scientific technology

Gamma-ray bursts: the biggest, most powerful explosions in the Universe since the Big Bang. They are a million trillion times brighter than the Sun. Each day, we detect a burst of gamma radiation coming from a random direction in the sky. Lasting anywhere from a fraction of a second to several minutes, these high-energy astronomical enigmas have a deadly power.

The monitoring of nuclear-weapon tests led researchers to the biggest bangs in the Universe
Until very recently, we really didn’t know very much about them. Gamma-ray bursts were only discovered in the late 1960s, quite by accident. During the Cold War, the US military sent up satellites to detect signs of illegal nuclear testing by the Soviet Union. These Vela satellites were fitted with gamma-ray detectors, since nuclear explosions release copious amounts of this extremely energetic radiation. The American military was surprised that their satellites instead detected great explosions of gamma-ray photons coming from space.

So what are these gamma-ray bursts? How are they formed, and where do they come from? Over the past 15 or so years, satellites and ground-based observations have provided a mass of data that has helped scientists to answer these questions.

Scientists have identified two kinds of gamma-ray burst (GRB): short duration (average 0.3 second) and long duration (average 30 seconds). Experts suspect that these form in totally different ways. Although they are fairly confident they understand the origin of long-duration GRBs, short duration GRBs remain a puzzle

A growing number of organizations are taking a cue from reality TV, offering prize money for successful solutions to science and technology problems.

Three major prizes are currently up for grabs from the X Prize Foundation, which aims to spur innovation. The $10 million Archon X Prize will reward any group or person who can sequence the human genome in 10 days or less for no more than $10,000 per genome. So far, eight teams have registered. The $10 million Progressive Automotive X Prize, recognizing high-efficiency, commercially viable vehicles, completed two rounds of judging this past year. Performance tests will start in the spring of 2010, with winners announced in September. And 21 teams are vying to land a privately funded rover on the moon in pursuit of the $30 million Google Lunar X Prize. Last October a smaller X Prize–operated contest, the Northrop Grumman Lunar Lander Challenge, awarded $1 million to Masten Space Systems and $500,000 to Armadillo Aerospace for their progress in building a commercial rocket capable of safe vertical takeoff and landing, as demonstrated by successful tests in the Mojave Desert.

Other groups were also busy in 2009. Entries poured in for the £10 million ($17 million) Saltire Prize, to be awarded by the government of Scotland for wave or tidal energy technology that can produce a continuous output of 100 gigawatt-hours for two years. More than 100 teams will begin competition this month. In September, the DVD rental company Netflix paid out a $1 million purse to a seven-member team that developed an algorithm to improve its predictions of customers’ movie preferences. Netflix plans to announce a sequel early this year. Meanwhile, a company called InnoCentive is hosting hundreds of open questions in science and technology. Rewards range from $5,000 to $1 million.

1 : God commanded, “Let there be light,” but it didn’t happen for nearly half a million years. That’s how long after the Big Bang the universe took to expand enough to allow photons (light particles) to travel freely.

2 : Those photons are still running loose, detectable as the cosmic microwave background, a microwave glow from all parts of the sky.

3 : Light moves along at full “light speed”—186,282.4 miles per second—only in a vacuum. In the dense matrix of a diamond, it slows to just 77,500 miles per second.

4 : Diamonds are the Afghan­istan of gemstones: Any entering photon quickly gets bogged down. It takes a lot of pinging back and forth in a thicket of carbon atoms to find an exit. This action is what gives diamonds their dazzling sparkle.

5 : Eyeglasses can correct vision because light changes speed when it passes from air to a glass or plastic lens; this causes the rays to bend.

6 : Plato fancied that we see by shooting light rays from our eyes.

7 : The Greek philosopher was not completely wrong. Like all living things, humans are bio­luminescent: We glow. We are brightest during the afternoon, around our lips and cheeks. The cause may be chemical reactions involving molecular fragments known as free radicals.

8 : Bioluminescence is the largest source of light in the oceans; 90 percent of all creatures who live below about 1,500 feet are luminous.

