Yale physicists have given Schrödinger’s famous cat a second box to play in, and the result may help further the quest for reliable quantum computing.
Schrödinger’s cat is a well-known paradox that applies the concept of superposition in quantum physics to objects encountered in everyday life. The idea is that a cat is placed in a sealed box with a radioactive source and a poison that will be triggered if an atom of the radioactive substance decays. Quantum physics suggests that the cat is both alive and dead (a superposition of states), until someone opens the box and, in doing so, changes the quantum state.
This hypothetical experiment, envisioned by one of the founding fathers of quantum mechanics in 1935, has found vivid analogies in laboratories in recent years. Scientists can now place a wave-packet of light, composed of hundreds of particles, simultaneously in two distinctly different states.
A team of Yale scientists created a more exotic type of Schrödinger’s cat-like state that has been proposed for experiments for more than 20 years. This cat lives or dies in two boxes at once, which is a marriage of the idea of Schrödinger’s cat and another central concept of quantum physics: entanglement. Entanglement allows a local observation to change the state of a distant object instantaneously. Einstein once called it “spooky action at a distance,” and in this case it allows a cat state to be distributed in different spatial modes.
The Yale team built a device consisting of two, 3-D microwave cavities and an additional monitoring port—all connected by a superconducting, artificial atom. The “cat” is made of confined microwave light in both cavities.
“This cat is big and smart. It doesn’t stay in one box because the quantum state is shared between the two cavities and cannot be described separately,” said Chen Wang, a postdoctoral associate at Yale and first author of a study in the journal Science, describing the research. “One can also take an alternative view, where we have two small and simple Schrodinger’s cats, one in each box, that are entangled.”
The research also has potential applications in quantum computation. A quantum computer would be able to solve certain problems much faster than classical computers by exploiting superposition and entanglement. Yet one of the main problems in developing a reliable quantum computer is how to correct for errors without disturbing the information.
“It turns out ‘cat’ states are a very effective approach to storing quantum information redundantly, for implementation of quantum error correction. Generating a cat in two boxes is the first step towards logical operation between two quantum bits in an error-correctible manner,” said coauthor Robert Schoelkopf, Sterling Professor of Applied Physics and Physics, and director of the Yale Quantum Institute.
Possible Viking Discovery Could Rewrite North American History
University of Alabama at Birmingham (UAB) archaeologist Sarah Parcak, Ph.D., along with a team of other leading experts, has discovered evidence of what may be North America’s second Viking site.
With the use of pioneering satellite imagery analysis, excavation, and investigation of archaeological evidence, the team has uncovered what could be the first new Norse site to be discovered in North America in over 50 years. If confirmed by further research, the site at Point Rosee in Newfoundland will show that the Vikings traveled much farther into North America than previously known, pushing the boundary of their explorations over 300 miles to the southwest.
The discovery is the subject of a two-hour special called “Vikings Unearthed,” which aired in April on the PBS Nova program.
To date, scientists have known of only one other Viking site, found on the very northern tip of Newfoundland in Canada, at L’Anse Aux Meadows. In the 1960s, archaeologists uncovered the foundations of 1,000-year-old Viking buildings, signs of metalworking, iron nails, and artifacts. The site appeared to pre-date Columbus’ voyages to the New World by some 500 years, confirming that Norse explorers had reached North America as suggested in the Vinland sagas. For more than 50 years, scientists have searched for another Norse site.
Using infrared images from 400 miles in space, Parcak and her team looked at tens of thousands of square miles along the Eastern Seaboard of the U.S. and Canada. Images taken in Point Rosee revealed possible man-made shapes under discolored vegetation. This intriguing evidence suggests the Vikings traveled farther south than previously known. The Newfoundland project was co-directed by Gregory Mumford, Ph.D., Parcak’s husband and professor in the UAB College of Arts and Sciences Department of Anthropology. Other team members include archaeologist Douglas Bolender and historian Dan Snow. Preliminary excavations took place over a period of two-and-a-half weeks in June 2015. The team planned a return to the site in the summer of 2016 to continue excavation and collect more samples.
Parcak recently made international headlines when she was named winner of the 2016 TED Prize. She is an expert in satellite remote sensing for archaeology and wrote the first textbook in the field. Her methods have helped locate 17 potential pyramids in Egypt, in addition to 3,100 forgotten settlements and 1,000 lost tombs. She has also made major discoveries throughout the Roman Empire. She is a National Geographic Senior Fellow, TED Senior Fellow, and a professor of archaeology at UAB. Parcak is also the founder and director of the UAB Laboratory for Global Observation.
