Scientific American reports: It was just over 20 years ago — a blink of a cosmic eye — that astronomers found the first planets orbiting stars other than our Sun. All these new worlds were gas-shrouded giants like Jupiter or Saturn and utterly inhospitable to life as we know it — but for years each discovery was dutifully reported as front-page news, while scientists and the public alike dreamed of a day when we would find a habitable world. An Earth-like place with plentiful surface water, neither frozen nor vaporized but in the liquid state so essential to life. Back then the safe bet was to guess that the discovery of such a planet would only come after many decades, and that when a promising new world’s misty shores materialized on the other side of our telescopes, it would prove too faraway and faint to study in any detail.
Evidently the safe bet was wrong. On Wednesday astronomers made the kind of announcement that can only occur once in human history: the discovery of the nearest potentially habitable world beyond our solar system. This world may be rocky like ours and whirls in a temperate orbit around the Sun’s closest stellar neighbor, the red dwarf star Proxima Centauri just over four light-years away. Their findings are reported in a study in the journal Nature.
Although technically still considered a “candidate” planet awaiting verification, most astronomers consulted for this story believe the world to be there. Scarcely more than the planet’s orbital period and approximate mass are known, but that is enough to send shivers down spines. Proxima Centauri shines with only about a thousandth of our Sun’s luminosity, meaning any life-friendly planets must huddle close. The newfound world, christened “Proxima b” by scientists, resides in an 11.2-day orbit where water — and thus the kind of life we understand — could conceivably exist. And it is likely to be little more than one-third heavier than Earth, suggesting it offers a solid surface upon which seas and oceans could pool. In a feat of discovery that could reshape the history of science and human dreams of interstellar futures, our species has uncovered a potentially habitable planet right next door. [Continue reading…]
The Guardian reports: China says it has launched the world’s first quantum satellite, a project Beijing hopes will enable it to build a coveted “hack-proof” communications system with potentially significant military and commercial applications.
Xinhua, Beijing’s official news service, said Micius, a 600kg satellite that is nicknamed after an ancient Chinese philosopher, “roared into the dark sky” over the Gobi desert at 1.40am local time on Tuesday, carried by a Long March-2D rocket.
“The satellite’s two-year mission will be to develop ‘hack-proof’ quantum communications, allowing users to send messages securely and at speeds faster than light,” Xinhua reported.
The Quantum Experiments at Space Scale, or Quess, satellite programme is part of an ambitious space programme that has accelerated since Xi Jinping became Communist party chief in late 2012.
“There’s been a race to produce a quantum satellite, and it is very likely that China is going to win that race,” Nicolas Gisin, a professor and quantum physicist at the University of Geneva, told the Wall Street Journal. “It shows again China’s ability to commit to large and ambitious projects and to realise them.”
The satellite will be tasked with sending secure messages between Beijing and Urumqi, the capital of Xinjiang, a sprawling region of deserts and snow-capped mountains in China’s extreme west.
Highly complex attempts to build such a “hack-proof” communications network are based on the scientific principle of entanglement. [Continue reading…]
The Washington Post reports: For a 2-billion-year-long span, ending about 715 million years ago, Venus was likely a much more pleasant spot that it is today. To observe Venus now is to witness a dry and toxic hellscape, where the planet heats up to a scorching 864 degrees Fahrenheit. A super-strong electric wind is believed to suck the smallest traces of water into space. With apologies to Ian Malcolm, life as we know it could not find a way.
But travel back in time a few billion years or so. Ancient Venus, according to a new computer model from NASA, would have been prime solar system real estate, to the point it may have been downright habitable.
That life would find Venus amenable hinges on two main factors. Venus would have needed much balmier temperatures, and it also would have needed a liquid ocean — which is a significant if, although elemental traces such as deuterium indicate water existed on Venus at one point. As Colin Wilson, an Oxford University planetary physicist, told Time in 2010, “everything points to there being large amounts of water in the past.”