9 : World War II aviators used to spot ships by the bio­luminescence in their wakes. In 1954 Jim Lovell (later the pilot of Apollo 13) used this trick to find his darkened aircraft carrier.

10 : Incandescent bulbs convert only 10 percent of the energy they draw into light, which is why Europe will outlaw them by 2012. Most of the electricity turns into unwanted heat.

11 : In the confined space of an Easy-Bake oven, a 100-watt bulb can create a temperature of 325 degrees Fahrenheit.

12 : Light has no mass, but it does have momentum. Later this year the Planetary Society will launch LightSail-1, attempting to capture the pressure of sunlight the way a boat’s sail gathers the wind.

13 : Laser beams bounced off mirrors left behind by Apollo astronauts show that the moon is moving 1.5 inches farther from Earth each year.

14 : Visible light makes up less than one ten-billionth of the electromagnetic spectrum, which stretches from radio waves to gamma rays.

15 : Goldfish can see infrared radiation that is invisible to us. Bees, birds, and lizards have eyes that pick up ultraviolet.

16 : Photography means “writing with light.” English astronomer John Herschel, whose father discovered infrared, coined the term.

17 : Shoot now: The “golden hour,” just after sunrise and before sunset, produces the prettiest shadows and colors for photographs.

18 : Day and night are everywhere the same length on the vernal equinox, which occurs this year on March 20.

19 : Auroras light up the night sky when solar wind particles excite atoms in the upper atmosphere. Oxygen mostly shines green; nitrogen contributes blue and red.

20 : But to the Inuits, auroras are spirits of the dead kicking around the head of a walrus.

Black holes are finally winning some respect. After long regarding them as agents of destruction or dismissing them as mere by-products of galaxies and stars, scientists are recalibrating their thinking. Now it seems that black holes debuted in a constructive role and appeared unexpectedly soon after the Big Bang. “Several years ago, nobody imagined that there were such monsters in the early universe,” says Penn State astrophysicist Yuexing Li. “Now we see that black holes were essential in creating the universe’s modern structure.”

Black holes, tortured regions of space where the pull of gravity is so intense that not even light can escape, did not always have such a high profile. They were once thought to be very rare; in fact, Albert Einstein did not believe they existed at all. Over the past several decades, though, astronomers have realized that black holes are not so unusual after all: Supermassive ones, millions or billions of times as hefty as the sun, seem to reside at the center of most, if not all, galaxies. Still, many people were shocked in 2003 when a detailed sky survey found that giant black holes were already common nearly 13 billion years ago, when the universe was less than a billion years old. Since then, researchers have been trying to figure out where these primordial holes came from and how they influenced the cosmic events that followed.

In August, researchers at the Kavli Institute for Particle Astrophysics and Cosmology at Stanford University ran a supercomputer simulation of the early universe and provided a tantalizing glimpse into the lives of the first black holes. The story began 200 million years after the Big Bang, when the universe’s first stars formed. These beasts, about 100 times the mass of the sun, were so large and energetic that they burned all their hydrogen fuel in just a few million years. With no more energy from hydrogen fusion to counteract the enormous inward pull of their gravity, the stars collapsed until all of their mass was compressed into a point of infinite density.

The first-generation black holes were puny compared with the monsters we see at the centers of galaxies today. They grew only slowly at first—adding just 1 percent to their bulk in the next 200 million years—because the hyperactive stars that spawned them had blasted away most of the nearby gas that they could have devoured. Nevertheless, those modest-size black holes left a big mark by performing a form of stellar birth control: Radiation from the trickle of material falling into the holes heated surrounding clouds of gas to about 5,000 degrees Fahrenheit, so hot that the gas could no longer easily coalesce. “You couldn’t really form stars in that stuff,” says Marcelo Alvarez, lead author of the Kavli study.

