Tornado Cluster Sizes Skyrocket, and No One Knows Why
Tornados are behaving strangely: The number of tornado outbreaks per year is fairly constant, but the number of tornados per outbreak has skyrocketed. And scientists aren't entirely sure why.
In an effort to learn more, researchers looked at meteorological factors related to tornado outbreaks, and then dug into the data to see whether these factors had changed over time, said study lead researcher Michael Tippett, an associate professor of applied physics and applied mathematics at Columbia University.
The analyses did yield a result, but an unexpected one, Tippett said. [The Top 5 Deadliest Tornado Years in US History]
"The meteorological factors that are related with tornado outbreaks have also become more extreme," Tippett told Live Science in an email. "The surprising finding was that the change in meteorological factors did not have the expected signature of climate change."
That's not to say that climate change isn't involved, he said, but it does leave two possibilities: "Either the recent increases are not due to a warming climate, or a warming climate has implications for tornado activity that we don't understand," Tippett said in a statement.
Windy research
Tippett said he became interested in tornadoes in the spring of 2011, when multiple deadly twister outbreaks struck the U.S. That includes the multivortex tornado that hit Joplin, Missouri, killing 158 people and injuring more than 1,000.
"The public was asking what caused these record-breaking outbreaks, and scientists didn't have an answer," Tippett said.
In the following years, Tippett and other scientists published studies on tornado clusters, a sequence of six or more tornadoes that happen within several days of one another. In the new study, Tippett and his colleagues found that the number oftwisters in the most extreme outbreaks has increased over the years, making these clusters more dangerous than in the past, he said.
For instance, between 1965 and 2015, over five-year periods, the estimated number of tornadoes in the most extreme outbreaks (clusters with 12 or more tornados) roughly doubled, from 40 in 1965 to almost 80 in 2015, he said.
Climate connection?
To see whether this mysterious increase was connected to climate change, Tippett and his colleagues looked at two data sets from the National Oceanic and Atmospheric Administration (NOAA), one that included tornado reports and another with observation-based estimates of meteorological factors associated with tornado outbreaks, he said.
They were particularly interested in a factor called "convective available potential energy" (CAPE), the amount of energy available for convection in which hot, less dense material rises, and cold, dense material sinks. CAPE is related to the vertical wind speed, meaning that higher CAPE values indicate that severe weather will be more extreme, according to WeatherOnline.
As the climate warms, CAPE is expected to increase, past studies have suggested, the researchers wrote in the study.
However, CAPE has stayed fairly steady. Instead, "we see trends in the winds," Tippett said. The wind metric he looked at, called storm relative helicity (SRH), is a measure of corkscrew-like upward winds, something that was not expected to increase with climate change, he said. [Tornado Chasers: See Spinning Storms Up-Close (Photos)]
The finding is unexpected but important, said Harold Brooks, a senior scientist at NOAA's National Severe Storms Laboratory, who was not involved with the study.
"The fact that they can explain the tornado changes by storm relative helicity changes is, in one aspect, not surprising (it's a much better predictor of whether a storm will make a tornado than CAPE is)," Brooks wrote in an email to Live Science. "But, in another aspect, [the results are] difficult to explain. We don't really have a good conceptual model for why high SRH values should increase as the planet warms."
Another viewpoint
The study is "intriguing," but it has several limitations, said Victor Gensini an associate professor of meteorology at the College of DuPage in Illinois.
For starters, the study includes tornados only from 1979 to the present, which is a "fairly short historical record," Gensini said in an email to Live Science. It's also possible that tornado reporting has gotten better over time, and that earlier records left out some tornadoes, he said.
In addition, past studies have shown an increase in the variability of the U.S. tornado season, and climate models suggest that future severe weather will become more variable, Gensini said. But, in general, "there are better environmental metrics to examine tornado environments that the authors failed to use here," he said. "This is just one study, and people shouldn't hang their hat on one study."
Stolen Mummy Hand Makes Its Way Home
The blackened, cloth-wrapped hand arrived in a parcel at Los Angeles International Airport in January 2013. It was listed as a sci-fi movie prop, valued at $66. But as officials with U.S. Customs and Border Protection learned, the hand was from a real Egyptian mummy, nearly 3,000 years old.
