Amazing Science
619.3K views | +140 today
Amazing Science
Amazing science facts - 3D_printing • aging • AI • anthropology • art • astronomy • bigdata • bioinformatics • biology • biotech • chemistry • computers • cosmology • education • environment • evolution • future • genetics • genomics • geosciences • green_energy • history • language • map • material_science • math • med • medicine • microscopy • nanotech • neuroscience • paleontology • photography • photonics • physics • postings • robotics • science • technology • video
Your new post is loading...
Scooped by Dr. Stefan Gruenwald
Scoop.it!

New Particle Points to Elusive Four-Quark Matter

New Particle Points to Elusive Four-Quark Matter | Amazing Science | Scoop.it
According to BESIII physicists, their discovery of a new particle named Zc (4020) hints at a novel class of four-quark objects.

 

The exotic subatomic particle could be the first clear indication that more than three quark particles can be produced experimentally. If it is what physicists think it is, the particle could provide clues about the force that holds nuclei together and perhaps about the earliest moments of the universe.

 

“We have very solid evidence of an unconventional particle,” says Ronald Poling, a physicist at the University of Minnesota in Minneapolis. “But it’s the interpretation — the possibility that it has four quarks — that makes it very exciting.”

 

Physicists have known since the 1960s that protons and neutrons are made up of quarks, as are hundreds of other particles. All of these particles can be divided into two categories: mesons, which contain two quarks, and baryons (including protons and neutrons), which contain three.

 

Over the last decade many physicists, including those at the Belle experiment in Japan and the BESIII experiment in China have fruitlessly searched for particles with more than three quarks. Probing a particle’s insides is tough because physicists can’t see quarks directly. Instead they have to measure all the properties they can for a given particle, such as its mass, charge and decay products, looking for unusual characteristics that can be explained only by a peculiar combination of quarks.

 

Quarks are the fundamental building blocks of nature. They combine to form protons, neutrons and hundreds of other particles called hadrons.

Until recently hadrons were believed to have only two possible structures. Baryons, including the proton and neutron, are made of three quarks. Mesons, like the pion and kaon, consist of a quark and an antiquark. All mesons and most baryons are highly unstable, living much less than a millionth of a second after production.

 

In April 2013, the BESIII experiment announced the discovery of a mysterious four-quark particle called Zc (3900). The properties of the Zc (3900) reveal that it consists primarily of a charm-flavored quark and its antiquark bound together similarly to the long-known charmonium states. The particle is different in that it carries an electric charge, signaling that a light quark-antiquark pair must also be lurking inside.

 

“While the theoretical picture remains to be finalized, more and more clues are suggesting that we are witnessing new forms of matter. And while a new ‘zoo’ of mysterious particles is emerging, it seems a new classification system may soon be at hand to understand it.”

______

Bibliographic information: Ablikim M et al. 2013. Observation of a charged charmoniumlike structure in e+e−→(D∗D¯∗)±π∓ at s√=4.26\,GeV. Physical Review Letters, submitted for publication; arXiv: 1308.2760


Ablikim M et al. 2013. Observation of a charged charmoniumlike structure Z_c(4020) and search for the Z_c(3900) in e+e- to pi+pi-h_c. Physical Review Letters, submitted for publication; arXiv: 1309.1896


Ablikim M et al. 2013. Observation of a charged (DD*bar)- mass peak in e+e- –> pi+ (DD*bar)- at Ecm=4.26 GeV. Physical Review Letters, submitted for publication; arXiv: 1310.1163


Ablikim M et al. 2013. Observation of e+e−→γX(3872) at BESIII. Physical Review Letters, submitted for publication; arXiv: 1310.4101

more...
No comment yet.
Scooped by Dr. Stefan Gruenwald
Scoop.it!

World's oldest living animal was 507 years old when scientists accidentally killed it

World's oldest living animal was 507 years old when scientists accidentally killed it | Amazing Science | Scoop.it

World's oldest creature - known as Ming the mollusc - is proven even older than previously thought. When scientists inadvertently killed what turned out to be the world’s oldest living creature, it was bad enough. Now, their mistake has been compounded after further research found it was even older – at 507 years.


The ocean quahog - a type of deep-sea clam - was dredged alive from the bottom of the North Atlantic near Iceland in 2006 by researchers. They then put it in a freezer, as is normal practice, unaware of its age.

 

It was only when it was taken to a laboratory that scientists from Bangor University studied it and concluded it was 400 years old.

The discovery made it into the Guinness Book of World Records however by this time, it was too late for Ming the Mollusc – named after the Chinese dynasty on the throne when its life began.

 

Now, after examining the ocean quahog more closely, using more refined methods, the researchers have found the animal was actually 100 years older than they first thought.

 

Dr. Paul Butler, from the University’s School of Ocean Sciences, said: “We got it wrong the first time and maybe we were a bit hasty publishing our findings back then. But we are absolutely certain that we’ve got the right age now.”

 

A quahog’s shell grows by a layer every year, in the summer when the water is warmer and food is plentiful. It means that when its shell is cut in half, scientists can count the lines in a similar way trees can be dated by rings in their trunks.

 

The growth rings can be seen in two places; on the outside of the shell and at the hinge where the two halves meet. The hinge is generally considered by scientists as the best place to count the rings, as it is protected from outside elements.

 

When researchers originally dated Ming, they counted the rings at the hinge. However because it was so old, many had become compressed. When they looked again at the outside of the shell, they found more rings. It means the mollusc was born in 1499 – just seven years after Columbus discovered America and before Henry VIII had even married his first wife, Catherine of Aragon in 1509.

more...
Connor Keesee's curator insight, December 5, 2013 12:30 PM

Oldest animal in history accidentally killed by scientists. The age of the shell is found by counting the rings on the outside just like a tree. The shell was found in the North Atlantic near Iceland in 2006 by researchers. The clam is called the Ming Mollusc. 

Nancy jodoin's curator insight, July 29, 2014 5:00 PM

This about the Ming dynasty with a twist.

Scooped by Dr. Stefan Gruenwald
Scoop.it!

Salk scientists for the first time generate "mini-kidney" structures from human stem cells

Salk scientists for the first time generate "mini-kidney" structures from human stem cells | Amazing Science | Scoop.it

For the first time, Salk scientists have grown human stem cells into early-stage ureteric buds, kidney structures responsible for reabsorbing water after toxins have been filtered out. In the laboratory, the scientists used mouse embryonic kidney cells (seen in red in the above picture) to coax the human stem cells to grow into the nascent mushroom-shaped buds (blue and green). Their discovery is a major step in developing regenerative techniques for growing replacement human kidneys.


