Category: Top Posts

The Quest to 3D-Print a Passenger Plane Engine — And Fly It

By Jennifer Walter | September 6, 2019 3:15 pm
One-third of GE’s Catalyst engine, a turboprop set to fly in the Cessna Denali, is 3D printed. It has the most 3D-printed parts of any plane engine in the world. (Credit: GE Aviation)

In 2014, eight engineers started a secret project behind the walls of GE Aviation’s headquarters. Their challenge? Build an aircraft engine with 3D printing instead of traditional manufacturing.

The engineers wanted to make an engine with fewer parts than normal – way fewer parts. The normal CT7 turboprop – a small engine that’s commonly used in helicopters – has about 900 pieces to it. By the time they finished their new prototype, dubbed the aCT7, the engine only had 16.

At the time, the engineers weren’t fixated on putting the engine into an actual aircraft. But their design experiment paved the way for an even bigger endeavor – creating a 3D-printed engine for an actual airplane that will carry actual passengers.

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CATEGORIZED UNDER: Technology, Top Posts

Why Neuroscience is Coming to Courtrooms

By Eryn Brown, Knowable Magazine | September 5, 2019 5:14 pm
courts neuroscience
(Credit: Knowable Magazine)

On March 30, 1981, 25-year-old John W. Hinckley Jr. shot President Ronald Reagan and three other people. The following year, he went on trial for his crimes.

Defense attorneys argued that Hinckley was insane, and they pointed to a trove of evidence to back their claim. Their client had a history of behavioral problems. He was obsessed with the actress Jodie Foster, and devised a plan to assassinate a president to impress her. He hounded Jimmy Carter. Then he targeted Reagan.

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CATEGORIZED UNDER: Mind & Brain, Top Posts

The Australopiths: Our Ancient, Ape-like Forefathers

By Bridget Alex | August 30, 2019 4:10 pm
Australopithecus afarensis
A reconstruction of the skull of Australopithecus afarensis. (Credit: Wikimedia Commons)

1.2 to 4.4 million years ago was a happening time in human evolution. It’s when our evolutionary branch — the hominins — diversified into about a dozen species, collectively known as Australopiths.

The most famous of these creatures is Lucy, the partial skeleton of a roughly 3-foot-6-inch female discovered in the 1970s. But Lucy is just one of many Australopiths known to science. Over the years researchers have unearthed more than 400 specimens attributed to her species Australopithecus afarensis from sites in Ethiopia, Kenya and Tanzania.

And beyond A. afarensis, numerous Australopith varieties once roamed the African continent. The first such fossil was found in 1924: the skull of a 3-year-old Australopithecus africanus from South Africa nicknamed the Taung Child. The latest, announced this week, was an Australopithecus anamensis specimen recovered from Woranso-Mille, Ethiopia.

So who were the Australopiths? They were hip-high hominins with brains about one-third our size, who resembled upright walking apes. There was a diversity of species that anthropologists still struggle to sort into a coherent family tree. And, most important of all, one the myriad Australopith lineages was ancestral to our species.

The Age of Australopithecus

Anthropologists use Australopith as a catchall term for hominins (species on the human branch after it split from chimpanzees) living between 1.2 and 4.4 million years ago, who moved on two legs, but had brains between 385 and 530 cm3 (1.6 – 2.2 cups). Although earlier ancestors probably walked upright, Australopiths were the first hominins that seem fully committed to bipedal life on the ground, out of the trees.

Their remains have been found across Africa, in areas where fossils preserve, but never beyond the continent. However, finds such as 2.1-million-year-old stone tools, reported from China in 2018, raise the possibility the hominins made it into Eurasia, though their fossils have yet to be discovered.

Males were considerably larger than females. For example, estimates for Lucy’s species A. afarensis put males around 4 foot 11 inches, weighing 100 pounds, whereas females averaged 3 foot 5 inches and 65 pounds. In living primates, such size differences between sexes usually means the males of that species compete fiercely for females. Anthropologists think this may have been the case with Australopiths, inferring societies where alpha males won many mates.

