Tag Archives: science

March 28, 2017 · 5:31 pm

Scientists discover world’s most ancient fossils

Published March 01, 2017

Scientists have discovered tiny fossils that are thinner than a human hair and are an astounding 3.7 billion years old, making them the oldest known fossils on Earth, University College London announced on Wednesday. They could even be as old as 4.2 billion years.

The fossils were likely created by bacteria that lived near hydrothermal vents and consumed iron. Those ancient critters lived an incredible 3.8 to 4.3 billion years ago.

“Our discovery supports the idea that life emerged from hot, seafloor vents shortly after planet Earth formed,”  Matthew Dodd, a PhD student at the University College London and the first author of a new study about the fossils, said in a statement. “This speedy appearance of life on Earth fits with other evidence of recently discovered 3,700 million year old sedimentary mounds that were shaped by microorganisms.”

The scientists found the fossils in a part of Quebec, Canada, known for having ancient sedimentary rock. The little fossils are much older than their closest competitors.

“The microfossils we discovered are about 300 million years older than the previously thought oldest microfossils,” Dominic Papineau, a lecturer at University College London and the study’s lead researcher, said in a video announcing the find. “So there are within a few hundred million years from the accretion of the solar system.”

In the statement, Papineau described these tiny fossils— they’re less than a millimeter long— as “direct evidence of one of Earth’s oldest life forms.”

Planet Earth itself is believed to be 4.5 billion years old.

One of the most exciting ramifications of the find is that since it shows that life began on Earth so long ago, perhaps the same thing could have happened in other places in our solar system— like Mars.

“These discoveries demonstrate life developed on Earth at a time when Mars and Earth had liquid water at their surfaces, posing exciting questions for extra-terrestrial life,” Dodd said, in the statement. “Therefore, we expect to find evidence for past life on Mars 4,000 million years ago, or if not, Earth may have been a special exception.”

The discovery was reported in a study published online Wednesday in the journal Nature.

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November 15, 2015 · 5:25 pm

For you hopeful THC fiends…lol…

marijuana-lplants_1024

Scientists engineer yeast to produce active marijuana compound, THC

Trying to replicate the “Ferrari of the plant world”.

 Yeast has been engineered to produce the main psychoactive compound in marijuana – tetrahydrocannabinol (THC). Responsible for the majority of marijuana’s psychological effects – including the high – THC can also be use to treat symptoms of HIV infection and chemotherapy and researchers are hoping their yeast will be able to pump it out more efficiently than producing synthetic versions.

“This is something that could literally change the lives of millions of people,” Kevin Chen from Hyasynth Bio, a Canada-based company that’s been engineering yeasts to produce both THC and cannabidiol – another active compound that has shown promise as a medical treatment – told The New York Times.

Now, researchers from the Technical University of Dortmund in Germany have outlined in the journal Biotechnology Letters how they looked into which genes the marijuana plant uses to produce THC, and then engineered those genes into their yeast. They then fed a cocktail of specially chosen molecules to the yeast, and it essentially ‘poops’ out the THC.

They’ve also reportedly managed to produce cannabidiol in the same way, but are yet to publish the details. The big challenge now will be figuring out how to replace these molecules with a raw material such as sugar to make the process cheap, easy, and commercially competitive.

The purpose isn’t to replace the marijuana plant, because let’s face it, it’s doing a pretty good job on its own. As Jonathan Page, an adjunct professor at the University of British Columbia in Canada who helped sequence the THC and cannabidiol genes, told Roxanne Khamsi at The New York Times: “Right now, we have a plant that is essentially the Ferrari of the plant world when it comes to producing the chemical of interest. Cannabis is hard to beat.”

The idea instead is to offer up an alternative for places such as Europe, where medicinal compounds from marijuana would be welcomed if they didn’t come in the form of a plant that could be illegally farmed. And synthetic versions of THC are currently available in pill form to treat several side effects of having HIV or chemotherapy, but the chemical synthesis involved is complicated and expensive.

What yeast could also offer is the potential to more efficiently test the medicinal properties of specific active compounds in marijuana, which have shown promise in treating everything from seizures and inflammation to cancer and parkinson’s disease. Yasmin Hurd, a professor of neuroscience and psychiatry at Icahn School of Medicine at Mount Sinai, told Tech Insider that using all the compounds in marijuana simultaneously is like “throwing 400 tablets in a cocktail and saying ‘take this,'” rather than figuring out which component of that cocktail is really beneficial for the specific disease.

Because right now, rigorous scientific evidence showing that marijuana and its constituents effectively treat the symptoms of many of the illnesses for which they’ve been prescribed is lacking.

“Marijuana is increasingly embraced as medicine, yet there is limited evidencethat it is effective against many of the conditions for which it is prescribed,” The New York Times reports. “Researchers hoping to separate fact from wishful thinking will need much better access to marijuana’s unique constituents. Modified yeast may provide them.”