Scientists had created precursors of kidney cells using stem cells as recently as this past summer, but the Salk team was the first to coax human stem cells into forming three-dimensional cellular structures similar to those found in our kidneys.


"Attempts to differentiate human stem cells into renal cells have had limited success," says senior study author Juan Carlos Izpisua Belmonte, a professor in Salk's Gene Expression Laboratory and holder of the Roger Guillemin Chair. "We have developed a simple and efficient method that allows for the differentiation of human stem cells into well-organized 3D structures of the ureteric bud (UB), which later develops into the collecting duct system."

more...
Simon Jean Nunez's curator insight, January 23, 2014 7:20 PM

"For the first time, the Salk researchers have generated three-dimensional kidney structures from human stem cells, opening new avenues for studying the development and diseases of the kidneys and to the discovery of new drugs that target human kidney cells." Really great work, what's next?

Scooped by Dr. Stefan Gruenwald
Scoop.it!

Scientists create single-atom bit, smallest memory in the world

Scientists create single-atom bit, smallest memory in the world | Amazing Science | Scoop.it

Karlsruhe Institute of Technology (KIT) researchers have taken a big step towards miniaturizing magnetic data memory down to a single-atom bit: they fixed a single atom on a surface so the magnetic spin remained stable for ten minutes.

 

“A single atom fixed to a substrate is [typically] so sensitive that its magnetic orientation is stable only for less than a microsecond,” said Wulf Wulfhekel of KIT.

 

A compound of several million atoms has been needed to stabilize a magnetic bit longer than that. That’s because the magnetic moments of these atoms are normally easily destabilized by interactions with electrons, nuclear spins, and lattice vibrations of the substrate.

 

The finding opens up the possibility of designing more compact computer memories and could also be the basis for quantum computers, Wulfhekel said.

 

In their experiment, the researchers placed a single holmium atom onto a platinum substrate. At temperatures close to absolute zero (about 1 degree Kelvin), the atom was nearly vibration-free. They measured the magnetic orientation of the atom using the fine tip of a scanning tunneling microscope. The magnetic spin changed after about 10 minutes — “about a billion times longer than that of comparable atomic systems,” Wulfhekel said.


Reference: 

Toshio Miyamachi et al., Stabilizing the magnetic moment of single holmium atoms by symmetry, Nature, 2013, DOI: 10.1038/nature12759
more...
No comment yet.
Scooped by Dr. Stefan Gruenwald
Scoop.it!

Fossilized insects prove: Mating technique has remained unchanged for 165 million years

Fossilized insects prove: Mating technique has remained unchanged for 165 million years | Amazing Science | Scoop.it

Permanently linked lovers suggest species' mating technique has remained unchanged for eons.

 

The moment the petite mort becomes a grand mort has been captured again. This pair of tiny insects — 15-millimetre-long froghoppers (Anthoscytina perpetua) from the Middle Jurassic — has now joined the ranks of animals fossilized at the moment of sexual intercourse.

 

Dong Ren, curator of insect fossils at the Capital Normal University in Beijing, and his colleagues scoured more than 1,200 fossilized froghopper specimens from Inner Mongolia and found only one pair of permanently linked lovers.

Although it will doubtless be scant consolation to these two individuals locked together belly to belly, they have become the oldest known fossil of copulating insects, reports Ren's team inPLoS ONE. And they suggest that froghoppers do not favour sexual experimentation: modern relatives of these ancient animals still mate using a similar choreography.

 

Or, as Ren and his team write, the animals’ “genitalic symmetry and mating position have remained static for over 165 million years”.

more...
No comment yet.
Scooped by Dr. Stefan Gruenwald
Scoop.it!

Single-cell genome sequencing gets better and better

Single-cell genome sequencing gets better and better | Amazing Science | Scoop.it

Researchers led by bioengineers at the University of California, San Diego have generated the most complete genome sequences from single E. coli cells and individual neurons from the human brain. The breakthrough comes from a new single-cell genome sequencing technique that confines genome amplification to fluid-filled wells with a volume of just 12 nanoliters. "Our preliminary data suggest that individual neurons from the same brain have different genetic compositions. This is a relatively new idea, and our approach will enable researchers to look at genomic differences between single cells with much finer detail," said Kun Zhang, a professor in the Department of Bioengineering at the UC San Diego Jacobs School of Engineering and the corresponding author on the paper.

 

The researchers report that the genome sequences of single cells generated using the new approach exhibited comparatively little "amplification bias," which has been the most significant technological obstacle facing single-cell genome sequencing in the past decade. This bias refers to the fact that the amplification step is uneven, with different regions of a genome being copied different numbers of times. This imbalance complicates many downstream genomic analyses, including assembly of genomes from scratch and identifying DNA content variations among cells from the same individual.

 

Sequencing the genomes of single cells is of great interest to researchers working in many different fields. For example, probing the genetic make-up of individual cells would help researchers identify and understand a wide range of organisms that cannot be easily grown in the lab from the bacteria that live within our digestive tracts and on our skin, to the microscopic organisms that live in ocean water. Single-cell genetic studies are also being used to study cancer cells, stem cells and the human brain, which is made up of cells that increasingly appear to have significant genomic diversity.

more...
Eduardo Camina Paniagua's curator insight, November 19, 2013 1:55 AM
DNA sequencing is the process of determining the precise order of nucleotides within a DNA molecule. It includes any method or technology that is used to determine the order of the four bases in a strand of DNA. The advent of rapid DNA sequencing methods has greatly accelerated biological and medical research and discovery.

Knowledge of DNA sequences has become indispensable for basic biological research, and in numerous applied fields such as diagnostic, and biological systemathics. The rapid speed of sequencing attained with modern DNA sequencing technology has been instrumental in the sequencing of complete DNA sequences, or genomes of numerous types and species of life, including the human genome and other complete DNA sequences of many animal, plant, and microbiall species.

Scooped by Dr. Stefan Gruenwald
Scoop.it!

Trapped seawater discovered near the Chesapeake Bay is up to 150 million years old

Trapped seawater discovered near the Chesapeake Bay is up to 150 million years old | Amazing Science | Scoop.it

Not only is the Chesapeake Bay so enormous it can be seen from space, it essentially came from outer space. An asteroid or huge chunk of ice slammed into Earth about 35 million years ago, splashing into the Early Cretaceous North Atlantic, sending tsunamis as far as the Blue Ridge Mountains and leaving a 56-mile-wide hole at the mouth of what is now the bay.