Theft Behind Planet 9 in Our Solar System
Through a computer-simulated study, astronomers at Lund University in Sweden show that it is highly likely that the so-called Planet 9 is an exoplanet. This would make it the first exoplanet to be discovered inside our own solar system. The theory is that our sun, in its youth some 4.5 billion years ago, stole Planet 9—sometimes called Planet X—from its original star.
An extrasolar planet, or exoplanet, is by definition a planet located outside our solar system. Now it appears that this definition is no longer viable. According to astronomers at Lund, there is a lot to indicate that Planet 9 was captured by the young sun and has been a part of our solar system completely undetected ever since.
“It is almost ironic that while astronomers often find exoplanets hundreds of light years away in other solar systems, there’s probably one hiding in our own backyard,” says Alexander Mustill, astronomer at Lund University.
Stars are born in clusters and often pass by one another. It is during these encounters that a star can “steal” one or more planets in orbit around another star. This, it is thought, is probably what happened when our own sun captured Planet 9.
In a computer-simulated model, Alexander, together with astronomers in Lund and Bordeaux, has shown that Planet 9 was probably captured by the sun when coming in close contact while orbiting another star.
“Planet 9 may very well have been ‘shoved’ by other planets, and when it ended up in an orbit that was too wide around its own star, our sun may have taken the opportunity to steal and capture Planet 9 from its original star. When the sun later departed from the stellar cluster in which it was born, Planet 9 was stuck in an orbit around the sun,” says Alexander Mustill.
There is still no image of Planet 9, not even a point of light. “We don’t know if it is made up of rock, ice, or gas. All we know is that its mass is probably ten times the mass of earth.”
It requires a lot more research before it can be ascertained that Planet 9 is the first exoplanet in our solar system. If the theory is correct, Alexander Mustill believes that the study of space and the understanding of the sun and the Earth will take a giant leap forward.
“This is the only exoplanet that we, realistically, would be able to reach using a space probe,” he says.
The article is published in Monthly Notices of the Royal Astronomical Society Letters (MNRAS Letters).
Survey Examines Americans’ Use of and Satisfaction with Homeopathic Medicines
While few report using homeopathy, many of those who do, find it helpful in addressing common health problems.
A new survey finds that homeopathic medicines are primarily used by a small segment of the U.S. population for common, self-limited conditions such as the common cold or back pain. The report published in the American Journal of Public Health also finds that homeopathy users, particularly those who also report visiting homeopathic practitioners, find the use of these products helpful and that they tend to use a greater variety of complementary and integrative medicine (CIM) modalities than do users of supplements and other CIMs. This is the first detailed report on the use of homeopathy in this country.
“The information provided by this survey is important to regulatory officials at the FDA (Food and Drug Administration) and the FTC (Federal Trade Commission), both of which have inquired about the public use and perception of these products,” says Michelle Dossett, MD, PhD, MPH, of the Benson-Henry Institute at Massachusetts General Hospital, lead and corresponding author of the paper. “Since most people purchase these products over the counter without physician guidance, it is reassuring to see that most use them for non-serious, self-limited conditions.”
Homeopathy is a 200-year-old system of medicine based on the Principal of Similars—that highly diluted substances can be used to treat symptoms similar to those that would be caused by large doses of those substances in healthy people. While it is controversial because of the extremely diluted nature of homeopathic medications, interest in homeopathy has increased in recent years. Although homeopathic medicines are usually stocked near supplements on drug store shelves, the authors note they are regulated differently from supplements, going through formal approval by the Homeopathic Pharmacopoeia Convention of the United States and conforming with FDA guidelines for good manufacturing practices.
The study analyzed data from the National Health Interview Survey, which is conducted annually by the National Center for Health Statistics of the Centers for Disease Control and Prevention. The 2012 survey included a number of questions about participants’ use of CIM and was completed by more than 34,500 adults. The study authors—based at Beth Israel Deaconess Medical Center, where Dossett was a research fellow at the time of the survey—divided respondents into four groups: those who used homeopathic products during the preceding 12 months, those who used supplements but did not use homeopathy, those who used other forms of CIM but not homeopathy or supplements, and those who did not use CIM.
The respondents who reported using homeopathy were more likely to be white, female, married, highly educated, aged 30 to 44 and lived in the western U.S. than were CIM users who did not use homeopathy. They also were more likely to report using other types of CIM, except for chiropractic or osteopathic manipulation, and to have used several different types of CIM.
While two-thirds of the 718 respondents who used homeopathy ranked it among their top three CIM therapies, only 140, or 19 percent, reported seeing a homeopathic practitioner during the preceding year. One-third of homeopathy users—both those who did and did not consult practitioners—reported using homeopathy for specific health conditions, most commonly head and chest colds. Those who did see a practitioner were significantly more likely to report that homeopathy was very important to maintaining their health and that it had helped their health problem ‘a great deal.’