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October 11, 2015 · 9:47 pm

Physicists Discover New Massless Particle; Could Revolutionize Electronics & Quantum Computing

Posted By: Jolene Creightonon: July 25, 2015

Hasan massless particle

Physics may have just taken a new leap forward, as three independent groups of physicists have found strong evidence for massless particles called “Weyl fermions,” which exist as quasiparticles – collective excitations of electrons. Ultimately, this discovery is over 80 years in the making, dating back to Paul Dirac.

In 1928, Dirac came up with an equation that described the spin of fermions (fermions are the building blocks that make up all matter). Within his equation, he discovered that, in relation to particles that have charge and mass, there should be a another particle and antiparticle—what we know as the electron and (its antiparticle) the positron.

Yet, there are more than one ways to skin a cat.

Other solutions to this equation hinted at more exotic kinds of particles. Enter Hermann Weyl, a German mathematician who, in 1929, come up with a solution that involved massless particles. These became known as “Weyl fermions.” And, for a number of years, physicists believed that neutrinos (subatomic particles that are produced by the decay of radioactive elements) were actually Weyl particles. Yet, further studies, which were published in 1998, indicated that neutrinos do, in fact, have mass, which means that they cannot be the aforementioned Weyl particles.

But now, we have evidence that Weyl fermions actually exist.

Unlocking the Find

The research comes thanks to Zahid Hasan over at Princeton University, who uncovered these particles in the semimetal tanatalum arsenide (which is referred to as TaAs). Hasan and his team suggested that  TaAs should contain Weyl fermions and (here is the important bit) it should have what is known as a “Fermi arc.” And in 2014, the team found evidence of such an arc.

Artist's rendition via ChutterStock

But that’s not all, another team, led by Hongming Weng at the Chinese Academy of Sciences, found similar evidence in an independent study that used the same methods. And Marin Soljačić and colleagues (hailing from MIT and the Univeristy of China) have seen evidence of Weyl fermions in a different material, specifically, a “double-gyroid” photonic crystal.

In this latter case, the team fired microwaves at the crystal and measured microwave transmission through it, varying the frequency of the microwaves throughout the experiment. Through this process, the team could map the structure of the crystal, allowing them to determine which microwave frequencies can travel through the crystal and which cannot. In the end, this revealed the presence of “Weyl points” in the structure, which is strong evidence for Weyl fermion states existing within the photonic crystal.

The Future of Physics

The significance of this find, quite literally, cannot be overstated. Hasan is clear to point this out, noting in the press release that, “The physics of the Weyl fermion are so strange, there could be many things that arise from this particle that we’re just not capable of imagining now.”

He goes on to note more specific applications: “It’s like they have their own GPS and steer themselves without scattering. They will move and move only in one direction since they are either right-handed or left-handed and never come to an end because they just tunnel through. These are very fast electrons that behave like unidirectional light beams and can be used for new types of quantum computing.” Soljačić, the head of the second study, adds that, “The discovery of Weyl points is not only the smoking gun to a scientific mystery, it paves the way to absolutely new photonic phenomena and applications.”

Ultimately, it is believed Weyl fermions could be very useful, in that, because they are massless, they can conduct electric charge much faster than normal electrons. Admittedly, this same feature is exhibited by electrons in graphene. Yet, graphene is a 2D material, Weyl fermions are thought to exist in more practical 3D materials.

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October 7, 2015 · 8:35 pm

The Theory Of Parallel Universes Is Not Just Maths – It Is Science That Can Be Tested

September 3, 2015 | by Eugene Lim

photo credit: Scientists are searching for collisions between different ‘universe bubbles’ in the cosmic microwave background. Geralt

The existence of parallel universes may seem like something cooked up by science fiction writers, with little relevance to modern theoretical physics. But the idea that we live in a “multiverse” made up of an infinite number of parallel universes has long been considered a scientific possibility – although it is still a matter of vigorous debate among physicists. The race is now on to find a way to test the theory, including searching the sky for signs of collisions with other universes.

It is important to keep in mind that the multiverse view is not actually a theory, it is rather a consequence of our current understanding of theoretical physics. This distinction is crucial. We have not waved our hands and said: “Let there be a multiverse”. Instead the idea that the universe is perhaps one of infinitely many is derived from current theories like quantum mechanics and string theory.

The Many-Worlds Interpretation

You may have heard the thought experiment of Schrödinger’s cat, a spooky animal who lives in a closed box. The act of opening the box allows us to follow one of the possible future histories of our cat, including one in which it is both dead and alive. The reason this seems so impossible is simply because our human intuition is not familiar with it.

But it is entirely possible according to the strange rules of quantum mechanics. The reason that this can happen is that the space of possibilities in quantum mechanics is huge. Mathematically, a quantum mechanical state is a sum (or superposition) of all possible states. In the case of the Schrödinger’s cat, the cat is the superposition of “dead” and “alive” states.

But how do we interpret this to make any practical sense at all? One popular way is to think of all these possibilities as book-keeping devices so that the only “objectively true” cat state is the one we observe. However, one can just as well choose to accept that all these possibilities are true, and that they exist in different universes of a multiverse.

