[RhetoricThug]

Source of cosmic 'ghost' particle revealed

Ghost-like particles known as neutrinos have been puzzling scientists for decades.

Part of the family of fundamental particles that make up all known matter, neutrinos hurtle unimpeded through the Universe, interacting with almost nothing.

The majority shoot right through the Earth as though it isn't even there, making them exceptionally difficult to detect and study.

Despite this, researchers have worked out that many are created by the Sun and even in our own atmosphere. But the source of one high energy group, known as cosmic neutrinos, has remained particularly elusive.

Now, in the first discovery of its kind, it turns out that a distant galaxy powered by a supermassive black hole may be shooting a beam of these cosmic neutrinos straight towards Earth.

It all starts with IceCube, a highly sensitive detector buried about two kilometres beneath the Antarctic ice, near the Amundsen-Scott South Pole Station.

"In order to get a measurable signal from the tiny fraction of neutrinos that do interact, neutrino physicists need to build extremely large detectors," explains Dr Susan Cartwright, a particle physicist at the University of Sheffield.

Measuring cosmic neutrinos against those created closer to home is, she told BBC News, "like trying to count fireflies in the middle of a firework display".

But on 22 September 2017, one of these neutrinos showed up near IceCube's cubic kilometre array and decided to interact with the surrounding material, creating another particle called a muon.

Lacking the neutrino's stealth mode, this muon crashed through the ice in the same direction as its progenitor, sparking against other atoms along the way and creating a visible trail that IceCube could capture.

"[IceCube] measures this trail of light," explains Prof Albrecht Karle from the University of Wisconsin-Madison, who was involved in the discovery. "We can do that quite precisely, so that we can measure the direction of [the neutrino's] track."

Using this, IceCube was able to work out the approximate region of sky that the particle had been travelling from.

Within 43 seconds, an alert was dispatched for telescopes to join in the hunt.

Two years previously, the IceCube team had decided that rather than hoard their potential findings for publication, they would send out these "astronomy telegrams", inviting other researchers to participate in the chase as soon as an event was detected.

"Traditionally in astronomy we looked at images of the sky, like it was static, but in reality it's a movie. All the time there are flashes and things moving and happening. So instead of publishing a paper and having astronomers look three years later at something we report, we went into real time mode," says Prof Karle.

Eight other observatories trained their eyes and ears on the neutrino's point of origin.

The tricky part, explains Prof Karle, is that even though IceCube can work this out to within half a degree of sky, that is still about the size of the Moon as we see it from the Earth's surface. Such a region can encompass a lot of galaxies and other objects.

However this time, there was good news.

A galaxy with a "monster" black hole about 100 million times the size of our Sun, was sitting in exactly the right spot.

About four billion light years from Earth, just off the left shoulder of the constellation Orion, this galaxy has an intensely bright core caused by the energy of its central black hole.

As matter falls in to the black hole, vast jets of charged particles emerge at right angles, making them massive particle accelerators.

They can extend to almost a million light years, just the jet. Which is of course bigger than the Large Hadron Collider at Cern," laughs Prof Karle.

It is perhaps unsurprising that the neutrino detected by IceCube arrived with 40 times more energy than particles accelerated at Cern, despite its long journey.

This particular galaxy type is known as a blazar, because one of the jets is trained directly towards Earth.

"So we are really in the line of fire. We are staring in to the eye of the monster so to speak," adds Prof Karle.

Although not originally high on the list of potential cosmic neutrino sources, this makes for strong evidence that blazars do generate the elusive particles.

"This is extremely exciting news," says Dr Cartwright, who was not involved in the study.

"We can hope that this observation will be followed by the identification of further neutrinos from flaring blazars."

After their initial detection, the IceCube team went back through previous records of neutrino interactions and found that several more had come from the direction of the same galaxy.

"The chance of this excess of neutrinos arising by chance is less than 0.03%," Dr Cartwright adds.

Confirming the discovery via the work of other observatories like the Eso's Very Large Telescope in Chile makes it the latest success for multi-messenger astronomy - detections combining electromagnetic information like visual and radio data with signals like gravitational waves and neutrinos.

https://www.bbc.co.uk/news/science-environment-44786125

Fantastic article! Thoughts?

[One Degree]

I had read the article previously. My thoughts were limited due to lack of understanding.
I was surprised by the Antarctic research center and the use of ice as a filter. Neat.
I also don’t understand how they could possibly follow them back to a source. I read their explanation, but it made no sense to me.
Increased speed from a black hole also seems counterintuitive. Apparently a lot we don’t understand about black holes.

