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The concept of time travel has always captured the imagination of physicists and laypersons alike. But is it really possible? Of course it is. We're doing it right now, aren't we? We are all traveling into the future one second at a time. But that was not what you were thinking. Can we travel much further into the future? Absolutely. If we could travel close to the speed of light, or in the proximity of a black hole, time would slow down enabling us to travel arbitrarily far into the future. The really interesting question is whether we can travel...

Scientists believe that quark-gluon plasma filled the entire Universe during the first few microseconds after the Big Bang when the Universe was still too hot for particles to come together to make atoms.The PHENIX team used the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory to recreate that matter.In a series of tests, the physicists smashed packets of small projectiles in different combinations (single protons, two-particle deuterons, and three-particle helium-3 nuclei) into much bigger gold nuclei.“RHIC is the only accelerator in the world where we can perform such a tightly controlled experiment, colliding particles made of one, two, and...

Making lemonade from lemons, two teams of physicists have used data from misguided satellites to put Albert Einstein’s theory of gravity, the general theory of relativity, to an unexpected test. The opportunistic experiment confirms to unprecedented precision a key prediction of the theory—that time ticks slower near a massive body like Earth than it does farther away. As Einstein explained, gravity arises because massive bodies warp space-time. Free-falling objects follow the straightest possible paths in that curved space-time, which to us appear as the parabolic arc of a thrown ball or the circular or elliptical orbit of a satellite. As...

Scientists at the University of Oxford may have solved one of the biggest questions in modern physics, with a new paper unifying dark matter and dark energy into a single phenomenon: a fluid which possesses 'negative mass." If you were to push a negative mass, it would accelerate towards you. This astonishing new theory may also prove right a prediction that Einstein made 100 years ago. Our current, widely recognised model of the Universe, called LambdaCDM, tells us nothing about what dark matter and dark energy are like physically. We only know about them because of the gravitational effects they...

Astronomer Mark Lacy and colleagues used the Atacama Large Millimeter Array in Chile to observe the universe’s first light, and found evidence of gusts flowing from a type of black hole called a quasar. The wind extends about 228,000 light-years away from the galaxy that surrounds the quasar. Previously, astronomers had seen signs of these winds only about 3,000 light-years from their galaxies.The result, published November 12 at arXiv.org, could help resolve questions about how black holes can grow with their galaxies, or shut galaxies down for good.Black holes are best known for gravitationally gobbling everything that veers too close....

Scientists from the Theory Department of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science (CFEL) in Hamburg, Germany have shown through theoretical calculations and computer simulations that the force between electrons and lattice distortions in an atomically thin two-dimensional superconductor can be controlled with virtual photons. This could aid the development of new superconductors for energy-saving devices and many other technical applications. The vacuum is not empty. It may sound like magic to laypeople but the problem has preoccupied physicists since the birth of quantum mechanics. The apparent void...

Scientists will use the break in operations to beef up the accelerator’s energy. The world’s most powerful particle accelerator has gone quiet. Particles took their last spin around the Large Hadron Collider on December 3 before scientists shut the machine down for two years of upgrades.Located at the particle physics laboratory CERN in Geneva, the accelerator has smashed together approximately 16 million billion protons since 2015, when it reached its current energy of 13 trillion electron volts. Planned improvements before the machine restarts in 2021 will bring the energy up to 14 trillion electron volts — the energy it was...

Most stars with the mass of the sun or larger have one or more companion stars, but when and how these multiple stars form is one of the controversial central problems of astronomy. Gravity contracts the natal gas and dust in an interstellar cloud until clumps develop that are dense enough to coalesce into stars, but how are multiple stars fashioned? Because the shrinking cloud has a slight spin, a disk (possibly a preplanetary system) eventually forms. In one model of binary star formation, this disk fragments due to gravitational instabilities, producing a second star. The other model argues that...

Two more women, including a fellow astronomer, say Neil deGrasse Tyson is guilty of inappropriate sexual conduct. Dr. Katelyn N. Allers, Associate Professor of Physics and Astronomy at Bucknell University, told me that she was “felt up” by Tyson at an after-party following a meeting of the American Astronomical Society (AAS) in 2009. AAS didn’t have a mechanism for reporting sexual harassment at the time, but Dr. Allers says she probably would report the incident if it had happened today. --- snip -- Dr. Allers didn’t feel like she was in danger during her encounter with Tyson, but she did...

Gravity is big and weird and difficult to study. It moves through space as a wave, sort of like how light does. But these waves are subtle and difficult to detect. They occur in measurable amounts only after massive events, like the collision of black holes. Humanity didn't spot its first gravitational wave until 2015. Then, in 2017, astronomers for the first time detected both gravitational waves and light from a single event: a neutron star collision. Now, researchers are using data from that event to confirm some basic facts about the universe. In a paper first uploaded Nov. 1...

