Massive Black Holes Caught in Death Spiral

BY DENNIS OVERBYE



The apocalypse is still on, apparently-at least in a galaxy about 3.5 billion light-years from here.

Last winter, astronomers at the California Institute of Technology reported that two supermassive black holes appeared to be spiraling toward a cataclysmic collision that could bring an end to that galaxy.

The evidence was a rhythmic flickering from the galaxy’s nucleus, a quasar known as PG1302-102, which Matthew Graham and his colleagues interpreted as the fatal mating dance of a pair of black holes with a total mass of more than a billion suns. Their merger, the astronomers calculated, could release as much energy as 100 million supernova explosions, mostly in the form of violent ripples in space-time known as gravitational waves that would blow the stars out of that hapless galaxy like leaves off a roof.

The supermassive black holes are all that remains of galaxies once all protons decay, but even these giants are not immortal. (Photo credit: Wikipedia)

Now a new analysis of the system by Daniel D’ Orazio of Columbia University in New York and his colleagues has added weight to that conclusion. Mr. D’ Orazio, a graduate student, and Zoltan Haiman and David Schiminovich propose that most of the light from the quasar is coming from a vast disk of gas surrounding the smaller of the two black holes.

As the black holes and their attendant disks swing around each other at high speeds, the light from the disk that is coming toward us receives a boost from relativistic effects-a so-called Doppler boost-the way a siren grows louder and more high-pitched as it approaches, giving rise to a periodic increase in brightness every five years.

The Columbia astronomers ‘model predicts that the variation would be two or three times greater in ultraviolet light than in visible light. And that is exactly what they found when they compared archival data from the Hubble Space Telescope and NASA’s Galex space telescope to the visible-light data previously analyzed by Dr. Graham’s group.

“What’s big is that the Doppler boost is inevitable,” Dr. Haiman said in an email. Given reasonable assumptions about the masses of the black holes, their model predicts the right ultraviolet data.

“This is rare in ‘messy’ astronomy,” he said, “to have an indisputable clean effect, which explains the data.”

Follow-up observations of ultraviolet and visible light emissions in the coming years could help clinch the case, the authors said. Their paper was published last month in the journal Nature.

Their model suggests that the black holes are orbiting each other at a distance of some 320 billion kilometers, less than tenth of a lightyear, a cosmic whisker. At that distance, the black holes would be rapidly losing energy by radiating gravitational waves and could spiral together into the final bang in as little as 100,000 years, Dr. Haiman said, depending on their relative masses.

An artist's conception of a supermassive black hole and accretion disk. (Photo credit: Wikipedia)

“Basically, the more massive the holes, the faster gravitational waves drive them together, and we do require them to be as massive as allowed to be ,” he said in an email. For their model to hold up, the larger of the black holes has to be a billion solar masses or more.

(Because the galaxy is so far away, the cataclysm might well have already happened more than three billion years ago, but the news still won’t reach us for another 100,000 years or so. So it is still in the future, as far as earthlings-whoever they will be by then-are concerned.)

E.Sterl Phinney, a Caltech astronomer and expert on supermassive black holes, agreed that Dr.Haiman’s model explained the quasar variations. “So Occam’s razor makes it attractive,” he said, referring to the long-held principle that physicists should adopt the simplest theory that fits the facts. But it was surprising, he said, to find two supermassive black holes that have gotten so close.

Black holes, predicted by Albert Einstein’s general theory of relativity, are objects so dense that not even light can escape from them. Every galaxy of note seems to have a supermassive black hole, weighing millions or billions of times as much as the sun, burping sparks of half-eaten stars and gas.

“A scientific theory is only as good as the tests which it has passed,” Mr. D’ Orazio said.

Einstein’s theory has passed all of the observational and experimental tests thrown at it so far. But some of its predictions can be tested only in the most extreme gravitational environments, namely black holes.



Taken from TODAY Saturday Edition, The New York Times International Weekly, October 3, 2015

A New Science Fiction Radiates a Rosier View

November 1931 issue of Everyday Science and Mechanics (Photo credit: Wikipedia)

BY NICK BILTON


Imagine living in a weird science-fiction story where everything you dreamed up actually came true.

Well, for decades science-fiction writers have been making bold predictions. But now writers are starting to realize that in predicting the future, they have helped shape it.

For example, sci-fi authors first envisioned credit cards, which go all the way back to 1888 when Edward Bellamy wrote about them in his novel “Looking Backward.”