Miaaaaultiverse Robert Couse-Baker/Flickr, CC BY-SA

The String Landscape

String theory is one of our most, if not the most promising avenue to be able to unify quantum mechanics and gravity. This is notoriously hard because gravitational force is so difficult to describe on small scales like those of atoms and subatomic particles – which is the science of quantum mechanics. But string theory, which states that all fundamental particles are made up of one-dimensional strings, can describe all known forces of nature at once: gravity, electromagnetism and the nuclear forces.

However, for string theory to work mathematically, it requires at least ten physical dimensions. Since we can only observe four dimensions: height, width, depth (all spatial) and time (temporal), the extra dimensions of string theory must therefore be hidden somehow if it is to be correct. To be able to use the theory to explain the physical phenomena we see, these extra dimensions have to be “compactified” by being curled up in such a way that they are too small to be seen. Perhaps for each point in our large four dimensions, there exists six extra indistinguishable directions?

A problem, or some would say, a feature, of string theory is that there are many ways of doing this compactification –10500 possibilities is one number usually touted about. Each of these compactifications will result in a universe with different physical laws – such as different masses of electrons and different constants of gravity. However there are also vigorous objections to the methodology of compactification, so the issue is not quite settled.

But given this, the obvious question is: which of these landscape of possibilities do we live in? String theory itself does not provide a mechanism to predict that, which makes it useless as we can’t test it. But fortunately, an idea from our study of early universe cosmology has turned this bug into a feature.

The Early Universe

During the very early universe, before the Big Bang, the universe underwent a period of accelerated expansion called inflation. Inflation was invoked originally to explain why the current observational universe is almost uniform in temperature. However, the theory also predicted a spectrum of temperature fluctuations around this equilibrium which was later confirmed by several spacecraft such as Cosmic Background Explorer, Wilkinson Microwave Anisotropy Probe and the PLANCK spacecraft.

While the exact details of the theory are still being hotly debated, inflation is widely accepted by physicists. However, a consequence of this theory is that there must be other parts of the universe that are still accelerating. However, due to the quantum fluctuations of space-time, some parts of the universe never actually reach the end state of inflation. This means that the universe is, at least according to our current understanding, eternally inflating. Some parts can therefore end up becoming other universes, which could become other universes etc. This mechanism generates a infinite number of universes.

By combining this scenario with string theory, there is a possibility that each of these universes possesses a different compactification of the extra dimensions and hence has different physical laws.

The cosmic microwave background. Scoured for gravitational waves and signs of collisions with other universes.NASA / WMAP Science Team/wikimedia

Testing The Theory

The universes predicted by string theory and inflation live in the same physical space (unlike the many universes of quantum mechanics which live in a mathematical space), they can overlap or collide. Indeed, they inevitably must collide, leaving possible signatures in the cosmic sky which we can try to search for.

The exact details of the signatures depends intimately on the models – ranging from cold or hot spots in the cosmic microwave background to anomalous voids in the distribution of galaxies. Nevertheless, since collisions with other universes must occur in a particular direction, a general expectation is that any signatures will break the uniformity of our observable universe.

These signatures are actively being pursued by scientists. Some are looking for it directly through imprints in the cosmic microwave background, the afterglow of the Big Bang. However, no such signatures are yet to be seen. Others are looking for indirect support such as gravitational waves, which are ripples in space-time as massive objects pass through. Such waves could directly prove the existence of inflation, which ultimately strengthens the support for the multiverse theory.

Whether we will ever be able to prove their existence is hard to predict. But given the massive implications of such a finding it should definitely be worth the search.

Eugene Lim is Lecturer in theoretical particle physics & cosmology at King’s College London

This article was originally published on The Conversation. Read the original article.

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July 26, 2015 · 12:44 pm

Science Just Invented a Simple, Painless Way to Get Superhuman Vision

Max Plenke's avatar image By Max Plenke May 19, 2015
Max Plenke's avatar image

Max Plenke

Max is a staff writer at Mic covering the way technology shapes our future. Previous credits include GQ, Esquire, Playboy and Las Vegas Weekly.
Follow @maxplenke

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April 21, 2015 · 3:47 pm

Dinosaur Feathers Discovered in Canadian Amber

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Dinosaur Feathers Discovered in Canadian Amber

Today a group of paleontologists announced the results of an extensive study of several well-preserved dinosaur feathers encased in amber. Their work, which included samples from many stages in the evolution of feathers, bolstered the findings of other scientists who’ve suggested that dinosaurs (winged and otherwise) had multicolored and transparent feathers of the sort you might see on birds today. The researchers also presented evidence, based on the feathers’ pigmentation and structures, that today’s bird feathers could have evolved from dinosaur feathers.

We’ve got a gallery of these intriguing feathers preserved in amber.

In a profile of lead researcher Ryan McKellar, The Atlantic‘s Hans Villarica writes:

These specimens represent distinct stages of feather evolution, from early-stage, single filament protofeathers to much more complex structures associated with modern diving birds . . . They can’t determine which feathers belonged to birds or dinosaurs yet, but they did observe filament structures that are similar to those seen in other non-avian dinosaur fossils.