The hand was apparently voluntarily forfeited by the importer, and this week, U.S. authorities repatriated it and four other illegally smuggled artifacts to Egypt as part of an ongoing investigation known as "Operation Mummy's Curse."
"It's sort of amazing the things people will try and ship across international borders," archaeologist Fredrik Hiebert, a National Geographic fellow, said in a video statement. [See Photos of the Mummy Hand and Other Artifacts Returned to Egypt]
In addition to the eighth-century-B.C. mummy hand, U.S. Immigration and Customs Enforcement, or ICE, also returned intricately painted ancient sarcophagi in a ceremony at the Egyptian embassy in Washington, D.C., on Thursday (Dec. 1).
"While we recognize that cultural property, art and antiquities are assigned a dollar value in the marketplace, the cultural and symbolic worth of these Egyptian treasures far surpasses any monetary value to the people of Egypt," ICE Director Sarah Saldaña said during her remarks.
ICE launched "Operation Mummy's Curse" in 2009 to bust a network of antiquities smugglers bringing illicit artifacts from other countries into the United States. Saldaña said her agency has made four arrests and two convictions in this investigation.
The operation has also recovered about 7,000 artifacts, not just from Egypt, but also from Greece, India and Iraq. ICE has already returned many of those cultural objects in past repatriation ceremonies. In March 2015, for example, ICE returned artifacts to Iraqi officials, including an ancient Sumerian ax that was being sold on Craigslist in 2012 as well as a gold-plated soap dish from Saddam Hussein's palace that turned up in Connecticut. In April 2015, ICE handed over dozens of other artifacts to Egypt, including a nesting sarcophagus the agency recovered from a garage in Brooklyn, New York.
Though international treaties and Egyptian laws protect Egyptian artifacts, a black market for antiquities thrives. Using satellite data, researchers have documented an uptick in illegal excavations across archaeological sites in Egypt over the last decade.
Smugglers using forged papers can bring looted material into the U.S. under the guise of a robust legal antiquities market. Census Bureau documents show that about $26 million worth of artifacts were exported from Egypt to the United States just during the first five months of 2016. But that could change. U.S. Secretary of State John Kerry signed an agreement with Egypt on Tuesday (Nov. 29) that imposes tougher import restrictions on Egyptian archaeological material that dates from 5200 B.C. to A.D. 1517.
Book Excerpt: 'Are Numbers Real?' (US 2016)
Have you ever wondered what humans did before numbers existed? How they organized their lives, traded goods, or kept track of their treasures? What would your life be like without them? Numbers began as simple representations of everyday things, but mathematics rapidly took on a life of its own, occupying a parallel virtual world. In "Are Numbers Real?," Brian Clegg explores the way that math has become more and more detached from reality, and yet despite this is driving the development of modern physics. Below is an excerpt from "Are Numbers Real?" (St. Martin's Press, 2016).
Not entirely surprisingly, infinity is a topic that never fails to stimulate the mind. Thoughts about the nature and existence of infinity go back all the way to the Ancient Greeks. They were certainly aware that a sequence of numbers like the positive integers, the simple counting numbers would go on forever. If there were a biggest integer—call it max—then there surely could always be max + 1, max + 2, and so on. But the whole idea of infinity made the Greeks uncomfortable. Their word for it, apeiron, suggested chaos and disorder.
The Greek philosopher who took the definitive approach to infinity for the period (a point of view that would remain dominant for centuries to come) was Aristotle, born in 384 BC in northern Greece. Aristotle argued that infinity was both necessary and impossible. He used examples of aspects of the universe that he considered infinite. The integers, as we have seen, or the span of time—which he argued had no end. And he believed that something could be divided up an infinite set of times. But equally he came up with a range of often confusing arguments as to why infinity could not exist in the real world. For example, he pointed out that a body is defined by its boundaries. If a body were infinite it would have no boundaries, hence it could not exist.