Additionally, solar power and radar were envisioned by Hugo Gernsback in his 1911 magazine stories; H.G. Wells anticipated voice mail in 1923; in- ear headphones and large flat-screen TVs were in Ray Bradbury’s 1953 novel, “Fahrenheit 451”; virtual reality was dreamed up by Arthur C. Clarke in 1956; Jules Verne told stories about electronic submarines all the way back in 1870; and Martin Cooper, who created the first mobile phone, said the idea came to him after watching “Star Trek.”

But not all of the predictions have been rosy. Atomic bombs first appeared in Wells’s 1914 novel “The World Set Free”; George Orwell aptly predicted -- and maybe contributed to -- a surveillance state in “Nineteen Eighty-Four”; and writers have been envisioning destructive weapons of all shapes and sizes, including biological warfare, for centuries.

Now some of these visionaries have banded together to offer stories that are more utopian, which they hope will contribute to a more positive future.

In 2011, Arizona State University’s president, Michael Crow, challenged Neal Stephenson, the author of several sci-fi novels, to stop writing dystopian stories, and offer ideas with a brighter outlook. The concept caught on and last month a group of writers, in collaboration with the university, released “Hieroglyph: Stories and Visions for a Better Future,” which hopes to be a blueprint for these new concepts.

“Sci-fi stories have helped shape technology at crucial points,” said Kathryn Cramer, co-editor of Hieroglyph. “But a lot of the past was dystopian. We’re hoping to show that there are a lot of things we can do better.”

Writers are pushing back in particular against Hollywood’s depiction of the future -- you know, where robots roam the earth killing puppies and enslaving humans.

For example, “Transcendence, “an action film this year, stars Johnny Depp, who plays a brilliant scientist who is resurrected as an artificial intelligence program that becomes evil. Or “12 Monkeys,” in which a man-made virus wipes out most of the planet’s population.

“I got into a little bit of a rut thinking that the way to be cool was to be cynical and dark,” Mr. Stephenson said. “I don’t regret that at all. Now I have a license to go out and try something with a different tone.”

His story in the new collection is about an engineer’s effort to build a 20-kilometer-tall skyscraper. Other tales envision an alternative Internet that is free from government snooping and corporate tracking, and is powered by thousands of homemade drones. Another story is about a group of hardware hackers and Burning Man devotees who build an autonomous 3-D printing robot that goes to the moon. A third imagines a future world without border fences.

The stories still offer plenty of drama, death and destruction, but many have a sort of happy ending. Cory Doctorow, a contributor to Hieroglyph, wrote that the stories are not “optimistic or pessimistic about the future. Instead they are hopeful about it.”

Last month, the editors of the collection took a trip collection took a trip around Silicon Valley, giving talks at big companies, including Google- which is building a bunch of robots that may one day roam the earth, but (one hopes) won’t enslave people-to try to persuade engineers to think differently.

While Mr. Stephenson isn’t so naïve as to think that these sci-fi narratives will make the world a better place, he hopes that they can have a constructive influence.

“There’s definitely some kind of a feedback loop,” he said, “between science fiction and technological fact.” 


Taken from TODAY Saturday Edition, The New York Times International Weekly, October 11, 2014

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Sea-Cloaked Mystery With Trillions of Clues

An image of two fish in the family Gonostomatidae: the Elongated bristlemouth, Gonostoma elongatum (top) and Bonapartia pedaliota (bottom). From Oceanic Ichthyology by G. Brown Goode and Tarleton H. Bean, published 1896. (Photo credit: Wikipedia)

BY WILLIAM J. BROAD


Habitats on land-rain forests, steppes, woodlands, deserts, alpine meadows, all well explored over the centuries-make up less than 1 percent of the planet’s biosphere. Why so little? The band of life is narrow. Fertile soil goes down only about a meter, and even the tallest trees stretch up only about 90 meters.

Water, however, is a different story. It covers more than 70 percent of the earth’s surface and goes down kilometers. Scientists put the ocean’s share of the biosphere at more than 99 percent. Fishermen know its surface waters and explorers its depths. But in general, compared with land, the ocean is unfamiliar.

Which helps explain why scientists have only recently come to realize that the bristlemouth, a fish of the middle depths that glows in the dark and can open its mouth extraordinarily wide, baring needlelike fangs, is the most numerous vertebrate on the earth.

“They’re everywhere,” Bruce H.Robison, a senior marine biologists at the Monterey Bay Aquarium Research Institute in California, said of the bony little fish. “Everybody agrees. It’s the most abundant on the planet.”

By human standards, the brute is tiny, smaller than a finger. But this strange little fish makes up for its diminutive size with staggering numbers, as well as a behavioral trick or two.

It starts life as a male and, in some cases, switches to a female. Scientists call it protandrous, a male-first hermaphrodite.