At least 11 Australopith varieties seem distinct enough in appearance, geologic age or geographic origin to be designated separate species. Anthropologists bicker over these classifications, so slightly different names are used by different researchers. And to make matters more confusing, some species, like Australopithecus afarensis, have “Australopith” in their scientific name and others, like Paranthropus robustus, do not. The Paranthropus varieties, also known as “robust,” have thicker, bigger facial features compared to “gracile” Australopithecus forms.

If you must know, to impress your next date, the list includes: Australopithecus afarensis, Australopithecus africanus, Australopithecus anamensis, Australopithecus bahrelghazali, Australopithecus deyiremeda, Australopithecus garhi, Australopithecus sediba, Kenyanthropus platyops, Paranthropus aethiopicus, Paranthropus boisei and Paranthropus robustus.

Researchers agree that one of the gracile species — or a yet undiscovered variety — was the direct ancestor of the genus Homo and, ultimately, living humans. The others were hominin branches that went extinct (though perhaps interbred with our primary ancestors). Which Australopiths were the great-great-great… grandparents of Homo sapiens is a matter of lively debate. Contenders have been proposed based on their temporal or geographic proximity to the earliest Homo fossils, or by how similar-looking the skeletons are in terms of novel features that evolve in our lineage. Potential ancestors include East African species A. afarensis, A. garhi, and K. platyops, as well as A. africanus and A. sediba from South Africa.

The matter may never be resolved. Because this period is too ancient for African fossil DNA to survive, anthropologists must reconstruct the Australopith family tree based on visible skeletal traits, leaving more room for ambiguity and interpretation.

Mega Chompers

Probably the most striking feature of these creatures is their honking huge back teeth. Although their bodies are just half our size, the chewing surfaces of Australopith molars are up to twice the area of Homo sapiens‘.

Australopith cheekbones are also large and their jaws are thick. The spots where chewing muscles attach, between the top of the head and neck, are well-developed. This combination of traits suggests Australopiths were eating tough foods like nuts, seeds, tubers or roots.

Teeth and chewing muscles are especially pronounced in the robust Australopiths, or those with Paranthropus in their scientific name. Gracile Australopiths have less-mega — but still big — chompers. Researchers assume this difference relates to diet, but debate the specific cause. Based on microscopic pits and scratches on their teeth, some say robust Australopiths consumed more hard, brittle foods like seeds, whereas gracile forms ate chewy resources like leaves.

Others have proposed that gracile Australopiths used tools to pulverize food, pointing to the fact that the earliest known stone artifacts appear during this period. At the 3.3 million-year-old site of Lomekwi, Kenya, researchers recovered stone cobbles deliberately bashed into tools with sharp edges between about 1 and 8 inches long. But, no hominin fossils were found at the site, so their exact makers are unknown.

If the hypothesis is correct, gracile and robust species would represent two distinct strategies for dealing with tough diets: One was cultural adaptation, whereby gracile Australopiths invented stone tools. The other was the biological evolution of mega-chompers and chewing muscles by robust forms.

Lucky They Survived

Looking back 3 million years, to the age of Australopiths, no one would have expected the hominin lineage to amount to much. Australopiths were short and slow, and probably made prime targets for predators. They lacked advantages of later hominins — big brains, advanced weapons, fire — as well as defenses of earlier, more ape-like ancestors, such as tree-climbing skills and large canine teeth.

Yet during this period hominins diversified into a multitude of species. Homo sapiens are here today because one of those lineages survived.

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Dating When Dinosaurs Lived is Difficult. This Paleontologist Has Made it Her Mission

By Laura Poppick, Knowable Magazine | August 30, 2019 12:46 pm
Stegosaur expert Susie Maidment of London’s Natural History Museum is studying rock strata in order to pin down the precise dates of dinosaur fossils from the Late Jurassic — the better to understand the biology and evolution of these ancient beasts. (Credit: Emily Osterloff/Natural History Museum)

At the base of a pale hill in the badlands of northeastern Wyoming, Susie Maidment hits her hammer against stone. She breaks off a fist-sized chunk, grabs a loose piece between her fingers and places it on her tongue. “Silty,” she announces as the sediment brushes the roof of her mouth.

Maidment’s graduate student, Joe Bonsor, takes note on his clipboard then brings a piece of rock close to his face and squints at it through a hand lens. The layer below this one has slightly larger sand particles, Maidment says — suggesting that the two formed under different conditions. It’s one of many bits of data needed for the job the two paleontologists have come over from the UK to do: piece together, layer by layer, the history of the Late Jurassic, from details in the rocks that formed at that time.