After what was clearly a considerable mental struggle, Aristotle finally decided that infinity was a potential, rather than a concept that was fulfilled in reality. This “potential infinity” was something that could be aimed for, but could never practically be achieved. Infinity existed, but could not be made real on demand. To illustrate the concept he used the neat example of the Olympic games. The games existed—there was no doubt of that. It wasn’t a fictional concept. But generally speaking, if someone asked you to show him or her the Olympic games, you couldn’t. The games were a potential entity, rather than something you could point at and identify. Aristotle was careful to point out, though, that some potential entities were going to become actual at a point in space or time, yet this wasn’t the case with infinity.
This neutered concept of potential infinity was exactly what Newton and Leibniz (see chapter 9) were dealing with when they devised calculus. The infinity of calculus is something that we head toward—it is a limit that is never practically reached. And the target is exactly what the familiar symbol for infinity, the lemniscate (∞) represents. It is the symbol for Aristotle’s potential infinity. The lemniscate was introduced by Newton’s contemporary, John Wallis, who had written a rather dull treatise on the three-dimensional shapes known as conic sections, which are the result of cutting a pair of cones positioned point to point along various planes. (No one can accuse mathematicians of not knowing how to have fun.) Wallis just throws in a line that says “let ∞ represent infinity” without ever explaining where this symbol comes from.
For the vast majority of mathematicians, with one notable exception, this was sufficient to carry all the way through to the nineteenth century. In fact, potential infinity was generally considered to be the only respectable way to think about the infinite. For example, Carl Friedrich Gauss, the eminent nineteenth- century German mathematician definitively remarked:
I protest against the use of an infinite quantity as an actual entity; this is never allowed in mathematics. The infinite is only a manner of speaking, in which one properly speaks of limits to which certain ratios can come as near as desired, while others are permitted to increase without bound.
The exception to this blinkered thinking was the remarkable Galileo Galilei. The first thing that springs to mind when Galileo is mentioned was his championing of the Copernican theory that put the Sun rather than the Earth at the center of the universe, leading to his trial by the Inquisition and permanent house arrest. However, in scientific terms his most significant work was the book he published in 1638 called Discorsi e Dimostrazioni Matematiche Intorno a Due Nuove Scienze (Discourses and Mathematical Demonstrations Concerning Two New Sciences). This was his masterpiece of physics, laying the ground for Newton’s triumphant completion of this work on mechanics, forces, and movement.
Like his book on Copernican theory that got him into so much trouble, this new work was structured as a conversation between three characters, a format that was very popular at the time. Written in conversational Italian rather than stuffy Latin, it remains far more readable today than the formal and often near-impenetrable work of Newton. Given his position, serving a life sentence for the publication, it was remarkable that Galileo got the book published at all. He attempted to do so originally in Venice, then proud of its independence from Rome, but there was still a requirement to get the go-ahead from the Inquisition, which had issued a blanket prohibition on printing anything that Galileo wrote.
If there was one thing that Galileo excelled in, it was stubbornness. Despite the prohibition, despite the risks of even indirectly evading it, when the Dutch publisher Lodewijk Elzevir visited Italy in 1636, Galileo managed to get a copy of his new manuscript to him. One fascinating aspect of the book as it finally came to print is the dedication. In earlier years, Galileo had always attempted to dedicate his writing to a power figure, who might as a result give him patronage. This book he dedicated to a former pupil who was now the French ambassador to Rome, Count François de Noailles. However, where previously Galileo could simply lavish as much praise as was possible (and plenty was possible in the sycophantic style of the time), here he had to be more careful, as the last thing he wanted to do was get Noailles into trouble with the Inquisition.
In the wording, Galileo combined deviousness with an apparent naïveté. It is highly unlikely that the Inquisition fell for his attempt at deception— though, in practice, they seemed to have turned a blind eye. According to Galileo:
I had decided not to publish any more of my work. And yet in order to save it from complete oblivion, it seemed wise to leave a manuscript copy in some place where it would be available at least to those who follow intelligently the subjects which I havetreated. Accordingly I chose first to place my work in your Lord- ship’s hands ...
