Warning: Furry Logic is not, as the title might suggest, a detailed exploration of mammals’ reasoning skills. Instead, it’s a fun, informative chronicle of how myriad animals take advantage of the laws of physics.

Science writers Matin Durrani and Liz Kalaugher cite a trove of recent (and often surprising) research findings. They draw on their backgrounds — Durrani is a physicist, Kalaugher a materials scientist — to explain how animals exploit sound, light, electricity and magnetism, among other things, in pursuit of food, sex and survival. These creatures don’t consciously use physics the way that humans design and use tools, of course, but they are evolutionary marvels nonetheless.
Peacocks, for example, produce low-frequency sounds while shimmying their tail feathers (SN Online: 04/27/16). The birds use these sounds — and not just the sight of those colorful plumes — to impress females and fend off competing males. At the other end of the sonic spectrum, some bats use stealth echolocation to track down their preferred prey. Moths targeted by these bats have sensors that can pick up these ultrasonic calls, but the bats squeak so softly that a moth can’t hear its stalker until it is less than a half-second’s flight away.

Durrani and Kalaugher let readers know when the science isn’t settled. Researchers aren’t quite sure how peahens pick up males’ infrasonic signals, for example. Scientists also haven’t figured out how the archerfish spits so precisely (SN: 10/4/14, p. 8), knocking prey off low-hanging branches above the water as often as 94 percent of the time. The submerged fish must somehow gauge the angle at which light bends as it enters the water and then accurately compensate for refraction while spewing a stream of water. Amazingly, this feat may be innate rather than learned via trial and error.

Readers need not understand the intricacies of polarized light, Earth’s magnetic field or surface tension to enjoy Furry Logic. Nor is this book an exhaustive account of the characteristics and behavior of every animal that uses such phenomena in interesting ways. There should be plenty of material for a sequel to this fascinating book.

An effort to reproduce findings of five prominent cancer studies has produced a mixed bag of results.

In a series of papers published January 19 in eLife, researchers from the Reproducibility Project: Cancer Biology report that none of five prominent cancer studies they sought to duplicate were completely reproducible. Replicators could not confirm any of the findings of one study. In other cases, replicators saw results similar to the original study’s, but statistical analyses could not rule out that the findings were a fluke. Problems with mice or cells used in two experiments prevented the replicators from confirming the findings.
“Reproducibility is hard,” says Brian Nosek, executive director of the Center for Open Science in Charlottesville, Va., an organization that aims to increase the reliability of science. It’s too early to draw any conclusions about the overall dependability of cancer studies, Nosek says, but he hopes redo experiments will be “a process of uncertainty reduction” that may ultimately help researchers increase confidence in their results.

The cancer reproducibility project is a collaboration between Nosek’s center and Science Exchange, a network of labs that conduct replication experiments for a fee. Replicators working on the project selected 50 highly cited and downloaded papers in cancer biology published from 2010 to 2012. Teams then attempted to copy each study’s methods, often consulting with the original researchers for tips and materials. The five published in eLife are just the first batch. Eventually, all of the studies will be evaluated as a group to determine the factors that lead to failed replications.
Critics charge that the first batch of replication studies did not accurately copy the originals, producing skewed results. “They didn’t do any troubleshooting. That’s my main complaint,” says cancer biologist Erkki Ruoslahti of Sanford Burnham Prebys Medical Discovery Institute in La Jolla, Calif.

Ruoslahti and colleagues reported in 2010 in Science that a peptide called iRGD helps chemotherapy drugs penetrate tumors and increases the drugs’ efficacy. In the replication study, the researchers could not confirm those findings. “I felt that their experimental design was set up to make us look maximally bad,” Ruoslahti says.

Replicators aren’t out to make anyone look bad, says cancer biologist Tim Errington of the Center for Open Science. The teams published the experimental designs before they began the work and reported all of their findings. What Ruoslahti calls troubleshooting, Errington calls fishing for a particular result. Errington acknowledges that technical problems may have hampered replication efforts, but that’s valuable data to determine why independent researchers often can’t reproduce published results. Identifying weaknesses will enable scientists to design better experiments and conduct research more efficiently, he argues.

