European scientists say they’ve figured out the recipe for water in space: Just add starlight.

They made the discovery while examining a dying star that is 500 light-years away from Earth, using an infrared observatory launched by the European Space Agency last year.

“This is a good example of how better instruments can change our picture completely,” said Leen Decin of the Catholic University of Leuven in Belgium.

{ CNN | Continue reading }

artwork { Roy Lichtenstein, Drowning Girl, 1963 }

Panspermia is the idea that life exists throughout the universe in comets, asteroids and interstellar dust clouds and that life of Earth was seeded from one or more of these sources. Panspermia holds that we are all extraterrestrials.
While this is certainly not a mainstream idea in science, a growing body of evidence suggests that it should be carefully studied rather than casually disregarded.

For example, various bugs have been shown to survive for months or even years in the harsh conditions of space. And one of the more interesting but lesser known facts about the Mars meteorite that some scientists believe holds evidence of life on Mars, is that its interior never rose above 50 degrees centigrade, despite being blasted from the Martian surface by an meteor impact and surviving a fiery a descent through Earth’s thick atmosphere.

If there is life up there, this evidence suggests that it could survive the trip to Earth.

All that seems well established. Now for the really controversial stuff.

In 2001, numerous people observed red rain falling over Kerala in the southern tip of India during a two month period. One of them was Godfrey Louis, a physicist at nearby Cochin University of Science and Technology. Intrigued by this phenomena, Louis collected numerous samples of red rain, determined to find out what was causing the contamination, perhaps sand or dust from some distant desert.

Under a microscope, however, he found no evidence of sand or dust. Instead, the rain water was filled with red cells that look remarkably like conventional bugs on Earth. What was strange was that Louis found no evidence of DNA in these cells which would rule out most kinds of known biological cells (red blood cells are one possibility but ought to be destroyed quickly by rain water).

{ The Physics arXiv Blog | Continue reading }

Astrophysicists think they know how to destroy a black hole. The puzzle is what such destruction would leave behind.

The idea of a body so massive that its escape velocity exceeds the speed of light dates back to the English geologist John Michell who first considered it in 1783. In his scenario, a beam of light would travel away from the massive body until it reached a certain height and then returned to the surface.

Modern thinking about black holes is somewhat different, not least because special relativity tells us that the speed of light is a universal constant. The critical concept that physicists focus on today is the event horizon: a theoretical boundary in space through which light and other objects can pass in one direction but not in the other. Since light cannot escape, the event horizon is what makes a black hole black.

The event horizon is somewhat of a disappointment to many astrophysicists because the interesting physics, the stuff beyond the known laws of the universe, all occurs inside it and is therefore hidden from us.

What physicists would like, therefore, is way to get rid of the event horizon and expose the inner workings to proper scrutiny. Doing this would destroy the black hole but reveal something far more bizarre and exotic.

Today, Ted Jacobson at the University of Maryland and Thomas Sotiriou and the University of Cambridge explain how this might be done in an entertaining and remarkably accessible account of the challenge.

{ The Physics arXiv Blog | Continue reading }

artwork { Ellsworth Kelly, Black Forms, 1955 | ink, graphite and collage on paper }

Errors in the way physicists estimate the effects of dark matter and dark energy on the leftover heat from the Big Bang has thrown their existence into doubt, say British scientists.

Physicists’ general model of the universe includes two ‘dark’ concepts.

Dark energy is a force that explains the way that galaxies accelerate away from each other, while dark matter was postulated to explain the observations that galaxies have more mass than can be accounted for by stars and gas.

Evidence for the ‘dark side’ comes primarily from studies of the Cosmic Background Radiation (CMB), the leftover ‘glow’ from the Big Bang, which has been analysed in detail by the Wilkinson Microwave Anisotropy Probe (WMAP), a NASA satellite telescope launched in 2001 that provided the first full-sky map of the CMB.

Now, some scientists say errors in the WMAP data may be larger than expected.

This would mean that there is no need to include dark matter and dark energy in models of the cosmos.

{ Cosmos | Continue reading }

Project Icarus is an ambitious plan to reassess our ability to send a spacecraft to another star. But is it any more than science fiction?

Until recently, planetary geologists had only a handful of subjects to study. The discovery of exoplanets has changed all that, however. The number of known planets orbiting other stars now approaches 500 and few astronomers seriously doubt that an Earth-like body will turn up somewhere soon.