John C. Avise, the author of “Hermaphroditism, “said the adult male bristlemouth tended to be smaller than the female and had a better developed sense of smell, apparently to find mates in the darkness.

“They occupy an environment that’s hard to access,” Dr. Avise said of the fish, so there is “precious little information” about their behavior.

Though the portrait of the bristlemouth is incomplete, scientists know enough to assert that it far outstrips all other contenders for the title of most common vertebrate on the planet. Ichthyologists put the likely figure for bristlemouths at hundreds of trillions –and perhaps quadrillions, or thousands of trillions.

“No other animal gets close,” said Peter C. Davison, a fish scientist at the Farallon Institute for Advanced Ecosystem Research, in Petaluma, Calif. “There are as much as a dozen per square meter of ocean.”

The bristlemouths are a rapacious family of fishes that include the wildly successful genus Cyclothone-Greek for “circular,” in apparent reference to the creature’s gaping mouth. They are also known as roundmouths.

The genus has 13 species, such as the shadow bristlemouth. The main distinguishing features are subtle differences in the fins and luminous organs. All members wield bristlelike teeth. Over all, the fish are 2.5 to 7.5 centimeters in length, tan to black in color, and at times display a kind of ghostly translucence.

The first hints of the fish’s ubiquity came during the voyage of the H.M.S. Challenger, a British ship that sailed the globe from 1872 to 1876 and helped lay the foundations of oceanography. It lowered nets at dozens of sites and hauled up the creatures from as deep as five kilometers.

The first scientist to view the animals in their dark habitat was William Beebe. In the early 1930s, Mr. Beebe, a senior explorer of what is now the Wildlife Conservation Society, plunged into the depths off Bermuda in a spherical submersible, gazed through its porthole- and saw aliens.

“Numberless little creatures “raced through his light beam, he wrote in his 1934 book, “Half Mile Down.” They turned out to be bristlemouths. A color plate in the book shows a group with jaws wide open while chasing a school of copepods, tiny crustaceans with long antennas.

Oceans textbooks from the 1970s to the 1990s said little about Cyclothones. Then came a new wave of research, centering on careful trawls of the deep ocean with a new generation of nets in which the mesh was much finer. No matter how far the nets plunged, up came vast numbers of bristlemouths.

Dr. Robison said bristlemouths have very small eyes that in the dim habitat seemed to play little or no role in finding prey. Instead, the fish apparently relies on sense organs that can detect movement and vibration in the surrounding water.

And the rows of glowing dots on the bristlemouth’s abdomen? Dr. Robison said they appeared to be camouflage that helped the creature hide from predators by matching the surrounding light.

It has taken roughly a century and a half, but science has finally come to know the bristlemouth fairly well, even if questions remain. Not so other creatures of the deep. If the tortuous route to identifying the dominant fish is any indication, it will take longer still to learn about the uncommon forms of life that roam the depths.

“We keep seeing lots of different critters we haven’t seen before,” Dr. Robison said of voyages in the Monterey Canyon, a deep gorge in California’s coastal seabed, and beyond. He added, “The deeper you go, the stranger things get.”


Taken from TODAY Saturday Edition, The New York Times International Weekly, July 11, 2015

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Ebola Nearly Claimed His Life, Then It Hid in His Eye

Satellite image of Sierra Leone (Photo credit: Wikipedia)

BY DENISE GRADY


ATLANTA - When Dr. Ian Crozier was released from Emory University Hospital in October after a long, brutal fight with Ebola that nearly ended his life, his medical team thought he was cured. But less than two months later, he was back at the hospital with fading sight, intense pain and soaring pressure in his left eye.

Test results were chilling: The inside of Dr. Crozier’s eye was teeming with Ebola.

His doctors were amazed. Months had passed since he became ill while working in an Ebola treatment ward in Sierra Leone as a volunteer for the World Health Organization. By the time he left Emory, his blood was Ebola-free.

Almost nothing was known about the ability of Ebola to lurk inside the eye, but despite the infection, Dr. Crozier’s tears and the surface of his eye were virus-free, so he posed no risk to anyone who had casual contact with him.

More than a year after the epidemic in West Africa was recognized, doctors are still learning about Ebola and Lingering effects on survivors. Now, however, with at least 10,000 survivors in Guinea, Liberia and Sierra Leone, patterns are emerging.

Dr. Crozier, 44, calls himself a poster child for “post-Ebola syndrome.” Besides eye trouble, he has had debilitating joint and muscle pain, deep fatigue and hearing loss.