Other researchers took issue with the replicators’ statistical analyses. One study sought to reproduce results from a 2011 Science Translational Medicine report. In the original study, Atul Butte, a computational biologist at the University of California, San Francisco, and colleagues developed a computer program for predicting how existing drugs might be repurposed to treat other diseases. The program predicted that an ulcer-fighting drug called cimetidine could treat a type of lung cancer. Butte and colleagues tested the drug in mice and found that it reduced the size of lung tumors. The replication attempt got very similar results with the drug test. But after adjusting the statistical analysis to account for multiple variables, the replication study could no longer rule out a fluke result. “If they want a headline that says ‘It didn’t replicate,’ they just created one,” Butte says. Errington says the corrections were necessary and not designed to purposely invalidate the original result. And when replication researchers analyzed both the original and replication study together, the results once again appeared to be statistically sound.

A failure to replicate should not be viewed as an indication that the original finding wasn’t correct, says Oswald Steward, a neuroscientist at the University of California, Irvine, who has conducted replication studies of prominent neuroscience papers but was not involved in the cancer replication studies. “A failure to replicate is simply a call to attention,” Steward says. Especially when scientists are building a research program or trying to create new therapies, it is necessary to make sure that the original findings are rock solid, he says. “We scientists have to really own this problem.”

Editor’s note: This story was updated January 26, 2017, to correct the starting point of the x-axis in the first graph.

The muddying of coastal waters by climate change could drastically increase levels of neurotoxic mercury in sea life, contaminating food supplies.

Shifting rainfall patterns may send 10 to 40 percent more water filled with dissolved bits of organic debris into many coastal areas by 2100. The material can cloud the water, disrupting marine ecosystems by shifting the balance of microbes at the base of the food web, new laboratory experiments suggest. That disruption can at least double methylmercury concentrations in microscopic grazers called zooplankton, researchers report January 27 in Science Advances.
The extra mercury could reverberate up the food web to fish that humans eat, warns study coauthor Erik Björn, a biogeochemist at Umeå University in Sweden. Even small amounts of methylmercury, a form of the metal easily absorbed by humans and other animals, can cause birth defects and kidney damage, he notes.

Pollution from human activities such as fossil fuel burning has already tripled the amount of mercury that has settled in the surface ocean since the start of the Industrial Revolution (SN: 9/20/14, p. 17). Climate changes spurred by those same activities are washing more dark organic matter into the oceans by, for instance, boosting wintertime rainfall in some regions.

Björn and colleagues replicated this increased runoff using 5-meter-tall vats filled with marine microbes and dashes of methylmercury. Vats darkened by extra organic matter showed an ecosystem shift from light-loving phytoplankton to dark-dwelling bacteria that eat the extra material, the researchers found.

Zooplankton nosh on phytoplankton, but they don’t directly eat the bacteria. Instead the bacteria are consumed by protozoa, which zooplankton then hunt. Methylmercury accumulates with each step up the food web. So the addition of the protozoa middle step, the researchers report, resulted in zooplankton methylmercury levels two to seven times higher than in vats without the extra organic matter. Methylmercury levels will continue to increase up the food web to fish and the humans who eat them, the researchers warn.

The results suggest that curbing mercury contamination is more complicated than simply controlling emissions, says Alexandre Poulain, an environmental microbiologist at the University of Ottawa. “First we need to control emissions, but we also need to account for climate change.”

Two cosmic magnifying glasses are giving astronomers a glimpse of some extremely faint galaxies that existed as far back as 600 million years after the Big Bang (13.8 billion years ago). Such views suggest that tiny galaxies in the early universe played a crucial role in cosmic reionization — when ultraviolet radiation stripped electrons from hydrogen atoms in the cosmos.

“That we detected galaxies as faint as we did supports the idea that a lot of little galaxies reionized the early universe and that these galaxies may have played a bigger role in reionization than we thought,” says Rachael Livermore, an astronomer at the University of Texas at Austin. She and colleagues report the results in the Feb. 1 Astrophysical Journal.
The team identified the dim galaxies in images taken with the Hubble Space Telescope while it was pointed at two closer clusters of galaxies. Those clusters act as a gravitational lens, brightening and magnifying the light of fainter objects much farther away. Subtracting the clusters’ light revealed distant galaxies up to one-tenth as bright as those spotted in previous studies (SN Online: 11/4/15).

