Showing posts with label Journal Science. Show all posts
Showing posts with label Journal Science. Show all posts
Saturday, December 9
Individual Molecules Entangled
For the first time, a team of Princeton physicists have been able to link together individual molecules into special states that are quantum mechanically "entangled." In these bizarre states, the molecules remain correlated with each other—and can interact simultaneously—even if they are miles apart, or indeed, even if they occupy opposite ends of the universe. This research was recently published in the journal Science. READ MORE...
Thursday, October 26
EIGHT-Billion-Year-Old Radio Signal Reaches Earth
Astronomers have detected a mysterious blast of radio waves that have taken 8 billion years to reach Earth. The fast radio burst is one of the most distant and energetic ever observed.
Fast radio bursts, or FRBs, are intense, millisecond-long bursts of radio waves with unknown origins. The first FRB was discovered in 2007, and since then, hundreds of these quick, cosmic flashes have been detected coming from distant points across the universe.
The burst, named FRB 20220610A, lasted less than a millisecond, but in that fraction of a moment, it released the equivalent of our sun’s energetic emissions over the course of 30 years, according to a study published Thursday in the journal Science.
Many FRBs release super bright radio waves lasting only a few milliseconds at most before disappearing, which makes fast radio bursts difficult to observe.
Radio telescopes have helped astronomers trace these quick cosmic flashes, including the ASKAP array of radio telescopes, located on Wajarri Yamaji Country in Western Australia. Astronomers used ASKAP to detect the FRB in June 2022 and determine where it originated.
“Using ASKAP’s array of (radio) dishes, we were able to determine precisely where the burst came from,” said study coauthor Dr. Stuart Ryder, astronomer at Macquarie University in Australia, in a statement.
“Then we used (the European Southern Observatory’s Very Large Telescope) in Chile to search for the source galaxy, finding it to be older and (farther) away than any other FRB source found to date and likely within a small group of merging galaxies.” READ MORE...
Monday, September 25
Smallest Known Way to Guide Light
Scientists at the University of Chicago found a glass crystal just a few atoms thick can trap and carry light—and could be used for applications. The material is visible as the thin line in the center of the plastic, held by study co-author Hanyu Hong. Credit: Jean Lachat
2D optical waveguides could pave the way for innovative technology.
Channeling light from one location to another is the backbone of our modern world. Across deep oceans and vast continents, fiber optic cables transport light containing data ranging from YouTube clips to banking transmissions—all within fibers as thin as a strand of hair.
University of Chicago Prof. Jiwoong Park, however, wondered what would happen if you made even thinner and flatter strands—in effect, so thin that they’re actually 2D instead of 3D. What would happen to the light?
Through a series of innovative experiments, he and his team found that a sheet of glass crystal just a few atoms thick could trap and carry light. Not only that, but it was surprisingly efficient and could travel relatively long distances—up to a centimeter, which is very far in the world of light-based computing.
The research, recently published in the journal Science, demonstrates what are essentially 2D photonic circuits, and could open paths to new technology.
“We were utterly surprised by how powerful this super-thin crystal is; not only can it hold energy, but deliver it a thousand times further than anyone has seen in similar systems,” said lead study author Jiwoong Park, a professor and chair of chemistry and faculty member of the James Franck Institute and Pritzker School of Molecular Engineering. “The trapped light also behaved like it is traveling in a 2D space.”
Guiding light
The newly invented system is a way to guide light—known as a waveguide—that is essentially two-dimensional. In tests, the researchers found they could use extremely tiny prisms, lenses, and switches to guide the path of the light along a chip—all the ingredients for circuits and computations. READ MORE...
Friday, August 5
Ultrasound Stickers See Inside the Body
MIT engineers designed an adhesive patch that produces ultrasound images of the body. The stamp-sized device sticks to skin and can provide continuous ultrasound imaging of internal organs for 48 hours. Credit: Felice Frankel
New stamp-sized ultrasound adhesives deliver clear images of the heart, lungs, and other internal organs.
When clinicians need live images of a patient’s internal organs, they often turn to ultrasound imaging for a safe and noninvasive window into the body’s workings. In order to capture these insightful images, trained technicians manipulate ultrasound wands and probes to direct sound waves into the body. These waves reflect back out and are used to produce high-resolution images of a patient’s heart, lungs, and other deep organs.
