CU News
News from the University of Colorado in Boulder.
Boulder High, CU grad astronaut Scott Carpenter dies at 88
Oct 11th
Scott Carpenter, a University of Colorado Boulder alumnus and a famed NASA Mercury astronaut who became only the second American to orbit Earth, died Thursday.
Carpenter, a Boulder native, entered CU-Boulder’s astronautical engineering program in 1945, eventually earning a bachelor of science degree. He orbited Earth three times on May 24, 1962, in NASA’s Aurora 7 capsule before splashing down in the Atlantic Ocean.
Carpenter was the first of 18 CU-Boulder astronaut affiliates to have flown in space. As one of the first NASA astronauts, Carpenter and his colleagues were celebrated in the Tom Wolfe book, “The Right Stuff,” which told the story of early military test pilots and the original Mercury 7 astronauts.
Born in Boulder on May 1, 1925, Carpenter and graduated from Boulder High School in 1943. He then entered the Navy’s V12a flight training program at Colorado College in Colorado Springs. He spent the next year training in California and Iowa, returning to Boulder in 1945 to study at CU-Boulder.
“In his two-decades long career as a Naval aviator, astronaut and aquanaut, Scott Carpenter brought honor and distinction to CU-Boulder while embodying the adventurous spirit of our nation,” said CU-Boulder Chancellor Philip P. DiStefano. “Our space program, and all space and ocean researchers everywhere, owe him a debt of gratitude. He will be sorely missed.”
In 1965 Carpenter took a leave of absence from NASA to participate in the Navy’s Man-in-the Sea Project as an aquanaut in the SEALAB II project off the coast of La Jolla, Calif. where he spent 30 days living and working on the ocean floor at a depth of more than 200 feet. Because of his groundbreaking deep-sea diving experiences with the Navy, Carpenter is hailed by many to be the first person to conquer both outer and inner space.
“My colleagues and I are deeply saddened by the passing of Astronaut Scott Carpenter,” said CU-Boulder aerospace engineering sciences Chair Penina Axelrad. “He has long been a member of the CU family and a tremendous inspiration for our aerospace faculty and students.”
In a 2012 interview with CU’s alumni magazine, the Coloradan, Carpenter spoke about his historic space journey. “I still remember what a thrill it was being up there — I liked the feeling of weightlessness, and the view I had of Earth.”
Carpenter and the other Mercury 7 astronauts created the Astronaut Scholarship Foundation in 1984. The foundation now involves more than 80 astronauts, awards 28 $10,000 scholarships annually and has dispersed more than $3 million to promising students in science and engineering since 1986.
As one of the original Mercury 7 astronauts, Carpenter followed Alan Shepard, Gus Grissom and Glenn into space and was followed by Wally Schirra, Gordon Cooper and Deke Slayton.
Carpenter was commissioned in the U.S. Navy in 1949 and flew a variety of missions during the Korean War. He attended Navy Test Pilot School in Maryland in 1954 and was assigned as an Air Intelligence Officer on the USS Hornet aircraft carrier. In April of 1959 he was selected by NASA to be an astronaut.
Although he was one course requirement short of graduating with a bachelor’s degree in aeronautical engineering when he left CU in 1949, the university awarded him his degree in 1962 following the successful Aurora 7 flight. When presenting the degree to Carpenter, then-CU President Quigg Newton noted that “his subsequent training as an astronaut has more than made up for his deficiency in the subject of heat transfer.”
In 1967 he became the Navy’s director of aquanaut operations during the SEALAB III experiment. After retiring from the Navy in 1969, he founded and became CEO of Sea Sciences Inc., a venture capital corporation that developed programs aimed at enhanced use of ocean resources and improved health of the planet. He worked closely with noted diver and scientist Jacques Cousteau and members of his Calypso team, and subsequently dove in most of the world’s oceans, including under Arctic ice.
Carpenter later became a consultant to industry and the private sector and has lectured around the world, narrated TV documentaries and written several books, including the 2002 New York Times best-seller, “For Spacious Skies: The Uncommon Journey of a Mercury Astronaut” co-authored with his daughter, Kris Stoever.
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CU study: Spruce beetle infestation in N. Colo. tied to drought
Oct 10th
A new University of Colorado Boulder study indicates drought high in the northern Colorado mountains is the primary trigger of a massive spruce beetle outbreak that is tied to long-term changes in sea-surface temperatures from the Northern Atlantic Ocean, a trend that is expected to continue for decades.
The new study is important because it shows that drought is a better predictor of spruce beetle outbreaks in northern Colorado than temperature alone, said lead study author Sarah Hart, a CU-Boulder doctoral student in geography. Drought conditions appear to decrease host tree defenses against spruce beetles, which attack the inner layers of bark, feeding and breeding in the phloem, a soft inner bark tissue, which impedes tree growth and eventually kills vast swaths of forest.
This spruce forest hit with a double whammy– Spruce bark beetles killed the trees then a forest fire burned it.
