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Albert Einstein's desk can still be found on the second floor of Princeton's physics department. Positioned in front of a floor-to-ceiling blackboard covered with equations, the desk seems to embody the spirit of the frizzy-haired genius as he asks the department's current occupants, "So, have you solved it yet?" Einstein never achieved his goal of a unified theory to explain the natural world in a single, coherent framework. Over the last century, researchers have pieced together links between three of the four known physical forces in a "standard model," but the fourth force, gravity, has always stood alone.No longer. Thanks...

Everything around you – your desk, your laptop, your coffee cup – in fact, even you – is made of stardust, the stuff forged in the fiery furnaces of stars that died before our sun was born. Probing the space surrounding a mysterious stellar corpse, scientists at the University of Arizona have made a discovery that could help solve a long-standing mystery: Where does stardust come from? When stars die, they seed the cosmos around them with the elements that go on to coalesce into new stars, planets, asteroids and comets. Most everything that makes up Earth, even life itself,...

Black holes are among the most mysterious places in the universe; locations where the very fabric of space and time are warped so badly that not even light can escape from them. According to Einstein's theory of general relativity, at their center lies a singularity, a place where the mass of many stars is crushed into a volume with exactly zero size. However, two recent physics papers, published on Dec.10 in the journals Physical Review Letters and Physical Review D, respectively, may make scientists reconsider what we think we know about black holes. Black holes might not last forever, and...

Danish physicist Niels Bohr was a scientific genius who also displayed a coincidental penchant for espionage and intrigue. He employed these skills, along with a bit of science, to foil the Nazi at several turns. His small crusade began in 1933 after the Nazis came to power in Germany. Over the next few years several scientists fled Germany with Bohr’s help. Many escapees went on to work on the Manhattan Project, including Edward Teller, James Franck and Otto Frisch. Some of them stayed with Bohr in Denmark, working at the Bohr Institute until moving elsewhere.

Scientists have long known that synthetic materials—called metamaterials—can manipulate electromagnetic waves such as visible light to make them behave in ways that cannot be found in nature. That has led to breakthroughs such as super-high resolution imaging. Now, UMass Lowell is part of a research team that is taking the technology of manipulating light in a new direction. The team—which includes collaborators from UMass Lowell, King's College London, Paris Diderot University and the University of Hartford -has created a new class of metamaterial that can be "tuned" to change the color of light. This technology could someday enable on-chip optical...

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...