Villarica also did io9 readers a favor and asked McKellar whether this discovery could lead to aJurassic Park scenario. McKellar said:

Put simply, no. The specimens that we examined are extremely small and would not be expected to contain any DNA material. To put this into context, the only genetic material that has been recovered from amber is from lumps of mummified insect muscle tissue in much younger Dominican amber that are approximately 17 million years old and well after the age of dinosaurs.

So much for our dreams of dino domination.

What you’ll notice in the gallery below is that the researchers are emphasizing two basic pieces of evidence: the similarity in coloration to today’s bird feathers, and the similarity in morphology or shape. Some of these feathers strongly resemble those of diving water birds today (and the researchers include one example of a modern diving bird feather so you can compare them). Other structures, however, look nothing like feathers of today. In a news report about McKellar’s findings in Science, Sid Perkins writes:

In one instance, the amber holds regularly spaced, hollow filaments, each of which is about 16 micrometers in diameter, about the size of the finest human hair. The filaments apparently have no cell walls, so they’re not plant fibers or fungal threads, McKellar says. And they don’t have features that look like small scales, as mammal hair does. “We don’t absolutely know what they are, but we’re pretty sure what they’re not,” he notes. They could be protofeathers, McKellar says.

Often this kind of structure is called “dinofuzz.”

Check out the feathers and the fuzz for yourself. All captions are taken from materials provided by the researchers in their paper, published today in Science.

Dinosaur Feathers Discovered in Canadian Amber

An isolated barb from a vaned feather, trapped within a tangled mass of spider’s web in Late Cretaceous Canadian amber. Pigment distribution within this feather fragment suggests that the barb may have been gray or black. Image via Science/AAAS

Dinosaur Feathers Discovered in Canadian Amber

Numerous individual filaments in Late Cretaceous Canadian amber. These filaments are morphologically similar to the protofeathers that have been found as compression fossils associated with some dinosaur skeletons. Pigment distributions within these filaments range from translucent (unpigmented) to near-black (heavily pigmented). Image via Science/AAAS

Dinosaur Feathers Discovered in Canadian Amber

Cross-section through a feather with basally-coiled barbules, accompanied by a microphysid plant bug. The helical coiling observed within these barbules is most obvious in isolated barbules within the image, and is directly comparable to coils found in modern bird feathers specialized for water uptake. The high number of coils in the amber-entombed feather is suggestive of diving behavior, but similar structures are also used by some modern birds to transport water to the nest. Image via Science/AAAS

Dinosaur Feathers Discovered in Canadian Amber

Series of six feather barbs in Late Cretaceous Canadian amber. Localized pigmentation creates a beaded appearance within each barbule: This has implications for the structural interpretation of fossil feathers exhibiting this general morphology. Pigment distribution within the specimen suggests that the feather would have originally been medium- or dark-brown in color. Image via Science/AAAS

Dinosaur Feathers Discovered in Canadian Amber

Photomicrograph of coiled barbules in Late Cretaceous Canadian amber. The cork-screw shaped structures in the image are the tightly coiled bases of feather barbules, and these are interrupted towards the bottom of the image, where they exit the amber piece. Image via Science/AAAS

Dinosaur Feathers Discovered in Canadian Amber

An isolated barb from a white belly feather of a modern grebe bird (Aechmophorus occidentalis), illustrating coiled barbule bases comparable to those in the Cretaceous specimen. In both cases, the coiling is a structural adaptation that allows the feather to absorb water.Image via Science/AAAS

Dinosaur Feathers Discovered in Canadian Amber

A feather barb within Late Cretaceous Canadian amber that shows some indication of original coloration. The oblong brown masses within the dark-field photomicrograph are concentrated regions of pigmentation within the barbules. In this specimen, the overall feather color appears to have been medium- or dark-brown. Image via Science/AAAS

Dinosaur Feathers Discovered in Canadian Amber

Overview of 16 clumped feather barbs in Canadian Late Cretaceous amber. Image via Science/AAAS

Dinosaur Feathers Discovered in Canadian Amber

Overview of six pigmented feather barbs in Canadian Late Cretaceous amber. Image via Science/AAAS

Dinosaur Feathers Discovered in Canadian Amber

Overview of isolated, unpigmented feather barb and a mite in Canadian Late Cretaceous amber.Image via Science/AAAS

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April 9, 2015 · 10:21 pm

Europeans’ white skin developed later than thought

By Jenn Gidman

Published April 08, 2015

Newser
Europeans' white skin developed later than thought

Sweden’s Crown Princess Victoria and Prince Daniel in 2011. Traits of white skin emerged more recently than thought in Europe. (AP Photo/Lehtikuva/Vesa Moilanen)

Science notes that Europe is often thought of as the “ancestral home of white people.” But a new DNA study suggests that pale skin and other traits we associate with the continent may have emerged only within the last 8,000 years—a “relatively recent” occurrence.

The study—published last month on the bioRxiv.com server and presented last week at the American Association of Physical Anthropologists’ annual meeting—compared genome DNA across three populations of farmers and hunter-gatherers who crossed over into Europe in discrete migrations within the past eight millennia, Science notes.