Even as Alvarez’s computer model offered a glimpse into the universe’s infancy, it sowed confusion about what happened next. In 2007 scientists spotted a billion-solar-mass black hole that existed some 840 million years after the Big Bang, the earliest and most distant one ever observed. (Black holes themselves are invisible, but astronomers detect them by looking for the brilliantly hot gas that swirls around them before getting sucked in.) This past September another research team announced it had found a large, star-forming galaxy surrounding that black hole. These discoveries were puzzling, to say the least. About 400 million years after the Big Bang, the universe still consisted of scattered stars and small, starving black holes. Less than 500 million years later, it was full of monster black holes embedded in vast galaxies. How did things change so rapidly?

Penn State’s Li is trying to find out. While Alvarez’s simulations focus mostly on individual stars and black holes, Li studies the interaction of those objects and their influence on large-scale structures in the early universe. Her work shows that the first black holes were enveloped by halos of dense, invisible matter tens of thousands of times more massive. Together, these constituted protogalaxies, building blocks of today’s galaxies. During a period of frequent, violent collisions among the protogalaxies, their resident black holes experienced rapid growth spurts by merging with one another and gobbling up new supplies of gas and dust. A 100-solar-mass black hole ballooned into a billion-mass beast within 800 million years, and in especially dense regions that growth could have occurred even more quickly. During this dynamic period, Li’s model shows, black holes suddenly became a lot more star-friendly. Merging protogalaxies sent out shockwaves that compressed dense clumps of gas, helping trigger widespread star birth even in regions previously dominated by black hole radiation. In a remarkably short period of time, black holes shifted from lightweight bullies to supermassive centerpieces of star-breeding galaxies.

The most distant black hole known, nearly 13 billion light-years away, is the white spot in the middle of this false-color image.Tomotsugu Goto/University of Hawaii
Although this simulation offers a comprehensive account of this formative epoch, Li concedes that her models are still just models; they are no match for direct observation. So while she and other theorists refine their calculations, other astronomers are using powerful telescopes to peer ever further back in time, looking for objects that are currently known only from computer simulations. “There are aggressive campaigns to search for the first supermassive black holes,” Li says. “We still may not have found the very first ones.” She says it would not surprise her if the earliest of these giant black holes appeared as little as 500 million years after the birth of the universe.

The recently refurbished Hubble Space Telescope will aid this search. This past April, one of Li’s Penn State colleagues discovered the burst of energy from a star that exploded, probably in the process of collapsing to form a black hole, when the cosmos was just 630 million years old.Hubble’s successor, the James Webb Space Telescope, will delve even deeper following its 2014 launch.

Soon, astronomers may be able to directly observe the improbable era when black holes were among the most important objects in the universe, helping to bring order to the Big Bang’s formlessness. “In theoretical and observational astronomy,” Li says, “this is the cosmic frontier.”

