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Einstein’s General Theory of Relativity predicted that massive objects will bend light as it travels past them. That means that any light passing very close to an invisible black hole—but not close enough to end up inside it—will be bent in a similar way to light passing through a lens. This is called gravitational lensing, and can be spotted when a foreground object aligns with a background object, bending its light. The method has already been used to study everything from clusters of galaxies to planets around other stars.

The authors of this new research combined two types of gravitational lensing observations in their search for black holes. It started with them spotting light from a distant star suddenly magnify, briefly making it appear brighter before going back to normal. They could not see any foreground object that was causing the magnification via the process of gravitational lensing, though. That suggested the object might be a lone black hole, something which had never been seen before. The problem was that it could also just have been a faint star.

Figuring out if it was a black hole or a faint star required a lot of work, and that’s where the second type of gravitational lensing observations came in. The authors repeatedly took images with Hubble for six years, measuring how far the star appeared to move as its light was deflected.

For all his genius, he had his tendency to be stuck in his ways — whether black holes, quantum mechanics, or flip-flopping on gravitational waves.

How can Einstein’s theory of gravity be unified with quantum mechanics? It is a challenge that could give us deep insights into phenomena such as black holes and the birth of the universe. Now, a new article in Nature Communications, written by researchers from Chalmers University of Technology, Sweden, and MIT, U.S., presents results that cast new light on important challenges in understanding quantum gravity.

A grand challenge in modern theoretical physics is to find a “unified theory” that can describe all the laws of nature within a single framework—connecting Einstein’s general theory of relativity, which describes the universe on a large scale, and quantum mechanics, which describes our world at the atomic level. Such a theory of “quantum gravity” would include both a macroscopic and microscopic description of nature.

“We strive to understand the laws of nature and the language in which these are written is mathematics. When we seek answers to questions in physics, we are often led to new discoveries in mathematics too. This interaction is particularly prominent in the search for quantum gravity—where it is extremely difficult to perform experiments,” explains Daniel Persson, Professor at the Department of Mathematical Sciences at Chalmers university of technology.

AS ASTRONOMER Royal, you have to assume Martin Rees isn’t in it for the money: £100 a year is the reward for advising the UK monarch on all matters astronomical.

It is just one of many hats Rees has worn, though – including president of both the Royal Astronomical Society and the Royal Society and, since 2005, as an appointed member of the UK’s House of Lords. His work as a government adviser and public face of science has come on the back of an equally distinguished career in cosmology stretching back more than half a century, encompassing seminal research on the nature of the big bang and black holes, extreme phenomena throughout the cosmos, the search for life elsewhere in the universe and, latterly, humanity’s own fate within it.

“People keep finding more of them,” said Ryan Hickox, an astronomer at Dartmouth College who recently helped locate one himself. “There may be a lot more of these things in these galaxies than we could find using the traditional techniques.”

Off the Map

Dwarf galaxies are relatively uncharted astronomical territory. Ten to 100 times lighter than the Milky Way, they lack the gravitational moxie to pull themselves into the tidy round shapes amenable to theorizing. They’re also patchy, dim and generally hard to study in detail. “They’re a total mess,” Volonteri said.

A mathematical analysis helps illuminate the puzzle over how information escapes from a black hole.

A RIKEN physicist and two colleagues have found that a wormhole—a bridge connecting distant regions of the Universe—helps to shed light on the mystery of what happens to information about matter consumed by black holes.

Einstein’s theory of general relativity predicts that nothing that falls into a black hole can escape its clutches. But in the 1970s, Stephen Hawking calculated that black holes should emit radiation when quantum mechanics, the theory governing the microscopic realm, is considered. “This is called black hole evaporation because the black hole shrinks, just like an evaporating water droplet,” explains Kanato Goto of the RIKEN Interdisciplinary Theoretical and Mathematical Sciences.

https://youtube.com/watch?v=M_p6Z_Qm1_s

Identifying the shape of massive astronomical object is not a simple task. Even with recent observations of gravitational waves the mass and angular momentum of the object remain known with large uncertainty. Moreover, it exists exotic objects, as wormholes who can mimic the shape of black holes for example. The gravitational spectrum of wormholes has a wide range of interpretations. A current challenge addressed by researcher R. A. Konoplya consists of mathematically describing wormholes in order to be able to eventually identify them in the space.

According to current theory a wormhole is a theoretical passage through space-time that could create shortcuts in the universe. The original wormhole solution was discovered by Einstein and Rosen (ER) in 1935 and later John Wheeler has shown their importance in quantum gravity. It was then discovered that it was possible to construct “traversable” wormhole solutions since the ER=EPR proposal. It also appears the quantum fluctuations of the space-time are such that a tiny wormhole could connect Planckian pixel with the entanglement mechanism of quantum space-time itself.

Black holes are among the most compelling mysteries of the universe. Nothing, not even light, can escape a black hole. And at the center of nearly every galaxy there is a supermassive black hole that’s millions to billions of times more massive than the sun. Understanding black holes, and how they become supermassive, could shed light on the evolution of the universe.

Three physicists at the U.S. Department of Energy’s (DOE) Brookhaven National Laboratory have recently developed a model to explain the formation of supermassive black holes, as well as the nature of another phenomenon: dark matter. In a paper published in Physical Review Letters, theoretical physicists Hooman Davoudiasl, Peter Denton, and Julia Gehrlein describe a cosmological phase transition that facilitated the formation of supermassive black holes in a dark sector of the universe.

A cosmological phase transition is akin to a more familiar type of phase transition: bringing water to a boil. When water reaches the exact right temperature, it erupts into bubbles and vapor. Imagine that process taking place with a primordial state of matter. Then, shift the process in reverse so it has a cooling effect and magnify it to the scale of the universe.

Scientists from Durham University and Kings College London have presented a theoretical review in a new study strongly supporting the search for axion dark matter.

The identity of dark matter, which makes up 85% of the matter in the universe, is one of the big unanswered questions in particle physics.

Scientists know of its existence because of its gravitational pull effects on stars and galaxies but what kind of particle it is, still remains a mystery.