When that happens, we’ll want to study it in unprecedented detail. We’ll want to know its mass, temperature, atmospheric composition, its colour, whether it has seas and continents and if so whether these support life, perhaps even of the intelligent kind. But above all we’ll want to know whether we can visit this place.

Such a trip will not be easy but it may not be entirely impossible. In fact, rocket scientists have dreamed up various plans for interplanetary probes. One of the more famous was Project Daedalus, a 1970s plan by the British Interplanetary Society for a nuclear-powered spacecraft capable of visiting Barnard’s Star some 6 light years away within a human lifetime.

Today, the British Interplanetary Society and another organisation called the Tau Zero Foundation have posted plans on the arXiv to redesign Daedalus in the light of the 30 years of advances that have taken place since the original. The new plan is called Project Icarus. (In Greek mythology, Icarus was the son of Daedalus who died after flying too close to the Sun and melting the wax that held his wings together.)

Icarus could be an interesting measure of the progress in nuclear propulsion technology in the 30 years since Daedalus was conceived.

{ The Physics arXiv Blog | Continue reading }

artwork { Simon Evans, Symptoms of Loneliness, 2009 | pen, paper, scotch tape, correction fluid | enlarge | more }

… something I’m quite interested in, and it’s related to the Cosmic Microwave Background (CMB). I’ve briefly mentioned the CMB before, but here’s a more decent introduction: when we say CMB we are talking about radiation that was created when the Universe was very very young  - around 300,000 years old. At that time the Universe was hot and radiation (or photons) were the dominant component of the Universe. Because it was so hot at that time, the Universe was actually opaque – matter was ionized, meaning electrons were bobbling about not really being attached to any nuclei because of the high temperature. What this means is that photons could not get very far without bumping into something – they could not travel in a straight line for any decent sort of time, and were perpetually scattered around. That’s essentially what opaque means. However, something special happened around 300,000 years into the Universe’s lifetime, and that was a decrease in temperature that allowed these electrons to settle into atoms, effectively setting the photons free. We call this the time of last-scattering.

{ we are all in the gutter | Continue reading }

Deciding what is and isn’t a planet is a problem on which the International Astronomical Union has generated a large amount of hot air. The challenge is to find a way of defining a planet that does not depend on arbitrary rules. For example, saying that bodies bigger than a certain arbitrary size are planets but smaller ones are not will not do. The problem is that non-arbitrary rules are hard to come by.

In 2006, the IAU famously modified its definition of a planet in a way that demoted Pluto to a second class member of the Solar System. Pluto is no longer a full blown planet but a dwarf planet along with a handful of other objects orbiting the Sun.

The IAU’s new definition of a planet isan object that satisfies the following three criteria. It must be in orbit around the Sun, have sufficient mass to have formed into a nearly round shape and it must have cleared its orbit of other objects.

Pluto satisfies the first two criteria but fails on the third because it crosses Neptune’s orbit(although, strangely, Neptune passes).

Such objects are officially called dwarf planets and their definition is decidedly arbitrary. In its infinite wisdom, the IAU states that dwarf planets are any transNeptunian objects with an absolute magnitude less than +1 (ie a radius of at least 420 km).

Today, Charles Lineweaver and Marc Norman at the Australian National University in Canberra focus on a new way of defining dwarf planets which is set to dramatically change the way we think about these obects.

The problem boils down to separating the potato-shaped objects in the Solar System from the spherical ones.

{ The Physics arXiv Blog | Continue reading }

photo { Max Langhurst }

Black holes may constitute all dark matter

Dark matter is the mysterious stuff that cosmologists believe fills our Universe. The evidence for its existence is that there is not enough visible mass to hold galaxies together. But since galaxies manifestly do not fly apart, there must be some invisible stuff, some missing mass, that generates the gravitational forces holding them together.

But there’s a problem with this idea. Two of them actually. First, physicists’ best guess at the laws of physics give a good description of all of the particles they’ve discovered so far and a few they expect to discover soon. The trouble is that none of these particles have the right kind of properties to be dark matter ie electrically neutral, long-lived and slow moving. But none of the known or reasonably hypothesised particles fits the bill. To make room for a dark matter particle, the laws of physics have to be changed in ways that many theorists feel uncomfortable with.

Second, despite a decade spent searching for dark matter with experiments costing tens of millions of dollars, nobody has laid eyes on the stuff. Most physicists think these experiments have found nothing: zip, zilch, zero.

