Top 10 discoveries about waves

Physics fans are a lot like surfers. Both think waves are really fun.

For surfers, it’s all about having a good time. For physicists, it’s about understanding some of nature’s most important physical phenomena. Yet another detection of gravitational waves, announced June 1, further reinvigorates the world’s science fans’ excitement over waves.

Waves have naturally always been a topic of scientific and mathematical interest. They play a part in an enormous range of physical processes, from heat and light to radio and TV, sonograms and music, earthquakes and holograms. (Waves used to even be a common sight in baseball stadiums, but fans got tired of standing up and down and it was really annoying anyway.)

Many of science’s greatest achievements have been discoveries of new kinds of waves or new insights into wave motion. Identifying just the Top 10 such discoveries (or ideas) is therefore difficult and bound to elicit critical comments from cult members of particular secret wave societies. So remember, if your favorite wave isn’t on this list, it would have been No. 11.

  1. Thomas Young: Light is a wave.
    In the opening years of the 19th century, the English physician Young tackled a long-running controversy about the nature of light. A century earlier, Isaac Newton had argued forcibly for the view that light consisted of (very small) particles. Newton’s contemporary Christiaan Huygens strongly disagreed, insisting that light traveled through space as a wave.

Through a series of clever experiments, Young demonstrated strong evidence for waves. Poking two tiny holes in a thick sheet of paper, Young saw that light passing through created alternating bands of light and darkness on a surface placed on the other side of the paper. That was just as expected if light passing through the two holes interfered just as water waves do, canceling out when crest met trough or enhancing when crests met “in phase.” Young did not work out his wave theory with mathematical rigor and so Newton’s defenders resisted, attempting to explain away Young’s results.

But soon Augustin Jean Fresnel in France worked out the math of light waves in detail. And in 1850, when Jean-Bernard-Léon Foucault showed that light travels faster in air than water, the staunchest Newton fans had to capitulate. Newton himself would have acknowledged that light must therefore consist of waves. (Much later, though, Einstein found a way that light could in fact consist of particles, which came to be called photons.)

  1. Michelson and Morley: Light waves don’t vibrate anything.
    Waves are vibrations, implying the need for something to vibrate. Sound vibrated molecules in the air, for instance, and ocean waves vibrated molecules of water. Light, supposedly, vibrated an invisible substance called the ether.

In 1887, Albert A. Michelson and his collaborator Edward Morley devised an experiment to detect that ether. Earth’s motion through the ether should have meant that light’s velocity would depend on its direction. (Traveling with the Earth’s motion, light’s speed wouldn’t be the same as traveling at right angles to the direction of motion.) Michelson and Morley figured they could detect that difference by exploiting the interference phenomena discovered by Young. But their apparatus failed to find any ether effect. They thought their experiment was flawed. But later Einstein figured out there actually wasn’t any ether.

  1. James Clerk Maxwell: Light is an electromagnetic wave.
    Maxwell died in 1879, the year Einstein was born, and so did not know there wasn’t an ether. He did figure out, though, that both electricity and magnetism could be explained by stresses in some such medium.

Electric and magnetic charges in the ether ought to generate disturbances in the form of waves, Maxwell realized. Based on the strengths of those forces he calculated that the waves would travel at the fantastic speed of 310 million meters per second, suspiciously close to the best recent measurements of the speed of light (those measurements ranged from 298 million to 315 million meters per second). So Maxwell, without the benefit of ever having watched NCIS on TV, then invoked Gibbs’ Rule 39 (there’s no such thing as a coincidence) and concluded that light was an example of an electromagnetic wave.

“It seems we have strong reason to conclude that light itself (including radiant heat, and other radiations if any) is an electromagnetic disturbance in the form of waves propagated through the electromagnetic field,” he wrote in 1864. His “other radiations, if any” turned out to be an entire spectrum of all sorts of cool waves, from gamma radiation to radio signals.

  1. Heinrich Hertz: Radio waves.
    Not very many people took Maxwell seriously at first. A few, though, known as the Maxwellians, promoted his ideas. One physicist who had faith in Maxwell, or at least in his equations, was Hertz, who performed experiments in his lab in Karlsruhe, Germany, that successfully produced and detected radio waves, eventually to be exploited by propagandists to spread a lot of illogical nonsense on talk radio.

His success inspired much more respect for the equations in Maxwell’s theory, which Hertz found almost magical: “It is impossible to study this wonderful theory without feeling as if the mathematical equations had an independent life and an intelligence of their own, as if they were wiser than ourselves,” Hertz said. His prime experimental success came in 1887, the same year that Michelson and Morley failed to detect the ether. Hertz died in 1894, long before his discovery was put to widespread use.

  1. John Michell: Seismic waves.
    Michell, an English geologist and astronomer, was motivated by the great Lisbon earthquake of 1755 to investigate the cause of earthquakes. In 1760 he concluded that “subterraneous fires” should be blamed, noting that volcanoes — “burning mountains” — commonly occur in the same neighborhood as frequent earthquakes.