The hills around us on this June day sprawl with dusty prickly pear cactus, juniper and sagebrush. Scorpions and rattlesnakes pose the most immediate threats. But during the Late Jurassic, streams and ponds would have flushed through the landscape, and dinosaurs — the creatures that make this spot so compelling to Maidment and Bonsor — would have sent prey scurrying into shadows.

Along our path, we stop to huddle over a two-inch fossil fragment that Bonsor picked up from the dry rubble — tangible remains of these long-departed animals. Maidment notes that every creature larger than a meter in size that lived on land during the Late Jurassic would have been a dinosaur — and anything with a bone as thick as this one would have come from one. “If it’s big and it’s from the Jurassic,” she says, “it’s a dinosaur bone.”

Dinosaur research has been steadily expanding in recent years, with new fossil discoveries and ever-improving fossil-scanning technology reshaping the way scientists understand these animals that dominated terrestrial ecosystems for more than 130 million years. But fossils on their own can reveal only so much about bigger-picture questions. Do differences in the head crests of hadrosaurs, say, or the skeletons of stegosaurs, represent evolutions through time, or the difference between males and females from the same time? If changes through time, how long did that evolution take, and what caused the shift? Where on the planet were dinosaurs most prevalent and diverse? Who fell prey to whom, and what type of terrain did these creatures carve their lives through? Unearthing additional fossils won’t tell you all these things. The answers, more often, rest in the rocks that surround the bones. And those rocks are, in many cases, not well studied.

Maidment, a paleontologist at the Natural History Museum in London, is leading the push to change that, at least for North America’s Late Jurassic. This summer, she and Bonsor teamed up with an international group of paleontologists in a dinosaur dig dubbed Mission Jurassic that aims to excavate new museum specimens and to explore the surrounding sediments for deeper details. They’re working in the Morrison Formation, a suite of rocks that has produced more Jurassic dinosaur bones than any other collection of rocks on the continent. Maidment’s ultimate goal: to develop the first-ever comprehensive chronology of the entire Morrison that maps out how the landscape changed through time and how different fossils fit into it.

Only once this framework has been established can researchers really begin to tease apart who’s related to whom and how these Late Jurassic dinosaurs evolved. “We think of dinosaurs as really, really well known,” Maidment says, “but they are actually not that well known at all.”

Your Favorite Stegosaurs and More

Mapping the chronology of the Morrison isn’t trivial. The formation stretches across roughly 1.2 million square kilometers from New Mexico and Arizona in the south all the way to Montana in the north. But it’s a challenge worth tackling, given what the formation holds. “These rocks have all of your favorite dinosaurs,” Maidment says, rattling off well-known names including stegosaurus, diplodocus and brontosaurus. “All the ones you knew when you were 7.”

sauropod in sandstone
Vertebrae of a sauropod encased in sandstone near Torrey, Utah. (Credit: Christopher Dean/University of Birmingham)

At 38, she’s focused on stegosaurs, and has distinguished herself as one of the world’s leading experts on this group of dinosaurs. In 2015, she led a team that described the most complete stegosaur skeleton ever discovered — a specimen that came from the Morrison (though she was not involved in excavating it).

She first visited this fruitful formation as a graduate student at the University of Cambridge in 2006 and has since returned five times to study fossil beds and sleuth out the Morrison’s ancient environmental history. “That’s going to be amazing information she can bring,” says Victoria Egerton, a paleontologist with positions at the Children’s Museum of Indianapolis and the University of Manchester, and one of the lead organizers of the Mission Jurassic dig.

Maidment also brings a somewhat uncommon mix to the research, of prestige for her paleontological lab work plus a strong knowledge of field geology — experience she gained as an undergraduate geology student at Imperial College London and by working as a geologist for an oil company before landing at London’s Natural History Museum in 2009.

The geologic work she and colleagues have conducted within the Morrison suggests that it formed over the course of 9 million years, give or take a few million, between about 156 million and 147 million years ago. But beyond that, researchers still have a poor sense of the ages of individual layers within the rocks where many fossils have come from. So paleontologists have resorted to grouping these fossils into a single unit of time — a practice that can lead to seriously flawed interpretations, Maidment says.