At ELWA Hospital in Monrovia, Liberia, run by the missionary group SIM, Dr.John Fankhauser, the medical director, said such ailments were the most common physical problems among the hundred or so people attending a special clinic for Ebola survivors.

In Sierra Leone, the picture is much the same, according to Dr. John S. Schieffelin, a physician from the Tulane University School of Medicine in New Orleans who volunteered there. He said a well-organized survivor group met regularly in Kenema.

“The main problems they’re telling me about are lots of body and joint pains, chronic headaches and women who stopped having menstrual periods, and for some it’s been several months,” Dr. Schieffelin said.” There’s quite a bit of vision problems.”

The inside of the eye is mostly shielded from the immune system to prevent vision damage. The barriers are not fully understood, but they include tightly packed cells in minute blood vessels that keep out certain cells, along with unique biological properties that inhibit the immune system. But this “immune privilege” can sometimes turn the inner eye into a sanctuary for viruses.

The question was whether Dr. Crozier’s sight could be saved. Severe inflammation suggested that the barriers that normally protect the eye from the immune system had been breached. So what was damaging Dr. Crozier’s eye? The virus, the inflammation or both?

The usual treatment for inflammation is steroids. But they can make an infection worse.

“What if it unleashed the virus?” Dr. Crozier said. “We were on a tightrope.”

Though Dr. Crozier was the patient, he was also part of his own medical team, and his focus on the scientific details helped counter his mounting fear that he was going blind. As he and his physicians struggled to balance treating the inflammation with fighting the infection, his eyesight continued to deteriorate.

He also had significant hearing loss on the same side. “The whole left side of your life is gone, “he said. “It was a very dark and depressing time.”

The biggest shock came when he glanced in the mirror one morning and saw that his eye color had changed from bright blue to a vivid green.

“It was like an assault,” he said. “It was so personal.”

Dr. Jay Varkey, an infectious-disease specialist who had handled much of Dr. Crozier’s care, got special permission from the United States Food and Drug Administration to use an experimental antiviral drug taken in pill form. (The doctors declined to name it.)

At first, there seemed to be no effect. But a week or so later, Dr. Crozier realized that if he turned his head this way and that, he could find “portals” through the obstructions in his eye.

His sight returned in a few months, and his eye turned blue again.

Was it the antiviral drug? He cannot be sure, but he think so.

Dr. Varkey said, “I think the cure was Ian’s own immune system.” He said he suspected the treatments had reduced Dr. Crozier’s symptoms and helped preserve his sight long enough for his immune system to kick in and clear out the virus-just as supportive care during the worst phase of his initial illness had kept him alive until his natural defenses could take over.

Dr. Crozier believes information from his case may help prevent blindness in Ebola survivors in West Africa. In April, he headed to Liberia with Dr. Steven Yeh, an ophthalmologist, and several other Emory physicians to see patients who had recovered from Ebola and examine their eyes.

“Maybe we can change the natural history of the disease for survivors,” Dr. Crozier said. “I want to start that conversation.”


Taken from TODAY Saturday Edition, The New York Times International Weekly, May 23, 2015

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When the Mind’s Eye Is Blind, It’s Hard to Picture an Image

English: Main regions of the vertebrate brain, shown for a shark and a human brain (the human brain is sliced along the midline). The two brains are not on the same scale. (Photo credit: Wikipedia)

BY CARL ZIMMER


In 2005, a 65-year-old retired building inspector paid a visit to the neurologist Adam Zeman at the University of Exeter Medical School in England. After a minor surgical procedure, the man-whom Dr. Zeman and his colleagues refer to as MX-had suddenly realized he could not conjure images in his mind.

Dr. Zeman could not find the condition in medical literature. He was intrigued. For decades, scientists had debated how the mind’s eye works, and how much we rely on it to store memories and to make plans for the future.

MX agreed to a series of exams. He proved to have a good memory for a man of his age, and he performed well on problem-solving tests. His only unusual mental feature was an inability to form mental images.

Dr. Zeman then scanned MX’s brain as he performed certain tasks. First, MX looked at faces of famous people and named them. The scientists found that certain regions of his brain became active, the same ones that become active in other people who look at faces.

Then the scientists showed names to MX and asked him to picture their faces. In normal brains, some of those face-recognition regions again become active. In MX’s brain, none did.

Yet MX could answer questions that would seem to require a working mind’s eye. He could tell the scientists the color of Tony Blair’s eyes, for example, and name the letters of the alphabet that have low-hanging tails, like g and j. These tests suggested his brain used some alternate strategy to solve visual problems.