Finding such faint galaxies implies that stars can form in much smaller galaxies than models have predicted and that there were enough of these small galaxies to drive reionization almost entirely by themselves. Reionization radically refashioned the universe so that charged atoms instead of neutral ones pervaded space. Understanding that transition may help astronomers explain how stars and galaxies arose in the early universe.

“Such measurements are really challenging to make,” says Brant Robertson, an astronomer at the University of California, Santa Cruz, who was not involved with the study. “They’re really at the forefront of this field, so there are some questions about the techniques the team used to detect these galaxies and determine how bright they actually are.”

A team of astronomers led by Rychard Bouwens of Leiden University in the Netherlands argues in a paper submitted to the Astrophysical Journal and posted October 2 online at arXiv.org that Livermore and colleagues haven’t, in fact, detected galaxies quite as faint as they have claimed. That keeps the door open for other objects, such as black holes accreting matter and spitting out bright light, to have played a part in reionization.

Robertson says the disagreements motivate further work, noting that Livermore and colleagues used a clever approach to spot what appear to be superfaint galaxies in the early universe. Now, the teams will have to see if that technique stands the test of time.

Livermore and colleagues plan to use the technique to search for faint galaxies lensed by other clusters Hubble has observed. Both teams, along with Robertson, are also looking to the October 2018 launch of the James Webb Space Telescope, which should be able to spot even fainter and more distant galaxies, to determine what drove reionization in the early universe.

Traces of Zika virus typically linger in semen no longer than three months after symptoms show up, a new study on the virus’ staying power in bodily fluids reveals.

Medical epidemiologist Gabriela Paz-Bailey of the U.S. Centers for Disease Control and Prevention and colleagues analyzed the bodily fluids — including blood, urine and saliva — of 150 people infected with Zika. In 95 percent of participants, Zika RNA was no longer detectable in urine after 39 days, and in blood after 54 days, researchers report February 14 in the New England Journal of Medicine. (People infected with dengue virus, in contrast, typically clear virus from the blood within 10 days, the authors note.)

Although the CDC recommends that men exposed to Zika wait at least six months before having sex without condoms, researchers found that, for most men in the study, Zika RNA disappeared from semen by 81 days.

Few people had traces of RNA in the saliva or in vaginal secretions. Most Zika infections transmitted sexually have been from men to women, but scientists have reported at least one female-to-male case.

The 20th century will go down in history — it pretty much already has — as the century of the physicist. Physicists’ revolutionizing of the scientific world view with relativity and quantum mechanics might have been enough to warrant that conclusion. Future historians may emphasize even more, though, the role of physicists in war and government. Two such physicists, one born at the century’s beginning and one still living today, typify that role through their work in developing weapons, advising politicians and shaping policy while still performing outstanding science.

Best known of the two is Enrico Fermi, the Italian intellectual giant who escaped from fascist Italy to America after winning a Nobel Prize for his research in nuclear physics.
When he arrived in the United States in 1939, Fermi almost immediately went to work studying nuclear fission, discovered only weeks earlier in Hitler’s Germany. Eventually Fermi took a major role in the Manhattan Project, leading the team that first demonstrated a controlled nuclear fission chain reaction.

Fermi, a foreigner, assumed a lead role because he was so widely recognized among the world’s physicists as infallible — hence his nickname “the pope.” In The Pope of Physics, Gino Segrè and Bettina Hoerlin chronicle Fermi’s life and science with insight and rich detail.
Fermi is often cited as the last of the great physicists who excelled both at theory and experiment. His theory of the weak nuclear interactions, produced in the early 1930s, remains a key segment of modern physicists’ understanding of matter and forces. His experimental work on neutrons won the Nobel (even though aspects of those experiments turned out to have been incorrectly interpreted).