Spruce beetles, like their close relatives, mountain pine beetles, are attacking large areas of coniferous forests across the West. While the mountain pine beetle outbreak in the Southern Rocky Mountains is the best known and appears to be the worst in the historical record, the lesser known spruce beetle infestation has the potential to be equally or even more devastating in Colorado, said Hart, lead author on the new study.
“It was interesting that drought was a better predictor for spruce beetle outbreaks than temperature,” said Hart of the geography department. “The study suggests that spruce beetle outbreaks occur when warm and dry conditions cause stress in the host trees.”
A paper on the subject was published online in the journal Ecology. Co-authors include CU-Boulder geography Professor Thomas Veblen; former CU-Boulder graduate student Karen Eisenhart, now at Edinboro University of Pennsylvania; and former CU-Boulder students Daniel Jarvis and Dominik Kulakowski, now at Clark University in Worcester, Mass. The National Science Foundation and the National Geographic Society funded the study.
The new study also puts to rest false claims that fire suppression in the West is the trigger for spruce beetle outbreaks, said Veblen.
Spruce beetles range from Alaska to Arizona and live in forests of Engelmann spruce and subalpine fir trees in Colorado. The CU-Boulder study area included sites in the White River, Routt, Arapaho, Roosevelt and Grand Mesa national forests as well as in Rocky Mountain National Park.
The CU-Boulder team assembled a long-term record of spruce beetle outbreaks from the northern Front Range to the Grand Mesa in western Colorado using a combination of historical documents and tree ring data from 1650 to 2011. Broad-scale outbreaks were charted by the team from 1843-1860, 1882-1889, 1931-1957 and 2004 to 2010.
The researchers used a variety of statistical methods to tease out causes for variations in the dataset at 18 sites in Colorado. “The extent to which we could distinguish between the warming signals and the drought signals was surprising,” said Veblen. “These are two things that easily can get mixed together in most tree ring analyses.”
European Spruce bark beetle
There are several lines of evidence that drought is the main driver of the spruce beetle outbreak. The new study showed when northwest Colorado was in a warm, wet climate period from 1976 to 1998, for example, both spruce beetle reproduction and tree defenses like “pitching” beetles out of tree interiors with resin were likely high. But during that period of warming, outbreak was minimal.
The strongest climate correlation to spruce beetle outbreaks was above average annual values for the Atlantic Multi-decadal Oscillation, or AMO, a long-term phenomenon that changes sea-surface temperatures in the North Atlantic. Believed to shift from cool to warm phases roughly every 60 years, positive AMO conditions are linked to warmer and drier conditions over much of North America, including the West.
Veblen said the AMO shifted from its cool to warm phase in the 1990s, meaning the climate phenomenon could be contributing to drought conditions in the West into the middle of this century. A 2006 tree-ring study involving Veblen, his former student, Thomas Kitzberger and researchers from several other institutions concluded that the warm phase of AMO also was correlated to increased wildfires in the West.
In addition to AMO, the researchers looked at two other ocean-atmosphere oscillations — the El Nino Southern Oscillation and the Pacific Decadal Oscillation — as well as past temperatures, precipitation and aridity to better understand the spruce beetle outbreaks. The team found that another effective predictor of drought conditions was summer “vapor pressure deficit,” a measurement of atmospheric dryness, said Veblen.
In the new study, the researchers were particularly interested in “radial growth” rates of tree rings from sub-canopy trees of various species in the study areas that thrived following outbreaks. One hallmark of spruce beetle outbreaks is that slow radial growth rates in such areas are followed by extremely rapid radial growth rates, an indication smaller trees flourish in the absence of the larger spruce trees because of decreased competition for water and increased opportunities for photosynthesis, said Hart.
The area of high-elevation forests affected by spruce beetles is growing in the West, Hart said. “In 2012, U.S. Forest Service surveys indicated that more area was under attack by spruce beetles than mountain pine beetles in the Southern Rocky Mountains, which includes southern Wyoming, Colorado and northern New Mexico,” she said. “The drought conditions that promote spruce beetle outbreak are expected to continue.”
Spruce beetles have even hit Alaska.
One big concern about spruce beetle outbreaks is their effects on headwater streams that are important for water resources, said Veblen. “In the short term, trees killed by spruce beetles will lead to less water use by trees and more water discharge into streams. But in the long term, the absence of the trees killed by beetles may lead to less persistence of snow and earlier runoff.”
Veblen said it might seem counterintuitive to some that spruce-fir subalpine forests in Colorado are larger by area than lodgepole/ponderosa pine forests. “It is probably because spruce and subalpine forests are found in more remote areas not as visible to most people,” he said. “But potentially, the current spruce beetle outbreak could affect a larger area than the mountain pine beetle outbreak.”
The study had its beginnings in 1986, when Veblen and his students began compiling spruce and subalpine fir tree rings from various study sites in the Colorado mountains. Tree rings from individual trees — which carry information about weather, climate and even events like volcanic eruptions — can be matched up and read with rings from other trees, much like the pages of a book, from year to year and even from season to season.
