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Alien Life Could Be Hiding Out on Far Fewer Planets Than We Thought

Alien Life Could Be Hiding Out on Far Fewer Planets Than We Thought

By Laura Geggel, Associate Editor | June 10, 2019

Where is complex alien life hanging out in the universe? Likely not on planets stewing in toxic gases, according to a new study that dramatically reduces the number of worlds where scientists will have the best luck finding ET.

In the past, researchers defined the “habitable zone” based on the distance between the planet and its star; planets that, like Earth, orbit at just the right distance to accommodate temperatures in which liquid water could exist on the planetary surface would be considered “habitable.” But while this definition works for basic, single-celled microbes, it doesn’t work for complex creatures, such as animals ranging from sponges to humans, the researchers said.

When these extra parameters — needed for complex creatures to exist — are taken into account, this habitable zone shrinks substantially, the researchers said. For instance, planets with high levels of toxic gases, such as carbon dioxide and carbon monoxide, would drop off the master list.

“This is the first time the physiological limits of life on Earth have been considered to predict the distribution of complex life elsewhere in the universe,” study co-researcher Timothy Lyons, a distinguished professor of biogeochemistry and director of the Alternative Earths Astrobiology Center at the University of California, Riverside (UCR), said in a statement.

To investigate, Lyons and his colleagues created a computer model of the atmospheric climate and photochemistry (a field that analyzes how different chemicals behave under visible or ultraviolet light) on a range of planets. The researchers began by looking at predicted levels of carbon dioxide, a gas that’s deadly at high levels but is also needed to keep temperatures above freezing (thanks to the greenhouse effect) on planets that orbit far from their host stars.

“To sustain liquid water at the outer edge of the conventional habitable zone, a planet would need tens of thousands of times more carbon dioxide than Earth has today,” study lead researcher Edward Schwieterman, a NASA postdoctoral fellow working with Lyons, said in the statement. “That’s far beyond the levels known to be toxic to human and animal life on Earth.

“Once carbon dioxide toxicity is factored into the equation, the traditional habitable zone for simple animal life is sliced in two, the researchers said. For complex life like humans, which is more sensitive to high levels of carbon dioxide, this safe zone shrinks to less than a third of the traditional area, the researchers found.

Complex life (blue) will likely be located in a so-called habitable zone that has the potential for liquid water. Other zones aren’t a promising in the search for life, including regions with toxic buildup of carbon dioxide (yellow) and carbon monoxide (red). These likely uninhabitable zones include exoplanets such as Proxima Centauri b and the TRAPPIST-1 planets e, f and g (black dots).

Under the new parameters, some stars have no safe-for-life zone; that includes Proxima Centauri and TRAPPIST-1, two of the sun’s closest neighbors. That’s because planets around these suns likely have high concentrations of carbon monoxide, the researchers said. Carbon monoxide can bind to hemoglobin in animal blood, and even small amounts of it can be deadly. (Conversely, another recent study argued that carbon monoxide might be a sign of extraterrestrial life, but as Schwieterman put it, “these [planets] would certainly not be good places for human or animal life as we know it on Earth.”)

The new guidelines may help researchers trim the number of planets where signs of alien life look promising, a boon to the field, given that there are almost 4,000 confirmed planets out there that orbit stars other than the sun.

“Our discoveries provide one way to decide which of these myriad planets we should observe in more detail,” study co-researcher Christopher Reinhard, a former UCR graduate student who is now an assistant professor of Earth and atmospheric sciences at the Georgia Institute of Technology, said in the statement. “We could identify otherwise-habitable planets with carbon dioxide or carbon monoxide levels that are likely too high to support complex life.”

The study was published online today (June 10) in The Astrophysical Journal.

Source: Alien Life Could Be Hiding Out on Far Fewer Planets Than We Thought






 

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ASTROPHYSICS

Stephen Hawking Was Right: Black Holes Can Evaporate, Weird New Study Shows

Stephen Hawking Was Right: Black Holes Can Evaporate, Weird New Study Shows

By Meredith Fore, Live Science Contributor | June 10, 2019

Stephen Hawking made one of his most famous predictions: that black holes eventually evaporate entirely.

According to Hawking’s theory, black holes are not perfectly “black” but instead actually emit particles. This radiation, Hawking believed, could eventually siphon enough energy and mass away from black holes to make them disappear. The theory is widely assumed to be true but was once thought nearly impossible to prove.

For the first time, however, physicists have shown this elusive Hawking radiation — at least in a lab. Though Hawking radiation is too faint to be detected in space by our current instruments, physicists have now seen this radiation in a black hole analog created using sound waves and some of the coldest, strangest matter in the universe. Black holes exert such an incredibly powerful gravitational force that even a photon, which travels at the speed of light, could not escape. While the vacuum of space is generally thought of as empty, the uncertainty of quantum mechanics dictates that a vacuum is instead teeming with virtual particles that flit in and out of existence in matter-antimatter pairs. (Antimatter particles have the same mass as their matter counterparts, but opposite electrical charge.)