Michell noted that “the motion of the earth in earthquakes is … partly propagated by waves, which succeed one another sometimes at larger and sometimes at smaller distances.” He cited witness accounts of quakes in which the ground rose “like the sea in a wave.” Much later seismologists developed a more precise understanding of the seismic waves that shake the Earth, using them as probes to infer the planet’s inner structure.

  1. Wilhelm Röntgen: X-rays.
    When Hertz discovered radio waves, he knew he was looking for the long-wavelength radiation foreshadowed in Maxwell’s equations. But a few years later, in 1895, Röntgen found the radio wave counterpart of the opposite end of the electromagnetic spectrum — by accident.
    Mysterious short-wavelength rays of an unknown type (therefore designated X) emerged when Röntgen shot cathode rays (beams of electrons) through a glass tube. Röntgen suspected that his creation might be a new kind of wave among the many Maxwell had anticipated: “There seems to exist some kind of relationship between the new rays and light rays; at least this is indicated by the formation of shadows,” Röntgen wrote. Those shadows, of course, became the basis for a revolutionary medical technology.

Besides providing a major new tool for observing shattered bones and other structures inside the body, X-rays eventually became essential tools for scientific investigation in astronomy, biology and other fields. And they shattered the late 19th century complacency of physicists who thought they’d basically figured everything out about nature. Weirdly, though, X-rays later turned out to be particles sometimes, validating Einstein’s ideas that light had an alter ego particle identity. (By the way, it turned out that X-rays aren’t the electromagnetic waves with the shortest wavelengths — gamma rays can be even shorter. Maybe they would be No. 11.)

  1. Epicurus: The swerve.
    Not exactly a wave in the ordinary sense, the swerve was a deviation from straight line motion postulated by the Greek philosopher Epicurus around 300 B.C. Unlike Aristotle, Epicurus believed in atoms, and argued that reality was built entirely from the random collisions of an infinite number of those tiny particles. Supposedly, he thought, atoms would all just fall straight down to the center of the universe unless some unpredictable “swerve” occasionally caused them to deviate from their paths so they would bounce off each other and congregate into complex structures.

It has not escaped the attention of modern philosophers that the Epicurean unpredictable swerve is a bit like the uncertainty in particle motions introduced by quantum mechanics. Which has its own waves.

  1. Louis de Broglie: Matter waves.
    In the early 1920s, de Broglie noticed a peculiar connection between relativity and quantum physics. Max Planck’s famous quantum formula related energy to frequency of a wave motion. Einstein’s special relativity related energy to the mass of a particle. De Broglie thought it would make a fine doctoral dissertation to work out the implications of two seemingly separate things both related to energy. If energy equals mass (times the speed of light squared) and energy equals frequency (time Planck’s constant), then voilà, mass equals frequency (times some combination of the constants). Therefore, de Broglie reasoned, particles (of mass) ought to also exist as waves (with a frequency).

That might have seemed wacky, but Einstein read de Broglie’s thesis and thought it made sense. Soon Walter Elsasser in Germany reported experiments that supported de Broglie, and in America Clinton Davisson and coworkers demonstrated conclusively that electrons did in fact exhibit wave properties.

De Broglie won the physics Nobel Prize in 1929; Davisson shared the 1937 Nobel with George Thomson, who had conducted similar experiments showing electrons are waves. Which was ironic, because George’s father, J.J. Thomson, won the 1906 Nobel for the work that revealed the existence of the electron as a particle. Eight decades later Ernst Ruska won a Nobel for his design of a powerful microscope that exploited the electron’s wave behavior.

  1. Max Born: Probability waves.
    De Broglie’s idea ignited a flurry of activity among physicists trying to figure out how waves fit into quantum theory. Niels Bohr, for instance, spent considerable effort attempting to reconcile the dual wave-particle nature of both electrons and light. Erwin Schrödinger, meanwhile, developed a full-fledged “wave mechanics” to describe the behavior of electrons in atoms solely from the wave perspective. Schrödinger’s math incorporated a “wave function” that was great for calculating the expected results of experiments, even though some experiments clearly showed electrons to be particles.

Born, a German physicist and good friend of Einstein’s, deduced the key to clarifying the wave function: It was an indicator of the probability of finding the particle in a given location. Combined with Werner Heisenberg’s brand-new uncertainty principle, Born’s realization led to the modern view that an electron is wavelike in the sense that it does not possess a definite location until it is observed. That approach works fine for all practical purposes, but physicists and philosophers still engage in vigorous debates today about the true physical status of the wave function.

  1. LIGO: Gravitational waves.
    Soon after he completed his general theory of relativity, Einstein realized that it implied the possibility of gravitational radiation — vibrations of spacetime itself. He had no idea, though, that by spending a billion dollars, physicists a century later could actually detect those spacetime ripples. But thanks to lasers (which maybe would have been No. 11), the Laser Interferometer Gravitational-Wave Observatory — two huge labs in Louisiana and Washington state — captured the spacetime shudders emitted from a pair of colliding black holes in September 2015.
    That detection is certainly one of the most phenomenal experimental achievements in the history of science. It signaled a new era in astronomy, providing astronomers a tool for probing the depths of the universe that are obscured from view with Maxwell’s “other radiations, if any.” For astronomy, gravitational radiation is the wave of the future.