[RhetoricThug]

This study is intriguing because "finer" or undetectable energy could play a role in consciousness. If consciousness is an underlying unified field, what kind of energy "passes" through our perceptional centers? We know that the human sensorium or seat of sensation involves touch. Hearing, seeing, smelling, tasting, etc; all forms of sensation involve touch when particles and waves interact with an evolutionary sensory apparatus (of which technology is an extension). Sensation is energy passing through us. I'm not sure if any reader of this thread has had an opportunity to experience sensory deprivation or perceptual isolation... It's true that mental processes change when you take away or add sensate stimuli, consciousness remains however. A person can damage the perceptual centers (tuning centers) and change their capacity for conscious activity, but that doesn't rule out the possibility that consciousness is a form of energy we're receiving (like a radio transmission).

What if there's a subtle or background energy/frequency that behaves like a cosmic or relic neutrino that has yet to be discovered by humankind, and what if such an energetic frequency is responsible for the "spark" of consciousness? After-all, why does conscious attention produce an observer effect in physics? Perhaps there's a feedback loop of communication happening between the observed and observer, and some-kind of all-pervasive yet elusive energy field or cosmological language acts as a medium or substrate for the observation interval (be it a break or bond, or both simultaneously) in a physical system. Such a notional suggestion reminds me of neuroscientist Karl Pribram and his holonomic brain theory (especially his lecture- Brain and perception: Holonomy and structure in figural processing).

As an information theory, consciousness is a self-organizing language. If you apply the holoflux theory of consciousness, Sheldrake's theory of morphic resonance (why do you think inventors on opposite sides of the planet produce the same idea at the same time?), and quantum entanglement, one might at least consider how consciousness is enfolded in a universal field or a perpetual inception which renews itself ad infinitum. The outward manifestations of consciousness, or 'things' we can experience, could unfold from this unified field as potential energy which reinforces the appearance of evolutionary processes because all potential energy is unfolding in a spacetime continuum. Furthermore, since we're entangled in a physical dimension, being present would constitute an information bias, and this why direct experience of denser layers of physical phenomena (sensation) obscure consciousness; consciousness is a self-organizing language responsible for the way we communicate through the mind/matter interface, and consciousness is a medium for the appearance of reality.

^ I don't agree with everything Hagelin says, but we're all in this together.

Lastly, thought I'd add this article to this thread.

Is Gravity Quantum?

The ongoing search for the graviton—the proposed fundamental particle carrying gravitational force—is a crucial step in physicists’ long journey toward a theory of everything

All the fundamental forces of the universe are known to follow the laws of quantum mechanics, save one: gravity. Finding a way to fit gravity into quantum mechanics would bring scientists a giant leap closer to a “theory of everything” that could entirely explain the workings of the cosmos from first principles. A crucial first step in this quest to know whether gravity is quantum is to detect the long-postulated elementary particle of gravity, the graviton. In search of the graviton, physicists are now turning to experiments involving microscopic superconductors, free-falling crystals and the afterglow of the big bang.

Quantum mechanics suggests everything is made of quanta, or packets of energy, that can behave like both a particle and a wave—for instance, quanta of light are called photons. Detecting gravitons, the hypothetical quanta of gravity, would prove gravity is quantum. The problem is that gravity is extraordinarily weak. To directly observe the minuscule effects a graviton would have on matter, physicist Freeman Dyson famously noted, a graviton detector would have to be so massive that it collapses on itself to form a black hole.

“One of the issues with theories of quantum gravity is that their predictions are usually nearly impossible to experimentally test,” says quantum physicist Richard Norte of Delft University of Technology in the Netherlands. “This is the main reason why there exist so many competing theories and why we haven’t been successful in understanding how it actually works.”

In 2015, however, theoretical physicist James Quach, now at the University of Adelaide in Australia, suggested a way to detect gravitons by taking advantage of their quantum nature. Quantum mechanics suggests the universe is inherently fuzzy—for instance, one can never absolutely know a particle's position and momentum at the same time. One consequence of this uncertainty is that a vacuum is never completely empty, but instead buzzes with a “quantum foam” of so-called virtual particles that constantly pop in and out of existence. These ghostly entities may be any kind of quanta, including gravitons.