Broderick's work builds on earlier research by two teams that studied the galactic center of the Milky Way in near-infrared. This included the work of Reinhard Genzel, an astronomer from the Max Planck Institute for Extraterrestrial Physics in Garching, Germany, as well as researchers Andrea Ghez and Mark Morris of University of California, Los Angeles. At the time, their work revealed that the center of the Milky Way wasn't steady, but instead would drastically brighten about once a day for about 30 or 40 minutes, Broderick said. Researchers think supermassive black holes exist at the center of most, if not...

Welcome to "On This Day ... in Space!" where we peer back in our archives to find historic moments in spaceflight and astronomy. So enjoy a blast from the past with Space.com's Hanneke Weitering to look back at what happened on this day in space! On Nov.  21, 1676, the Danish astronomer Ole Rømer discovered the speed of light . Before Rømer figured it out, scientists thought that light travels instantaneously, or infinitely fast. Rømer disproved this almost by accident when he was studying Jupiter's moon Io. He was trying to figure out how long it takes Io to orbit Jupiter in hopes...

Currently, the two most popular methods for producing fusion power are the inertial confinement approach, and the tokamak reactor. In the former case, lasers are used to fuse pellets of deuterium (H², or “heavy hydrogen”) to create a fusion reaction. In the latter, the process involves a torus-shaped confinement chamber that uses magnetic fields and an internal current to confine high-energy plasma. Whereas other tokamak reactors rely on magnetic coils to keep a plasma torus stable, the Chinese EAST reactor relies on the magnetic fields produced by the moving plasma itself to keep the torus in check. This makes it...

Full title: Star spinning so ‘extremely fast’ it risks causing ‘one of the most powerful explosions in the universe’ It's one of a pair of stars that could be involved in one of the universe's biggest explosions, experts suggest. Scientists say the previously unknown star system is wrapped in an "elegant spiral dust cloud", making it look "spectacular".At its heart is a pair of massive Wolf-Rayet stars, according to an international team of researchers who published the findings in the Nature Astronomy journal. Wolf-Rayet stars are special in that they're among the hottest in the universe.They blast out powerful winds...

Galaxy clusters are cosmic structures containing hundreds or even thousands of galaxies. Multi-million-degree gas fills the space in between the individual galaxies. The mass of the hot gas is about six times greater than that of all the galaxies combined.This superheated gas is invisible to optical telescopes, but shines brightly in X-rays, so an X-ray telescope like Chandra is required to study it.By combining X-rays with other types of light, such as radio waves, a more complete picture of these important cosmic objects can be obtained.Using X-ray and radio data, a team of astronomers led by Leiden Observatory’s Dr. Francesco...

A lot of scientists think that major quantum effects like entanglement, in which particles separated by vast distances mysteriously link up their states, shouldn't work for living things. But a new paper argues that it already has — that scientists in 2016 have already created a sort of Schrödinger's cat — only with quantum-entangled bacteria. Usually, we describe quantum physics as a set of rules that governs the behavior of extremely tiny things: light particles, atoms and other infinitesimally small objects. The larger world, at the bacterial scale (which is also our scale — the chaotic realm of life) isn't...

Circling our galaxy is a stealthy giant. Astronomers have discovered a dwarf galaxy, called Antlia 2, that is one-third the size of the Milky Way itself. As big as the Large Magellanic Cloud, the galaxy’s largest companion, Antlia 2 eluded detection until now because it is 10,000 times fainter. Such a strange beast challenges models of galaxy formation and dark matter, the unseen stuff that helps pull galaxies together. “It’s a very odd object and kind of exciting because we don’t know yet how to interpret all of its properties,” says Andrey Kravtsov of The University of Chicago in Illinois,...

Scientists at Lawrence Livermore National Laboratory in California suspect that midsize black holes might be just the right size to provide enough gravitational force to reignite a dead white dwarf star — the stellar corpse of a star that's about the mass of the sun and that's used up its nuclear fuel. To test their idea, the team members ran supercomputer simulations of dozens of different close-encounter scenarios between these dead stars and midsize black holes. Every time a white dwarf got close to the Goldilocks black hole, the star reignited. The gravitational force from the black hole would cause the...

A feminist academic affiliated with the University of Arizona has invented a new theory of “intersectional quantum physics,” and told the world about it in a journal published by Duke University Press. Whitney Stark argues in support of “combining intersectionality and quantum physics” to better understand “marginalized people” and to create “safer spaces” for them, in the latest issue of The Minnesota Review.

‘Binary and absolute differences’ are ‘exploitative’ A feminist academic affiliated with the University of Arizona has invented a new theory of “intersectional quantum physics,” and told the world about it in a journal published by Duke University Press. Whitney Stark argues in support of “combining intersectionality and quantum physics” to better understand “marginalized people” and to create “safer spaces” for them, in the latest issue of The Minnesota Review. Because traditional quantum physics theory has influenced humanity’s understanding of the world, it has also helped lend credence to the ongoing regime of racism, sexism and classism that hurts minorities, Stark...