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CU research: Microchips using light instead of wires boosts speed exponentially
Sep 30th
CU, MIT breakthrough in photonics
could allow for faster and faster electronics
could allow for faster and faster electronics
A pair of breakthroughs in the field of silicon photonics by researchers at the University of Colorado Boulder, the Massachusetts Institute of Technology and Micron Technology Inc. could allow for the trajectory of exponential improvement in microprocessors that began nearly half a century ago—known as Moore’s Law—to continue well into the future, allowing for increasingly faster electronics, from supercomputers to laptops to smartphones.
The research team, led by CU-Boulder researcher Milos Popovic, an assistant professor of electrical, computer and energy engineering, developed a new technique that allows microprocessors to use light, instead of electrical wires, to communicate with transistors on a single chip, a system that could lead to extremely energy-efficient computing and a continued skyrocketing of computing speed into the future.
Popovic and his colleagues created two different optical modulators—structures that detect electrical signals and translate them into optical waves—that can be fabricated within the same processes already used in industry to create today’s state-of-the-art electronic microprocessors. The modulators are described in a recent issue of the journal Optics Letters.
First laid out in 1965, Moore’s Law predicted that the size of the transistors used in microprocessors could be shrunk by half about every two years for the same production cost, allowing twice as many transistors to be placed on the same-sized silicon chip. The net effect would be a doubling of computing speed every couple of years.
The projection has held true until relatively recently. While transistors continue to get smaller, halving their size today no longer leads to a doubling of computing speed. That’s because the limiting factor in microelectronics is now the power that’s needed to keep the microprocessors running. The vast amount of electricity required to flip on and off tiny, densely packed transistors causes excessive heat buildup.
“The transistors will keep shrinking and they’ll be able to continue giving you more and more computing performance,” Popovic said. “But in order to be able to actually take advantage of that you need to enable energy-efficient communication links.”
Microelectronics also are limited by the fact that placing electrical wires that carry data too closely together can result in “cross talk” between the wires.
In the last half-dozen years, microprocessor manufacturers, such as Intel, have been able to continue increasing computing speed by packing more than one microprocessor into a single chip to create multiple “cores.” But that technique is limited by the amount of communication that then becomes necessary between the microprocessors, which also requires hefty electricity consumption.
Using light waves instead of electrical wires for microprocessor communication functions could eliminate the limitations now faced by conventional microprocessors and extend Moore’s Law into the future, Popovic said.
Optical communication circuits, known as photonics, have two main advantages over communication that relies on conventional wires: Using light has the potential to be brutally energy efficient, and a single fiber-optic strand can carry a thousand different wavelengths of light at the same time, allowing for multiple communications to be carried simultaneously in a small space and eliminating cross talk.
Optical communication is already the foundation of the Internet and the majority of phone lines. But to make optical communication an economically viable option for microprocessors, the photonics technology has to be fabricated in the same foundries that are being used to create the microprocessors. Photonics have to be integrated side-by-side with the electronics in order to get buy-in from the microprocessor industry, Popovic said.
“In order to convince the semiconductor industry to incorporate photonics into microelectronics you need to make it so that the billions of dollars of existing infrastructure does not need to be wiped out and redone,” Popovic said.
Last year, Popovic collaborated with scientists at MIT to show, for the first time, that such integration is possible. “We are building photonics inside the exact same process that they build microelectronics in,” Popovic said. “We use this fabrication process and instead of making just electrical circuits, we make photonics next to the electrical circuits so they can talk to each other.”
In two papers published last month in Optics Letters with CU-Boulder postdoctoral researcher Jeffrey Shainline as lead author, the research team refined their original photonic-electronic chip further, detailing how the crucial optical modulator, which encodes data on streams of light, could be improved to become more energy efficient. That optical modulator is compatible with a manufacturing process—known as Silicon-on-Insulator Complementary Metal-Oxide-Semiconductor, or SOI CMOS—used to create state-of-the-art multicore microprocessors such as the IBM Power7 and Cell, which is used in the Sony PlayStation 3.
The researchers also detailed a second type of optical modulator that could be used in a different chip-manufacturing process, called bulk CMOS, which is used to make memory chips and the majority of the world’s high-end microprocessors.
Vladimir Stojanovic, who leads one of the MIT teams collaborating on the project and who is the lead principal investigator for the overall research program, said the group’s work on optical modulators is a significant step forward.
“On top of the energy-efficiency and bandwidth-density advantages of silicon-photonics over electrical wires, photonics integrated into CMOS processes with no process changes provides enormous cost-benefits and advantage over traditional photonic systems,” Stojanovic said.
The CU-led effort is a part of a larger project on building a complete photonic processor-memory system, which includes research teams from MIT led by Stojanovic, Rajeev Ram and Michael Watts, a team from Micron Technology led by Roy Meade and a team from the University of California, Berkeley, led by Krste Asanovic. The research was funded by the Defense Advanced Research Projects Agency and the National Science Foundation.
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