Physicists detect waves from a black hole collision for the fourth time - Axios
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Physicists detect waves from a black hole collision for the fourth time

Illustration: Rebecca Zisser / Axios

Physicists today reported observing waves in space and time from the collision of two black holes 1.8 billion light years away. It's the fourth time in two years these ripples formed from black hole mergers have been spotted, but this time they were able to more precisely locate where the collision took place in our universe.

Why it matters: It demonstrates that three detectors — two are nearly aligned and one is not — can be used to track these events in three dimensions. Ultimately, physicists want to combine observations from these detectors with those from optical telescopes to both "see" and "hear" events like neutron stars colliding, which could explain the origins of heavy elements, and test Einstein's general theory of relativity.

What they saw: On August 14, the Laser Interferometer Gravitational-Observatory (LIGO) detectors in Washington and Louisiana along with the Virgo detector in Italy observed waves from two black holes (one 31 times the mass of the Sun and the other 25 times the mass) combining to form one 53 times larger in mass than the Sun.

They also analyzed how the gravitational waves distorted space and time. What they saw was consistent with Einstein's prediction that they would "stretch and squeeze spacetime in the plane perpendicular to their direction of travel."

Sound smart: The sum of the two colliding black holes was three solar masses more than the black hole that formed, meaning the mass of three Suns was converted into the energy of the gravitational waves.

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Trump signs policy directive to send Americans back to the moon

Trump with astronaut Buzz Aldrin while signing an executive order to re-establish the National Space Council in June. Photo: Evan Vucci / AP

President Trump signed a policy directive for NASA to "refocus America's space program on human exploration and discovery." He said the move "marks a first step in returning American astronauts to the Moon for the first time since 1972."

Go deeper: Vice President Mike Pence says Americans will go to the moon, and then Mars

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Saturn moon map reveals seas, underground rivers

A mosaic image of Titan's liquid methane and ethane seas. Photo: JPL-CALTECH / NASA / ASI / USGS

The most complete map to date of Saturn’s moon Titan reveals a mountainous world with a network of liquid methane and ethane lakes and seas connected by underground rivers, writes Lisa Grossman for Science News. Scientists already knew that Titan had something like Earth’s water cycle, but with methane. This is the latest finding from the Cassini mission to show the startling geological complexity of the hazy, gassy moon.

Why it matters: Scientists are very interested in Titan’s geology because they believe the hydrocarbon-rich planet has the potential to support some form of life. An interconnected water system, like the one on Earth, could influence the way any such life would develop. “Looking for actual evidence that the lakes could be communicating was a fundamental question from Cassini,” study coauthor Alexander Hayes tells Grossman, “This is the final paper that gives the best evidence that it exists.”

What they did: When Cassini flew over Titan 13 years ago, the robot scanned the planet and measured elevation. They used radar to identify lakes, seas and mountain ranges.

What they found: When they analyzed the altitude of Titan’s largest bodies of liquid methane, they found they were all at about the same level, like sea level on Earth. For them to stay level, they need to be connected. The map also details mountain ranges across the planet, including the southern hemisphere, and reveals high-altitude dry lakebeds that could be sinkholes or the remnants of volcanoes.

What’s next: The map, which was published December 2 in the journal Geophysical Research Letters, will likely be used by other scientists studying the Saturnian moon’s geology. “Within hours of the paper actually being available online, people we’ve never collaborated with started contacting [Hayes’ co-author, Paul Corlies] to ask how to get the data,” Hayes told Grossman.

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In early trial, new drug silences Huntington’s disease gene

An experimental drug could slow the spread of Huntington's disease, giving hopes to patients suffering from uncontrolled movements and mental confusion associated with the disease, reports The Guardian. An early-stage trial of the drug was conducted with 46 patients in the UK, Germany and Canada.

Why it matters: Huntington's disease is an inherited condition resulting from a genetic mutation. Current treatments can only help minimize the symptoms, instead of slowing it down.

Professor Sarah Tabriz at UK's University College of London said in a statement on Monday that the drug has lowered the level of the “toxic disease-causing protein in the nervous system, and the drug was safe and well-tolerated. The key now is to move quickly to a larger trial to test whether the drug slows disease progression.”