Venusian temperatures, too, appear to have been far cooler when the solar system was younger. NASA’s Goddard Institute for Space Studies, in a report published Thursday in the journal Geophysical Research Letters, calculated that the average surface temperature 2.9 billion years ago was about 50 degrees Fahrenheit. Such temperature would have made Venus, surprisingly for a planet closer to the Sun, a bit chillier than Earth was at the time. [Continue reading…]
Kevin Hartnett writes: Standard geometric objects can be described by simple rules — every straight line, for example, is just y = ax + b — and they stand in neat relation to each other: Connect two points to make a line, connect four line segments to make a square, connect six squares to make a cube.
These are not the kinds of objects that concern Scott Sheffield. Sheffield, a professor of mathematics at the Massachusetts Institute of Technology, studies shapes that are constructed by random processes. No two of them are ever exactly alike. Consider the most familiar random shape, the random walk, which shows up everywhere from the movement of financial asset prices to the path of particles in quantum physics. These walks are described as random because no knowledge of the path up to a given point can allow you to predict where it will go next.
Beyond the one-dimensional random walk, there are many other kinds of random shapes. There are varieties of random paths, random two-dimensional surfaces, random growth models that approximate, for example, the way a lichen spreads on a rock. All of these shapes emerge naturally in the physical world, yet until recently they’ve existed beyond the boundaries of rigorous mathematical thought. Given a large collection of random paths or random two-dimensional shapes, mathematicians would have been at a loss to say much about what these random objects shared in common.
Yet in work over the past few years, Sheffield and his frequent collaborator, Jason Miller, a professor at the University of Cambridge, have shown that these random shapes can be categorized into various classes, that these classes have distinct properties of their own, and that some kinds of random objects have surprisingly clear connections with other kinds of random objects. Their work forms the beginning of a unified theory of geometric randomness. [Continue reading…]
Alex Riley writes: As they drove on featureless dirt roads on the first Tuesday of 2010, John Dabiri, professor of aeronautics and bioengineering at the California Institute of Technology, and his then-student Robert Whittlesey, were inspecting a remote area of land that they hoped to purchase to test new concepts in wind power. They named their site FLOWE for Field Laboratory for Optimized Wind Energy. Situated between gentle knolls covered in sere vegetation, the four-acre parcel in Antelope Valley, California, was once destined to become a mall, but those plans fell through. The land was cheap. And, more importantly, it was windy.
Estimated at 250 trillion Watts, the amount of wind on Earth has the potential to provide more than 20 times our current global energy consumption. Yet, only four countries — Spain, Portugal, Ireland, and Denmark — generate more than 10 percent of their electricity this way. The United States, one of the largest, wealthiest, and windiest of countries, comes in at about 4 percent. There are reasons for that. Wind farm expansion brings with it huge engineering costs, unsightly countryside, loud noises, disruption to military radar, and death of wildlife. Recent estimates blamed turbines for killing 600,000 bats and up to 440,000 birds a year. On June 19, 2014, the American Bird Conservancy filed a lawsuit against the federal government asking it to curtail the impact of wind farms on the dwindling eagle populations. And while standalone horizontal-axis turbines harvest wind energy well, in a group they’re highly profligate. As their propeller-like blades spin, the turbines facing into the wind disrupt free-flowing air, creating a wake of slow-moving, infertile air behind them. [Continue reading…]
Geoff Manaugh writes: In Ghost Fleet, a 2015 novel by security theorists Peter Singer and August Cole, the next world war begins in space.
Aboard an apparently civilian space station called the Tiangong, or “Heavenly Palace,” Chinese astronauts—taikonauts—maneuver a chemical oxygen iodine laser (COIL) into place. They aim their clandestine electromagnetic weapon at its first target, a U.S. Air Force communications satellite that helps to coordinate forces in the Pacific theater far below. The laser “fired a burst of energy that, if it were visible light instead of infrared, would have been a hundred thousand times brighter than the sun.” The beam melts through the external hull of the U.S. satellite and shuts down its sensitive inner circuitry.
From there, the taikonauts work their way through a long checklist of strategic U.S. space assets, disabling the nation’s military capabilities from above. It is a Pearl Harbor above the atmosphere, an invisible first strike.
“The emptiness of outer space might be the last place you’d expect militaries to vie over contested territory,” Lee Billings has written, “except that outer space isn’t so empty anymore.” It is not only science fiction, in other words, to suggest that the future of war could be offworld. The high ground of the global battlefield is no longer defined merely by a topographical advantage, but by strategic orbitals and potential weapons stationed in the skies above distant continents.