Flight demands may have steered the evolution of bird egg shape

The mystery of why birds’ eggs come in so many shapes has long been up in the air. Now new research suggests adaptations for flight may have helped shape the orbs.

Stronger fliers tend to lay more elongated eggs, researchers report in the June 23 Science. The finding comes from the first large analysis of the way egg shape varies across bird species, from the almost perfectly spherical egg of the brown hawk owl to the raindrop-shaped egg of the least sandpiper.
“Eggs fulfill such a specific role in birds — the egg is designed to protect and nourish the chick. Why there’s such diversity in form when there’s such a set function was a question that we found intriguing,” says study coauthor Mary Caswell Stoddard, an evolutionary biologist at Princeton University.

Previous studies have suggested many possible advantages for different shapes. Perhaps cone-shaped eggs are less likely to roll out of the nest of cliff-dwelling birds; spherical eggs might be more resilient to damage in the nest. But no one had tested such hypotheses across a wide spectrum of birds.

Stoddard and her team analyzed almost 50,000 eggs from 1,400 species, representing about 14 percent of known bird species. The researchers boiled each egg down to its two-dimensional silhouette and then used an algorithm to describe each egg using two variables: how elliptical versus spherical the egg is and how asymmetrical it is — whether it’s pointier on one end than the other.

Next, the researchers looked at the way these two traits vary across the bird family tree. One pattern jumped out: Species that are stronger fliers, as measured by wing shape, tend to lay more elliptical or asymmetrical eggs, says study coauthor L. Mahadevan, a mathematician and biologist at Harvard University.
Mahadevan cautions that the data show only an association, but the researchers propose one possible explanation for the link between flying and egg shape. Adapting to flight streamlined bird bodies, perhaps also narrowing the reproductive tract. That narrowing would have limited the width of an egg that a female could lay. But since eggs provide nutrition for the chick growing inside, shrinking eggs too much would deprive the developing bird. Elongated eggs might have been a compromise between keeping egg volume up without increasing girth, Stoddard suggests. Asymmetry can increase egg volume in a similar way.

Testing a causal connection between flight ability and egg shape is tough “because of course we can’t replay the whole tape of life again,” says Claire Spottiswoode, a zoologist at the University of Cambridge who wrote a commentary accompanying the study. Still, Spottiswoode says the evidence is compelling: “It’s a very plausible argument.”

Santiago Claramunt, associate curator of ornithology at the Royal Ontario Museum in Toronto, isn’t convinced that flight adaptations played a driving role in the evolution of egg shape. “Streamlining in birds is determined more by plumage than the shape of the body — high performing fliers can have rounded, bulky bodies” he says, which wouldn’t give elongated eggs the same advantage over other egg shapes. He cites frigate birds and swifts as examples, both of which make long-distance flights but have fairly broad bodies. “There’s certainly more going on there.”

Indeed, some orders of birds showed a much stronger link between flying and egg shape than others did. And while other factors — like where birds lay their eggs and how many they lay at once — weren’t significantly related to egg shape across birds as a whole, they could be important within certain branches of the bird family tree.

Baby-led weaning won’t necessarily ward off extra weight

When my younger daughter was around 6 months old, we gave her mashed up prune. She grimaced and shivered a little, appearing to be absolutely disgusted. But then she grunted and reached for more.

Most babies are ready for solid food around 6 months of age, and feeding them can be fun. One of the more entertaining approaches does not involve a spoon. Called baby-led weaning, it involves allowing babies to feed themselves appropriate foods.

Proponents of the approach say that babies become more skilled eaters when allowed to explore on their own. They’re in charge of getting food into their own mouths, gumming it and swallowing it down — all skills that require muscle coordination. When the right foods are provided (yes to soft steamed broccoli; no to whole grapes), babies who feed themselves are no more likely to choke than their spoon-fed peers.

Some baby-led weaning proponents also suspected that the method might ward off obesity, and a small study suggested as much. The idea is that babies allowed to feed themselves might better learn how to regulate their food intake, letting hunger and fullness guide them to a reasonable calorie count. But a new study that looked at the BMIs of babies who fed themselves and those who didn’t found that babies grew similarly with either eating style.

A clinical trial of about 200 mother-baby pairs in New Zealand tracked two different approaches to eating and their impact on weight. Half of the moms were instructed to feed their babies as they normally would, which for most meant spoon-feeding their babies purees, at least early on. The other half was instructed that only breast milk or formula was best until 6 months of age, and after that, babies could be encouraged to feed themselves. These mothers also received breastfeeding support.

At the 1- and 2-year marks, the babies’ average BMI z-scores were similar, regardless of feeding method, researchers report July 10 in JAMA Pediatrics. (A BMI z-score takes age and sex into account.) And baby-led weaning actually produced slightly more overweight babies than the other approaches, but not enough to be meaningful. At age 2, 10.3 percent of baby-led weaning babies were considered overweight and 6.4 percent of traditionally-fed babies were overweight. The two groups of babies seemed to take in about the same energy from food, analyses of the nutritional value and amount of food eaten revealed.

