Science News Review

New Theories and X-Rated Space Follies

Dec 13 at 6:06pm by Aileen

Quantum Iron in the Core, Killer ETs and Indecent Singularities

Researchers have recently discovered some new things about both our own planet’s core and our close encounters of the closest kind with extraterrestrial billard balls. Beginning here at home, geophysics researchers published a paper in Science reporting that Deep Earth Model Challenged by New Experiment.

Apparently the iron concentrated in the lower Earth mantle behaves quite differently than previous models predicted. Instead of finding a particular, thin “transition zone” at a certain depth where the temperature and pressure ‘flips’ the spin of electrons in Iron atoms to a paired state (a quantum effect that affects the density of the iron compounds), the experiments found a whole new region in the lower mantle where both high and low spin states coexist in the same crystal structure.

This continuous transition zone grew to a thickness of nearly 750 miles, comprising the entire region between the depths of 620 and 1,365 miles beneath the surface of the Earth.

Meanwhile, a team of planetary geologists reported in the PNAS journal that Extraterrestrial Impact is Likely Source of Sudden Ice Age Extinctions.

About 12,900 years ago wooly mammoths, giant sloths, saber-toothed cats, other giant animals and a condor with a 16-foot wingspan disappeared from the fossil record, as did evidence of human remains over entire swaths of North America.

They say that one or more comets or meteorites exploded over the earth or slammed into it, triggering catastrophic climate change. The culprit in this dramatic cooling of the period is apparently carbon, which I suppose we aren’t supposed to notice is the cited culprit today for predicted catastrophic climate change in precisely the opposite direction. Ah, well. It’s always something.

Farther away from our immediate neighborhood, researchers from Duke University and the University of Cambridge think they’ve come up with a way to determine if some black holes out there in the universe might not be black at all, but instead are running around indecently naked!

Some Black Holes May Not Be Black challenges the cosmic censorship hypothesis, which holds that singularities must be properly shielded from outside view by an “event horizon,” a region from which not even light can escape.

Researchers Arlie Petters of Duke and Marcus Werner of Cabridge used gravitational lensing to calculate whether a spinning black hole (those discovered and suspected do appear to spin, some at more than 1,000 revolutions a minute) could ever shed its event horizon to become naked. Surprisingly (to everyone), they can…

“In work supported by the National Science Foundation in the United States and the Science and Technology Facilities Council in the United Kingdom, the pair employed a finding that a black hole could be shed of its event horizon and become a naked singularity if its angular momentum – an effect of its spin – is greater than its mass.”

Sir Roger Penrose, who with Stephen Hawking developed the original singularity theorems derived from Einstein’s theory of general relativity, once remarked that “God abhors a naked singularity.” We humans might wonder why a naked gravity well would seem so indecent, but it seems that in close vicinity to such a phenomenon time would behave very strangely. Even Petters isn’t so sure he wants to meet a naked singularity…

“If you ask me whether I believe that naked singularities exist, I will tell you that I’m sitting on the fence,” said Petters. “In a sense, I hope they are not there. I would prefer to have covered-up black holes. But I’m still open-minded enough to entertain the ‘otherwise’ possibility.”

Maybe naked singularities are like pornography, we’ll know it if we see it. We can still hope this burlesque show stays far away from our cosmic neighborhood, where decent people live!

Links:

Deep Earth Model Challenged by New Experiment

Extraterrestrial Impact is Likely Source of Sudden Ice Age Extinctions

Some Black Holes May Not Be Black