For example, studies of Morrison fossils have begun to reveal differences in skeletons found in the southern portion of the formation compared to similar ones found in the north — including stegosaurs that Maidment has studied. But without ages assigned to these fossils, researchers can’t know if their differences represent changes through time, or place-based differences from the same time. That’s an important distinction to make as researchers build family trees and try to understand the broader story of dinosaur evolution.

“If you’re dividing time into 10 million years, you are smushing together a whole load of different ecosystems and different animals that never would have lived together,” Maidment says. By way of context: Just 12 million years of evolution produced humans, gorillas and chimps from a single common ancestor.

Paleobiologist Anjali Goswami, a colleague of Maidment at the Natural History Museum who studies vertebrate fossils from other parts of the world, says that establishing a robust timeline is key to untangling the Morrison, and that Maidment’s efforts here are vital. “The error in what we are trying to estimate is really huge. She’s doing a lot of really time-consuming fieldwork to try to remedy those errors.”

That fieldwork includes the painstaking task of collecting what geologists call stratigraphic logs: inch-by-inch observations of sediment layers (or strata) from the base of a rock face to the top (from the oldest sediments to the youngest) — sometimes spanning hundreds of feet of stone. It’s why Maidment stuck the silt in her mouth (a common geologic test of sediment size) and what has consumed her time in the Morrison over the past seven years.

The activity is slow but rhythmic: Extend the tape measure; note where you are in the rock face and how far you’ve come from the previous layer; knock off a piece of the layer with your rock hammer; get the sample as close to your face as possible while still able to focus on it beneath your hand lens; note the size of the sediment and the quality of its layers; and, if you’re inclined, put a bit in your mouth.

maidment viewing rock
Susie Maidment and Joe Bonsor examine properties of rock through hand lenses. (Credit: Laura Poppick)

Jot down notes, confer with your field partner to confirm your interpretation of your observations, and then move on to the next layer directly above. If a plant or other obstruction appears in the way, skirt to the right or left in a straight line to find the next well-exposed area and proceed upward, forward in geological time.

The end product in the field notebook looks like a vertical barcode decorated with symbols that indicate size of sediments, thickness of layers, and the ancient environments these layers might represent. Wavy layers often form in watery places where sand ripples might develop, so they may represent a stream bed or coastline. Flat layers may represent a calmer environment like a lake bottom. Sand and silt fall faster through water than clay, which settles in places where tides and currents slacken.

On their own, these individual barcodes aren’t very helpful. A single ripple layer can form in a number of different environments, including a small stream. But with many barcodes collected across a region, scientists can start to find patterns across corresponding layers, build connections, and sculpt a three-dimensional illustration of how the landscape might have unfurled and morphed through time — shifts from wet to dry to coastal to riverine, each iteration layered one on top of the next.

Since 2012, Maidment has collected more than 20 of these stratigraphic logs across the Morrison and has worked to correlate them with 245 additional ones that others have collected over the years. While collecting them has been a massive, multi-decade effort accomplished by many scientists, Maidment is the first to pull them all together into a cohesive framework, work that’s been accepted for publication in the Journal of Sedimentary Research.

“She’s really someone who is pushing ahead with that in a way that I don’t think other people have been,” says Roger Benson, a paleobiologist at the University of Oxford who wrote an article in the 2018 Annual Review of Ecology, Evolution, and Systematics last year on the lingering unknowns in dinosaur biology and evolution. He sees the well-studied rocks of the Morrison as somewhat of a Rosetta Stone for other less-studied rocks of the same age, and what Maidment finds could help unravel the story of Late Jurassic dinosaurs not just in North America, but elsewhere. “The work she is doing is really important and fundamental,” he says.

Sedimentary Log
A stratigraphic log from a site called Cisco Landing, near Moab in Utah. (Credit: Susie Maidment)

Fascinated From the Start

As we drive down a dirt road to the Mission Jurassic dig site, over cattle guards and through several barbed wire ranching gates, Maidment describes her decades-long commitment to unraveling the story of dinosaurs.