So, on the one hand Galileo was thanking Noailles for his help. But at the same time he didn’t want to make it sound as if Noailles had been directly responsible for the publication, so he threw in some mysterious intermediaries:
I was notified by the Elzevirs that they had these works of mine in press and that I ought to decide upon a dedication and send them a reply at once. This sudden unexpected news led me to think that the eagerness of your Lordship to revive and spread my name by passing these works on to various friends was the real cause of their falling into the hands of printers who, because they had already published other works of mine, now wished to honor me with a beautiful and ornate edition of this work.
He could thank Noailles, but also managed to blame un- named friends of the ambassador for passing the manuscript to the printer. It’s clear that the idea that all this had happened without Galileo’s knowledge until the book was almost ready to print was a fiction. Not only did he ensure that Elzevir received a copy of the manuscript on his Italian visit, there was a considerable correspondence between Galileo and Elzevir over the content of the book. Galileo was the kind of author that cause publishers to tear their hair out, wanting to tweak his output to the last possible moment before going to print. This is bad enough with today’s electronic printing, but was a nightmare when each page had to be carefully set up in movable type and made into a physical printing plate. But whether the Inquisition was fooled or simply looked the other way, it did not intervene and the book was published, if unavailable for sale in Galileo’s native Italy.
The “two new sciences” in the book’s title were those of the nature of solid matter and an analysis of motion, and it was in the first section that the topic of infinity came up. In trying to understand why solid matter sticks together so effectively—why, for instance, a piece of metal is so hard to break up—one of Galileo’s protagonists suggested that it is the vacuum between the tiny particles of matter that held them together. (He was wrong, it is electromagnetism, but it wasn’t a bad idea.) This theory was queried by Simplicio, whose role in the book was to challenge new thinking, mostly sticking to Ancient Greek ideas. Simplicio argued that there could only be a tiny bit of vacuum in so small a space, which could only apply a tiny force—far smaller than the powerful force that holds a piece of metal together.
Here Are the States with the Lowest & Highest Diabetes Rates
Diabetes is on the rise in the United States, and a new poll looks at where the disease is most and least common.
In the poll, from Gallup-Healthways, researchers surveyed a nationally representative sample of more than 176,000 Americans in all 50 states in 2015. The participants were asked whether they had ever been diagnosed with diabetes in their lifetime.
The three states with the lowest rates of diabetes were Utah, Rhode Island and Colorado. In these states, 7.5 to 8 percent of the survey participants said they had diabetes. In contrast, Alabama and West Virginia had the highest rates of diabetes, with about 16 percent of the participants in those two states saying they had been diagnosed with the disease.
The poll also looked at the rate of diabetes in cities nationwide. The city with the lowest rate of diabetes was Boulder, Colorado, where slightly less than 5 percent of residents said they had diabetes, followed by Bellingham, Washington, where about 6 percent said they had diabetes. The two cities with the highest rates of diabetes were Mobile, Alabama, and Charleston, West Virginia, where more than 17 percent of residents said they had diabetes. [Diabetes in America: Full List of State Rankings]
The results were published Wednesday (Nov. 30) in a report from Gallup-Healthways.
"Lower rates of diabetes could point to citizens of a particular state or community practicing healthier behaviors, which, in turn, could lead to better health outcomes and lower incidence of chronic conditions," Gallup-Healthways said in its report. "But a lower rate could also signal underdiagnoses" of diabetes, the report said.
The overall rate of diabetes in the United States in 2016 was 11.5 percent, up from 10.6 percent in 2008, Gallup-Healthways said. (The 2016 data is based on a separate poll conducted from Jan. 1 through Nov. 6 of 2016, according to Gallup-Healthways.) That means there were about 2.2 million more Americans with diabetes in 2016 than in 2008, Gallup-Healthways said.
The increase in diabetes has paralleled a rise in obesity, which is a risk factor for type 2 diabetes. In 2016, about 28 percent of Americans were obese, which is a nearly 3 percentage-point increase from the rate in 2008, Gallup-Healthways said. Type 2 diabetes has been linked with obesity. Type 1 diabetes, which used to be called juvenile diabetes, is an autoimmune disorder and is not linked with unhealthy lifestyle or diet choices. The Gallup-Healthways survey did not distinguish between Type 1 and Type 2 diabetes.