Normally, after a pair of virtual particles appears, they immediately annihilate each other. Next to a black hole, however, the extreme forces of gravity instead pull the particles apart, with one particle absorbed by the black hole as the other shoots off into space. The absorbed particle has negative energy, which reduces the black hole’s energy and mass. Swallow enough of these virtual particles, and the black hole eventually evaporates. The escaping particle becomes known as Hawking radiation.

This radiation is weak enough that it’s impossible right now for us to observe it in space, but physicists have thought up very creative ways to measure it in a lab.

Physicist Jeff Steinhauer and his colleagues at the Technion – Israel Institute of Technology in Haifa used an extremely cold gas called a Bose-Einstein condensate to model the event horizon of a black hole, the invisible boundary beyond which nothing can escape. In a flowing stream of this gas, they placed a cliff, creating a “waterfall” of gas; when the gas flowed over the waterfall, it turned enough potential energy into kinetic energy to flow faster than the speed of sound.

Instead of matter and antimatter particles, the researchers used pairs of phonons, or quantum sound waves, in the gas flow. The phonon on the slow side could travel against the flow of the gas, away from the waterfall, while the phonon on the fast side could not, trapped by the “black hole” of supersonic gas.

“It’s like if you were trying to swim against a current that was going faster than you could swim,” Steinhauer told Live Science. “You’d feel like you were going forward, but you were really going back. And that’s analogous to a photon in a black hole trying to get out of the black hole but being pulled by gravity the wrong way.”

Hawking predicted that the radiation of emitted particles would be in a continuous spectrum of wavelengths and energies. He also said that it could be described by a single temperature that was dependent only on the mass of the black hole. The recent experiment confirmed both of these predictions in the sonic black hole.

“These experiments are a tour de force,” Renaud Parentani, a theoretical physicist at Laboratoire de Physique Théorique of Paris-Sud University, told Live Science. Parentani also studies analog black holes but from a theoretical angle; he was not involved in the new study. “It’s a very precise experiment. From the experimental side, Jeff [Steinhauer] is really, at the moment, the world-leading expert of using cold atoms to probe black hole physics.”

Parentani, however, emphasized that this study is “one step along a long process.” In particular, this study did not show the phonon pairs being correlated on the quantum level, which is another important aspect of Hawking’s predictions.

“The story will continue,” said Parentani. “It is not at all the end.”

Source: Stephen Hawking Was Right: Black Holes Can Evaporate, Weird New Study






 

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‘God Plays Dice with the Universe,’ Einstein Writes in Letter About His Qualms with Quantum Theory

‘God Plays Dice with the Universe,’ Einstein Writes in Letter About His Qualms with Quantum Theory

By Mindy Weisberger, Senior Writer | June 12, 2019

In a letter that Albert Einstein wrote in 1945, the famous physicist sketched two diagrams demonstrating a novel approach to the thought experiment called the Einstein-Podolsky-Rosen (EPR) paradox.

Three letters written by Albert Einstein in 1945 are up for auction and offer an intriguing glimpse into the renowned physicist’s criticisms of how scientists were interpreting physics at the quantum level.

The letters, which were addressed to Caltech theoretical physicist Paul Epstein, describe Einstein’s qualms about quantum theory, which he called “incomplete” in one letter.

Another letter details the thought experiment that led to a quantum concept known as “spooky action at a distance” — when separated particles behave as if they were linked. The letters — eight pages of German writing and hand-drawn diagrams — will hit the auction block at Christie’s in New York today (June 12) at 2 p.m. ET, as part of the “Fine Printed Books and Manuscripts Including Americana” auction.

Einstein’s words in the letters demonstrate his fraught relationship with quantum physics, or the theories that describe the world of the very small (atoms and the subatomic particles inside them). For decades, he famously clashed with physicist Niels Bohr, whose views on the workings of the quantum world stated that particles behave differently when they are observed.

This introduced a fundamental element of uncertainty into the behavior of quantum particles; Einstein soundly rejected this perspective. Instead, Einstein argued that the rules for even tiny particles must be consistent whether the particles were observed or not.

“God tirelessly plays dice”

Einstein described his “private opinion” of quantum physics in one of the 1945 letters by referencing a phrase that he had already made famous: “God does not play dice with the universe.” In the letter, he wrote: “God tirelessly plays dice under laws which he has himself prescribed.” This variation clarified his argument that quantum particles must adhere to certain rules that don’t change randomly, and that the quantum world required better explanations for particle behavior, according to the item description.

While Einstein admitted in the letter that quantum theory in its present form was “a highly successful experiment,” he added that it had been undertaken “with inadequate means.”

In another letter written on Nov. 8, 1945, Einstein maps the origins of his thought experiment behind quantum entanglement, using text and diagrams to explain how he first imagined it. Einstein presented this idea in a paper published in 1935; the concept — co-authored with Boris Podolsky and Nathan Rosen — became known as the Einstein-Podolsky-Rosen (EPR) paradox, or spooky action at a distance, according to the American Physical Society.

Einstein and his colleagues meant for this paradox to demonstrate inherent flaws in perceptions of the quantum world. When Epstein responded to Einstein’s Nov. 8 letter with skepticism, Einstein reworked the EPR paradox, sending another version of the thought experiment in a letter dated Nov. 28, 1945.