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Study finds global warming will boost economy for warm-weather activities

Newly assembled bike share bicycles staged for distribution in Philadelphia. Photo: Matt Rourke / AP

A new paper uses a big, multi-year dataset from bike-sharing programs in North America to conclude that climate change could boost the wider outdoor recreation economy for warm-weather activities.

Bottom line for North America: The authors see economic gains of $900 million annually for cycling alone and $20.7 billion per year for outdoor recreation more broadly by 2060.

More from the study, conducted by Resources For the Future fellow Casey Wichman and University of Massachusetts resource economics expert Nathan Chan:

  • Why study bike-sharing? "[C]ycling shares common attributes with other forms of outdoor recreation, such as running, hiking, and swimming, which are all low-fixed-cost, everyday activities with benefits that depend on the pleasantness of weather conditions," the study notes.
  • Why it matters: "Despite extensive research detailing the effects of climate change on economic production, human health, and natural capital, we have relatively few causal estimates of climate change effects in other realms, especially nonmarket activities. In this paper, we help fill this gap by quantifying impacts for leisure," the paper states.
  • Yes, but: They're not saying global warming is a good thing. The authors note in a blog post that climate change will impose huge net costs on the U.S. and elsewhere, but add that their research can help with providing a full accounting for its many impacts.
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The mental health crisis among young Americans, by the numbers

Illustration: Sam Jayne / Axios

One in five American young adults under the age of 25 lives with a mental illness or behavioral disorder, NBC reports, citing the Centers for Disease Control and Prevention.

The big picture: Per the CDC's research, the state of young adult mental health in the U.S. is only worsening, with the suicide rate among teenage girls reaching a 40-year high in 2015. Here's a look at the numbers that tell the story of this crisis.

The numbers:

  • 15 million, or 1 in 5, American children and young adults battle mental illnesses or learning disorders.
  • 10 million, or two-thirds of them, are undiagnosed or aren't receiving treatment.
  • Among children ages 3 to 17: 6.8% are diagnosed with ADHD, 3.0% suffer from anxiety, 2.1% suffer from depression
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A way to treat genetic disease without editing the genome

The Belmonte lab's advanced in vivo Cas9-based epigenetic gene activation system enhances skeletal muscle mass and fiber size growth in a treated mouse (right) compared with an independent control (left). The fluorescent microscopy images show purple staining of the laminin glycoprotein in tibialis anterior muscle fibers. (Credit: Salk Institute)

Soon, we might not just be editing DNA itself, but how and when the genes it encodes are expressed. In a paper published Thursday in the journal Cell, scientists from the Salk Institute report using the gene-editing tool CRISPR in mice to alleviate symptoms of type 1 diabetes and Duchenne muscular dystrophy, without making edits to the actual genome. Instead, they used CRISPR to turn the genes on and off.

Why it matters: Genetic editing to treat disease raises questions about the ethics of permanently changing someone’s DNA. These edits are reversible. CRISPR also involves cutting both strands of DNA, which some scientists are concerned could lead to unexpected and unwanted mutations. By altering the expression of genes rather than the genetic material itself, researchers hope to avoid these potential problems and treat diseases that aren't caused by genetic mutations.

Sound smart: Epigenetics is the study of how our genes are regulated. Every cell in our body contains the same DNA, but those cells behave differently depending on which genes are turned on or off. That happens when molecules attach to them and prevent the genetic blueprint from being read. These changes are involved in a host of diseases, including some cancers, but also allow us to adjust to our environment without editing our actual genetic material. Scientists hope to harness this power to treat illnesses.

What they did: To treat type 1 diabetes, the researchers used CRISPR to convince liver cells to behave like a pancreas and produce insulin. For Duchenne muscular dystrophy, which causes muscle wasting, they turned on genes that code for follistatin, a protein that codes muscles.

Yes, but: This technique isn’t for every disease, study authors Hsin-Kai (Ken) Liao and Fumiyuki Hatanaka tell Axios. It can’t correct diseases caused by mutations, for example — something that many scientists hope CRISPR gene editing will be able to do. But it can also treat some diseases that traditional gene editing cannot.

What’s next: This study didn’t look to see if the technique was safe — just if it worked. Liao and Hatanaka say they need to make sure the body’s immune system doesn’t attack the CRISPR system being used.