The trial found a few other differences between the two groups. Babies who did baby-led weaning exclusively breastfed for longer, a median of about 22 weeks. Babies in the other group were exclusively breastfed for a median of about 17 weeks. Babies in the baby-led weaning group were also more likely to have held off on solid food until 6 months of age.

While baby-led weaning may not protect babies against being overweight, the study did uncover a few perks of the approach. Parents reported that babies who fed themselves seemed less fussy about foods. These babies also reportedly enjoyed eating more (though my daughter’s prune fake-out face is evidence that babies’ inner opinions can be hard to read). Even so, these data seem to point toward a more positive experience all around when using the baby-led weaning approach. That’s ideal for both experience-hungry babies and the parents who get to savor watching them eat.

Spread of misfolded proteins could trigger type 2 diabetes

Type 2 diabetes and prion disease seem like an odd couple, but they have something in common: clumps of misfolded, damaging proteins.

Now new research finds that a dose of corrupted pancreas proteins induces normal ones to misfold and clump. This raises the possibility that, like prion disease, type 2 diabetes could be triggered by these deformed proteins spreading between cells or even individuals, the researchers say.

When the deformed pancreas proteins were injected into mice without type 2 diabetes, the animals developed symptoms of the disease, including overly high blood sugar levels, the researchers report online August 1 in the Journal of Experimental Medicine.
“It is interesting, albeit not super-surprising” that the deformed proteins could jump-start the process in other mice, says Bruce Verchere, a diabetes researcher at the University of British Columbia in Vancouver. But “before you could say anything about transmissibility of type 2 diabetes, there’s a lot more that needs to be done.”

Beta cells in the pancreas make the glucose-regulating hormone insulin. The cells also produce a hormone called islet amyloid polypeptide, or IAPP. This protein can clump together and damage cells, although how it first goes bad is not clear. The vast majority of people with type 2 diabetes accumulate deposits of misfolded IAPP in the pancreas, and the clumps are implicated in the death of beta cells.

Deposits of misfolded proteins are a hallmark of such neurodegenerative diseases as Alzheimer’s and Parkinson’s as well as prion disorders like Creutzfeldt-Jakob disease (SN: 10/17/15, p. 12).

Since IAPP misfolds like a prion protein, neurologist Claudio Soto of the University of Texas Health Science Center at Houston and his colleagues wondered if type 2 diabetes could be transmitted between cells, or even between individuals. With this paper, his group “just wanted to put on the table” this possibility.

The mouse version of the IAPP protein cannot clump — and mice don’t develop type 2 diabetes, a sign that the accumulation of IAPP is important in the development of the disease, says Soto. To study the disease in mice, the animals need to be engineered to produce a human version of IAPP. When pancreas cells containing clumps of misfolded IAPP, taken from an engineered diabetic mouse, were mixed in a dish of healthy human pancreas cells, it triggered the clumping of IAPP in the human cells.
The same was true when non-diabetic mice got a shot made with the diabetic mouse pancreas cells. The non-diabetic mice developed deposits of clumped IAPP that grew over time, and the majority of beta cells died. When the mice were alive, more than 70 percent of the animals had blood sugar levels beyond the healthy range.

Soto’s group plans to study if IAPP could be transmitted in a real world scenario, such as through a blood transfusion. They’ve already begun work on transfusing blood from mice with diabetes to healthy mice, to see if they can induce the disease. “More work needs to be done to see if this ever operates in real life,” Soto says.

Even if transmission of the misfolded protein occurs only within an individual, “this opens up a lot of opportunities for intervention,” Soto says, “because now you can target the IAPP.”

Verchere also believes IAPP is “a big player” in the progression of type 2 diabetes, and that therapies that prevent the clumps of proteins from forming are needed. Whether or not future research supports the idea that the disease is transmissible, the study is “good for appreciating the potential role of IAPP in diabetes.”

Normally aloof particles of light seen ricocheting off each other

Cross two flashlight beams and they pass right through one another. That’s because particles of light, or photons, are mostly antisocial — they don’t interact with each other. But now scientists have spotted evidence of photons bouncing off other photons at the Large Hadron Collider at CERN, the European particle physics lab in Geneva.

“This is a very basic process. It’s never been observed before, and here it is finally emerging from the data,” says theoretical physicist John Ellis of King’s College London who was not involved with the study. Researchers with the ATLAS experiment at the LHC report the result August 14 in Nature Physics.
Because photons have no electric charge, they shouldn’t notice one another’s presence. But there’s an exception to that rule. According to quantum mechanics, photons can briefly transform into transient pairs of electrically charged particles and antiparticles — such as an electron and a positron — before reverting back to photons. Predictions made more than 80 years ago suggest that this phenomenon allows photons to interact and ricochet away from one another.