Decades ago, scientists found that virtual particles can generate detectable forces. For example, the Casimir effect is the attraction or repulsion seen between two mirrors placed close together in vacuum. These reflective surfaces move due to the force generated by virtual photons winking in and out of existence. Previous research suggested that superconductors might reflect gravitons more strongly than normal matter, so Quach calculated that looking for interactions between two thin superconducting sheets in vacuum could reveal a gravitational Casimir effect. The resulting force could be roughly 10 times stronger than that expected from the standard virtual-photon-based Casimir effect.

Recently, Norte and his colleagues developed a microchip to perform this experiment. This chip held two microscopic aluminum-coated plates that were cooled almost to absolute zero so that they became superconducting. One plate was attached to a movable mirror, and a laser was fired at that mirror. If the plates moved because of a gravitational Casimir effect, the frequency of light reflecting off the mirror would measurably shift. As detailed online July 20 in Physical Review Letters, the scientists failed to see any gravitational Casimir effect. This null result does not necessarily rule out the existence of gravitons—and thus gravity’s quantum nature. Rather, it may simply mean that gravitons do not interact with superconductors as strongly as prior work estimated, says quantum physicist and Nobel laureate Frank Wilczek of the Massachusets Institute of Technology, who did not participate in this study and was unsurprised by its null results. Even so, Quach says, this “was a courageous attempt to detect gravitons.”

Although Norte’s microchip did not discover whether gravity is quantum, other scientists are pursuing a variety of approaches to find gravitational quantum effects. For example, in 2017 two independent studies suggested that if gravity is quantum it could generate a link known as “entanglement” between particles, so that one particle instantaneously influences another no matter where either is located in the cosmos. A tabletop experiment using laser beams and microscopic diamonds might help search for such gravity-based entanglement. The crystals would be kept in a vacuum to avoid collisions with atoms, so they would interact with one another through gravity alone. Scientists would let these diamonds fall at the same time, and if gravity is quantum the gravitational pull each crystal exerts on the other could entangle them together.

The researchers would seek out entanglement by shining lasers into each diamond’s heart after the drop. If particles in the crystals’ centers spin one way, they would fluoresce, but they would not if they spin the other way. If the spins in both crystals are in sync more often than chance would predict, this would suggest entanglement. “Experimentalists all over the world are curious to take the challenge up,” says quantum gravity researcher Anupam Mazumdar of the University of Groningen in the Netherlands, co-author of one of the entanglement studies.

Another strategy to find evidence for quantum gravity is to look at the cosmic microwave background radiation, the faint afterglow of the big bang, says cosmologist Alan Guth of M.I.T. Quanta such as gravitons fluctuate like waves, and graviton fluctuations would have imprinted themselves on the structure of the newborn universe. When the cosmos then expanded staggeringly in size within a sliver of a second after the big bang, according to Guth’s widely supported cosmological model known as inflation, this evidence of quantum gravity would have been amplified across the universe. It could become visible as swirls in the polarization, or alignment, of photons from the cosmic microwave background radiation.

However, the intensity of these patterns of swirls, known as B-modes, depends very much on the exact energy and timing of inflation. “Some versions of inflation predict that these B-modes should be found soon, while other versions predict that the B-modes are so weak that there will never be any hope of detecting them,” Guth says. “But if they are found, and the properties match the expectations from inflation, it would be very strong evidence that gravity is quantized.”

One more way to find out whether gravity is quantum is to look directly for quantum fluctuations in gravitational waves, which are thought to be made up of gravitons that were generated shortly after the big bang. The Laser Interferometer Gravitational-Wave Observatory (LIGO) first detected gravitational waves in 2016, but it is not sensitive enough to detect the fluctuating gravitational waves in the early universe that inflation stretched to cosmic scales, Guth says. A gravitational-wave observatory in space, such as the Laser Interferometer Space Antenna (LISA), could potentially detect these waves, Wilczek adds.

In a paper recently accepted by the journal Classical and Quantum Gravity, however, astrophysicist Richard Lieu of the University of Alabama, Huntsville, argues that LIGO should already have detected gravitons if they carry as much energy as some current models of particle physics suggest. It might be that the graviton just packs less energy than expected, but Lieu suggests it might also mean the graviton does not exist. “If the graviton does not exist at all, it will be good news to most physicists, since we have been having such a horrid time in developing a theory of quantum gravity,” Lieu says.

Still, devising theories that eliminate the graviton may be no easier than devising theories that keep it. “From a theoretical point of view, it is very hard to imagine how gravity could avoid being quantized,” Guth says. “I am not aware of any sensible theory of how classical gravity could interact with quantum matter, and I can't imagine how such a theory might work.”

https://www.scientificamerican.com/arti ... y-quantum/