 

But a newly published research paper written by U.S. Geological Survey scientists shows that wasn’t the end of it. While drilling holes in southern Virginia to study the impact crater, the scientists discovered “the oldest large body of ancient seawater in the world,” a survivor of that long-gone sea, resting about a half-mile underground near the bay, according to the USGS.

 

“What we essentially discovered was trapped water that’s twice the salinity of modern seawater,” said Ward Sanford, a USGS hydrologist. “In our attempt to find out the origin, we found it was Early Cretaceous seawater. It’s really water that’s from the North Atlantic.”

 

The findings showing that the water is probably between 100 million and 150 million years old were published in the journal Nature.

 

The Chesapeake Bay Impact Crater was discovered in 1999 by a tandem of USGS and Virginia Department of Environmental Quality scientists.

 

They theorized that a huge rock or chunk of ice slammed into an ancient ocean, sending enormous pieces of debris skyward and forcing monster tsunamis hundreds of miles inland.

 

Over centuries, the crater became hidden under 400 to 1,200 feet of sand, silt and clay, hampering its discovery for decades. “It’s the largest crater discovered so far in the United States, and it’s one of only a few oceanic impact craters that have been documented worldwide,” USGS hydrologist David Powars said at the time.

more...
No comment yet.
Scooped by Dr. Stefan Gruenwald
Scoop.it!

Million Lines of Code - Information Is Beautiful

Million Lines of Code - Information Is Beautiful | Amazing Science | Scoop.it

Is a million lines of code a lot? How many lines of code are there in Windows? Facebook? iPhone apps? How about a bacterium, a human being, or all the data in the genome database at NIH?

more...
odysseas spyroglou's curator insight, November 17, 2013 8:42 AM

More data for data. More statistics, better decisions.

Marc Kneepkens's curator insight, November 18, 2013 9:27 AM

Glad to see that the Human Genome is still way out there.



Scooped by Dr. Stefan Gruenwald
Scoop.it!

Accidental discovery: 400-fold increase in electrical conductivity of a crystal through light exposure

Accidental discovery: 400-fold increase in electrical conductivity of a crystal through light exposure | Amazing Science | Scoop.it
Quite by accident, Washington State University researchers have achieved a 400-fold increase in the electrical conductivity of a crystal simply by exposing it to light.

 

WSU doctoral student Marianne Tarun chanced upon the discovery when she noticed that the conductivity of some strontium titanate shot up after it was left out one day. At first, she and her fellow researchers thought the sample was contaminated, but a series of experiments showed the effect was from light. "It came by accident," said Tarun. "It's not something we expected. That makes it very exciting to share."


The phenomenon they witnessed—"persistent photoconductivity"—is a far cry from superconductivity, the complete lack of electrical resistance pursued by other physicists, usually using temperatures near absolute zero. But the fact that they've achieved this at room temperature makes the phenomenon more immediately practical.


And while other researchers have created persistent photoconductivity in other materials, this is the most dramatic display of the phenomenon. "The discovery of this effect at room temperature opens up new possibilities for practical devices," said Matthew McCluskey, co-author of the paper and chair of WSU's physics department. "In standard computer memory, information is stored on the surface of a computer chip or hard drive. A device using persistent photoconductivity, however, could store information throughout the entire volume of a crystal."

more...
No comment yet.
Scooped by Dr. Stefan Gruenwald
Scoop.it!

New hologram technology created with tiny nanoantennas

New hologram technology created with tiny nanoantennas | Amazing Science | Scoop.it

Researchers at Purdue University have created tiny holograms using a "metasurface" capable of the ultra-efficient control of light, representing a potential new technology for advanced sensors, high-resolution displays and information processing.

 

The metasurface, thousands of V-shaped nanoantennas formed into an ultrathin gold foil, could make possible "planar photonics" devices and optical switches small enough to be integrated into computer chips for information processing, sensing and telecommunications, said Alexander Kildishev, associate research professor of electrical and computer engineering at Purdue University.

 

Laser light shines through the nanoantennas, creating the hologram 10 microns above the metasurface. To demonstrate the technology, researchers created a hologram of the word PURDUE smaller than 100 microns wide, or roughly the width of a human hair.

 

"If we can shape characters, we can shape different types of light beams for sensing or recording, or, for example, pixels for 3-D displays. Another potential application is the transmission and processing of data inside chips for information technology," Kildishev said. "The smallest features - the strokes of the letters - displayed in our experiment are only 1 micron wide. This is a quite remarkable spatial resolution."

 

Metasurfaces could make it possible to use single photons - the particles that make up light - for switching and routing in future computers. While using photons would dramatically speed up computers and telecommunications, conventional photonic devices cannot be miniaturized because the wavelength of light is too large to fit in tiny components needed for integrated circuits.

 

Nanostructured metamaterials, however, are making it possible to reduce the wavelength of light, allowing the creation of new types of nanophotonic devices, said Vladimir M. Shalaev, scientific director of nanophotonics at Purdue's Birck Nanotechnology Center and a distinguished professor of electrical and computer engineering.

more...
No comment yet.
Scooped by Dr. Stefan Gruenwald
Scoop.it!

Region of brain identified that is responsible for nicotine withdrawal symptoms

Region of brain identified that is responsible for nicotine withdrawal symptoms | Amazing Science | Scoop.it

Headaches, anxiety, irritability—these and other symptoms of nicotine withdrawal can significantly deter smokers from being able to kick the habit. Now, in what may be a significant step toward alleviating those symptoms, UMass Medical School neuroscientist Andrew R. Tapper, PhD, and colleagues have identified the region of the brain in which they originate.

“We were surprised to find that one population of neurons within a single brain region could actually control physical nicotine withdrawal behaviors,” said Dr. Tapper, associate professor of psychiatry and interim director of the Brudnick Neuropsychiatric Research Institute at UMMS.

 

The Tapper lab discovered that physical nicotine withdrawal symptoms are triggered by activation of GABAergic neurons (neurons that secrete GABA, the brain’s predominant inhibitory neurotransmitter), in the interpeduncular nucleus, an area deep in the midbrain that has recently been shown to be involved in nicotine intake. Their study was published in the Nov. 14 issue of the journal Current Biology.

 

“Most of the work in the field has been focused on the immediate effects of nicotine, the addictive component in tobacco smoke, on reward circuits in the brain,” Tapper explained. “But much less is known regarding what happens when you take nicotine away from someone who has been smoking for a long time that causes all these terrible withdrawal symptoms. Our main goal was to understand what brain regions are activated—or deactivated—to cause nicotine withdrawal symptoms.