Segrè (whose uncle was a collaborator of Fermi’s) and Hoerlin explore the personal and political influences on Fermi’s science and relate in detail his experiences in the effort during World War II to develop the atomic bomb. His postwar government service included membership on the General Advisory Committee to the new U.S. Atomic Energy Commission. He was also on the University of Chicago faculty until his abrupt death in 1954 from stomach cancer. He was 53.
Briefly mentioned in Segrè and Hoerlin’s account is a visit near the end of Fermi’s life from one of his former graduate students, Richard Garwin. To Garwin, Fermi mentioned regret at not having been even more involved in public policy. Perhaps, Segrè and Hoerlin suggest, that conversation inspired Garwin, “who went on to have an extraordinarily distinguished career as a presidential adviser on science and security issues.”

As Fermi’s postdoc at Chicago, Garwin also spent time at the lab in Los Alamos, N.M., where the atomic bomb had been built. By 1951, the lab’s focus was on the hydrogen bomb, or the Super, powered by fusion in addition to fission. Despite input from Fermi and significant insights from the mathematician Stanislaw Ulam and physicist Edward Teller, designing the Super had proven an insuperable problem. Garwin offered to help; Teller assigned him the task of designing an experiment demonstrating how the Super could work. In a couple of weeks, Garwin handed in the blueprint for the actual bomb itself.

In True Genius, veteran science writer Joel Shurkin recounts this story in detail for the first time. For decades, popularizations credited Teller with the development of the hydrogen bomb; Garwin’s role was long classified. Late in life, Teller, who died in 2003, revealed Garwin’s crucial role, which was eventually reported in the New York Times.

As Shurkin emphasizes, Garwin designed the bomb because it was a technical problem that he knew how to solve. But he spent the rest of his career devoted to arms control (both as an adviser inside government and a critic from the outside).

Garwin made significant contributions to physics as well — many modern technological conveniences, such as the GPS satellite system, owe their existence to Garwin’s insights. Last November, in recognition of all these achievements, President Barack Obama awarded Garwin the Presidential Medal of Freedom.

Shurkin’s account of Garwin’s life is detailed but often hard to follow, sometimes jumping from decade to decade (not always in order) in the space of a few paragraphs. And the book is marred by poor fact-checking (tritium is certainly not an isotope of lithium; Otto Hahn was a chemist, not a physicist; and Niels Bohr’s mother was Jewish, not his father). And peculiarly the title, the book’s publicity material says, refers to Fermi’s description of Garwin as a “true genius,” while the text of the book quotes Fermi as calling Garwin a “real” genius.

Nevertheless, Shurkin’s account is by far the best (virtually only) complete record of the life of a scientist who devoted his career to serving the public good — while also doing extraordinary science. Garwin really, truly, is a genius.

Black holes are a bit like babies when they eat: Some food goes in, and some gets flung back out into space. Astronomers now say they understand how these meals become so messy — and it’s a trait all black holes share, no matter their size.

Magnetic fields drive the turbulent winds that blow gas away from black holes, says Keigo Fukumura, an astrophysicist at James Madison University in Harrisonburg, Va. Using X-rays emitted from a relatively small black hole siphoning gas from a nearby star, Fukumura and colleagues traced the winds flowing from the disk of stellar debris swirling around the black hole. Modeling these winds showed that magnetism, not other means, got the gas moving in just the right way.
The model was previously used to explain the way winds flow around black holes millions of times the mass of the sun. Showing that the model now also works for a smaller stellar-mass black hole suggests that magnetism may drive winds in black holes of all sizes. These results, published online March 6 in Nature Astronomy, could give clues to how black holes consume and expel matter and also to why some galaxies stop forming stars.

Astronomers first proposed that magnetic fields powered the winds around black holes in the 1970s, but the idea has been controversial. Directly observing the winds is impossible. Their existence is inferred by a black hole’s X-ray spectrum — an inventory of light broken up by wavelength.

In 2005, astronomers used the Chandra X-ray Observatory to capture the X-ray spectrum of a relatively puny black hole with seven times the mass of the sun. The companion star it feeds on has about twice the heft of the sun. The system, called GRO J1655-40, is about 11,000 light-years away in the constellation Scorpius.

