharges. Wendelstein 7-X, the world’s largest fusion device of the stellarator type, is to investigate the suitability of this configuration for use in a power plant.

physics nuclear energy nuclear fusion
A RARE WAVE IN EARTH’S MAGNETIC FIELD “When a stream of solar wind hits Earth, magnetometers around the Arctic Circle normally go haywire, their needles swinging chaotically as local magnetic fields react to the buffeting of the solar wind. On Nov....

A RARE WAVE IN EARTH’S MAGNETIC FIELD

When a stream of solar wind hits Earth, magnetometers around the Arctic Circle normally go  haywire,    their needles swinging chaotically as local magnetic fields react to the buffeting of the solar wind. On Nov. 18th, however, something quite   different happened. Solar wind hit Earth and produced … a pure, almost-musical sine wave:

Rob Stammes recorded the event from the Polarlightcenter, a magnetic observatory in the Lofoten Islands of Norway. “A very stable ~15 second magnetic oscillation commenced and persisted for several hours,” he says. “The magnetic field was swinging back and forth by 0.06 degrees, peak to peak, with the regularity of a metronome.”

Source: spaceweather.com
earth physics