Before The Big Bang

Until very recently, asking what happened at or before the Big Bang was considered by physicists to be a religious question. General relativity theory just doesn’t go there – at T=0, it spews out zeros, infinities, and errors – and so the question didn’t make sense from a scientific view.

But in the past few years, a new theory called Loop Quantum Gravity (LQG) has emerged. The theory suggests the possibility of a “quantum bounce,” where our universe stems from the collapse of a previous universe. Yet what that previous universe looked like was still beyond answering.

Physicists have now developed a simplified LQG model that gives an intriguing answer: a pre-Big Bang universe might have looked a lot like ours.

“The significance of this concept is that it answers what happened to the universe before the Big Bang,” Singh told PhysOrg.com. Our study shows that the universe on the other side is very classical as ours.”

“This means that the twin universe will have the same laws of physics and, in particular, the same notion of time as in ours,” Singh said. “The laws of physics will not change because the evolution is always unitary, which is the nicest way a quantum system can evolve. In our analogy, it will look identical to its twin when seen from afar; one could not distinguish them.”

That means that our universe today, roughly 13.7 billion years after the bounce, would share many of the same properties of the pre-bounce universe at 13.7 billion years before the bounce. In a sense, our universe has a mirror image of itself, with the Big Bang (or bounce) as the line of symmetry.

Ultimately, Corichi and Singh’s model might even tell us what a future universe would look like. Depending on how fast our present universe is accelerating – which will ultimately determine its fate – there’s a possibility that a generalization of the model would predict a re-collapse of our own universe.

Ref.: Quantum bounce and cosmic recall. 2008. Corichi, Alejandro, and Singh, Parampreet. In press, Physical Review Letters.

Oldest Human Coprolite Found

Human mitochondrial DNA from dried excrement recovered from Oregon's Paisley Caves is the oldest found yet in the New World -- dating to 14,300 years ago, some 1,200 years before Clovis culture.

The Paisley Caves are located in the Summer Lake basin near Paisley, about 220 miles southeast of Eugene on the eastern side of the Cascade Range. The series of eight caves are wave-cut shelters on the highest shoreline of pluvial Lake Chewaucan, which rose and fell in periods of greater precipitation during the Pleistocene.

Clovis culture began sometime between 13,200 and 12,900 years ago. Skeletal remains dating to Clovis culture have proven elusive, leaving researchers with little hard evidence beyond tell-tale cultural components such as the distinctive fluted Clovis points and other tools.

Exactly who these people living in the Oregon caves were is not known. At this point, we know they most likely came from Siberia or Eastern Asia, and we know something about what they were eating, which is something we can learn from coprolites. We're talking about human signature.

“Had the human coprolites at the Paisley Caves not been analyzed for DNA and subjected to rigorous dating methodology,” he added, "the pre-Clovis age of the artifacts recovered with the megafaunal remains could not have been conclusively proven. In other words, the pre-Clovis-aged component of this site could very well have been missed or dismissed by archaeologists.” link

Ref: DNA from Pre-Clovis Human Coprolites in Oregon, North America. 2008. M. T. P. Gilbert et al. Science, published on-line April 3.

Is DNA Repair a Substitute For Sex?

Bdelloid rotifers seem to get along just fine without sex. What’s more, they have done so over millions of years of evolution, resulting in at least 370 species. These hardy creatures somehow escape the usual drawback of asexuality – extinction!

Bdelloid rotifers have been able to give up sex and survive because they have evolved an extraordinary efficient mechanism for repairing harmful mutations to their DNA.

In animals that do have sex, DNA repair is accomplished during meiosis, when chromosomes pair up (one from the father, one from the mother) and “fit” genes on one chromosome can serve as templates to repair damaged genes on the other chromosome. The bdelloid, though, always seems to reproduce asexually, by making a clone of itself. How then, does it cope with deleterious mutations?

Scientists demonstrated the enormous DNA repair capacity of bdelloid rotifers by zapping them with ionizing radiation (gamma rays), which has the effect of shattering its DNA into many pieces. “We kept exposing them to more and more radiation, and they didn’t die and they didn’t die and they didn’t die,” says Mark Welch. Even at five times the levels of radiation that all other animals are known to endure, the bdelloids were able to continue reproducing.

Philodina roseola

The bdelloids’ DNA repair capacity probably evolved due to a different environmental adaptation – tolerance of extreme dryness. Bdelloids, which live in ephemeral aquatic habitats such as temporary freshwater pools and on mosses, are able to survive complete desiccation (drying out) at any stage of their life cycle. They just curl up and go dormant for weeks, months, or years, and when water becomes available, they spring back to life. Desiccation, like ionizing radiation, breaks up the rotifers’ DNA into many pieces. Presumably, the same mechanisms they use to survive desiccation as part of their life cycle also protect them from ionizing radiation.