GRO J1655-40’s X-rays revealed its turbulent winds. Some astronomers argued the data provided evidence that powerful magnetic fields fueled the winds. Others, however, suggested the winds resulted from extremely hot gas swirling around the black hole.

“I think the new paper clears this controversy up,” says Andrew Fabian, an astrophysicist at the University of Cambridge who was not involved with the new study. The model Fukumura developed, he says, is extremely detailed and accounts for characteristics of GRO J1655-40’s X-ray spectrum that other models can’t explain.
Features of the spectrum, for example, suggest that the winds are dense and move moderately quickly, but don’t blow far from the black hole. That matches models of magnetically fueled wind. Models related to the heat of the gas alone make the winds blow too far.

The magnetic fields form from the electric current generated by electrons and protons swirling in a pancake-shaped accretion disk. Parts of the disk spin around the black hole at different speeds, which amplifies the fields. That, in turn, turns the accretion disk into a vortex, pulling matter into the black hole and fueling winds that blow some of it outward.

“A good fraction of the mass actually gets kicked out of the black hole,” Fukumura says. “If it didn’t get thrown off, we wouldn’t see it.”

The magnetic fields probably arc around the black hole from pole to pole. But no one knows for sure because they are hard to detect. Recently, the Event Horizon Telescope, which pointed several telescopes at the center of the Milky Way, did spot patterns in the way the light of our galaxy’s central, supermassive black hole was oriented that signaled it has magnetic fields. Astronomers plan to use the telescope array to search for more evidence of magnetic fields around black holes next month.

Studying the magnetic fields of black holes reveals information about the structure of their accreting disks and the winds that blow from them. “Winds from black hole disks can be very powerful,” Fabian notes. “In the case where the black hole is massive and at the center of a galaxy, the wind can push all the gas out of the host galaxy, stopping further star formation and causing the galaxy to appear red and dead.”

Some bedbugs are better climbers than others, and the bloodsuckers’ climbing prowess has practical implications.

To detect and monitor bedbugs, people use an array of strategies from DIY setups to dogs. Pitfall traps, which rely on smooth inner walls to prevent escape, are highly effective for detecting and monitoring an infestation. The traps are sold around the world, but they have only been tested with common bedbugs (Cimex lectularius) — the most, well, common species in the United States.

As it turns out, tropical bedbugs (C. hemipterus) can easily scale the walls of pitfall traps, Chow-Yang Lee, an entomologist at Malaysia’s University of Science, and his colleagues found in lab tests. While 24 to 76 percent of tropical bedbug strains escaped traps, only 0 to 2 percent of common strains made it out. In measurements of vertical frictional force, tropical bedbugs also came out on top. Further investigation of the species’ feet revealed extra hairs on the tibial pads of tropical bugs. These may give their legs a better grip on trap walls, the researchers propose March 15 in the Journal of Economic Entomology.

Tropical bedbugs live in some regions of Africa, Australia, Japan, China and Taiwan — and have recently resurfaced in Florida.

Many babies born early spend extra time in the hospital, receiving the care of dedicated teams of doctors and nurses. For these babies, the hospital is their first home. And early experiences there, from lights to sounds to touches, may influence how babies develop.

Touches early in life in the NICU, both pleasant and not, may shape how a baby’s brain responds to gentle touches later, a new study suggests. The results, published online March 16 in Current Biology, draw attention to the importance of touch, both in type and number.

Young babies can’t see that well. But the sense of touch develops early, making it a prime way to get messages to fuzzy-eyed, pre-verbal babies. “We focused on touch because it really is some of the basis for communication between parents and child,” says study coauthor Nathalie Maitre, a neonatologist and neuroscientist at Nationwide Children’s Hospital in Columbus, Ohio.

Maitre and her colleagues studied how babies’ brains responded to a light puff of air on the palms of their hands — a “very gentle and very weak touch,” she says. They measured these responses by putting adorable, tiny electroencephalogram, or EEG, caps on the babies.

The researchers puffed babies’ hands shortly before they were sent home. Sixty-one of the babies were born early, from 24 to 36 weeks gestation. At the time of the puff experiment, they had already spent a median of 28 days in the hospital. Another group of 55 babies, born full-term, was tested in the three days after birth.