MENLO PARK, Calif. — The film “2001: A Space Odyssey” presents a dramatic vision of the future, where sentient robots double as secretaries, performing daily tasks and simple services for their human masters.
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Peter DaSilva for The New York Times
Norman Winarsky, a vice president at SRI.
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Peter DaSilva for The New York Times
The founders of Chattertrap, a kind of personal assistant, David Schairer, left, Henry Nothhaft Jr. and Gary Griffiths.
Now, SRI International, the research institute, is hoping to bring the concept of virtual personal assistants closer to reality — without the malevolent malfunctions, of course.
“We are looking to augment human capability,” said Norman Winarsky, vice president for licensing and strategic programs at SRI. “But with artificial intelligence.”
Established in 1946 by Stanford University, SRI created early prototypes of the computer mouse and the technologies involved in ultrasound and HDTV.
Although SRI does roughly 80 percent of its work for the federal government, many of its technologies have been adapted for commercial purposes. Recently, the institute has set its sights on the mobile phone and Web market, especially on creating applications that perform personal functions.
“We have companies in every space: drug discovery, flexible circuits, new medical devices, solar, clean tech,” said Mr. Winarsky, who oversees the establishment of new companies that are spun off from SRI. “But right now, half of the companies we’re thinking of creating are strongly related to virtual personal assistants.”
SRI’s newest venture is a Web-based personalized news feed, Chattertrap, that monitors what people are reading to learn what they like, and then serves up articles and links that suit their interests.
Another recent project is a mobile application, Siri, that allows people to perform Web searches by voice on a cellphone. Siri users can speak commands like “find a table at an Italian restaurant for six at 8 tonight,” and the application can translate the request and use GPS functions and search algorithms to find an answer.
Siri’s software is sophisticated enough that over time, it can even remember if someone prefers places that serve Northern Italian cuisine, rather than Sicilian, and make recommendations around that preference.
The application has already been a big hit; in April, Apple acquired Siri for a price said to be as high as $200 million. But some analysts wonder whether SRI will be able to duplicate this kind of success. Variations on the virtual personal assistant concept have been around for a while. Two services, for example — Remember the Milk and Jott — are types of electronic crutches intended to help users be more efficient at ticking off items in their daily to-do lists.
But SRI is betting that its expertise in artificial intelligence will help make software that can break away from the pack. And it has high hopes that Chattertrap will be as successful as Siri.
“The popular news sites aren’t always the most interesting,” said Gary Griffiths, one of the two entrepreneurs SRI recruited to guide Chattertrap. “But by using technology to evolve with you as you use it, watching what you’re doing and giving more of what you like and less of what you’re ignoring, we can create a very personal information service.”
Although Chattertrap is in a limited test period right now, the company hopes to allow more users later this summer and release the product in its entirety by the end of the year.
Chattertrap has already caught the eye of Li Ka-shing, a Chinese billionaire who has invested in Facebook and the music-streaming service Spotify. Mr. Li recently led a $1.5 million round of venture financing in the Chattertrap project.

SRI’s newfound interest in mobile and Web applications was born, in part, from a research project commissioned by the Defense Department to develop software that can learn, in an effort to create a more efficient way for the military to communicate and stay organized in the field. The project’s underlying technology, a combination of adaptive machine learning and natural-language processing, has spawned several offshoots.
Each year, SRI tests the marketability of roughly 2,000 technology ventures, but typically only three or four are ever established as independent businesses.

Charles S. Golvin, an analyst with Forrester Research who follows the mobile industry, said SRI was tapping into the mobile market at a time when the need to simplify searching is greater than ever.

“The old paradigm of having a desktop computer in front of you with a large screen to search around for what you want is going away,” Mr. Golvin said. “More and more, the information you want online is coming from the palm of your hand.”

Since most mobile phones have small, cramped screens and tiny keyboards, voice-activated search and speech recognition become much more powerful, Mr. Golvin said.
“It’s a very compelling offer for a mobile company,” he said.

In addition, companies like Apple and Google are sizing up the market opportunity for location-based search and the potential advertising opportunities that come with it, said Brent Iadarola, director of mobile research at Frost & Sullivan.

“The acquisition that Apple has made provides powerful clues as to what the mobile landscape will look like in the future,” Mr. Iadarola said.

“When you’re in a mobile environment there’s a higher propensity to spend, and tying that into mobile advertising could be lucrative.”

Still, he said, it’s not clear yet whether SRI can recreate the same type of successes it had with Siri with its future virtual personal assistants. “That was hitting it out of the ballpark, in my opinion,” he said. “I don’t know if they can replicate that.”

Mr. Winarsky said the intellectual property licensed to Apple as part of the acquisition of Siri is a fraction of what has been generated by the institute.

“Siri is the first and in some cases, the simplest, of what we’ll do,” he said.
Mr. Winarsky said SRI was in the early stages of determining what will be the next start-up to become an independent company.

One area he is particularly excited about is translation, he said.
“Virtually every industry and platform has a need for translation services,” he said.
In addition, he said, a virtual personal assistant could be of great use to the health industry and patients, by helping figure out which procedures are covered by insurance or quickly finding and booking a doctor’s appointment.

“We’ll only be able to tell in 20 years,” he said. “But I truly believe this is the dawn of a new era of artificial intelligence. It is on the vanguard of a great revolution in computer science.”