Extreme Resistance of Bdelloid Rotifers to Ionizing Radiation.2008. Gladyshev, E., and M. Meselson . Proc. Natl. Acad. Sci. 105 (13): 5139-5144.

Evidence for degenerate tetraploidy in bdelloid rotifers. 2008. Mark Welch, D.B., J.L. Mark Welch and M. Meselson. Proc. Natl. Acad. Sci. 105 (13): 5145-5149.

Died This Day: Hermann Rorschach

Watchmen & Rorschach © DC Comics

Rorschach (Nov. 8, 1884 - April 2, 1922) was a Swiss psychiatrist who devised the inkblot test that bears his name and that is widely used clinically for diagnosing psychopathology. His secondary-school nickname was Kleck, meaning "inkblot," because of his interest in sketching.

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In 1917, he learned of Szyman Hens, who had studied the fantasies of his subjects using inkblot cards. Rorschach began in 1918 using 15 accidental inkblots, asking patients, "What might this be?" He knew the human tendency to project interpretations and feelings onto ambiguous stimuli. The subjective responses of his subjects enabled him to distinguish among them on the basis of their perceptive abilities, intelligence, and emotional characteristics. His published results (1921) drew little interest until after his death. link

Jack Kirby Explains The Origin of Mankind

The Eternals created by Jack Kirby & © Marvel Comics

Jack Kirby retold the origin of the Earth and the evolution of Mankind more than once in his career as he introduced his wild new concepts to the comic book reading world. Here’s his take from ‘The Eternals’:

CLICK TO ENLARGE & READ

Jack explains what it's all about:

Read it all in the next issue of, "THE ETERNALS!"

Read Jack's "Origin of Homo mermanus"

The Hardness of Squid Beaks

Abstract: The beak of the Humboldt squid Dosidicus gigas represents one of the hardest and stiffest wholly organic materials known. As it is deeply embedded within the soft buccal envelope, the manner in which impact forces are transmitted between beak and envelope is a matter of considerable scientific interest

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Challengers of the Unknown © DC Comics

Here, we show that the hydrated beak exhibits a large stiffness gradient, spanning two orders of magnitude from the tip to the base. This gradient is correlated with a chemical gradient involving mixtures of chitin, water, and His-rich proteins that contain 3,4-dihydroxyphenyl-L-alanine (dopa) and undergo extensive stabilization by histidyl-dopa cross-link formation.

These findings may serve as a foundation for identifying design principles for attaching mechanically mismatched materials in engineering and biological applications.

The Transition from Stiff to Compliant Materials in Squid Beaks. 2008. Ali Miserez et al. Science 319: 1816-1819.

Living Upside-Down Shapes Spiders for Energy Saving

Art by Frank Cho

Researchers investigating spider species which live, feed, breed and ‘walk’ in an upside-down hanging position have found that their lifestyle drives a shape in spiders that confers high energy efficiency, as in oscillatory pendulums.

The great majority of land animals evolved legs capable of supporting the weight of their whole bodies, enabling them to move around with their heads above their feet. However, many spider species found it more convenient to literally turn their world upside down. They spend most of their lives hanging suspended by their legs, and ‘walk’ by swinging under the influence of gravity.

One of the focal questions was the evolutionary importance of ‘bridging’ – the technique many spiders use to move between remote plants by building their own silk bridges, which they cross by ‘walking’ suspended upside-down from them. Earlier research by other authors indicated that for monkeys this suspensory way of locomotion might be a more energetically efficient way of transportation than ‘regular’ walking on the ground.

“We discovered that spiders that live upside-down have evolved disproportionately longer legs relative to ‘normal’ spiders, which enables them to move faster while bridging than while ‘normally walking’ on the ground. Particularly ‘clumsy’ walkers are larger spiders, because their long legs – otherwise so convenient for bridging – do not allow an easy lifting of their relatively large body mass” says Dr. Jordi Moya-Laraño from Spain, the principal investigator on this project.





These results have implications for the evolution and ecology of spiders. For example, small spiders that hang from their webs should be able to leave their webs in search for prey by walking on the ground, as found in some tiny spiders, something that large spiders will be unable to do efficiently. link

Ref: Morphological Evolution of Spiders Predicted by Pendulum Mechanics. 2008. Jordi Moya-Laraño et al. PLOS One e1841.