He concluded the letter by reiterating his long-held criticism of the idea that the quantum realm couldn’t be described definitively, saying “it is this view against which my instinct revolts.”

However, recent experiments have suggested that despite Einstein’s protestations, the behavior of particles at the quantum level is likely influenced by randomness after all.

Together, the letters are expected to fetch more than $200,000 at the auction, according to the Christie’s website.

Source: ‘God Plays Dice with the Universe,’ Einstein Writes in Letter About His Qualms with Quantum Theory






 

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ASTROPHYSICS

World’s Largest Atom Smasher May Have Just Found Evidence for Why Our Universe Exists

Physicists have observed a difference in the decay of particles containing the charm quark and its antiparticle, perhaps helping to explain why matter exists at all.

Every particle of matter has an antiparticle, which is identical in mass but with an opposite electrical charge. When matter and antimatter meet, they annihilate one another. That’s a problem. The Big Bang should have created an equivalent amount of matter and antimatter, and all of those particles should have destroyed each other rapidly, leaving nothing behind but pure energy. [Strange Quarks and Muons, Oh My! Nature’s Tiniest Particles Dissected]

Clearly, that didn’t happen. Instead, about 1 in a billion quarks (the elementary particles that make up protons and neutrons) survived. Thus, the universe exists. What that means is that particles and antiparticles must not behave entirely identically, Stone told Live Science. They should instead decay at slightly different rates, allowing for an imbalance between matter and antimatter. Physicists call that difference in behavior the charge-parity (CP) violation.

The notion of the CP violation came from Russian physicist Andrei Sakharov, who proposed it in 1967 as an explanation for why matter survived the Big Bang.

“This is one of the criteria necessary for us to exist,” Stone said, “so it’s kind of important to understand what the origin of CP violation is.”

There are six different types of quarks, all with their own properties: up and down, top and bottom and charm and strange. In 1964, physicists first observed the CP violation in real life in strange quarks. In 2001, they saw it happen with particles containing bottom quarks. (Both discoveries led to Nobel prizes for the researchers involved.)

Physicists had long theorized that it happened with particles containing charm quarks, too, but no one had ever seen it.

FINISH READING: World’s Largest Atom Smasher May Have Just Found Evidence for Why Our Universe Exists


 





 

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On Earth As In The Heavens

DID YOU KNOW…

(12). “Of course, not all things and phenomena in the cosmos have counterparts on Earth…What matters is the universality of the physical laws that describe them.”

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Microwave ovens essentially don’t heat food; they heat the water in the food

DID YOU KNOW…

(11). “…water is the most common ingredient in food, and microwave ovens primarily heat water.”

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Universality Of Physical Laws

DID YOU KNOW…

(10). “…if we land on another planet with a thriving alien civilization, they will be running on the same laws that we discovered and tested here on Earth – even if the aliens harbor different social and political beliefs.”

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Universe invisible beyond spherical edge

DID YOU KNOW…

(8). “…there is a distance in every direction from us where the recession velocity for a galaxy equals the speed of light. At this distance and beyond, light from all luminous objects loses all its energy before reaching us. The universe beyond this spherical edge is thus rendered invisible and, as far as we know, unknowable.”

(9). “Among all constants, the speed of light is the most famous. No matter how fast you go, you will never overtake a beam of light.”

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Universe Had A Beginning after all

DID YOU KNOW…

 

(7). “What we do know, and what we can assert, without hesitation, is that the universe had a beginning. The universe continues to evolve. And yes, every one of our body’s atoms is traceable to the big bang and to the thermo-nuclear furnaces within high mass stars that exploded more than five billion years ago.”

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Sun Sheds Its Skin

DID YOU KNOW…

(6). “The sun loses material from its surface at a rate of one million tons per second.”

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Stars Outnumber Words Uttered By Humans?

DID YOU KNOW…

(5). “There are more stars in the universe than grains of sand on any beach, more stars than seconds have passed since Earth formed, more stars than words and sounds ever uttered by all the humans who ever lived.”

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Nobody owns the air they breathe, believe it or not

DID YOU KNOW THIS…

(4). “A single breath of air draws in more air molecules than there are single breathfuls of air in Earth’s entire atmosphere. That means some of the air you just breathed passed through the lungs of Napolean, Beethoven, Lincoln, and Billy the Kid.”

 

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How old is the water you drink?

DID YOU KNOW…

(3). “There are more molecules of water in a cup of the stuff than there are cups of water in all the world’s oceans. Every cup that passes through a single person and eventually rejoins the world’s water supply hold enough molecules to mix 1,500 of them into every cup of water in the world. No way around it: some of the water you just drank passed through the kidneys of Socrates, Genghis Khan and Joan of Arc.”

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Do huge genetic gaps among earths creatures exist?

DID YOU KNOW…

2. ASTROPHYSICS FACTS

(2). “If a huge genetic gap separated us from our closest relative in the animal kingdom, we could justifiably celebrate our brilliance. We might be entitled to walk around thinking we’re distant and distinct from our fellow creatures. But no such gap exists. Instead, we are one with the rest of nature, fitting neither above nor below, but within.”

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