What scientists found: a handful of genes tied to diet and skin pigmentation that withstood natural selection and thrived in the northern regions. The data indicates hunter-gatherers who settled in Spain, Hungary, and Luxembourg about 8,500 years ago lacked two specific genes—SLC24A5 and SLC45A2—and had darker skin, Science notes.

But hunter-gatherers hunkered down further north in Sweden had both those light-skin genes and also a third gene that leads to blue eyes (and possibly fair skin and blond hair).

When the third demographic, the Near East farmers, arrived, they also carried the SLC24A5 and SLC45A2 genes, so paler skin started emerging throughout the continent as the populations interbred.

Although researchers don’t offer a definitive answer as to why natural selection picked those genes to thrive in the north, one paleoanthropologist speculated at the meeting that the lack of sun in the northern parts of Europe required people to adapt by developing lighter skin to better absorb more vitamin D, as well as the LCT gene that allowed them to digest the sugars their ancestors couldn’t in milk, also filled with vitamin D.

(This one infant could tell us where the first Americans came from.)

This article originally appeared on Newser: Europeans’ White Skin Came Later Than Thought

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December 14, 2014 · 8:52 pm

This tree produces 40 different types of fruit

This tree produces 40 different types of fruit
SCIENCEALERT STAFF    21 JUL 2014
40-fruits

Image: Sam Van Aken

An art professor from Syracuse University in the US, Van Aken grew up on a family farm before pursuing a career as an artist, and has combined his knowledge of the two to develop his incredible Tree of 40 Fruit.

In 2008, Van Aken learned that an orchard at the New York State Agricultural Experiment Station was about to be shut down due to a lack of funding. This single orchard grew a great number of heirloom, antique, and native varieties of stone fruit, and some of these were 150 to 200 years old. To lose this orchard would render many of these rare and old varieties of fruit extinct, so to preserve them, Van Aken bought the orchard, and spent the following years figuring out how to graft parts of the trees onto a single fruit tree.

Working with a pool of over 250 varieties of stone fruit, Van Aken developed a timeline of when each of them blossom in relationship to each other and started grafting a few onto a working tree’s root structure. Once the working tree was about two years old, Van Aken used a technique called chip grafting to add more varieties on as separate branches. This technique involves taking a sliver off a fruit tree that includes the bud, and inserting that into an incision in the working tree. It’s then taped into place, and left to sit and heal over winter. If all goes well, the branch will be pruned back to encourage it to grow as a normal branch on the working tree.

After about five years and several grafted branches, Van Aken’s first Tree of 40 Fruit was complete.

Aken’s Tree of 40 Fruit looks like a normal tree for most of the year, but in spring it reveals a stunning patchwork of pink, white, red and purple blossoms, which turn into an array of plums, peaches, apricots, nectarines, cherries and almonds during the summer months, all of which are rare and unique varieties.

Not only is it a beautiful specimen, but it’s also helping to preserve the diversity of the world’s stone fruit. Stone fruits are selected for commercial growing based first and foremost on how long they keep, then how large they grow, then how they look, and lastly how they taste. This means that there are thousands of stone fruit varieties in the world, but only a very select few are considered commercially viable, even if they aren’t the best tasting, or most nutritious ones.

Van Aken has grown 16 Trees of 40 Fruit so far, and they’ve been planted in museums, community centres, and private art collections around the US. He now plans to grow a small orchard of these trees in a city setting.

Of course, the obvious question that remains is what happens to all the fruit that gets harvested from these trees? Van Aken told Lauren Salkeld at Epicurious:

“I’ve been told by people that have [a tree] at their home that it provides the perfect amount and perfect variety of fruit. So rather than having one variety that produces more than you know what to do with, it provides good amounts of each of the 40 varieties. Since all of these fruit ripen at different times, from July through October, you also aren’t inundated.”

Read the rest of the interview here.

 

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May 23, 2014 · 5:41 pm

Astronomers Have Found the First Earth-Sized, Habitable Zone Planet

Astronomers Have Found the First Earth-Sized, Habitable Zone Planet

Robert T. Gonzalez

4/17/14 12:05pm

Scientists today announced the discovery of Kepler-186f, a faraway planet that’s perhaps the most Earth-like yet discovered. It’s the same size as our home world, and at the right distance from its parent star to have liquid water. So, have we at last discovered Earth 2?

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Above: An artist’s conception of Kepler-186f Credit: NASA Ames/SETI Institute/JPL-CalTech

“The ultimate goal of all this searching for exoplanets – the real reason we’re doing this – is to answer the question ‘are we alone?'” So says Tom Barclay, a research scientist working with NASA’s planet-hunting Kepler mission, and co-author of the paper recounting the discovery of Kepler-186f, published in today’s issue of Science.

Barclay says that the answer to that big, ultimate question is almost certainly contained in the answers to a host of smaller ones, starting with: Are there other places out there like Earth? Today, Barclay tells us, it’s clearer than ever that “the answer to that question is ‘Yes.'”