This light-by-light scattering is extremely rare, making it difficult to measure. But photons with more energy interact more often, providing additional chances to spot the scattering. To produce such energetic photons, scientists slammed beams of lead nuclei together in the LHC. Photons flit in and out of existence in the lead nuclei’s strong electromagnetic fields. When two nuclei got close enough that their electromagnetic fields overlapped, two photons could interact with one another and be scattered away.

To measure the interaction, ATLAS scientists sifted through their data to find collisions in which only two photons — the two that scattered away from the collision — appeared in the aftermath. “That’s the trickiest part of the whole thing,” says physicist Peter Steinberg of Brookhaven National Laboratory in Upton, N.Y., a member of the ATLAS collaboration. The scientists had to ensure that, in their enormous, highly sensitive particle detector, only two photons appeared, and convince themselves that no other particles had gone unaccounted for. The researchers found 13 such events over 19 days of data collection. Although other processes can mimic light-by-light scattering, the researchers predict that only a few such events were included in the sample.

The number of scattering events the researchers found agrees with the predictions of the standard model, physicists’ theory of particle physics. But a more precise measurement of the interaction might differ from expectations. If it does, that could hint at the existence of new, undiscovered particles.

This newfound hermit crab finds shelter in corals, not shells

A new species of hermit crab discovered in the shallow waters of southern Japan has been enjoying the perks of living like a peanut worm. Like the worms, the 7- to 8-millimeter-long hermit crab uses corals as a covering, researchers report September 20 in PLOS ONE.

Other kinds of hermit crabs live in coral reefs, but typically move in and out of a series of mollusk shells as the crabs grow. Diogenes heteropsammicola is the first hermit crab known to form a mutually beneficial relationship with two species of mobile corals called walking corals. Unlike more familiar coral species, these walking corals don’t grow in colonies and aren’t attached to the seafloor. Instead, each host coral grows with and around a crab, forming a cavity in the coral skeleton that provides a permanent home for the crustacean. In exchange, the crab helps the coral “walk.”
Walking corals are already known to be in a symbiotic relationship with a different sea creature — flexible, marine peanut worms called sipunculids. A symbiotic shift between such distantly related species as the worms and the crab is rare because organisms in a mutualistic relationship tend to be specialized and completely dependent on one other, says study coauthor Momoko Igawa, an ecologist at Kyoto University in Japan.
But similar to the worms, D. heteropsammicola appears to be well-adapted to live in the corals. Its extra slim body can slip inside the corals’ narrow cavity. And unlike other hermit crabs — whose tails curve to the right to fit into spiral shells — D.heteropsammicola’ s tail is symmetrical and can curl either way, just like the corals’ opening.
“Being able to walk around in something that is going to grow larger as you grow larger, that’s a big plus,” says Jan Pechenik, a biologist at Tufts University in Medford, Mass., who was not involved in the study. A typical hermit crab that can’t find a larger shell to move into “really is in trouble.”

D. heteropsammicola’s relationship with walking corals may begin in a similar way as it does with sipunculan worms, Igawa says. A walking coral larva latches onto a tiny mollusk shell containing a juvenile hermit crab and starts to grow. When the hermit crab outgrows the shell, the crustacean moves into the readily available host coral’s crevice, and the shell remains encapsulated in the coral.

By observing the hermit crab in an aquarium, Igawa and coauthor Makoto Kato, also an ecologist at Kyoto University, determined that the crab provides the corals with the same services as the worms: transportation and preventing the corals from being overturned by currents or buried in sediment.

Igawa hopes to search for this new hermit crab in Indonesia, a region where walking corals are normally found. Plus, because walking coral fossils are easy to come by in Japan, she also wants “to reveal the evolutionary history of the symbioses of walking corals [with] sipunculans and hermit crabs by observing these fossils.”

Seeing an adult struggle before succeeding inspires toddlers to persevere too

I recently wrote about the power that adults’ words can have on young children. Today, I’m writing about the power of adults’ actions. Parents know, of course, that their children keep a close eye on them. But a new study provides a particularly good example of a watch-and-learn moment: Toddlers who saw an adult struggle before succeeding were more likely to persevere themselves.

Toddlers are “very capable learners,” says study coauthor Julia Leonard, a cognitive developmental psychologist at MIT. Scientists have found that these youngsters pick up on abstract concepts and new words after just a few exposures. But it wasn’t clear whether watching adults’ actions would actually change the way toddlers tackle a problem.

To see whether toddlers could soak up an adult’s persistence, Leonard and her colleagues tested 262 13- to 18-month-olds (the average age was 15 months). Some of the children watched an experimenter try to retrieve a toy stuck inside a container. In some cases, the experimenter quickly got the toy out three times within 30 seconds — easy. Other times, the experimenter struggled for the entire 30 seconds before finally getting the toy out. The experimenter then repeated the process for a different problem, removing a carabiner toy from a keychain. Some kids didn’t see any experimenter demonstration.

Just after watching an adult struggle (or not), the toddlers were given a light-up cube. It had a big, useless button on one side. Another button — small and hidden — actually controlled the lights. The kids knew the toy could light up, but didn’t know how to turn the lights on.