{ The Physics arXiv Blog | Continue reading }

photo { Nick Waplington, S-M Club Ceiling, 2004 }

If we are ever contacted by aliens, the man I’m having lunch with will be one of the first humans to know. His name is Paul Davies and he’s chair of the Seti (Search For Extraterrestrial Intelligence) Post-Detection Task Group. They’re a group of the world’s most eminent scientists and will be, come the big day, the planet’s alien welcome committee.

{ Guardian | Continue reading }

photo { Tim Barber }

“The government has been telling us the truth,” declared David Clarke, a senior lecturer in journalism at Sheffield Hallam University, who has a side interest in U.F.O.’s. “There are a lot of weird things in the sky, and some of them we can’t explain, but there’s not a shred of evidence for a single alien visitation.”

Which is, frankly, a letdown, as is the government’s prosaic explanation of why, for decades, it has meticulously documented reports of U.F.O. sightings. (…)

In the old days, the United States systematically compiled reports of U.F.O. sightings, too. But its last program, known as Project Blue Book, was closed down in 1969 after government officials concluded that if something was out there, it was not anything they wanted to investigate.

{ NY Times, 2008 | Continue reading }

previously/related { Now, just where might this Great Filter be located? }

Mirage: The Omnidroid 9000 is a top-secret military fighting robot. Artificial intelligence allows it to solve any problem it’s presented with, and, unfortunately…

Mr. Incredible: Let me guess. It became smart enough to wonder why it had to take orders.

Mirage: We lost control, and now it’s loose in the jungle, threatening our facility.

{ The Incredibles, 2004 }

Dave: Open the pod bay doors, HAL.

HAL: I’m sorry, Dave. I’m afraid I can’t do that.

Dave: What’s the problem?

HAL: I think you know what the problem is just as well as I do.

Dave: I don’t know what you’re talking about, HAL.

HAL: I know that you and Frank were planning to disconnect me, and I’m afraid that’s something I cannot allow to happen.

{ 2001: A Space Odyssey, 1968 }

{ 1 | 2 }

UFO spotters, Raëlian cultists, and self-­certified alien abductees notwithstanding, humans have, to date, seen no sign of any extraterrestrial civilization. We have not received any visitors from space, nor have our radio telescopes detected any signals transmitted by any extraterrestrial civilization. The Search for Extra-Terrestrial Intelligence (SETI) has been going for nearly half a century, employing increasingly powerful telescopes and data-­mining techniques; so far, it has consistently corroborated the null hypothesis. As best we have been able to determine, the night sky is empty and silent. (…)

Here is another fact: the observable universe contains on the order of 100 billion galaxies, and there are on the order of 100 billion stars in our galaxy alone. In the last couple of decades, we have learned that many of these stars have planets circling them; several hundred such “exoplanets” have been discovered to date. Most of these are gigantic, since it is very difficult to detect smaller exoplanets using current methods. (In most cases, the planets cannot be directly observed. Their existence is inferred from their gravitational influence on their parent suns, which wobble slightly when pulled toward large orbiting planets, or from slight fluctuations in luminosity when the planets partially eclipse their suns.) We have every reason to believe that the observable universe contains vast numbers of solar systems, including many with planets that are Earth-like, at least in the sense of having masses and temperatures similar to those of our own orb. We also know that many of these solar systems are older than ours.

From these two facts it follows that the evolutionary path to life-forms capable of space colonization leads through a “Great Filter,” which can be thought of as a probability barrier. The filter consists of one or more evolutionary transitions or steps that must be traversed at great odds in order for an Earth-like planet to produce a civilization capable of exploring distant solar systems. You start with billions and billions of potential germination points for life, and you end up with a sum total of zero extraterrestrial civilizations that we can observe. The Great Filter must therefore be sufficiently powerful–which is to say, passing the critical points must be sufficiently improbable–that even with many billions of rolls of the dice, one ends up with nothing: no aliens, no spacecraft, no signals. At least, none that we can detect in our neck of the woods.

Now, just where might this Great Filter be located? There are two possibilities: It might be behind us, somewhere in our distant past. Or it might be ahead of us, somewhere in the decades, centuries, or millennia to come. Let us ponder these possibilities in turn.