Ultrasound imaging currently requires bulky and specialized equipment available only in hospitals and doctor’s offices. However, a new design developed by MIT engineers might make the technology as wearable and accessible as buying Band-Aids at the drugstore.
The engineers presented the design for the new ultrasound sticker in a paper published on July 28 in the journal Science. The stamp-sized device sticks to skin and can provide continuous ultrasound imaging of internal organs for 48 hours.
To demonstrate the invention, the researchers applied the stickers to volunteers. They showed the devices produced live, high-resolution images of major blood vessels and deeper organs such as the heart, lungs, and stomach. As the volunteers performed various activities, including sitting, standing, jogging, and biking, the stickers maintained a strong adhesion and continued to capture changes in underlying organs.
In the current design, the stickers must be connected to instruments that translate the reflected sound waves into images. According to the researchers, the stickers could have immediate applications even in their current form.
For example, the devices could be applied to patients in the hospital, similar to heart-monitoring EKG stickers, and could continuously image internal organs without requiring a technician to hold a probe in place for long periods of time. READ MORE...
Friday, June 24
Droughts Pave Way for Islam
Extreme dry conditions contributed to the decline of the ancient South Arabian kingdom of Himyar.
Combined with political unrest and war, the droughts left behind a region in disarray, thereby creating the conditions on the Arabian peninsula that made possible the spread of the newly emerging religion of Islam.
On the plateaus of Yemen, traces of the Himyarite Kingdom can still be found today: terraced fields and dams formed part of a particularly sophisticated irrigation system, transforming the semi-desert into fertile fields. Himyar was an established part of South Arabia for several centuries.
However, despite its former strength, during the sixth century AD the kingdom entered into a period of crisis, which culminated in its conquest by the neighboring kingdom of Aksum (now Ethiopia). A previously overlooked factor, namely extreme drought, may have been decisive in contributing to the upheavals in ancient Arabia from which Islam emerged during the seventh century. These findings were recently reported by researchers led by Professor Dominik Fleitmann in the journal Science.
Petrified water acts as climate record
Fleitmann’s team analyzed the layers of a stalagmite from the Al Hoota Cave in present-day Oman. The stalagmite’s growth rate and the chemical composition of its layers (see box) are directly related to how much precipitation falls above the cave. As a result, the shape and isotopic composition of the deposited layers of a stalagmite represent a valuable record of historical climate. READ MORE...
Tuesday, August 17
Our Metabolism
A new international study counters the common belief that our metabolism inevitably declines during our adult lives. Well, not until we’re in our 60s, anyway.
Researchers found that metabolism peaks around age 1, when babies burn calories 50 percent faster than adults, and then gradually declines roughly 3 percent a year until around age 20.
From there, metabolism plateaus until about age 60, when it starts to slowly decline again, by less than 1 percent annually, according to findings published Thursday in the journal Science.
To tease out the specific impact of age on metabolism, the researchers adjusted for factors such as body size (bigger bodies burn more calories overall than smaller ones) and fat-free muscle mass (muscles burn more calories than fat).
“Metabolic rate is really stable all through adult life, 20 to 60 years old,” said study author Herman Pontzer, an associate professor of evolutionary anthropology at Duke University and author of “Burn,” a new book about metabolism.
To tease out the specific impact of age on metabolism, the researchers adjusted for factors such as body size (bigger bodies burn more calories overall than smaller ones) and fat-free muscle mass (muscles burn more calories than fat).
“Metabolic rate is really stable all through adult life, 20 to 60 years old,” said study author Herman Pontzer, an associate professor of evolutionary anthropology at Duke University and author of “Burn,” a new book about metabolism.
“There's no effect of menopause that we can see, for example. And you know, people will say, 'Well when I hit 30 years old, my metabolism fell apart.' We don't see any evidence for that, actually.”
Pontzer and colleagues studied a database of more than 6,400 people, ages 8 days to 95 years, from 29 countries worldwide who had participated in “doubly labeled water” tests.
Pontzer and colleagues studied a database of more than 6,400 people, ages 8 days to 95 years, from 29 countries worldwide who had participated in “doubly labeled water” tests.
With this method, individuals drink water in which some of the hydrogen and oxygen have been replaced with isotopes of these elements that can be traced in urine samples. READ MORE
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