 

They did this through a series of experiments performed in mouse models with sophisticated neurochemistry and brain imaging methods, including recently developed optogenetics techniques in which specific neurons can be activated by light.

 

Most surprising was their discovery that nicotine withdrawal symptoms can be activated or deactivated independent of nicotine addiction. “When we activated the GABAergic neurons in the interpeduncular nucleus, mice suffered withdrawal symptoms even if they had no previous nicotine exposure,” Tapper noted.

 

These findings are promising because existing treatments intended to help people quit smoking are not always effective. “There are very few treatments to help people quit smoking,” Tapper said. “If you can dampen the activity of this brain region chemically during nicotine withdrawal then you would hopefully be able to help someone quit smoking because you could reduce some of the withdrawal symptoms that they are experiencing.”

more...
Zayd El-Ali's curator insight, December 12, 2013 10:15 PM

One population of neurons in a section of the brain controls the symptoms of withdrawal. If this, based on the article, is true. Then a drug could be used to contain this area of the brain with these specific neurons in order to prevent the effects the withdrawal.  I included this article because the Importance of this new research can lead other scientist to build on the foundation provided, and even get one step closer for a cure to the effects of withdrawal. 

Scooped by Dr. Stefan Gruenwald
Scoop.it!

Biologists find a crab with three eyes, two rostra, and a dorsal antenna-like structure

Biologists find a crab with three eyes, two rostra, and a dorsal antenna-like structure | Amazing Science | Scoop.it

First described by zoologist Charles Chilton in 1882, Amarinus lacustris is an omnivorous, freshwater spider crab found in rivers of south-eastern Australia, New Zealand and nearby islands. The species grows up to 1 cm wide and has an H-shaped groove on its back.

 

The malformed specimen was found in Hoteo River, a river that feeds into Kaipara Harbour, north of Manukau and Waitemata Harbours, near Auckland, New Zealand. It has three compound eyes and a third antenna-like structure on the back of its carapace.

 

“In New Zealand, Amarinus lacustris is the only freshwater crab and is common in a number of streams and rivers of the Auckland and Waikato Regions, and all specimens collected thus far have been normal,” Dr Stephen Moore from the University of Auckland with co-authors wrote in the paper published in the journal Arthropod Structure & Development.

 

They described the three-eyed mutant: “the lateral two eyes are situated in the outer angles which are formed between the lateral sides of the two rostra and the carapace margin, i.e. in the expected position. The third eye lies at the same horizontal level in the middle between the two lateral eyes, underneath the anterior opening of the notch between the two rostra. The median eye is slightly larger than the lateral ones and it has an oval shape with its large axis horizontally oriented.”

more...
Malibu Divers's curator insight, November 17, 2013 10:58 AM

Checkout this 3-eyed crab

Rescooped by Dr. Stefan Gruenwald from Tracking the Future
Scoop.it!

Quantum 'world record' smashed: Quantum memory state held stable at RT for 39 min

Quantum 'world record' smashed: Quantum memory state held stable at RT for 39 min | Amazing Science | Scoop.it

A fragile quantum memory state has been held stable at room temperature for a "world record" 39 minutes - overcoming a key barrier to ultrafast computers.

 

"Qubits" of information encoded in a silicon system persisted for almost 100 times longer than ever before. Quantum systems are notoriously fickle to measure and manipulate, but if harnessed could transform computing. The new benchmark was set by an international team led by Mike Thewalt of Simon Fraser University, Canada.

 

"39 minutes may not seem very long. But these lifetimes are many times longer than previous experiments”. "This opens the possibility of truly long-term storage of quantum information at room temperature," said Prof Thewalt, whose achievement is detailed in the journal Science.

In conventional computers, "bits" of data are stored as a string of 1s and 0s.


Via Szabolcs Kósa
more...
luiy's curator insight, November 16, 2013 12:48 PM

"Qubits" of information encoded in a silicon system persisted for almost 100 times longer than ever before.

 

Quantum systems are notoriously fickle to measure and manipulate, but if harnessed could transform computing.

 

The new benchmark was set by an international team led by Mike Thewalt of Simon Fraser University, Canada.

Continue reading the main story“Start Quote

"39 minutes may not seem very long. But these lifetimes are many times longer than previous experiments”

Stephanie SimmonsOxford University

"This opens the possibility of truly long-term storage of quantum information at room temperature," said Prof Thewalt, whose achievement is detailed in the journal Science.

In conventional computers, "bits" of data are stored as a string of 1s and 0s.

 

But in a quantum system, "qubits" are stored in a so-called "superposition state" in which they can be both 1s and 0 at the same time - enabling them to perform multiple calculations simultaneously.

Scooped by Dr. Stefan Gruenwald
Scoop.it!

NASA: Sun expected to flip its magnetic field upside down, reversing polarity

NASA: Sun expected to flip its magnetic field upside down, reversing polarity | Amazing Science | Scoop.it

The sun's magnetic field is about to flip upside down as it reverses its polarity. In August Nasa said the reversal would happen in three to four months time, although that it would be impossible to pinpoint a more specific date.


Solar physicist Todd Hoeksema from Stanford University said that the reversal would have "ripple effects" across the whole of the solar system.

According to Nasa the sun's magnetic field changes polarity approximately every 11 years. In comparison the last time the Earth's magnetic field flipped was almost 800,000 years ago.


The pole reversal happens at the peak of each solar cycle as the sun's "inner magnetic dynamo" reorganises itself. The exact internal mechanism that drives the magnetic shift is not yet entirely understood by researchers, although the sun's magnetic field has been monitored on a daily basis by Scientists at Stanford's Wilcox Solar Observatory.


This will be the fourth such shift that the observatory has monitored.

Throughout the 11 year solar cycle new polarity builds up as 'sunspots' which are areas of intense magnetic activity that appear as blotches near the equator of the sun's surface.


 

As to what effect this may have, scientists said it could be widespread. The sun's magnetic field exerts its influence in a wide space, known as the heliosphere. The heliosphere stretches well beyond Pluto and is as far reaching as NASA's Voyager probes close to the edge of interstellar space. During a magnetic flip the sun is also typically at its peak.

 

Another possible impact is that the sun's altered magnetic field could interact with the Earth's own magnetic field which could increase the number and range of auroras.


more...
No comment yet.
Scooped by Dr. Stefan Gruenwald
Scoop.it!