If the filter is in our past, there must be some extremely improbable step in the sequence of events whereby an Earth-like planet gives rise to an intelligent species comparable in its technological sophistication to our contemporary human civilization. Some people seem to take the evolution of intelligent life on Earth for granted: a lengthy process, yes; ­complicated, sure; yet ultimately inevitable, or nearly so. But this view might well be completely mistaken. There is, at any rate, hardly any evidence to support it. Evolutionary biology, at the moment, does not enable us to calculate from first principles how probable or improbable the emergence of intelligent life on Earth was. Moreover, if we look back at our evolutionary history, we can identify a number of transitions any one of which could plausibly be the Great Filter.

For example, perhaps it is very improbable that even ­simple self-replicators should emerge on any Earth-like planet. Attempts to create life in the laboratory by mixing water with gases believed to have been present in the Earth’s early atmosphere have failed to get much beyond the synthesis of a few simple amino acids. No instance of abiogenesis (the spontaneous emergence of life from nonlife) has ever been observed. (…)

The other possibility is that the Great Filter is still ahead of us. This would mean that some great improbability prevents almost all civilizations at our current stage of technological development from progressing to the point where they engage in large-scale space colonization. For example, it might be that any sufficiently advanced civilization discovers some tech­nology–perhaps some very powerful weapons tech­nology–that causes its extinction. (…) …a nuclear war fought with arms stockpiles much larger than today’s (perhaps resulting from future arms races); a genetically engineered superbug; environmental disaster; an asteroid impact; wars or terrorist acts committed with powerful future weapons; super­intelligent general artificial intelligence with destructive goals; or high-energy physics experiments. (…)

So where is the Great Filter? Behind us, or not behind us?

If the Great Filter is ahead of us, we have still to confront it. If it is true that almost all intelligent species go extinct before they master the technology for space colonization, then we must expect that our own species will, too, since we have no reason to think that we will be any luckier than other species. (…)

What has all this got to do with finding life on Mars? Consider the implications of discovering that life had evolved independently on Mars (or some other planet in our solar system). That discovery would suggest that the emergence of life is not very improbable. If it happened independently twice here in our own backyard, it must surely have happened millions of times across the galaxy. This would mean that the Great Filter is less likely to be confronted during the early life of planets and therefore, for us, more likely still to come.

{ Nick Bostrom/Technology Review | Continue reading }

Final proof that Mars has bred life will be confirmed this year, leading NASA experts believe. The historic discovery will come not on Mars itself but from chunks of the red planet here on Earth.

David McKay, chief of astrobiology at NASA’s Johnson Space Centre in Houston, says powerful new microscopes and other instruments will establish whether features in martian meteorites are alien fossils.

He says evidence for life in the space rocks could have been claimed by the UK if British scientists had used readily-available electron microscopes. Instead, images of colonies of martian bacteria were collected by American scientists.

The NASA team is already convinced that colonies of micro-organisms are visible inside three martian rocks that landed on Earth. If so, this would have profound implications for our understanding of life in the universe.

{ Scientific American | Continue reading }

New observations of galactic clusters have revealed a controversial phenomenon called “dark flow,” which could be a sign of parallel universes.

{ Seed magazine | Continue reading }

related { Do quantum computers offer proof of parallel universes? | And: New quantum theory topples Einstein’s spacetime. }

illustration { panther house }

Why does the universe looks the way it does?

This seems on the one hand a very obvious question. On the other hand, it is an interestingly strange question, because we have no basis for comparison. The universe is not something that belongs to a set of many universes. We haven’t seen different kinds of universes so we can say, oh, this is an unusual universe, or this is a very typical universe. Nevertheless, we do have ideas about what we think the universe should look like if it were “natural”, as we say in physics. Over and over again it doesn’t look natural. We think this is a clue to something going on that we don’t understand.

One very classic example that people care a lot about these days is the acceleration of the universe and dark energy. In 1998 astronomers looked out at supernovae that were very distant objects in the universe and they were trying to figure out how much stuff there was in the universe, because if you have more and more stuff — if you have more matter and energy — the universe would be expanding, but ever more slowly as the stuff pulled together. What they found by looking at these distant bright objects of type 1A supernovae was that, not only is the universe expanding, but it’s accelerating. It’s moving apart faster and faster. Our best explanation for this is something called dark energy, the idea that in every cubic centimeter of space, every little region of space, if you empty it out so there are no atoms, no dark matter, no radiation, no visible matter, there is still energy there. There is energy inherent in empty spaces.

