Tag: general relativity

The First Black Hole Ever Discovered is More Massive Than We Thought

Neel V. Patel, writing at MIT Technology Review: Einstein first predicted the existence of black holes when he published his theory of general relativity in 1916, describing how gravity shapes the fabric of spacetime. But astronomers didn’t spot one until 1964, some 6,070 light-years away in the Cygnus constellation. Geiger counters launched into space detected cosmic x-rays coming from a region…

Extreme black holes have hair that can be combed

Black holes are considered amongst the most mysterious objects in the universe. Part of their intrigue arises from the fact that they are actually among the simplest solutions to Einstein’s field equations of general relativity. In fact, black holes can be fully characterized by only three physical quantities: their mass, spin and charge. Since they have no additional “hairy” attributes to…

Wormholes may be lurking in the universe—and new studies are proposing ways of finding them

Albert Einstein’s theory of general relativity profoundly changed our thinking about fundamental concepts in physics, such as space and time. But it also left us with some deep mysteries. One was black holes, which were only unequivocally detected over the past few years. Another was “wormholes”—bridges connecting different points in spacetime, in theory providing shortcuts for space travelers. Source: https://phys.org/news/2021-01-wormholes-lurking-universeand-ways.html…

Happy birthday to Isaac Newton

Isaac Newton, born on January 4, 1643, discovered the laws of motion and other principles that laid the foundation of physics and astronomy. Source: https://earthsky.org/human-world/this-date-in-science-isaac-newtons-birthday…

Are Fragments of Energy the Fundamental Building Blocks of the Universe?

hcs_$reboot shares a remarkable new theory from Larry M. Silverberg, an aerospace engineering professor at North Carolina State University (with colleague Jeffrey Eischen). They’re proposing that matter is not made of particles (or even waves), as was long thought, but fragments of energy. [W]hile the theories and math of waves and particles allow scientists to make incredibly accurate predictions about the…

To Explain Away Dark Matter, Gravity Would Have To Be Really Weird

To discard the theory of dark matter, “you’ll need to replace it with something even more bizarre: a force of gravity that, at some distances, pulls massive objects together and, at other distances, pushes them apart.” That’s how Science magazine describes a new study, adding that “The analysis underscores how hard it is to explain away dark matter” — even though…

Explaining gravity without string theory

For decades, most physicists have agreed that string theory is the missing link between Einstein’s theory of general relativity, describing the laws of nature at the largest scale, and quantum mechanics, describing them at the smallest scale. However, an international collaboration headed by Radboud physicists has now provided compelling evidence that string theory is not the only theory that could form…

Astronomers release a black hole family portrait

“Black hole family portrait” is a fancy way of saying “new catalog.” But it’s a very important and exciting catalog, released October 28, 2020 by gravitational wave astronomers, containing 39 new signals from black hole or neutron star collisions. Source: https://earthsky.org/todays-image/ligo-virgo-new-catalog-gwtc-2-black-hole-family-portrait…

Black hole ‘family portrait’ is most detailed to date

An international research collaboration including Northwestern University astronomers has produced the most detailed family portrait of black holes to date, offering new clues as to how black holes form. An intense analysis of the most recent gravitational-wave data available led to the rich portrait as well as multiple tests of Einstein’s theory of general relativity. (The theory passed each test.) Source:…