Electron Appears Completely Round, No Electric Dipole Found

Electron Appears Completely Round, No Electric Dipole Found | Amazing Science | Scoop.it

Scientists are unanimous that their current theory of physics is incomplete. Yet every effort to expose a deeper theory has so far disappointed. Now the most sensitive test yet of the shape of an electron—a property that could expose underlying “new physics”—has failed to find hints of anything novel. The finding rules out a number of favored ideas for extending physics, including some versions of a popular idea called supersymmetry.

 

The result came from a search for the so-called electric dipole moment in the electron. A familiar example of a dipole is a bar magnet, which is shaped like a dumbbell with a north and a south pole. Electrons are traditionally thought of as spherical, but if they had dipole moments, they would be slightly squashed. “It’s a question of: Does the electron look the same no matter which way you look at it?” explains physicist Jony Hudson of Imperial College London. “The dipole moment is physicists’ technical way to describe if it’s symmetric or not.”

 

The Standard Model of particle physics, which describes all the known particles in the universe, predicts a practically zero electric dipole moment for the electron. Yet theories that include additional, yet-to-be-detected particles predict a much larger dipole moment. Physicists have been searching for this dipole moment for 50 years. Now a group called the ACME collaboration, led by David DeMille of Yale University and John Doyle and Gerald Gabrielse of Harvard University, has performed a test 10 times more sensitive than previous experiments, and still found no signs of an electric dipole moment in the electron. The electron appears to be spherical to within 0.00000000000000000000000000001 centimeter, according to ACME’s results, which were posted on the preprint site arXiv. “It’s a surprise,” says Ed Hinds, also of Imperial College London, who worked with Hudson on the previous best limit, set in 2011. “Why on Earth is it still zero?”

 

The experiments are probing the quantum nature of an electron. According to quantum mechanics, all particles, including the electron, should give rise to a cloud of virtual particles around them that continually sweep in and out of existence. If the standard model is all there is, then these virtual particles would be everyday, run-of-the-mill particles. But if more exotic particles are out there, they should pop up in the virtual clouds around electrons, causing the clouds to be asymmetric—in other words, causing an electric dipole moment.

 

To search for this asymmetry, scientists spin electrons to test whether they are round or oblong. Whereas a billiards ball will spin smoothly, an egg will wobble. The same goes for an electron with an electric dipole moment. The ACME researchers looked at electrons in thorium monoxide molecules, whose heavy mass and special characteristics would make wobbling more conspicuous. “Their choice of molecule is very clever,” says Hudson, whose experiment uses another molecule, called terbium fluoride. “I’m sort of jealous—I wish I’d thought of that.” Previous generations of experiments looked for the effect on single atoms, which turned out to be much more difficult. The ACME scientists relied on careful measurements with microwave spectroscopy to notice any wobbling, and labored to keep their experiment free of magnetic fields or other contaminants that could cause systematic errors. “It’s hard because there are a lot of things that can mimic the effect, and the dipole moment is just so small,” says Ben Sauer, another member of the Imperial College London team.

more...
No comment yet.
Scooped by Dr. Stefan Gruenwald
Scoop.it!

Bacteria incorporate pieces of old DNA in their own genome, scientists discover

Bacteria incorporate pieces of old DNA in their own genome, scientists discover | Amazing Science | Scoop.it

From a bacteria’s perspective, the environment is one big DNA waste yard. Now researchers from Denmark and Norway have shown that bacteria can take up small as well as large pieces of old DNA from this scrapheap and include it in their own genome.

 

This discovery may have major consequences both in connection with resistance to antibiotics in hospitals and in our perception of the evolution of life itself. Our surroundings contain large amounts of strongly fragmented and damaged DNA, which is being degraded. Some of it may be thousands of years old.

 

Laboratory experiments with microbes and various kinds of DNA have shown that bacteria take up very short and damaged DNA from the environment and passively integrate it in their own genome.

Furthermore, this mechanism has also been shown to work with a modern bacteria’s uptake of 43.000 years old mammoth DNA.

 

The discovery of this second-hand use of old or fragmented DNA may have major future consequences. Postdoc Søren Overballe-Petersen from the Center for GeoGenetics at the Natural History Museum of Denmark first author on the paper, says it is well-known that bacteria can take up long intact pieces of DNA. “But so far the assumption has been that short DNA fragments were biologically inactive. Now we have shown that this assumption was wrong. As long as you have just a tiny amount of DNA left over there is a possibility that bacteria can re-use the DNA.”

 

“One consequence of this is in hospitals that have persistent problems with antibiotic resistance,” says Kaare M. Nielsenfrom University of Tromsø in Norway. “In some cases, they will have to start considering how to eliminate DNA remnants. So far, focus has been on killing living pathogen bacteria, but this is no longer enough in the cases where other bacteria afterwards can use the DNA fragments which contain the antibiotic resistance.

 

“The research group’s results reveal that the large reservoir of fragments and damaged DNA in the surroundings preserve the potential to change the bacteria’s genomes even after thousands of years. This is the first time a process has been described which allows cells to acquire genetic sequences from a long gone past. We call this phenomenon “Anachronistic Evolution” or “Second-hand Evolution.”

more...
No comment yet.
Scooped by Dr. Stefan Gruenwald
Scoop.it!

Glowing Worms Illuminate Roots of Behavior in Animals

Glowing Worms Illuminate Roots of Behavior in Animals | Amazing Science | Scoop.it

Researchers develop novel method to image worm brain activity and screen early stage compounds aimed at treating autism and anxiety.


A research team at Worcester Polytechnic Institute (WPI) and The Rockefeller University in New York has developed a novel system to image brain activity in multiple awake and unconstrained worms. The technology, which makes it possible to study the genetics and neural circuitry associated with animal behavior, can also be used as a high-throughput screening tool for drug development targeting autism, anxiety, depression, schizophrenia, and other brain disorders.

 

The team details their technology and early results in the paper "High-throughput imaging of neuronal activity in Caenorhabditis elegans," published on-line in advance of print by the journal Proceedings of the National Academy of Sciences .

 

"One of our major objectives is to understand the neural signals that direct behavior—how sensory information is processed through a network of neurons leading to specific decisions and responses," said Dirk Albrecht, PhD, assistant professor of biomedical engineering at WPI and senior author of the paper. Albrecht led the research team both at WPI and at Rockefeller, where he served previously as a postdoctoral researcher in the lab of Cori Bargmann, PhD, a Howard Hughes Medical Institute Investigator and a co-author of the new paper.