Though the big button did nothing, that didn’t stop the children from poking it. But here’s the interesting part: Compared with toddlers who had just watched an adult succeed effortlessly, or not watched an adult do anything at all, the toddlers who had seen the adult struggle pushed the button more. These kids persisted, even though they never found success.

The sight of an adult persevering nudged the children toward trying harder themselves, the researchers conclude in the Sept. 22 Science. Leonard cautions that it’s hard to pull parenting advice from a single laboratory-based study, but still, “there may be some value in letting children see you work hard to achieve your goals,” she says.

Observing the adults wasn’t the only thing that determined the toddlers’ persistence, not by a long shot. Some kids might simply be more tenacious than others. In the experiments, some of the children who didn’t see an experimenter attempt a task, or who saw an experimenter quickly succeed, were “incredibly gritty,” Leonard says. And some of the kids who watched a persistent adult still gave up quickly themselves. That’s not to mention the fact that these toddlers were occasionally tired, hungry and cranky, all of which can affect whether they give up easily. Despite all of this variation, the copycat effect remained, so that kids were more likely to persist when they had just seen a persistent adult.

As Leonard says, this is just one study and it can’t explain the complex lives of toddlers. Still, one thing is clear, and it’s something that we would all do well to remember: “Infants are watching your behavior attentively and actively learning from what you do,” Leonard says.

These spiders may have the world’s fastest body clocks

WASHINGTON, D.C. — If it takes you a while to recover from a few lost hours of sleep, be grateful you aren’t an orb weaver.

Three orb-weaving spiders — Allocyclosa bifurca, Cyclosa turbinata and Gasteracantha cancriformis — may have the shortest natural circadian rhythms discovered in an animal thus far, researchers reported November 12 at the Society for Neuroscience’s annual meeting.

Most animals have natural body clocks that run closer to the 24-hour day-night cycle, plus or minus a couple hours, and light helps reset the body’s timing each day. But the three orb weavers’ body clocks average at about 17.4, 18.5 and 19 hours respectively. This means the crawlers must shift their cycle of activity and inactivity — the spider equivalent of wake and sleep cycles — by about five hours each day to keep up with the normal solar cycle.
“That’s like flying across more than five time zones, and experiencing that much jet lag each day in order to stay synchronized with the typical day-night cycle,” said Darrell Moore, a neurobiologist at East Tennessee State University in Johnson City.

“Circadian clocks actually keep us from going into chaos,” he added. “Theoretically, [the spiders] should not exist.”

For most animals, internal clocks help them perform recurring daily activities, like eat, sleep and hunt, at the most appropriate time of day. Previous studies have shown that animals that are out of sync with the 24-hour solar cycle are usually less likely to produce healthy offspring than those that aren’t.
Moore and his colleagues were surprised to find the short circadian clocks while studying aggression and passivity in an orb weaver. The team was trying to see if there was a circadian component to these predatory and preylike behaviors, when they discovered C. turbinata’s exceptionally short circadian cycles. “I was looking at this thing thinking, ‘That can’t be right,’” said Moore.

To measure spiders’ natural biological clocks without the resetting effect of the sun, the researchers placed 18 species of spiders in constant darkness and monitored their motion. Three orb weaver species in particular had incredibly short cycles of activity and inactivity.

As far as the researchers know, the short cycle does not seem to be a problem for these spiders. In fact, it might even be useful. Short clocks may help these orb weavers avoid becoming the proverbial “worm” to the earliest birds, the researchers hypothesize. Since the spiders become more active at dusk and begin spinning their webs three to five hours before dawn, they can avoid predators that hunt in the day.

Throughout the day, the spiders remain motionless on their web, prepared to pounce on their next meal. By midday, the spiders’ truncated circadian clocks should have reset, sparking a new round of activity. But in the five to seven hours of daylight left, the orb weavers remain inactive. It’s hard to say whether the spiders are actually resting, Moore said. The researchers suspect that light may delay the onset of another short circadian cycle each day, helping the spiders stay synchronized with the 24-hour environmental cycle.

“The method or molecular mechanism will be really fascinating to figure out,” said Sigrid Veasey, a neuroscientist at the University of Pennsylvania’s Perelman School of Medicine. She is curious to know how the spiders can be so far off from “normal” circadian periods, and still be able to match their activity to the 24-hour light and dark cycle.

Determining the differences between short and normal period clocks in spiders may help researchers find out why and how different circadian clocks are suited to the particular environmental challenges of each species, Moore said.

Blowflies use drool to keep their cool

SAN FRANCISCO — Blowflies don’t sweat, but they have raised cooling by drooling to a high art.

