UFO'S of UAP'S, ASTRONOMIE, RUIMTEVAART, ARCHEOLOGIE, OUDHEIDKUNDE, SF-SNUFJES EN ANDERE ESOTERISCHE WETENSCHAPPEN

IN BRIEF

New research using the Cassini orbiter has shown that one of Titan’s largest seas, Ligeia Mare, is composed of pure methane and not ethane, as was previously thought. And it is a terribly rich sea.

EXPLORING THE STRANGE SEAS OF TITAN

Titan’s a weird moon. Scientists have known this for some time, ever since the Voyager series of probes returned images of an enigmatic, planet-sized world shrouded in an impenetrable orange fog of organics.

But the NASA/ESA Cassini-Huygens mission has changed all that. Little by little, the layers of Titan’s mysteries have been peeled back—and the information they revealed does not disappoint.

Titan’s atmosphere is about 95% nitrogen, with the rest comprising complex hydrocarbons floating in suspension; it has lakes and seas too, which cover about 1.6 million square km (620,000 square mi) of the moon’s surface—roughly 2% of Titan’s total surface area. Most of these liquid bodies are concentrated in the northern hemisphere, with three large seas clustered near the north pole

Only a single large lake exists in the southern hemisphere.

It was thought that these seas were largely composed of ethane, which is copiously produced through photodissociation of methane in Titan’s atmosphere, and precipitates thence to rain down onto the moon’s surface—kind of a hydrocarbonic analogue to our terrestrial “hydrologic cycle.”

But Titan, apparently, still has a few surprises left in store for us.

PLUMBING THE DEPTHS

In a new study published in the Journal of Geophysical Research: Planets, a team has confirmed that Ligeia Mare—Titan’s second-largest sea, about the size of Lakes Huron and Michigan combined—is composed almost entirely of pure liquid methane.

The data for the study was collected by Cassini’s radar imager, which can penetrate the moon’s thick photochemical smog, from 2007 to 2015.

**A false-color radar image of Ligeia Mare, Titan’s vast methane sea. Credit: NASA/JPL-Caltech/ASI/Cornell**

It’s not currently clear why the sea should be so unexpectedly methane-rich. “Either Ligeia Mare is replenished by fresh methane rainfall, or something is removing ethane from it,” speculates Alice Le Gall, lead author of the study.

“It is possible that the ethane ends up in the undersea crust, or that it somehow flows into the adjacent sea, Kraken Mare, but that will require further investigation.”

Indeed it will. Already, the team’s conducted some pretty sophisticated oceanographic surveys of Ligeia Mare—in an extraterrestrial first, the team used the radar instrument to sound the methane ocean’s seafloor and determine its depth. They were startled to learn that Ligeia Mare can reach depths of 160 m (525 ft) at its deepest; moreover, they found that the seabed is composed of a rich sludge of organic compounds.

Illustration of the “hydrocarbonic” cycle of Titan, showing organic compounds filtering into the moon’s methane seas. Credit: ESA

It’s thought that organics, formed from the reaction of methane and nitrogen, precipitate from Titan’s atmosphere and flow into its seas, where they dissolve in the liquid methane and sink to the bottom. Further studies indicated that there’s even something like hydrocarbon “wetlands” along Ligeia Mare’s shoreline.

“It’s a marvelous feat of exploration that we’re doing extraterrestrial oceanography on an alien moon,” beams Steve Wall, deputy lead of the radar instrument team for the Cassini orbiter.

I, for one, can’t wait to see what else they’ll turn up on this weird moon.

IN BRIEF

Scientists may have found signs that phonons, the very small packets of energy that make up sound waves, were leaking out of sonic black holes, just as Hawking’s equations predicted.

SURVIVING A BLACK HOLE

Some 42 years ago, renowned theoretical physicist Stephen Hawking proposed that not everything that comes in contact with a black hole succumbs to its unfathomable nothingness. Tiny particles of light (photons) are sometimes ejected back out, robbing the black hole of an infinitesimal amount of energy, and this gradual loss of mass over time means every black hole eventually evaporates out of existence.

Known as Hawking radiation, these escaping particles help us make sense of one of the greatest enigmas in the known Universe, but after more than four decades, no one’s been able to actually prove they exist, and Hawking’s proposal remained firmly in hypothesis territory.

But all that could be about to change, with two independent groups of researchers reporting that they’ve found evidence to back up Hawking’s claims, and it could see one of the greatest living physicists finally win a Nobel Prize.