To study neuronal activity, Albrecht’s lab uses the tiny worm Caenorhabditis elegans (C. elegans), a nematode found in many environments around the world. A typical adult C. elegans is just 1 millimeter long and has 969 cells, of which 302 are neurons. Despite its small size, the worm is a complex organism able to do all of the things animals must do to survive. It can move, eat, mate, and process environmental cues that help it forage for food or react to threats. As a bonus for researchers, C.elegans is transparent. By using various imaging technologies, including optical microscopes, one can literally see into the worm and watch physiological processes in real time.


In addition to watching the head neurons light up as they picked up odor cues, the new system can trace signaling through "interneurons." These are pathways that connect external sensors to the rest of the network (the "worm brain") and send signals to muscle cells that adjust the worm's movement based on the cues. Numerous brain disorders in people are believed to arise when neural networks malfunction. In some cases the malfunction is dramatic overreaction to a routine stimulus, while in others it is a lack of appropriate reactions to important cues. Since C. elegans and humans share many of the same genes, discovering genetic causes for differing neuronal responses in worms could be applicable to human physiology. Experimental compounds designed to modulate the action of nerve cells and neuronal networks could be tested first on worms using Albrecht’s new system. The compounds would be infused in the worm arena, along with other stimuli, and the reaction of the worms’ nervous systems could be imaged and analyzed.

more...
No comment yet.
Scooped by Dr. Stefan Gruenwald
Scoop.it!

Stanford scientists create a low-cost, long-lasting water splitter made of silicon and nickel

Stanford scientists create a low-cost, long-lasting water splitter made of silicon and nickel | Amazing Science | Scoop.it
The new device uses light to split water into oxygen and hydrogen, a clean-burning fuel that can be used to generate electricity on demand.

 

Stanford University scientists have created a silicon-based water splitter that is both low-cost and corrosion-free. The novel device – a silicon semiconductor coated in an ultrathin layer of nickel – could help pave the way for large-scale production of clean hydrogen fuel from sunlight, according to the scientists. Their results are published in the Nov. 15, 2013, issue of the journal Science.

 

"Solar cells only work when the sun is shining," said study co-author Hongjie Dai, a professor of chemistry at Stanford. "When there's no sunlight, utilities often have to rely on electricity from conventional power plants that run on coal or natural gas."

A greener solution, Dai explained, is to supplement the solar cells with hydrogen-powered fuel cells that generate electricity at night or when demand is especially high. 

 

To produce clean hydrogen for fuel cells, scientists have turned to an emerging technology called water splitting. Two semiconducting electrodes are connected and placed in water. The electrodes absorb light and use the energy to split the water into its basic components, oxygen and hydrogen. The oxygen is released into the atmosphere, and the hydrogen is stored as fuel.

 

When energy is needed, the process is reversed. The stored hydrogen and atmospheric oxygen are combined in a fuel cell to generate electricity and pure water.  

 

The entire process is sustainable and emits no greenhouse gases. But finding a cheap way to split water has been a major challenge. Today, researchers continue searching for inexpensive materials that can be used to build water splitters efficient enough to be of practical use.

more...
No comment yet.
Scooped by Dr. Stefan Gruenwald
Scoop.it!

Cicada Killers versus Cow Killers

Cicada Killers versus Cow Killers | Amazing Science | Scoop.it

In the summer, bare soil can attract two scary-looking insects with threatening names:cicada killer and cow killer. Fortunately for people, they will sting only if handled aggressively. One's sting feels like a pinprick, the other's is quite painful.

 

Cicada killers, also known as giant gound hornets, save their venom for dog-day cicadas, the big green cicadas that appear every summer, damaging small tree branches as they slice them open to lay eggs. The female wasp patrols tree canopies in search of cicadas, which she paralyzes with a sting. She takes wing with her oversize prey and drags it down her four-foot-long nesting burrow. She places one or two cicadas in a chamber, lays an egg on the stunned insects and carefully seals the enclosure.

 

A wasp larva soon hatches to consume the cicadas, matures and spends the winter underground — unless it is itself eaten by the larva of a cow killer.

 

Cow killers, more often known as velvet ants, aren't ants; they are wingless female wasps that lay eggs on the pupae and mature larvae of cicada killers and other ground-nesting solitary wasps and bees. When velvet ant larvae hatch, they consume their defenseless hosts. Female velvet ants can deliver a powerful sting. It isn't venomous enough to kill a cow, but to a human, it feels as though it could. Female velvet ants are not aggressive and will attempt to escape if pursued. They must be cornered or stepped on before they will resort to stinging, and will even emit a warning squeak before doing so.

more...
No comment yet.
Scooped by Dr. Stefan Gruenwald
Scoop.it!

The 10,000th near-Earth object is discovered and recorded

The 10,000th near-Earth object is discovered and recorded | Amazing Science | Scoop.it

A grand total of 10,000 asteroids and comets that pass near Earth have now been discovered. The 10,000th near-Earth object – asteroid 2013 MZ5 – was detected on 18th June by the Pan-STARRS-1 telescope in Hawaii. 98% of all near-Earth objects discovered were first detected by NASA-supported surveys, including this one.


"Finding 10,000 near-Earth objects is a significant milestone," said Lindley Johnson, program executive for the Near-Earth Object Observations Program at NASA Headquarters. "But there are at least 10 times that many more to be found before we can be assured we will have found any and all that could impact and do significant harm to the citizens of Earth." During Johnson's decade-long tenure, 76 percent of the NEO discoveries have been made.

 

Near-Earth objects (NEOs) are asteroids or comets that can approach within 28 million miles (45 million km) of the Earth.


For comparison, the average distance from Earth to the Moon is 238,900 miles (384,500 km). They range in size from just a few feet, to as large as 25 miles (41 km) in the case of 1036 Ganymed.

 

Asteroid 2013 MZ5 is approximately 1,000 feet (300 metres) across. Its orbit is well understood and will not approach close enough to Earth to be considered potentially hazardous.

 

"The first near-Earth object was discovered in 1898," said Don Yeomans, long-time manager of NASA's Near-Earth Object Program Office in California. "Over the next hundred years, only about 500 had been found. But then, with the advent of NASA's NEO Observations program in 1998, we've been racking them up ever since. And with new, more capable systems coming on line, we are learning even more about where the NEOs are currently in our solar system, and where they will be in the future."


Of these 10,000 discoveries, nearly 10 percent are larger than 3,280 ft (1,000 m) – roughly the size that could produce global consequences should one impact Earth. However, NASA has determined that none of these larger NEOs currently pose any impact threat and probably only a few dozen more remain undiscovered.