She spent her childhood collecting fossil ammonites along the cliffs of the Jurassic Coast in southern England, but traces her specific fixation on dinosaurs back to a conversation she had with her grandfather when she was 6, when he asked what she wanted to be when she grew up. “At the time I was wavering viciously between scientist and princess,” she deadpans. Her grandfather, an electrical engineer, gently pushed for scientist. She wasn’t sure what options existed in science, but knew she liked dinosaurs, so he suggested she study them. Since then, that’s been her pursuit. “It’s always what I wanted to do,” she says.

We arrive at the dig site, and I join Bonsor as he crouches with a group of other students. They kneel on pads and methodically brush away dusty layers to excavate the remains of a sauropod — a long-necked, long-tailed plant eater from a group of the most massive animals ever to live on land.

Using a metal trowel to discard clumps of dirt and a razor blade to carve finer details, Bonsor comes across an object with the distinct reddish hue of bone. “This has always been my goal,” he says as he gazes at his first-ever dinosaur find. “Pretty much this second has been my life goal.”

The allure of discovering new fossils certainly motivates Maidment as well. But she says that she often finds the sediments even more enticing than the dinosaurs — especially if they contain datable material.

maidment and stegosaurus
Maidment during her PhD years. This stegosaur, a mix of real and cast bones, is on display at Utah State University Eastern’s Prehistoric Museum in Price, Utah. (Credit: Reese Barrick/College of Eastern Utah)

But locating rocks with that material isn’t easy, says David Eberth, an emeritus geologist at the Royal Tyrrell Museum in Alberta who has conducted extensive fieldwork studying younger dinosaur-rich rocks in Canada. “You have to go where the rocks will talk to you,” he says.

Eberth is referring to rocks that contain the mineral zircon, the preferred material scientists use to date Earth’s oldest remains. Tiny zircon crystals are especially helpful for two reasons: They’re strong and can stay intact across millions of years, and they contain the radioactive element uranium. Uranium decays to the element lead at a known rate, so researchers can measure the ratio of uranium to lead in a zircon to calculate its age.

Zircons form in volcanos, so researchers look for them in ancient volcanic ash layers where they would have been buried relatively soon after they formed. But ash doesn’t always fall neatly alongside fossil beds, and trying to process zircons from sediments broken down from ash can be challenging. The cost and difficulty of doing zircon work mean many spots in the Morrison lack zircon dates. This is where stratigraphic logs become helpful in assigning ages to fossils: Though zircons may be absent from some fossil sites, they are present in others, and geologists can extrapolate the age of one sediment layer by correlating it with a corresponding layer of known age elsewhere in the rock formation. Work like this, Eberth says, “is absolutely key to making any sense of patterns we see coming out of the Morrison.”

But you need more than zircon dates and stratigraphic logs, he adds. Sometimes seemingly corresponding layers look alike but do not actually match up; the resemblance could be coincidental. “You can’t tell,” he says. “You need a huge multidisciplinary tool kit to tell you” — including other lines of evidence from the sediment layers.

Researchers also correlate the chemistry of the strata — chemostratigraphy — by looking at the ratios of different elements in the rocks. And they carefully note the orientation of magnetic mineral grains within the strata — magnetostratigraphy. Only when these multiple lines of evidence match up can scientists solidify the timing of layers. “Then,” Eberth says, “you start putting the animals in it.”

During past field seasons, Maidment has collected cores of Morrison rock for magnetostratigraphy and samples of ash for zircon analysis. This time, she is keeping an eye out for more volcanic ash layers. Otherwise — tape measure in one hand and hand lens in the other — she’s fully focused on collecting observations for a new stratigraphic log that she’ll transfer to a computer and add to her mounting collection from across the formation.

Maidment’s efforts to compile all existing Morrison logs into a single comprehensive framework will help make the most of the relatively few reliable zircon dates that she and colleagues have collected over the years. “That would be a big contribution,” says Kenneth Galli, a geologist at Boston College whose team has collected and analyzed zircons from the Morrison.

And by bridging this gap between geology and paleontology, she’s filling a niche that others aren’t necessarily equipped for, says Amanda Owen, a sedimentologist at the University of Glasgow in Scotland who has studied the Morrison extensively and whose stratigraphic logs helped inform Maidment’s chronology.