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New dinosaur discovery highlights fake fossil concerns

Visitors to the American Museum of Natural History examining a replica of a 122-foot-long dinosaur on display. Photo: Mary Altaffer / AP

The distinction between authentic and fake dinosaur fossiles is similar to that of artwork: sometimes blatantly obvious, and other times apparent to only experts. Some are questioning whether a fossil of a new dinosaur called Halszkaraptor— with "a bill like a duck but teeth like a croc's, a swanlike neck and killer claws," according to the AP — is real.

Why it's happening: There's a large market for fossils, which has led people "trying to earn a buck" to forge them for cash, Ed Yong writes at the Atlantic.

  • Forgers can make fossils appear more dramatic or novel by adding feathers, reconstructing tiny features, or even gluing specimens together to make them appear as one.
  • But one of the red flags about Halszkaraptor for Steve Brusatte from the Unviersity of Edinburgh is its murky past. Per Yong, the fossil traveled from Mongolia to Japan and Britain, and then France, which gives "few reassurances and many chances for tampering."
  • Philip Currie, at the Unviersity of Alberta, was one of the scientists called in to test Halszkaraptor's authenticity. He used a synchorotron to observe the "continuity of the bones and the rocks," and said he's "at least a 9" out of 10 on how sure he is that the fossil is real.
  • Currie told the Atlantic the only way to be absolutely positive, is if another team finds another fossil of the same specimen on their own.

Keep in mind: Fake fossils generally have "little impact" on our knowledge of dinosaurs, the Atlantic reports, because they aren't typically the subject of scientific research.

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Hormonal birth control linked to breast cancer, study says

A one-month pack of hormonal birth control pills. Photo: Rich Pedroncelli / AP

Women who use hormonal birth control — pills or devices that release hormones — are at a slightly higher risk for breast cancer, per a new study published in the New England Journal of Medicine.

Why it matters: It "upends widely held assumptions about modern contraceptives for younger generations of women," who think hormonal contraceptives are safer than old methods that contained higher amounts of estrogen, the New York Times reports.

The numbers: Scientists studied 1.8 million Danish women for over a decade and found those who used hormonal contraceptives had about a 20% increased risk of developing breast cancer. Among women who used hormonal birth control for more than 10 years, the risk rose to 38%. The study estimates 55 cases of breast cancer among every 100,000 women who do not use hormonal contraceptives and 68 cases among every 100,000 who do.

The bottom line: The study showed a relatively small increased risk for cancer among women who used these forms of contraceptives. Still, “there was a hope that the contemporary preparations would be associated with lower risk ... This is the first study with substantial data to show that’s not the case," David J. Hunter, a professor of epidemiology and medicine at the University of Oxford, told the NYT.

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Map of Southern California fires

Here's a look at where fires have been detected in Southern California as of 4 p.m. Eastern Time using data from NASA's MODIS and VIIRS instruments.

Data: NASA's MODIS and VIIRS instruments, CAL FIRE; Map: Lazaro Gamio / Axios
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A rare fossil find and a new horseshoe crab

Vaderlimulus horseshoe crab fossil. Photo: New Mexico Museum of Natural History & Science

Before there were birds, mammals and dinosaurs, horseshoe crabs were here. Over the past 450 million years, these relatives of scorpions and spiders (not crabs) passed through five mass extinctions. They stuck to the coasts for the most part so there was little pressure for them to evolve. The horseshoe crabs you see today look similar to their earliest ancestors.

What's new: A recent fossil find in Idaho indicates that in the time in between some ancient horseshoe crabs were more diverse than previously thought. The 245-million-year-old specimen, from when the state sat on the coast of the supercontinent Pangea, is "a missing puzzle piece," Allan Lerner, a research associate in paleontology at the New Mexico Museum of Natural History and Science, tells Axios.

The past: Every now and again, horseshoe crabs ventured out — or rather in — to freshwater environments. When they did, their morphology is thought to have changed. The fossil record during this time is sparse though because horseshoe crabs lack an exoskeleton with minerals that can be preserved except under exceptional conditions.

The discovery: The fossil found in Idaho is so far the only specimen of a new genus called Vaderlimulus with a large — "extravagant would be a good word," Lerner says — helmet and small body that evolved as it expanded into a freshwater environment. Eventually it went extinct though Lerner says they aren't sure why.

The future: This discovery shows horseshoe crabs used to be diverse. But today, only four species remain, and they're in decline due to human actions.

"We shouldn't take for granted that because they have lived as long as they have they will survive," Lerner says.