 

The vast majority of NEOs are smaller than a kilometre, with the number of objects of a particular size increasing as their sizes decrease. For example, there are estimated to be around 15,000 about one-and-a-half football fields in size (460 ft, or 140 m) and over a million that are one-third of a football field in size (100 ft, or 30 m). An NEO hitting the Earth would need to be 100 feet (30 metres) or larger to cause significant devastation in populated areas. Almost 30 percent of the 460-ft-sized NEOs have been found, but less than 1 percent of the smaller NEOs have been detected. The asteroid that wiped out the dinosaurs, around 65 million years ago, is thought to have been 6 miles (10 km) in diameter. A simulation of an impact on this scale – which occurs about once every 100 million years on average.


more...
No comment yet.
Scooped by Dr. Stefan Gruenwald
Scoop.it!

Future Timeline of Our Solar System, Our Galaxy and Our Universe

Future Timeline of Our Solar System, Our Galaxy and Our Universe | Amazing Science | Scoop.it

The biological and geological future of the Earth can be extrapolated based upon the estimated effects of several long-term influences. These include the chemistry at the Earth's surface, the rate of cooling of the planet's interior, the gravitational interactions with other objects in the Solar System, and a steady increase in the Sun's luminosity. An uncertain factor in this extrapolation is the ongoing influence of technology introduced by humans, such as geoengineering, which could cause significant changes to the planet. The current biotic crisis is being caused by technology and the effects may last for up to five million years. In turn, technology may result in the extinction of humanity, leaving the planet to gradually return to a slower evolutionary pace resulting solely from long-term natural processes.

 

Over time intervals of hundreds of millions of years, random celestial events pose a global risk to the biosphere, which can result in mass extinctions. These include impacts by comets or asteroids with diameters of 5–10 km (3.1–6.2 mi) or more, and the possibility of a massive stellar explosion, called a supernova, within a 100-light-year radius from the Sun, called a Near-Earth supernova. Other large-scale geological events are more predictable. If the long-term effects of global warming are disregarded, Milankovitch theory predicts that the planet will continue to undergo glacial periods at least until the quaternary glaciation comes to an end. These periods are caused by eccentricity, axial tilt, and precession of the Earth's orbit. As part of the ongoing supercontinent cycle, plate tectonics will probably result in a supercontinent in 250–350 million years. Some time in the next 1.5–4.5 billion years, the axial tilt of the Earth may begin to undergo chaotic variations, with changes in the axial tilt of up to 90°.

 

During the next four billion years, the luminosity of the Sun will steadily increase, resulting in a rise in the solar radiation reaching the Earth. This will cause a higher rate of weathering of silicate minerals, which will cause a decrease in the level of carbon dioxide in the atmosphere. In about 600 million years, the level of CO 2 will fall below the level needed to sustain C3 carbon fixation photosynthesis used by trees. Some plants use the C4 carbon fixation method, allowing them to persist at CO 2 concentrations as low as 10 parts per million. However, the long-term trend is for plant life to die off altogether. The die off of plants will be the demise of almost all animal life, since plants are the base of the food chain on Earth.

 

In about 1.1 billion years, the solar luminosity will be 10% higher than at present. This will cause the atmosphere to become a "moist greenhouse", resulting in a runaway evaporation of the oceans. As a likely consequence, plate tectonics will come to an end. Following this event, the planet's magnetic dynamo may come to an end, causing the magnetosphere to decay and leading to an accelerated loss of volatiles from the outer atmosphere. Four billion years from now, the increase in the Earth's surface temperature will cause a runaway greenhouse effect. By that point, most if not all the life on the surface will be extinct. The most probable fate of the planet is absorption by the Sun in about 7.5 billion years, after the star has entered the red giant phase and expanded to cross the planet's current orbit.

more...
No comment yet.
Scooped by Dr. Stefan Gruenwald
Scoop.it!

Astronomers discover the largest structure in the universe - 10 Billion light years across

Astronomers discover the largest structure in the universe - 10 Billion light years across | Amazing Science | Scoop.it

What’s the largest structure in the Universe? That’s a question that has intrigued scientists for centuries. Today, they get an answer thanks to astronomers who say they’ve discovered the largest structure ever observed and one that dwarfs the previous record-holder by billions of light years. The new structure is ten billion light years across and almost as far away but nobody had spotted it…until now.


Astronomer’s ideas about the universe’s largest structures have changed dramatically in the last 100 years. At the beginning of the 20th century, they began to suspect that stars were clustered together to form “island universes” or galaxies which themselves were separated by vast distances.

The question was eventually settled in the 1920s by Edwin Hubble and others who measured the distance to different galaxies, thereby proving that they were much further away than stars . These galaxies, they thought, were the largest structures in the universe and distributed more or less uniformly throughout space.

 

It wasn’t until 1989 that astronomers found something even bigger. In the 1970s and 80s, they had begun to systematically measure the distances to large numbers of galaxies and this eventually allowed them to produce a 3D map of them.

 

To their surprise, the galaxies were not distributed evenly but instead formed filamentary structures with walls and voids. They called the largest of these “the Great Wall”, a structure that is 200 million light years away and some 500 million light years long.

 

To give some sense of scale, our galaxy, the Milky Way, is separated from its nearest neighbour, the Andromeda Galaxy, by about 0.75 Megaparsecs (Mpc) or 2.5 million light-years.

 

Whole clusters of galaxies can be 2-3 Mpc across but LQGs can be 200 Mpc or more across. Based on the Cosmological Principle and the modern theory of cosmology, calculations suggest that astrophysicists should not be able to find a structure larger than 370 Mpc.

 

Dr Clowes' newly discovered LQG however has a typical dimension of 500 Mpc. But because it is elongated, its longest dimension is 1200 Mpc (or 4 billion light years) - some 1600 times larger than the distance from the Milky Way to Andromeda.

 

Dr Clowes said: "While it is difficult to fathom the scale of this LQG, we can say quite definitely it is the largest structure ever seen in the entire universe. This is hugely exciting – not least because it runs counter to our current understanding of the scale of the universe.

 

'Even travelling at the speed of light, it would take 4 billion light years to cross. This is significant not just because of its size but also because it challenges the Cosmological Principle, which has been widely accepted since Einstein. Our team has been looking at similar cases which add further weight to this challenge and we will be continuing to investigate these fascinating phenomena."

more...
No comment yet.
Scooped by Dr. Stefan Gruenwald
Scoop.it!