In hot times, sturdy, big-eyed Chrysomya megacephala flies repeatedly release — and then retract — a droplet of saliva, Denis Andrade reported January 4 at the annual meeting of the Society for Integrative and Comparative Biology. This process isn’t sweating. Blowfly droplets put the cooling power of evaporation to use in a different way, said Andrade, who studies ecology and evolution at the Universidade Estadual Paulista in Rio Claro, Brazil.
As saliva hangs on a fly’s mouthparts, the droplet starts to lose some of its heat to the air around it. When the fly droplet has cooled a bit, the fly then slurps it back in, Andrade and colleagues found. Micro-CT scanning showed the retracted droplet in the fly’s throatlike passage near the animal’s brain. The process eased temperatures in the fly’s body by about four degrees Celsius below ambient temps. That may be preventing dangerous overheating, he proposed. The same droplet seemed to be released, cooled, drawn back in and then released again several times in a row.

Andrade had never seen a report of this saliva droplet in-and-out before he and a colleague noticed it while observing blowfly temperatures for other reasons. But in 2012, Chloé Lahondère and a colleague described how Anopheles stephensi mosquitoes that exude a liquid droplet that dangles and cools, but at the other end of the animals.

Mosquitoes, which let their body temperatures float with that of their environment, can get a heat rush when drinking from warm-blooded mammals. While drinking, the insects release a blood-tinged urine droplet, which dissipates some of the heat. There’s some fluid movement within the droplet, says Lahondère, now at Virginia Tech in Blacksburg, but whether any of the liquid gets recaptured by the body the way fly drool is, she can’t say.

Lakers vs. Warriors final score, results: Golden State forces Game 6 as Anthony Davis suffers head injury

Faced with a do-or-die situation in Game 5, the Warriors came up big.

A 121-106 win at Chase Center kept Golden State’s season alive as they successfully avoided elimination at the hands of the Lakers. The series will now head back down to Los Angeles for Game 6, where LeBron James and Co. will have another chance to punch their ticket to the Western Conference Finals.

Stephen Curry led the way for the Warriors with 27 points and eight assists. Andrew Wiggins finished with 25 points and seven rebounds, while Draymond Green had one of his best games of the postseason with 20 points and 10 rebounds.

A bad night got even worse for LA when Anthony Davis was forced to leave the game late in the fourth quarter. He appeared to take a shot to the face from Golden State’s Kevon Looney, and TNT’s Chris Haynes reported that he was taken down the tunnel in a wheelchair. The Lakers now face an anxious wait to see whether he’ll be good to go for a massive Game 6.

The Sporting News was tracking all the key moments as the Warriors defeated the Lakers in Game 5 of the Western Conference semifinals:

Lakers vs. Warriors score
Team Q1 Q2 Q3 Q4 Final
Lakers 28 31 23 24 106
Warriors 32 38 23 28 121
Lakers vs. Warriors live score, updates, highlights from Game 5
12:31 a.m. FINAL — The final buzzer rings out, and we’re headed to a Game 6. Curry finishes with 27 points, Wiggins with 25 and Draymond Green with 20.

12:27 a.m. — Darvin Ham has raised the white flag and sent in his reserves. Golden State is going to get the win, and their season is going to continue. An excellent performance by the Warriors tonight with their backs against the wall.

12:24 a.m. — Both teams continue to trade blows, but with time ticking down, the Warriors look like they’re going to cruise to a win here. Davis still hasn’t returned to the court, and it sounds like he may be dealing with some dizziness and vision difficulties. He’ll probably be sidelined for the rest of the game.

12:19 a.m. — Steph with a big shot! A triple from the corner extends the lead back to 14 points! It’s Warriors 109, Lakers 95 as we enter the final minutes.

12:16 a.m. — Draymond gets the crowd on its feet with a nice jumper, but Austin Reaves answers at the other end with a three from way downtown! The Lakers have chipped away and the lead is now down to just nine points with 5:25 left.
12:14 a.m. — Davis is having to head down the tunnel and towards the locker room after that injury. TNT’s Chris Haynes reported he looked a little shaky on his feet and needed some help to stay upright. Let’s hope he’s OK.

12:09 a.m. — Gary Payton II finishes with the hoop and harm over LeBron, and the crowd is loving it. To add insult to injury for the Lakers, Anthony Davis appeared to take an elbow to the face on the other end. He appears to be in significant discomfort, and he is forced to head to the bench.

12:03 a.m. — Any momentum the Lakers may have had has quickly vanished early in the fourth quarter. Curry drains a pull-up jumper with the shot clock winding down, then Wiggins converts on a running floater in the lane to stretch the lead back to 15 points. LA is running out of time here.
11:55 p.m. END OF THIRD QUARTER — The Lakers use a mini-run to cut into the lead slightly. LeBron converts on a layup with time winding down in the quarter, and we enter the final frame with Golden State up 93-82. James appeared to land on the foot of Wiggins on that last shot, and he was grimacing a little bit as he walked away. Something to keep an eye on.

11:49 p.m. — With the third quarter winding down, the Warriors are showing no signs of letting up. Curry just blew right by three defenders for an easy layup, and once again Darvin Ham has used a timeout to try and spark something from his team.

11:41 p.m. — How about Draymond Green in this game? He’s been sensational so far, racking up 18 points on 6 of 10 shooting from the field. He just converted on another layup to make it 85-70, Warriors.