The Smell of Ancient Eons

As Maidment, Bonsor and I continue our way up the silty hill to complete their log for the day, Maidment knocks off a gray stone and hands a piece to me. I bring it to my face and notice a strikingly familiar but out-of-place odor — the dank, musky smell of a lake.

Maidment confirms that rocks can, incredibly, retain the smell of their origins millions of years after they form. I could actually be holding a piece of lake bottom.

bonsor digging
Maidment’s graduate student Joe Bonsor (left) works on excavating a dinosaur bone. “Pretty much this second has been my life goal,” he says. (Credit: Laura Poppick)

Soon after, ominous storm clouds descend and we hustle back to the central dig site to take cover. But our minds are still stuck in the Jurassic. “It’s very relaxing,” Maidment says of the sensory experience of collecting logs: the smell of rock, the taste of sediment. “I love doing it.”

Before the incoming rain kicks us off the dig site, a hubbub forms around one of the fossil quarries. Paul Kenrick, a paleobiologist from the London museum, has found a fragment the length of a thumbnail.

Maidment examines the find between her fingers and tentatively identifies it as a piece of a femur. Based on its curvature, she thinks it might have come from a small therapod — a meat-eating dinosaur that would have been magnitudes smaller than the sauropods the team has been digging up. “The small stuff is less well known, it’s rarer,” she says as people huddle close to get a look. “It shows that there are other things in here.”

The rain starts to fall as we pile into trucks and head down the dirt road before it becomes slippery and impassible. As we leave, we rattle over beds of undiscovered bone. Those bones will bring the team back the next day — but it’s the surrounding layers that will bring the bones to life.

10.1146/knowable-081419-1

Laura Poppick is a freelance science and environmental journalist based in Portland, Maine. As a former earth scientist, she also put sediments in her mouth and spent many an hour collecting stratigraphic logs. Twitter: @laurapoppick

This article originally appeared in Knowable Magazine, an independent journalistic endeavor from Annual Reviews. Sign up for the newsletter.

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CATEGORIZED UNDER: Living World, Top Posts
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A String of Unusual Experiments Claim to Show Plants Can Think. Few Scientists Are Buying It

By Anna Funk | August 28, 2019 1:00 pm
Mimosa plants have long inspired intrigue with their ability to move when touched. (Credit: Discover/Stipple engraving by R. Earlom, 1789, after G. Romney. Credit: Wellcome CollectionCC BY)

When The Secret Life of Plants came out in 1973, Lincoln Taiz was a graduate student, just embarking on what would become a many-decades long career in plant biology. Plants, the book revealed, can make their own trace elements through fusion, just like the sun. More, they can recognize people. If someone committed a crime in front of them — plants’ fear could be measured with a simple lie detector test. And the book took it one step further, claiming that plants are conscious.

Taiz didn’t buy it.

“I could see the senior people in my field getting very exercised about this,” he recalls. “It’s embarrassing to plant biologists to have people believing stuff like that.”

The plant science community, he says, “teamed up with animal biologists and they did experiments to try and repeat some of these things, and of course it was all completely false.”

Yet the idea that plants may be sentient has not gone away; in fact, it has continued to gain interest — even in the scientific community. Monica Gagliano at the University of Sydney is now one of the most outspoken researchers on the subject. Her thrilling claims can be found in a laundry list of news outlets from the Economist, to Forbes, and yes, Discover. On Monday, The New York Times became the latest outlet to profile her.

But in science, extraordinary claims require extraordinary evidence — and an increasing number of plant scientists are pointing out: The evidence just isn’t there.

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How Galaxies Live, Breathe and Die

By Ann Finkbeiner, Knowable Magazine | August 28, 2019 10:32 am
gas and galaxies
Gas glows white, lit by a stellar nursery, in this view of a region within the Large Magellanic Cloud, the Milky Way’s largest satellite galaxy. Most cosmic gas is not so visible and lies outside of galaxies — in halos surrounding galaxies and in the vast spaces in between. Yet the gas determines galactic life cycles. (Credit: ESA/Hubble & NASA)

Most of what astronomers know about the universe comes from what they can see. So their ideas have been prejudiced toward stars and galaxies, which are bright. But most of the regular matter in the universe is in the form of gas, which is dim. Gas called the intergalactic medium fills the space between galaxies; the gas of the circumgalactic medium surrounds galaxies more closely. The gas in both places regulates the birth, life and death of the galaxies, and holds a detailed history of the universe. Only lately have astronomers been able to detect it.