UNDERSTANDING THE THEORY

Let’s go back to 1974, when all of this began. Hawking had gotten into an argument with Princeton University graduate student, Jacob Bekenstein, who suggested in his PhD thesis that a black hole’s entropy – the ‘disorder’ of a system, related to its volume, energy, pressure, and temperature – was proportional to the area of its event horizon.

As Dennis Overbye explains for The New York Times, this was a problem, because according to the accepted understanding of physical laws at the time – including Hawking’s own work – the entropy and the volume of a black hole could never decrease.

Hawking investigated the claims, and soon enough, realised that he had been proven wrong. “[D]r Hawking did a prodigious calculation including quantum theory, the strange rules that govern the subatomic world, and was shocked to find particles coming away from the black hole, indicating that it was not so black after all,” Overbye writes.

Hawking proposed that the Universe is filled with ‘virtual particles’ that, according to what we know about how quantum mechanics works, blink in and out of existence and annihilate each other as soon as they come in contact – except if they happen to appear on either side of a black hole’s event horizon. Basically, one particle gets swallowed up by the black hole, and the otherradiates away into space.

The existence of Hawking radiation has answered a lot of questions about how black holes actually work, but in the process, raised a bunch of problems that physicists are still trying to reconcile.

“No result in theoretical physics has been more fundamental or influential than his discovery that black holes have entropy proportional to their surface area,”says Lee Smolin, a theoretical physicist from the Perimeter Institute for Theoretical Physics in Canada.

While Bekenstein received the Wolf Prize in 2012 and the American Physical Society’s Einstein prize in 2015 for his work, which The New York Times says are often precursors to the Nobel Prize, neither scientist has been awarded the most prestigious prize in science for the discovery. Bekenstein passed away last year, but Hawking is now closer than ever to seeing his hypothesis proven.

The problem? Remember when I said the escaping photons were stealing an infinitesimal amount of energy from a black hole every time they escaped? Well, unfortunately for Hawking, this radiation is so delicate, it’s practically impossible to detect it from thousands of light-years away.

A WAY FORWARD?

**The measured thermal spectrum of the Hawking radiation. The solid curve is the measurement. The dashed curve is the theoretical thermal spectrum.**

But physicist Jeff Steinhauer from Technion University in Haifa, Israel, thinks he’s come up with a solution – if we can’t detect Hawking radiation in actual black holes thousands of light-years away from our best instruments, why not bring the black holes to our best instruments?

As Oliver Moody reports for The Times,Steinhauer has managed to created a lab-sized ‘black hole’ made from sound, and when he kicked it into gear, he witnessed particles steal energy from its fringes.

Reporting his experiment in a paper posted to the physics pre-press website,arXiv.org, Steinhauer says he cooled helium to just above absolute zero, then churned it up so fast, it formed a ‘barrier’ through which sound should not be able to pass.

“Steinhauer said he had found signs that phonons, the very small packets of energy that make up sound waves, were leaking out of his sonic black hole just as Hawking’s equations predict they should,” Moody reports.

To be clear, the results of this experiment have not yet been peer-reviewed – that’s the point of putting everything up for the public to see on arXiv.org. They’re now being mulled over by physicists around the world, and they’re already proving controversial, but worthy of further investigation.

“The experiments are beautiful,” physicist Silke Weinfurtner from the University of Nottingham in the UK, who is running his own Earth-based experiments to try and detect Hawking radiation, told The Telegraph. “Jeff has done an amazing job, but some of the claims he makes are open to debate. This is worth discussing.”

Meanwhile, a paper published in Physical Review Letters last month has found another way to strengthen the case for Hawking radiation. Physicists Chris Adami and Kamil Bradler from the University of Ottawa describe a new technique that allows them to follow a black hole’s life over time.

That’s exciting stuff, because it means that whatever information or matter that passes over the event horizon doesn’t ‘disappear’ but is slowly leaking back out during the later stages of the black hole’s evaporation.

“To perform this calculation, we had to guess how a black hole interacts with the Hawking radiation field that surrounds it,” Adami said in a press release. “This is because there currently is no theory of quantum gravity that could suggest such an interaction. However, it appears we made a well-educated guess because our model is equivalent to Hawking’s theory in the limit of fixed, unchanging black holes.”

Both results will now need to be confirmed, but they suggest that we’re inching closer to figuring out a solution for how we can confirm or disprove the existence of Hawking radiation, and that’s good news for its namesake.

As Moody points out, Peter Higgs, who predicted the existence of the Higgs boson, had to wait 49 years for his Nobel prize, we’ll have to wait and see if Hawking ends up with his own.

{ http://futurism.com/ }