When China shot down one of its own weather satellites in January 2007, the event was, among other things, a clear demonstration to the United States that China could wage war beyond the Earth’s atmosphere. In the decade since, both China and the United States have continued to pursue space-based armaments and defensive systems. A November 2015 “Report to Congress,” for example, filed by the U.S.-China Economic and Security Review Commission (PDF), specifically singles out China’s “Counterspace Program” as a subject of needed study. China’s astral arsenal, the report explains, most likely includes “direct-ascent” missiles, directed-energy weapons, and also what are known as “co-orbital antisatellite systems.” [Continue reading…]
The Observer reports: You’ll find the Future of Humanity Institute down a medieval backstreet in the centre of Oxford. It is beside St Ebbe’s church, which has stood on this site since 1005, and above a Pure Gym, which opened in April. The institute, a research faculty of Oxford University, was established a decade ago to ask the very biggest questions on our behalf. Notably: what exactly are the “existential risks” that threaten the future of our species; how do we measure them; and what can we do to prevent them? Or to put it another way: in a world of multiple fears, what precisely should we be most terrified of?
When I arrive to meet the director of the institute, Professor Nick Bostrom, a bed is being delivered to the second-floor office. Existential risk is a round-the-clock kind of operation; it sleeps fitfully, if at all.
Bostrom, a 43-year-old Swedish-born philosopher, has lately acquired something of the status of prophet of doom among those currently doing most to shape our civilisation: the tech billionaires of Silicon Valley. His reputation rests primarily on his book Superintelligence: Paths, Dangers, Strategies, which was a surprise New York Times bestseller last year and now arrives in paperback, trailing must-read recommendations from Bill Gates and Tesla’s Elon Musk. (In the best kind of literary review, Musk also gave Bostrom’s institute £1m to continue to pursue its inquiries.)
The book is a lively, speculative examination of the singular threat that Bostrom believes – after years of calculation and argument – to be the one most likely to wipe us out. This threat is not climate change, nor pandemic, nor nuclear winter; it is the possibly imminent creation of a general machine intelligence greater than our own. [Continue reading…]
Discover Magazine reports: A peculiar new molecule hovering within a star-forming dust cloud in deep in space could help explain why life on Earth is the way it is.
The cloud, called Sagittarius B2, resides near the center of the Milky Way, and it’s there that researchers from the California Institute of Technology discovered an organic element that displays a key property shared by all life. Propylene oxide is the first element discovered outside of our solar system to exhibit chirality, or the presence of two distinct, mirror-image forms. Many complex molecules have this property, including myriad organic molecules necessary for life. The chemical formula of these two versions is exactly the same, but the structure is flipped.
All life on Earth is composed of chiral molecules, and the versions organisms use, either right- or left-handed, determines fundamental properties of their biology. For example, all living things only use the right-handed form of the sugar ribose to form the backbone of DNA, giving it that the signature twist. You can think of molecular handedness by picturing gloves — hence the “handed terminology”. The gloves, or molecules, may look similar, but you could never put a left-handed glove on your right hand. [Continue reading…]
Adam Frank writes: Last month astronomers from the Kepler spacecraft team announced the discovery of 1,284 new planets, all orbiting stars outside our solar system. The total number of such “exoplanets” confirmed via Kepler and other methods now stands at more than 3,000.
This represents a revolution in planetary knowledge. A decade or so ago the discovery of even a single new exoplanet was big news. Not anymore. Improvements in astronomical observation technology have moved us from retail to wholesale planet discovery. We now know, for example, that every star in the sky likely hosts at least one planet.
But planets are only the beginning of the story. What everyone wants to know is whether any of these worlds has aliens living on it. Does our newfound knowledge of planets bring us any closer to answering that question?
A little bit, actually, yes. In a paper published in the May issue of the journal Astrobiology, the astronomer Woodruff Sullivan and I show that while we do not know if any advanced extraterrestrial civilizations currently exist in our galaxy, we now have enough information to conclude that they almost certainly existed at some point in cosmic history. [Continue reading…]