Shortly after its birth, the universe was filled with gas, mostly hydrogen. Over time, here and there, gravity pulled the gas into clouds which turned into galaxies and in which stars ignited. Stars shine by thermonuclear burning of the gas; of those that die in explosions, some blow the gas back out of the galaxies. Out in intergalactic space, the gas cools and gets denser, until gravity pulls it back into the galaxy where new stars form. The process repeats: Gravity condenses gas into galaxies and stars, stars blow up and kick the gas out, gravity cycles the gas back in and makes new stars.

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CATEGORIZED UNDER: Space & Physics, Top Posts
MORE ABOUT: cosmology, galaxies

Babies Need Healthy Microbiomes. But Where Do Microbiomes Come From?

By Jyoti Madhusoodanan | August 22, 2019 2:57 pm
Feeding Baby
(Credit: Odua Images/Shutterstock)

A human’s genes are laid down at conception. A fetus’ heart, brain and other organs start to form five weeks later. At six months, an unborn child has most of its body parts. But there is one essential component missing: the helpful bacteria, often referred to as the microbiome, that will inhabit its gut, skin and other organs.

Our first interactions with microbes set the stage for health throughout our lives. Babies’ microbiomes have been linked to healthy brain development, asthma, allergies, obesity and more. But when and where do these earliest encounters occur? Understanding where our microbiomes originate is as important as knowing our genetic risk of cancer or heart disease.

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Can One Beer a Day Increase Your Cancer Risk? The Science Says Yes

By Megan Schmidt | August 21, 2019 4:50 pm
no beer for me
Does alcohol cause cancer? Here’s what recent research tells us.
(Credit: Mateone/Shutterstock)

Humans and the bottle go a long way back. Archaeologists have found our love of alcohol began some 9,000 years ago (and maybe even 10 million years ago, according to some reports).

Evidence of people boozin’ it up has been found in nearly every society throughout history. And today, alcohol is still ingrained in cultures around the world, especially in places like the Midwest – dubbed the Binge Drinking Belt of the United States. Summer barbecue? Beer me. Stressed? Unwind with some wine. Bored? Hang out with Jack Daniels and Sailor Jerry. 

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CATEGORIZED UNDER: Health & Medicine, Top Posts
MORE ABOUT: personal health

Scientists Tell Us How to Be Better Wine Tasters

By Sarah White | August 21, 2019 12:58 pm
Wine Tasting
The world of wine is complex. But there are a few simple things you can do to up your skills. (Credit: nd3000/Shutterstock)

Only 256 people in the world can call themselves Master Sommeliers: experts at tasting, describing and selling wine. They’re so rare because each sip of wine is a perceptual puzzle: Over 25 different taste and smell variables (sweetness, acidity, texture, finish, etc.) define each wine.

But you don’t have to be a super-taster or super-smeller to become a wine expert (although if you are, it wouldn’t hurt). With just a little bit of science in your toolkit, you can train both your senses and thoughts to be a little more discerning — and start to approach that expert level.

The Triangle Test

The best way to start on your journey toward wine wisdom is to try what’s called the “triangle test.” It’s used frequently in wine research.

Have a friend secretly fill two glasses with the same wine and a third with a different, but similar, wine. Compare the tastes until you feel confident guessing the odd one out.

Dissimilar wines make this test very easy, so try two wines that are mostly alike but vary in ways you can actually taste. But research doesn’t recommend trying to taste for the difference between vintage and non-vintage wines — even experts can only guess these right slightly more often than they would by random chance.

The Acid Test

Next, you can start training your tongue to discern levels of specific flavors. One of the wine dimensions you can taste, and get better at tasting with time, is acidity, according to Janice Wang, a research psychologist studying wine perception.

Fill glasses with water and add different amounts of lemon juice. Taste them, noticing the subtle differences in acidities.

The Alcohol Test

Wang, along with her chemist husband Domen Prešern, used a similar setup to help train members of Oxford University’s Blind Tasting Society to discriminate the level of alcohol in wine.