Bipedal Human Ancestor 'Lucy' Was a Tree Climber, Too
"Lucy," an early human ancestor that lived 3 million years ago, walked on two legs. But while she had her feet firmly planted on the ground, her arms were reaching for the trees, a new study shows.
High-resolution computed X-ray tomography (CT) scans of long bones in Lucy's arms reveal internal structures suggesting that her upper limbs were built for heavy load bearing — much like chimpanzees' arms, which they use to pull themselves up tree trunks and to swing between branches.
This adds to a growing body of evidence that although Lucy's pelvis, leg bones and feet supported bipedal walking, her upper body was adapted for at least partial life in trees — far more so than in modern humans.
Lucy was discovered in 1974 in Ethiopia, and for decades she represented the only known skeleton of the hominid species Australopithecus afarensis. Scientists knew from other fossil finds that females of the species were smaller than males, according to the Smithsonian National Museum of Natural History, and the size of Lucy's skeleton indicated that she was female.
While her skeleton was only 40 percent complete, it included long bones from her arms (humerus) and legs (femur), a partial shoulder blade and part of her pelvis, which helped scientists determine she was bipedal.
But scientists have argued that anatomical features also suggest that Lucy was partly arboreal — a tree dweller.
The researchers delved into a digital archive of more than 35,000 CT "slices" — single images of bone cross-sections — to peer inside Lucy's left and right humerus and her left femur, to see what they might reveal about her tree-climbing habits. They then compared the internal structures to bones from other fossil hominids, chimpanzees and modern humans.
Load-bearing arms
The study is grounded in mechanical engineering principles, lead author Christopher Ruff, a professor of functional anatomy and evolution at the Johns Hopkins University School of Medicine, said in a statement.
He explained that bones required to support a lot of heavy lifting are bulkier in order to bear the extra strain. Other studies have even shown that bones can bulk up over time in response to high-stress demands, according to study co-author John Kappelman, a paleoanthropologist with the University of Texas at Austin.
"It is a well-established fact that the skeleton responds to loads during life, adding bone to resist high forces and subtracting bone when forces are reduced," Kappelman said in the statement. "Tennis players are a nice example: Studies have shown that the cortical bone in the shaft of the racquet arm is more heavily built up than that in the non-racquet arm," he added.
Structural proportions in Lucy's bones told the scientists that she was far more adapted for climbing than modern humans. And like chimpanzees, she likely spent a good portion of time in trees, perhaps to escape from predators or to find food.
An ape-like shoulder
Before this study, there was some debate among scientists about how Lucy may have divided her time between the ground and the trees, according to Will Harcourt-Smith, an associate professor of anthropology at Lehman College in the City University of New York, and a research associate in the vertebrate paleontology department at the American Museum of Natural History.
"The argument about whether Lucy was a full committed biped was heavily challenged in the 1980s by a number of studies," Harcourt-Smith told Live Science. "When you look at the anatomy — an ape-like shoulder joint, aspects of the wrist, elbow and foot — there are all these features that indicate she was still climbing in trees a significant part of the time.
Lucy's shoulder joint, in particular, hinted that she was probably a tree climber, he added. "The orientation of the joint essentially indicates she would have had a range of motion more conducive to pulling herself up in the trees," Harcourt-Smith explained.
Another A. afarensis discovery in 2012 — a 3-year-old girl called "Selam" — offered additional evidence that this species was at least partly arboreal. Selam's shoulder blades were angled like apes', suggesting that her arms were adapted for active climbing, even at this early age. [Image Gallery: 3-Year-Old Human Ancestor Revealed]
"And then along comes this new study, looking at cross-sectional profiles of the long bone, and the stress and strain that would have gone through those bones," Harcourt-Smith said.
"I think it's a very strong biomechanical argument that they had these strong upper limbs that were outside the range of variations seen in humans, and were much more like an ape. So it's very complementary to that initial work on the shoulder bones," he added.
The findings were published online Wednesday (Nov. 30) in the journal PLOS ONE.