11:32 p.m. — The Lakers are off to a terrible start in this half, and in the blink of an eye the Warriors have stretched their lead to 18 points! Wiggins caps off a 9-2 Golden State flurry with a one-handed putback slam and Darvin Ham takes a timeout to stop the bleeding. That could be a huge momentum swing in this game.
11:27 p.m. START OF SECOND HALF — And away we go in the third quarter. Can the Warriors hold off the Lakers to stay alive?

11:20 p.m. — Davis leads all scorers with 18 points at the half while Wiggins leads Golden State with 16. James has 17 and Curry has 12, including that buzzer-beater to make it an eleven-point game.

11:11 p.m. END OF FIRST HALF — Stephen Curry lights up Chase Center with a three to beat the buzzer! That’s just his second trey of the night, but it sends the Warriors into the locker room with a 70-59 lead! They ended the half on a 16-5 run to take control of Game 5.
11:03 p.m. — We knew a run was coming from one of these teams, and this time it has come from the Warriors! Poole connects from deep, then Wiggins follows it up with a triple of his own. After a Lakers timeout, the home team leads 64-56 with less than two minutes left in the half.

10:56 p.m. — LeBron isn’t cooling off, and he drives for a layup then knocks down a three moments later to tie things up at 50 apiece. Back and forth we go.

10:51 p.m. — Andrew Wiggins gets a bucket and a foul, then does it again less than 40 seconds later! That pair of three-point plays puts the Warriors back in the lead by five with seven minutes remaining in the first half.

10:45 p.m. — Now LeBron is starting to get going! He buries a pair of three-pointers to take his tally to 12 points on the night and give the Lakers the lead. After he sinks a pair of free throws, it’s 41-40, LA.
10:37 p.m. END OF FIRST QUARTER — Whew, time to catch your breath! A Jordan Poole floater with six seconds left on the clock has made it 32-28 Warriors at the end of the first quarter. They could really use a good performance from him tonight. If the game continues like this, we’re in for a treat.

10:35 p.m. — This game has been fast-paced and a lot of fun so far. Davis continues to fill it up and he’s up to 13 points as we near the end of the first quarter. But 20-year-old Moses Moody has knocked down a pair of threes to keep Golden State’s lead intact. They’re up 30-26 with just over a minute left in the period.

10:27 p.m. — But here come the Lakers! Anthony Davis is getting himself involved, and his putback dunk cuts the Warriors’ lead to just five points. He has nine points already in the early going.

10:20 p.m. — This has been one heck of a start by the Warriors. Gary Payton II drains a three, Draymond converts on another layup and then Stephen Curry opens his account for the night with a three from way downtown. The home team is out to a 17-5 lead less than five minutes into the game.
10:17 p.m. — Draymond Green is off to a fast start! He buries a three to get the Warriors on the board, and his layup through contact draws a foul and leads to a three-point play. Golden State leads 9-3 early.

10:12 p.m. — And there’s the opening tip. We are underway in San Francisco.

10:07 p.m. — Knicks-Heat just wrapped up. meaning Warriors-Lakers is up next on TNT. Can Golden State do what New York did and stave off elimination at home in Game 5?

9:59 p.m. — Steph was doing Steph things in pregame warmups.
9:52 p.m. — No surprises from the Lakers with their starting lineup.
9:46 p.m. — For the second game in a row, Gary Payton II gets the start for Golden State.
What channel is Lakers vs. Warriors on?
Date: Wednesday, May 10
TV channel: TNT
Live streaming: Sling TV
Lakers vs. Warriors will air on TNT. Viewers can also stream the game on Sling TV.

Fans in the U.S. can watch the NBA Playoffs on Sling TV, which is now offering HALF OFF your first month! Stream Sling Orange for $20 in your first month to catch all the games on TNT, ESPN & ABC. For games on NBA TV, subscribe to Sling Orange & Sports Extra for $27.50 in your first month. Local regional blackout restrictions apply.

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What time is Lakers vs. Warriors tonight?
Date: Wednesday, May 10
Time: 10 p.m. ET | 7 p.m. PT
Lakers vs. Warriors will tip off around 10 p.m. ET (7 p.m. local time) on Wednesday, May 10. The game will be played at the Chase Center in San Francisco.

Lakers vs. Warriors odds
Golden State is a 7.5-point favorite heading into Game 5.

 Warriors    Lakers

Spread -7.5 +7.5
Moneyline -350 +260
For the full market, check out BetMGM.

Lakers vs. Warriors schedule
Here is the complete schedule for the second-round series between Los Angeles and Golden State:

Date Game Time (ET) TV channel
May 2 Lakers 117, Warriors 112 10 p.m. TNT
May 4 Warriors 127, Lakers 100 9 p.m. ESPN
May 6 Lakers 127, Warriors 97 8:30 p.m. ABC
May 8 Lakers 104, Warriors 101 10 p.m. TNT
May 10 Game 5 10 p.m. TNT
May 12 Game 6* TBD ESPN
May 14 Game 7* TBD ABC