Full-term babies had a strong brain reaction to the hand puff. (This reaction was missing when researchers pointed the air nozzle away from the babies, a control that ruled out the effects of the puff’s sound.) Preterm babies had weaker brain reactions to the hand puff, the researchers found.

But the story doesn’t stop there. The researchers also looked at the number and type of touches — positive or negative — the preemies received while in the hospital.
Preemies who received a greater number of positive early touches, such as breastfeeding, skin-to-skin cuddles and massage, had stronger brain responses to the puffs than preemies who received fewer. More worryingly, preemies who had a greater number of negative touch experiences, including heel pricks, IV insertions, injections and tape removal, tended to have diminished brain responses to the puffs.

About a third of the premature babies in the study didn’t receive any positive touches that the researchers counted. Between birth and the time of the hand-puff experiment, the median number of positive touch experiences for the preemies in the study was 4. In contrast, the median number of painful procedures was 32.

The study turns up links, not cause. That means scientists can’t say whether the early touches, both positive and negative, are behind the differences in brain response. But it’s possible that early tactile experiences pattern the brain in important ways, Maitre says. If so, then the results have big implications.

Oftentimes, parents don’t have the luxury of snuggling their baby, particularly when parental leave is limited and babies are being treated far from home. Nurses, doctors and other medical professionals provide other forms of care. But anything parents, medical professionals or even volunteer cuddlers can do to shift the balance of positive and negative touches might encourage babies’ development, giving these smallest and newest of people the best start possible.

A black hole weighing more than a billion suns appears to have gotten the boot toward the outer edges of its galaxy.

Data from the Hubble Space Telescope and other observatories reveal a supermassive black hole zipping away from the center of its galaxy at a 7.5-million-kilometer-per-hour clip. It’s moving so quickly that it could leave the galaxy for good in 20 million years, says Marco Chiaberge of the Space Telescope Science Institute in Baltimore.
Only gravitational waves — ripples in the fabric of spacetime — could give the black hole such a kick, Chiaberge and colleagues report March 30 in Astronomy & Astrophysics. Hints of huge black holes ejected from a galactic center have been reported before (SN: 5/24/08, p. 12). This discovery offers some of the most convincing evidence that black holes can get kicked out of their galaxies by gravitational waves and suggests that it occurs more often than astronomers thought.

“This is a very nice candidate for a recoiling supermassive black hole,” says Francesca Civano of the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass. Recoiling black holes are created when two monster black holes from different galaxies merge, says Civano, who was not involved in the new study. If the black holes have different masses and rotate at different rates, the collision can generate gravitational waves more strongly in one direction, booting the newly merged black hole the other way.

A radiation-gushing supermassive black hole called quasar 3C 186 and its host galaxy, about 8 billion light-years from Earth in the constellation Lynx, tipped off Chiaberge and colleagues to the recoiling black hole. The team noticed that the quasar wasn’t at the center of the galaxy, where it typically should be. “We knew this was clearly weird. It was clearly different than all of the other quasars and galaxies we were seeing,” Chiaberge says.

The team calculated that the quasar was 35,000 light-years from its host galaxy’s center — about 10,000 light-years more than the distance separating the sun and the center of the Milky Way. 3C 186 is a well-studied object, so the team sifted through past observations of the quasar and galaxy and found data revealing how fast the gas surrounding the monster black hole moves. The researchers compared it with how fast the star-forming gas in the galaxy moves. The monster black hole was traveling much more quickly, with a velocity that would have to come from something forceful, equivalent to 100 million stars exploding simultaneously. Gravitational waves could provide such a kick.

The Hubble images also revealed curved wisps of stars and gas extending from the galaxy. Such faint tails suggest that the galaxy collided with another galaxy in the past, giving weight to the team’s claim that gravitational waves from colliding black holes could have given 3C 186 its kick.

Evidence of recoiling black holes is hard to find, but it’s the easiest explanation for the data in the new paper, Civano says. The new work, she notes, also suggests recoiling black holes could be more common than astronomers thought, but missed in earlier observations. “They might just be hidden in well-known sources, like 3C 186,” she says.