NASA releases new images that show Saturn, its rings and moons, as well as Earth, Venus, and Mars

NASA releases new images that show Saturn, its rings and moons, as well as Earth, Venus, and Mars | Amazing Science | Scoop.it

On July 19, 2013, in an event celebrated the world over, NASA's Cassini spacecraft slipped into Saturn's shadow and turned to image the planet, seven of its moons, its inner rings -- and, in the background, our home planet, Earth.

 

With the sun's powerful and potentially damaging rays eclipsed by Saturn itself, Cassini's onboard cameras were able to take advantage of this unique viewing geometry. They acquired a panoramic mosaic of the Saturn system that allows scientists to see details in the rings and throughout the system as they are backlit by the sun. This mosaic is special as it marks the third time our home planet was imaged from the outer solar system; the second time it was imaged by Cassini from Saturn's orbit; and the first time ever that inhabitants of Earth were made aware in advance that their photo would be taken from such a great distance.

 

The moons Prometheus, Pandora, Janus and Epimetheus are also visible in the mosaic near Saturn's bright narrow F ring. Prometheus (53 miles, or 86 kilometers, across) is visible as a faint black dot just inside the F ring and at the 9 o'clock position. On the opposite side of the rings, just outside the F ring, Pandora (50 miles, or 81 kilometers, across) can be seen as a bright white dot. Pandora and Prometheus are shepherd moons and gravitational interactions between the ring and the moons keep the F ring narrowly confined. At the 11 o'clock position in between the F ring and the G ring, Janus (111 miles, or 179 kilometers, across) appears as a faint black dot. Janus and Prometheus are dark for the same reason Mimas is mostly dark: we are looking at their non-illuminated sides in this mosaic. Midway between the F ring and the G ring, at about the 8 o'clock position, is a single bright pixel, Epimetheus. Looking more closely at Enceladus, Mimas and Tethys, especially in the brightened version of the mosaic, one can see these moons casting shadows through the E ring like a telephone pole might cast a shadow through a fog.

more...
No comment yet.
Scooped by Dr. Stefan Gruenwald
Scoop.it!

Newest Hack: IBM makes Watson available to the average programmer via API

Newest Hack: IBM makes Watson available to the average programmer via API | Amazing Science | Scoop.it
IBM has upped the ante in the API game by making its Watson question-answering system available as a service. That’s right, Watson could soon power your smartphone app.

 

IBM didn’t have to flaunt its debatable cloud dominance over Amazon Web Services on the sides of public buses if it wanted to upstage the cloud kingpin at its user conference this week — Big Blue could have just led with the news that its famous, Jeopardy!-champ-destroying Watson system is now available as a cloud service.

 

That’s right: Developers who want to incorporate Watson’s ability to understand natural language and provide answers need only have their applications make a REST API call to IBM’s new Watson Developers Cloud. “It doesn’t require that you understand anything about machine learning other than the need to provide training data,” Rob High, IBM’s CTO for Watson, said in a recent interview about the new platform.

 

More on the the details later, but first the big picture. If IBM actually delivers a workable cloud platform around Watson and developers actually take advantage of it to build new, smart applications.

 

IBM stands to make money from the Watson Developers Cloud but the primary goal is to create a large community of developers in the world of cognitive computing — “what we believe is the dominant form of computing in the future,” High said. “We’ve come to the conclusion that this is too big and important to hold to our [ourselves],” he noted.

 

Indeed, IBM has been trying to grow the community and capabilities of cognitive computing, even beyond what Watson can do around understanding language. The company recently launched a university partnership that focuses on numerous aspects of cognitive computing, including the field of deep learning that is driving significant advances in computer vision and other facets of text analysis and natural language processing. And IBM has for years been mapping brains and working on microchips that mimic the brain’s architecture.

 

The real beauty of these types of systems is not just in the intelligence of the computers, but also in how they affect the thought processes of people using them, High said. He noted an early Watson user who learned pretty quickly after using Watson that he had been asking the wrong questions of his data all along.

 

“When you get a very rapid response to our questions, we drive our level of concentration much more deeply,” High explained. “And in concentrating more deeply, we think about things we haven’t thought of before.”

more...
No comment yet.
Scooped by Dr. Stefan Gruenwald
Scoop.it!

The Red Edge of Purple Bacteria and the Search for Alien Life Signature in Space

The Red Edge of Purple Bacteria and the Search for Alien Life Signature in Space | Amazing Science | Scoop.it

When Earth was ruled by purple bacteria, its bio-signature would still have been recognisable, say astrobiologists who think similar signs might be visible on other planets.

 

In the 1980s, when NASA built the Galileo probe destined for Jupiter, the plan was to launch it in the cargo bay of the space shuttle complete with a powerful booster rocket that would send it directly on its way to the giant planet. But after the Challenger tragedy in 1986, the safety review that followed concluded that it would not be a good idea to place an unlit rocket inside any future shuttle. And since no other rocket was powerful enough to lift the space probe and its booster, NASA had to find another way of getting Galileo to Jupiter.

 

The solution was to send Galileo around Venus, back around Earth and back to Venus again before catapulting it on its way towards Jupiter. This new mission profile gave the mission scientists an idea. Galileo, they realized, would be the first spacecraft to fly past Earth on its way to somewhere else. And that gave them a unique opportunity to use Galileo’s powerful suite of instruments to look for signs of life on the home planet.

 

Astrobiologists have always been keenly interested in finding signs of life on other planets. The new mission would provide a powerful control experiment of their capabilities. In the event, Galileo gathered a great deal of evidence that pointed to something interesting happening on the surface of Earth. The results, said the Galileo team, “are strongly suggestive of life on Earth.”

 

One of the more interesting features was in the spectrum of light reflected from the surface. The team noted that a pigment on the surface strongly absorbed light in the red part of the spectrum. This has since become known as “the red edge” and astrobiologists think that if life on other planets is anything like that on Earth, then a similar feature ought to be visible in the light reflected from life-bearing exoplanets too.


So what kind of signature might this exovegetation produce? Today, we get an answer thanks to the work of Esther Sanromá at the Universidad de La Laguna in Spain and a few pals who have calculated what Earth’s signature would have looked like during the Archaen era 3 billion years ago when the planet was probably ruled by purple bacteria.

 

At that time, the Sun was only about 80 per cent as bright as it is today and Earth was very different place. The atmosphere was dominated by nitrogen, carbon dioxide and water vapor.

 

Life had sprung into existence just 800 million years earlier and the first photosynthetic life was a purple bacteria that did not produce oxygen as a by-product—hence the lack of oxygen in the atmosphere.

 

Since these bacteria absorb light, this ought to have been visible in the spectrum of light reflected from the surface. So what kind of “edge” would this have produced?

more...
No comment yet.