A Habitable World

Kepler-186f shares a number of key characteristics with our home planet. For starters, it’s roughly the same size. Size is important when it comes to planets. Astronomers suspect that smaller bodies tend to be more rocky, and less gaseous, than larger worlds. How does Kepler-186f rank relative to the exoplanets we’ve discovered to date? When Kepler scientists announced a year ago the discovery of Kepler-62f, a planet roughly 40% bigger than Earth, they called it one of the most similar objects to Earth yet discovered. Kepler-186f, by comparison, is a mere 10% bigger than Earth. In fact, of the five planets that make up the Kepler-186 system, not a single one of them possesses a radius more than 1.5-times that of our home planet.

But planets that are Earth-sized (and smaller) have been detected before. What really sets Kepler-186f apart is its distance from its parent star. The outermost planet in its solar neighborhood, Kepler-186f orbits at the edges of what astronomers call the “habitable zone” of its star, i.e. the region around a star within which planets can potentially host liquid water and, scientists believe, life.

For a planet to be habitable, it must engage in something of a balancing act. It needs enough solar radiation to keep its water in a liquid state, while still remaining distant enough to keep that water from vaporizing outright. There are other things that can dictate whether a planet can host water – how much radiation its atmosphere lets through, for example – but it’s this not-too-much, not-too-little business that astronomers see as the biggest key to habitability (and why the habitable zone is known colloquially as the “Goldilocks Zone”).

A Very Different Sun

Barclay says there’s one major characteristic Kepler-186f doesn’t share with Earth. In Kepler-186’s size and orbital distance, he says, “we have two things that we would need to call it an Earth twin,” but a true twin, Barclay says, would orbit a Sun-like star. Kepler-186f orbits an M-dwarf, a class of star cooler and dimmer than our own. If you want to get technical, Barclay says, Kepler-186f “isn’t so much an Earth-twin as it is an Earth cousin.”

But these two cousins could still look an awful lot alike. Barclay says that because Kepler-186f receives roughly one-third the energy that we do on Earth, the light it receives would appear redder, its sun a few shades oranger than our own. We don’t know if the planet has an atmosphere, but, assuming the gases surrounding it are similar to those enveloping Earth, its skies would appear slightly duller than what we’re used to here at home. A sunny day on Kepler-186f, he says, would look similar to a day here on Earth about an hour before sunset.

Two Out of Three Isn’t Bad

Kepler’s mission is to find planets that meet three criteria: they must be rocky, Earth-like worlds; they must be within habitable zones; and they must have stars like our own Sun. A find like Kepler-186f, which meets two of those three criteria, suggests the search for Earth 2.0 could be nearing its end. “What we’re seeing more and more is that there are places that do look like Earth out there, that remind us of home,” says Barclay.

So what’s the holdup on that third criterion? According to Barclay, Earth-like planets orbiting Sun-like stars take longer to identify and confirm than those orbiting relatively wimpy stars like M-dwarfs. There are two big reasons for this. The first is that Kepler detects exoplanets by measuring how much light they block when they orbit in front of their parent stars. Astronomers call this a “transit.”

When a planet transits its parent star, Kepler detects a brief dip in the star’s light – but the ratio of planet size to star size affects how obvious that signal is. Imagine a tennis ball flying across the face of one of those big, honking prison spotlights. Now imagine that same tennis ball flying across the face of a cheapo, handheld flashlight. Bigger, brighter stars are like the prison light, while smaller, cooler ones (like M-dwarfs) are more like the handheld; if you fix the size of the planet and shrink the the size of the star, the signal goes up, making its orbiting planets easier for Kepler to detect.

The second reason is that cooler stars tend to have planets with smaller orbits. A smaller orbit means you can spot more transits in a smaller window of time, and say with greater certainty that the signals you’re picking up are, in fact, attributable to orbiting planets. Kepler might expect to see an Earth-like planet transit a Sun-like star roughly once every 365 days. The scientists observing Kepler-186f saw it pass before its parent star at more than twice that frequency. Remember: Kepler’s only been in orbit since 2009. In a few years, we could be up to our ears in planets that meet all three of the criteria laid out above. In fact, astronomers have made it clear that they expect this. It’s really just a matter of time.

All that being said, it’s unlikely anyone reading this will ever set foot on Kepler-186f. At 500 light years away, it’s not exactly in our backyard, cosmically speaking. But it is a landmark discovery, nonetheless – and there’s no telling what we’ll find tomorrow.

Read the full details on Kepler-186f, and the rest of the Kepler-186 system, in today’s issue of Science.

