Technology General Relativity Proven to Work in 'Extreme Gravity'

07:30  05 july  2018
07:30  05 july  2018 Source:

The interstellar space rock that mystified astronomers is actually a comet

  The interstellar space rock that mystified astronomers is actually a comet A mysterious space rock, first spotted in 2017, bewildered astronomers — was it an icy comet, a rocky asteroid, or something entirely new? As the object, called ‘Oumuamua, hurtles away from us, the mystery may be solved: it’s accelerating like a comet. Researchers tracked the space rock’s trajectory on its way out of this solar system, using telescopes on the ground and the powerful Hubble Space Telescope to keep watch even as the interstellar visitor faded out of site. They discovered that ‘Oumuamua’s speed couldn’t just be the result of gravity.

General relativity (GR, also known as the general theory of relativity or GTR) is the geometric theory of gravitation published by Albert Einstein in 1915 and the current description of gravitation in modern

Tests of general relativity serve to establish observational evidence for the theory of general relativity . The first three tests, proposed by Einstein in 1915

a star in space © Provided by IBT Media

An international team of astronomers has conducted a new test of Albert Einstein’s famous theory of general relativity (GR), finding that it works even in extreme gravitational environments, according to a study published in the journal Nature.

Since the great German physicist published his groundbreaking theory in 1915—which describes the nature of gravity—it has been tested numerous times by scientists around the world.

However, while GR has passed most of these tests, some researchers hypothesize that there are certain situations where alternative theories of gravity could be at play. Such situations could include instances of extreme gravity, for example.

As campaign attacks begin, GOP Maryland Gov. Hogan calls Democrat Jealous 'risky,' 'extreme'

  As campaign attacks begin, GOP Maryland Gov. Hogan calls Democrat Jealous 'risky,' 'extreme' Republican Gov. Larry Hogan wasted little time kicking off his re-election effort by announcing Wednesday that his newly-minted Democratic rival, Ben Jealous, is “too risky” and “too extreme” for Maryland. Less than 15 hours after Jealous won the Democratic primary election, Hogan held a news conference in Annapolis to say that voters will see “a very clear difference” between the two candidates set to face off Nov. 6 — the same difference that helped him defeat former Lt. Gov. Anthony Brown and succeed former Gov. Martin O’Malley four years ago.

Testing General Relativity with Stellar Orbits around the Supermassive Black Hole in Our Galactic Center, Physical Review Letters (2017). They have been collecting data for 20 years and are just now "opening up a new method of looking at how gravity works ".

General relativity : Black holes. What happens when extreme gravity pierces the fabric of space-time? General relativity at 100: Einstein’s unfinished masterpiece. Einstein’s general theory of relativity is an undoubted work of genius.

So, to test GR in extreme gravity, the researchers conducted observations of a massive three-star system known as PSR J0337+1715, located 4,200 light-years from Earth, which was discovered by the same astronomers in 2014.

PSR J0337+1715 consists of two white dwarfs and a neutron star. White dwarfs are small, dense stars comparable in size to the Earth, but with a mass closer to the Sun. Neutron stars, on the other hand are even smaller and denser. They form after a massive star explodes as a supernova when it comes to the end of its life, a process which sees the core collapse.

The neutron star in PSR J0337+1715 is what’s known as a pulsar—a highly magnetized, rapidly rotating neutron star which emits beams of electromagnetic radiation through space like a lighthouse. These beams can be detected on Earth.

Human lifespan may not have peaked after all: study

  Human lifespan may not have peaked after all: study Has the maximum lifespan for a human already been reached? Scientists have long debated whether or not the ultimate lifespan in people has been attained. A 2016 study in the journal Nature argued that it has, in 1997, when Frenchwoman Jeanne Calmant died at the record-breaking age of 122.

General relativity works very well for gravity of ordinary strength, the variety experienced by humans on Earth or by planets as they orbit the sun. Another way to test general relativity in extreme regimes would be to look at the properties of gravitational waves.

In summary, Verlinde’s emergent gravity has withstood the first-line bullshit test. Yes, it’s compatible with general relativity . More generally , what are your criteria for a theory to work " extremely well" if it's not about explaining "the amount of stuff that it describes"?

The researchers tracked the star system for six years using the Green Bank Telescope in West Virginia, the Arecibo Observatory in Puerto Rico and the Westerbork Synthesis Radio Telescope in the Netherlands.

In the system, the neutron star is in orbit with one of the white dwarfs, while the second white dwarf orbits both of these stars. By tracking the trio, the scientists wanted to find out whether the neutron star and inner white dwarf were affected differently by the gravity of the outer white dwarf.

However, the scientists found practically no detectable difference, indicating that general relativity describes this scenario accurately, meaning alternative theories of gravity are not required.

"If there is a difference, it is no more than three parts in a million," Nina Gusinskaia, a co-author of the study from the University of Amsterdam, said in a statement. "Now, anyone with an alternative theory of gravity has an even narrower range of possibilities that their theory has to fit into, in order to match what we have seen."

Scientists Are Sending Astronaut Mice to Space to Study Biology

  Scientists Are Sending Astronaut Mice to Space to Study Biology To see how space will affect our internal biology, NASA is sending a team of rodent astronauts to space.The space mice team consists of 10 identical sibling from two different mice families. Half of them will spend 90 days in orbit, while the other half will be living in a NASA simulator that “replaces the exact minute-by-minute conditions - but with gravity - inside the Space Station.” Researchers will investigate what happens to the microbiome - trillions of bacteria and other microorganisms that live in human guts - in space, and how circadian rhythms, which regulate our sleep and activity patterns, might play a role.

The theory of General Relativity — the prevailing theory of Gravity and Electromagnetism — is one hundred years old this month. But that’s exactly how general relativity and positive spacetime curvature work .

General relativity was Einstein’s theory of gravity , published in 1915, which extended special relativity to take into account non-inertial frames of reference Einstein immediately realized that his theory of special relativity worked only when an object moved in a straight line at a constant speed.

According to Ingrid Stairs, another co-author of the study from the University of British Colombia, it is important for scientists to keep testing general relativity.

"Every single time we've tested Einstein's theory of relativity so far, the results have been consistent," she said. "But we keep looking for departures from relativity because that might help us understand how to describe gravity and quantum mechanics with the same mathematical language."

Einstein’s theories have been receiving significant attention lately among researchers.

A recent study, published in the journal Science, also tested GR, confirming that it works even in a distant galaxy—something that has never been demonstrated before.

Meanwhile, findings from another Science study have bolstered another theory first proposed by the physicist in 1911, which describes how heat moves through solids.

Brexit Meets Gravity .
Why May is trying to keep the customs unionThese days I’m writing a lot about trade policy. I know there are more crucial topics, like Alan Dershowitz. Maybe a few other things? But getting and spending go on; and to be honest, in a way I’m doing trade issues as a form of therapy and/or escapism, focusing on stuff I know as a break from the grim political news.

—   Share news in the SOC. Networks

Topical videos:

This is interesting!