Since then, scientists have surveyed other people who say they cannot summon mental images-as if their mind’s eye were blind. Many of the survey respondents differed from MX in an important way. While he originally had a mind’s eye, they never did.

Reported in the journal Cortex, the condition has received a name: aphantasia, based on the Greek word phantasia, which Aristotle used to describe the power that presents imagery to our minds.

If aphantasia is real, it is possible that injury causes some cases while others begin at birth.

Thomas Ebeyer, a 25-year-old Canadian student, discovered his condition four years ago while talking with a girlfriend. He was shocked that she could remember what a friend had been wearing a year before. She replied that she could see a picture of it in her mind.

“I had no idea what she was talking about,” he said. He was then surprised to discover that everyone he knew could summon images to their minds.

Like many other survey subjects, he could count his windows without picturing his house.

It’s weird and hard to explain,” he said. “I know the facts. I know where the windows are.”

Dr. Zeman is trying to ascertain how common aphantasia is. He has sent the questionnaire to thousands of people and wants to hear from more. He can be reached at a.zeman@exeter.ac.uk.


Taken from TODAY Saturday Edition, The New York Times International Weekly, July 4, 2015

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Planet Mercury Is Shown To Be More Than a Little Bore

English: Artist's rendering of the MESSENGER spacecraft orbiting Mercury (Photo credit: Wikipedia)

By KENNETH CHANG


NASA’s Messenger spacecraft, in orbit around Mercury for the past four years, came to an abrupt end on April 30 when it crashed into the surface.

That event brought to a close a mission that has painted an unexpected portrait of Mercury, once thought a boring round rock not much different from Earth’s moon. Mercury, the smallest planet in our solar system, is only slightly larger than the moon, although it has more drastic temperature swings – 427 degrees Celsius during the day, minus 184 degrees at night.

“It’s really been exciting to see a planet unfold, a planet that is one of our neighbors,” said Sean C. Solomon, the principal investigator for the mission. “Almost every aspect of Mercury has had its share of surprises.”

Messenger – a shortening of Mercury Surface, Space Environment, Geo-chemistry and Ranging – discovered that Mercury shrank slightly as it cooled over billions of years; mapped ancient lava flows; found enigmatic shallow depressions that are some of the youngest and brightest features on the surface; and confirmed the presence of ice in perpetually dark crates near the poles.

The water ice, perhaps a billion tons, was not a complete surprise. Radio telescope observations from Earth had hinted at something reflective, and the shadowed craters are extremely cold. Beyond confirming the suspected, Messenger also made a new discovery: The ice was covered by an unexplained dark layer.

“We have a reasoned hypothesis,” Dr. Solomon said. The material could be carbon-rich compounds, similar to substances found in certain meteorites and in comets. “It’s tarlike in its consistency,” he said. “It’s as dark as tar.”

The biggest scientific finding of the mission, Dr. Solomon said, was that Mercury was rich in “volatiles,” elements like chlorine, sulfur, potassium and sodium that easily evaporate at moderate temperatures. Mercury is small and dense, full of iron, and the thinking about how it formed was that it must have been heated to temperatures that should have boiled off the volatiles. Yet the volatiles are still there.

Scientists now have to come up with new ideas to explain how Mercury formed. When NASA launched Messenger in 2004, knowledge of Mercury was sparse. The only close-ups had come in three flybys by NASA’s Mariner 10 in the 1970’s

For more than six years, Messenger took a circuitous route through the inner solar system, making flybys of Earth, Venus and Mercury, to slow itself down enough to enter orbit around Mercury. On March 18, 2011, finally arrived.

The orbital portion of the mission was to last one year, then was extended twice.

Even the craft’s destruction could provide insights by digging up what lies beneath the surface- but it will be some time before anyone will see what that is. NASA does not have any follow-up Mercury missions set, but an ambitious European and Japanese collaboration called BepiColombo is scheduled to launch in 2017. It is to arrive at Mercury in 2024.

That mission consists of two orbiters, one focusing on the planet, the other on the surrounding space environment, in greater and finer detail than Messenger.

Johannes Benkhoff, the project scientist for BepiColombo at the European Space Agency, described Messenger as “really a fantastic mission.”

“It’s perfect that we have BepiColombo to follow on” Messenger’s findings, Dr. Benkhoff said. “They have provided a lot of new results, unexpected results.”

BepiColombo is named after Giuseppe Colombo, an Italian scientist nicknamed Bepi who came up with the orbital trajectories that enabled NASA’s Mariner10 flybys.

Dr. Solomon is looking forward to the next trip to Mercury I still want to learn more about, “he said.


Taken from TODAY Saturday Edition, The New York Times International Weekly, May 9, 2015

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