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January 24, 2014 · 6:55 am

Ranking the most powerful forces in the Universe

Reposted from http://www.stumbleupon.com/su/1YetgF/:LYdzCxjD:TeSAV+gi/www.sentientdevelopments.com/2009/06/ranking-most-powerful-forces-in.html/

June 24, 2009

Ranking the most powerful forces in the Universe

There are a large number of forces at work in the Universe, some more powerful than others — and I’m not talking about the four fundamental forces of nature. A force in the context I’m talking about is any phenomenon in Universe that exhibits a powerful effect or influence on its environment. Many of these phenomenon quite obviously depend on the four basic forces to function (gravity, electromagnetism, the weak interaction and the strong interaction), but it’s the collective and emergent effects of these fundamental forces that I’m interested in.
And when I say power I don’t just mean the capacity to destroy or wreak havoc, though that’s an important criteria. A force should also be considered powerful if it can profoundly reorganize or manipulate its environment in a coherent or constructive way.
Albert Einstein once quipped that the most powerful force in the Universe was compound interest. While he does have a point, and with all due respect to the Master, I present to you my list of the four most powerful phenomenon currently making an impact in the Universe:
4. Supermassive Black Holes
There’s no question that black holes are scary; it’s the only part of the Universe that can truly destroy itself.
Indeed, Einstein himself, whose Theory of Relativity opened the door to the modern study of black holes, noted that “they are where God has divided by zero.” And it’s been said that the gravitational singularity, where the laws of physics collapse,  is the most complex mystery of science that still defies human knowledge.
Somewhat counterintuitively, black holes take the weakest of the four basic forces, gravity, to create a region of space with a gravitational field so powerful that nothing, not even light, can escape its pull. They’re called “black” because they absorb all the light that hits them and reflect nothing. They have a one-way surface, the event horizon, into which objects can fall, but out of which nothing (save for Hawking Radiation) can escape.
Black holes can also vary in size and gravitational intensity. Supermassive black holes are a million to a billion times the mass of a typical black hole. Most galaxies, if not all, are believed to contain supermassive black holes at their centers (including the Milky Way).
And recent studies are now suggesting that they are much larger than previously thought. Computer models reveal that the supermassive black hole at the heart of the giant galaxy M87 weighs the same as 6.4 billion suns—two to three times heavier than previous estimates.
That’s a lot of pull.
Indeed, should anything have the misfortune of getting close enough to a supermassive black hole, whether it be gas, stars or entire solar systems, it would be sucked into oblivion. Its gravitational pull would be so overwhelming that it would hurl gas and stars around it at almost the speed of light; the violent clashing would heat the gas up to over a million degrees.
Some have suggested that the supermassive black hole is the most powerful force in the Universe. While its ability to destroy the very fabric of space and time itself is undeniably impressive (to say the least), its localized and limited nature prevent it from being ranked any higher than fourth on my list. A black hole would never subsume an entire Galaxy, for example, at least not within cosmologically long time frames.
3. Gamma-Ray Bursts
The power of gamma-ray bursts (GRB) defies human comprehension.
Imagine a hypergiant star at the end of its life, a massive object that’s 150 times larger than our own. Extremely high levels of gamma radiation from its core is causing its energy to transform to matter. The resultant drop in energy causes the star to collapse. This results in a dramatic increase in the thermonuclear reactions that was burning within it. All this added energy overpowers the gravitational attraction and it explodes in a fury of energy — the hypergiant has gone hypernova.
This is not the stuff of fiction or theory — explosions like this have been observed. Hypernovas of this size can instantly expel about 10X46 joules. This is more energy than our sun produces over a period of 10 billion years. 10 billion years! In one cataclysmic explosion!
Hypernovas can wreak tremendous havoc in its local area, effectively sterilizing the region. These explosions produce highly collimated beams of hard gamma-rays that extend outward from the exploding star. Any unfortunate life-bearing planet that should come into contact with those beams would suffer a mass extinction (if not total extinction depending on its proximity to the supernova). Gamma-rays would eat up the ozone layer and indirectly cause the onset of an ice age due to the prevalence of NO2 molecules.
Supernovas can shoot out directed beams of gamma-rays to a distance of 100 light years, while hypernovas disburse gamma ray bursts as far as 500 to 1,000 light years away.
We are currently able to detect an average of about one gamma-ray burst per day. Because gamma-ray bursts are visible to distances encompassing most of the observable Universe — a volume encompassing many billions of galaxies — this suggests that gamma-ray bursts are exceedingly rare events per galaxy. Determining an exact rate is difficult, but for a galaxy of approximately the same size as the Milky Way, the expected rate (for hypernova-type events) is about one burst every 100,000 to 1,000,000 years.
Thankfully, hypergiant Eta Carinae, which is on the verge of going nova, is well over 7,500 light years away from Earth. We’ll be safe when it goes off, but you’ll be able to read by its light at night-time.
But not so fast — our safety may not be guaranteed. Some scientists believe that gamma-ray busters may be responsible for sterilizing giagantic swaths of the galaxy — in some cases as much as a quarter of the galaxy. Such speculation has given rise to the theory that gamma-ray bursters are the reason for the Fermi Paradox; exploding stars are continually stunting the potential for life to advance, making it the 3rd most powerful force in the Universe.
2. Self-Replication
A funny thing started to happen about 8 billion years ago: pieces of the Universe started to make copies of itself. This in turn kindled another phenomena: natural selection.
While this might not seem so impressive or powerful in its own right, it’s the complexification and the emergent effects of this process that’s interesting; what began as fairly straight forward cellular replication, at least on Earth, eventually progressed into viruses, dinosaurs, and human beings.
Self-replicating RNA/DNA has completely reshaped the planet, its surface and atmosphere molded by the processes of life. And it’s a process that has proven to be remarkably resilient. The Earth has been witness to some extremely calamitous events over its history, namely the Big Five Mass Extinctions, but life has picked itself up, dusted off, and started anew.
Now, what makes self-replication all the more powerful is that it is not limited to biological substrate. Computer viruses and memes provide other examples of how self-replication can work. Replicators can also be categorized according to the kind material support they require in order to go about self-assembly. In addition to natural replicators, which have all or most of their design from nonhuman sources (i.e. natural selection), there’s also the potential for:

  • Autotrophic replicators: Devices that could reproduce themselves in the wild and mine their own materials. It’s thought that non-biological autotrophic replicators could be designed by humans and could easily accept specifications for human products.
  • Self-reproductive systems: Systems that could produce copies of itself from industrial feedstocks such as metal bar and wire.
  • Self-assembling systems: Systems that could assemble copies of themselves from finished and delivered parts. Simple examples of such systems have been demonstrated at the macro scale.

It’s conjectured that a particularly potent form of self-replication will eventually come in the form of molecular manufacturing and the introduction of self-replicating nanobots. One version of this vision is connected with the idea of swarms of coordinated nanoscale robots working in tandem.
Microscopic self-replicating nanobots may not sound particularly powerful or scary, but what is scary is the prospect for unchecked exponential growth. A fear exists that nanomechanical robots could self-replicate using naturally occurring materials and consume the entire planet in their hunger for raw materials. Alternately they could simply crowd out natural life, outcompeting it for energy. This is what has been referred to as the grey goo or ecophagy scenario. Some estimates show, for example, that the Earth’s atmosphere could be destroyed by such devices in a little under two years.
Self-replication is also powerful in terms of what it could mean for interstellar exploration and colonization. By using exponentially self-replicating Von Neumann probes, for example, the Galaxy could be colonized in as little as one to ten million years.
And of course, if you can build you can destroy; the same technology could be used to sterilize the Galaxy in the same amount of time [for more on this topic read my article, “Seven ways to control the Galaxy with self-replicating probes“].
Consequently, self-replication sits at #2 on my list; its remarkable ability to reshape matter, adapt, grow, consume, build and destroy make it a formidable force to be reckoned with.
1. Intelligence
Without a doubt the most powerful force in the universe is intelligence.
The capacity to collect, share, reorganize and act on information is unlike anything else in this universe. Intelligent beings can build tools, adapt to and radically change their environment, create complex systems and act with reasoned intention. Intelligent beings can plan, solve problems, think abstractly, comprehend ideas, use language and learn.
In addition, intelligence can reflect on itself, predict outcomes and avoid peril; autonomous systems, for the most part, are incapable of such action.
Humanity, a particularly intelligent bunch owing to a few fortuitous evolutionary traits, has — for better or worse — become a force of nature on Earth. Our species has reworked the surface of the planet to meet its needs, significantly impacting on virtually every other species (bringing many to extinction) and irrevocably altering the condition of the atmosphere itself. Not content to stay at home, we have even sent our artifacts into space and visited our very own moon.
While some cynics may scoff at so-called human ‘intelligence’, there’s no denying that it has made a significant impact on the biosphere.
Moreover, what we think of as intelligence today may be a far cry from what’s possible. The advent of artificial superintelligence is poised to be a game-changer. A superintelligent agent, which may or may not have conscious or subjective experiences, is an intellect that is much smarter than the best human brains in practically every field, including problem solving, brute calculation, scientific creativity, general wisdom and social skills. Such entities may function as super-expert systems that work to execute on any goal it is given so long as it falls within the laws of physics and it has access to the requisite resources. That’s power. And that’s why it’s called the Technological Singularity; we have no idea how such an agent will behave once we get past the horizon.
Another more radical possibility (if that’s not radical enough) is that the future of the Universe itself will be influenced by intelligent life. The nature of intelligence and its presence in the Universe must always be called into question. There exists only one of two possibilities: intelligence is either 1) cosmological epiphenomenon, or 2) an intrinsic part of the Universe’s inner workings. If it’s the latter, perhaps we have some work to do in the future to ensure the Universe’s survival or to take part in its reproductive strategy.
Theories already exist in regards to stellar engineering — where a local sun could be tweaked in such a way to extend its lifespan. Future civilizations may eventually figure out how to re-engineer the Universe itself (such as re-working the constants) or create an escape hatch to basement universes. Thinkers who have explored these possibilities include Milan Cirkovic,  John Smart, Ray Kurzweil, Alan Guth and James N. Gardner (for example, see Gardner’s book Biocosm: The New Scientific Theory of Evolution: Intelligent Life is the Architect of the Universe).
Intelligence as a force may not be particularly impressive today when considered alongside supermassive black holes, gamma-ray bursts and exponential self-replication. But it may be someday. The ability of intelligence to re-engineer its environment and work towards growth, refinement and self-preservation give it the potential to become the most powerful force in the Universe.

Posted by at6/24/2009

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