They filled glasses with different mixtures of vodka and water. “But it was terrible,” said Prešern, who, if he had to (reluctantly) repeat the experience, would have filtered the mixtures to reduce the potent, and telling, smell.

Scent Training

To help you figure out how to label the smells of wine, Wang recommends visiting a farmer’s market and just taking time to smell the roses, fruits and spices. This will expose you to the full spectrum of smells, she says.

Know Your Wines

But sensing flavors in wine is only half of the sommelier’s toolkit. Wine experts also have a deep knowledge of what certain wines usually taste like and why they taste that way. Wang and Prešern strongly encourage new wine tasters to become intimately familiar with a large amount of wine information before starting blind tasting practice.

Luckily, there’s help for this, too. Tons of expert sources have already compiled lists of the typical characteristics of wine varieties, which are freely available online.

To study, start with 10 classic wine varieties. Copy these descriptions onto individual index cards. On the other side, put the type of wine and where it is from. Assess your knowledge by guessing the type of wine from the description and vice versa. Instead of shuffling the cards randomly, try using these guidelines:

  • If you have no idea what the answer is, place the card in the next three cards
  • If you have a close guess, place the card in the next 4-7 cards
  • If you guess perfectly, place the card at the back of the deck
  • If you guess a card perfectly three times, take it out of the deck and replace it with two new cards

Flights of Fancy

Armed with better senses and knowledge of how to label your senses, you’ll be ready for the best learning tool: tasting wine with others. For the closest approximation of a Master Sommelier blind tasting exam, you’ll need a flight of six whites and six reds, a few other people and thirty minutes to silently sniff, slurp, spit and scribble.

Ideally, according to Wang and Prešern, someone should be responsible for selecting the flight of wines to taste so that no tasters have prior knowledge of what the wines could be. Knowing just one of the possible wines could result in you comparing every glass to that one kind of wine instead of tasting in as unbiased a way as possible.

As you work your way through the flight, try to write as much as you can about what you smell and taste. If there are any wines that tasted the same, sample these back-to-back to tease out the finer differences.

Once everyone is done sampling, what’s in each glass can be revealed. Discuss your descriptions with the rest of the group, and don’t be afraid to be wrong. The reasoning process is more important than getting the right answer. Wang said that even as president of the Oxford Blind Tasting Society, she would incorrectly guess the wine varietal or origin 80 percent of the time during practice, but her incorrect guesses weren’t far off.

It helps to have a range of expertise in the room to hear different takes on what you tasted. You might also learn which flavors you consistently attend to more than others.

But if you can’t find an expert, Wang recommends crowd-sourced wine reviews on sites like Purple Pages or Vivino. These descriptions are much more trustworthy than those on the back of the bottle, which are just meant to sell wine, says Prešern.

Purchasing Power

Now that you’re a wine expert, how should you go about figuring out which wines to buy?

If you — or the person you’re buying it for — can’t tell the difference, you can save money by avoiding the most highly rated wines, says Charles Spence, Wang’s PhD advisor and collaborator. And, he adds, if the wine comes in a box, has a fancy label or is in a heavier bottle, that alone will bias the drinker into having a more favorable opinion of the wine.

Prešern’s advice is to “be adventurous” and try wines you wouldn’t normally seek out to expand your palate.

Cheers and happy tasting.

CATEGORIZED UNDER: Mind & Brain, Top Posts
MORE ABOUT: nutrition, senses

Why a Polish Village Hasn’t Seen a Baby Boy Born for Almost 10 Years

By Craig Anderson, University of Glasgow | August 21, 2019 10:47 am
Baby Girl
One Polish town has seen an unlikely string of female births stretching for nearly a decade. (Credit: Omar Lopez/Unsplash)

The tiny Polish village of Miejsce Odrzanskie has become the unlikely source of international media attention over the past fortnight as a result of what the New York Times called “a strange population anomaly”. It has now been almost a decade since the last boy was born in this place, with the most recent 12 babies all having been girls.

The mayor of the region is quoted in the article as saying there has been “scientific interest” – presumably from geneticists – in exploring what has led to this unusual sequence. He also discusses some glaringly unscientific advice the town has been given on how to conceive boys, ranging from changing mothers’ diets to “keeping an ax(e) under your marital bed”.

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