{ A Conversation with Sean Carroll | Edge | Continue reading }

artwork { Lucio Fontana, Concetto Spaziale, 1958-60 }

Aliens from outer space are already among us on earth, say Bulgarian government scientists who claim they are already in contact with extraterrestrial life.

Work on deciphering a complex set of symbols sent to them is underway, scientists from the country’s Space Research Institute said.

They claim aliens are currently answering 30 questions posed to them.

Lachezar Filipov, deputy director of the Space Research Institute of the Bulgarian Academy of Sciences, confirmed the research.

He said the centre’s researchers were analysing 150 crop circles from around the world, which they believe answer the questions.

“Aliens are currently all around us, and are watching us all the time,” Mr Filipov told Bulgarian media.

“They are not hostile towards us, rather, they want to help us but we have not grown enough in order to establish direct contact with them.”

“The human race was certainly going to have direct contact with the aliens in the next 10 to 15 years,” he said.

{ The Telegraph | Continue reading }

related { Proof of the existence of extraterrestrial life may be closer than we think, thanks to a surge of research in astrobiology. | Times Higher Education }

{ One of the great mysteries of our Solar System is why Uranus is tilted on its side. Collision-Free theory explains why. | Photo taken by the spacecraft Voyager 2 in 1986 }

For all its tumult — erupting stars, colliding galaxies, collapsing black holes — the cosmos is a surprisingly orderly place. Theoretical calculations have long shown that the entropy of the universe — a measure of its disorder — is but a tiny fraction of the maximum allowable amount.

A new calculation of entropy upholds that general result but suggests that the universe is messier than scientists had thought — and slightly further along on its gradual journey to death, two Australian cosmologists conclude. (…) Tthe collective entropy of all the supermassive black holes at the centers of galaxies is about 100 times higher than previously calculated. Because supermassive black holes are the largest contributor to cosmic entropy, the finding suggests that the entropy of the universe is also about 100 times larger than previous estimates.

Entropy quantifies the number of different microscopic states that a physical system can have while looking the same on a large scale. For instance, an omelet has higher entropy than an egg because there are more ways for the molecules of an omelet to rearrange themselves and still remain an omelet than for an egg, notes cosmologist Sean Carroll of the California Institute of Technology in Pasadena.

A black hole is the entropy champ because there are myriad ways for all the material that has fallen into it to be arranged microscopically while the black hole retains the same numerical values for its observable properties — charge, mass and spin.

{ ScienceNews | Continue reading }

This world is arranged as it had to be if it were to be capable of continuing with great difficulty to exist; if it were a little worse, it would be no longer capable of continuing to exist. Consequently, since a worse world could not continue to exist, it is absolutely impossible; and so this world itself is the worst of all possible worlds.

{ Schopenhauer, The World as Will and Representation, II, 46, 1818 }

artwork { Georgia O’Keeffe, Abstraction Blue, 1927 }

In the early years of the “space race” (1957-1975) two men sought to test a scientifically simple yet culturally complicated theory: that women might be innately better suited for space travel than men. In 1960 the thought of a woman in space was a radical one, and justifiably so. On the ground 75% of American women did not work outside the home and females were banned from military flight service altogether. In marriage, wives were required to have their husband’s permission to take out a bank loan, buy property, or purchase large household goods such as a refrigerator. Despite the social odds, a Harvard-educated surgeon and a U.S. Air Force General sought to determine if, from a purely practical perspective, women were suitable for space flight.

The latest look at the intersection of physiology, spaceflight and politics is captured in a new article entitled “A Forgotten Moment in Physiology: The Lovelace Woman in Space Program (1960-1962),” written by Kathy Ryan, Jack Loeppky and Donald Kilgore.

{ EurekAlert | Continue reading }

photo { Katerina Jebb }

previously { How many people are in space right now? }

In the search for extraterrestrial life, some scientists say we’re focusing too much on finding signs of existence as we know it, and in the process, we may be missing more strange forms of life that don’t rely on water or carbon metabolism.

Now researchers from Austria have started a systematic study of solvents other than water that might be able to support life outside our planet. They’re hoping their research will lead to a shift in what they call the “geocentric mindset” of our attempts to detect extraterrestrial life. (…)

While water is liquid only between zero and 100 degrees Celsius, other solvents are liquid over a much larger temperature range. For instance, because ammonia stays liquid at a lower temperature, an ocean of ammonia could exist on a planet much further from its host star.

{ Wired | Continue reading }