Quantum fluctuations have been shown to affect macroscopic objects

Quantum fluctuations have been shown to affect macroscopic objects

View this email in your browser Wednesday 1 July 2020

Hello Nature readers, Today we learn that there are flying snakes and their wiggle helps them glide. Plus, we grapple with 40-kilogram quantum objects and dig into the difficult question of herd immunity to COVID-19.

Flying snakes (Chrysopelea) are the only known limbless vertebrates capable of flight.

Shimmy helps snakes fly through the air Winding from side to side keeps flying snakes stay stable and helps them to glide further. Watch how researchers used motion-capture technology to study snake gliding in precise detail in this video from Nature. Nature | 4 min videoReference: Nature paper

How flatworms regrow their eyes Flatworms have uncanny regenerating abilities: they can regrow into a whole organism from a body piece as small as one-279th of the original size. Researchers now have shown that specialized cells hidden throughout the body act as guides for regeneration. When the flatworm Schmidtea mediterranea is growing new eyes, the cells help eye neurons to grow connections to the brain. Similar guidepost cells have an important role in embryo development in many animals, says biologist Peter Reddien, but are absent in typical adult organisms. New York Times | 3 min readReference: Science paper

Democrats offer ambitious climate plan A Democrat-led US government committee charged with coming up with a detailed climate plan has released its recommendations for saving the world. One of the report’s overall targets is net-zero carbon-dioxide emissions in the United States before 2050. To get there, the report offers 12 ‘pillars’, including investing in green-technology industries and strengthening support for climate-science research. “I am very heartened to see the detail and ambition that the committee has put forward,” says energy-policy researcher Leah Stokes, who kindly broke down the 500+-page report in a Twitter thread. How much of the plan will be implemented comes down to the outcome of the imminent US elections in November. Vox | 10 min readReference: Solving the Climate Crisis report (or just the 2-page summary)

COVID-19 coronavirus update The thorny problem of herd immunity The concept of ‘herd immunity’ is fairly simple. When enough people are immune to COVID-19 — whether by vaccination or by having survived infection — the spread starts to slow because there are not enough people to infect. But how many need to be immune before that happens? It’s a tricky question, especially when the protection is acquired naturally, rather than by immunization. People are physically different in their susceptibility to infection. And where you live, and your living conditions, make a difference, too. The threshold could be much higher in densely packed cities — and the hardest-hit places in the world might already be close to reaching it.Quanta | 8 min read

NOTABLE QUOTABLE “What was thought to be unimaginable turns out to be the reality we’re facing right now.” The United States, which has struggled to contain its COVID-19 outbreak, is on a path to recording 100,000 new cases per day, says physician Anthony Fauci, the director of the US National Institute of Allergy and Infectious Diseases and the face of the country’s pandemic response. (STAT | 4 min read)

Features & opinion

A simple, measurable goal for biodiversity? Last month, a team of researchers proposed creating one headline number to measure how well we are protecting biodiversity. They suggested that countries should aim to keep extinctions to “well below” 20 known species worldwide every year. The idea deserves serious consideration and thorough assessment, argues a Nature editorial. Nature | 5 min read

How digital cameras changed us The totality of humankind is expected to take more than 1.4 trillion photographs in 2020 — the vast majority of those through mobile phones, and almost all of them digital. The technology has come a long way since 1974, when a young engineer named Steven Sasson “MacGyvered” the first prototype digital camera: a 100-by-100-pixel, toaster-size device that recorded images on a cassette tape. Digital images have become so crucial to scholars’ work that some are starting to wonder whether they should get formal training in digital photography, writes historian Allison Marsh. “Today, people aren’t just watching history. They’re recording it and sharing it in real time.” IEEE Spectrum | 8 min read

News & views

LIGO overcomes quantum limit The Laser Interferometer Gravitational-wave Observatory (LIGO) works by continuously monitoring the distance between mirrors that face each other and are several kilometres apart. Its detectors bounce lasers between the mirrors to sense changes in that distance on the order of one part in 1022. The quest to improve LIGO’s sensitivity has hit a wall owing to the law of quantum uncertainty, which says that the position and momentum of an object cannot both be measured to arbitrary precision. To beat that limit, physicists at LIGO and at its sister observatory Virgo have recently tweaked their lasers to introduce quantum correlations between the positions of the mirrors and the laser light. Now, LIGO physicists have demonstrated that their 40-kilogram mirrors do indeed act as quantum objects. “This is remarkable, because such fluctuations occur at size scales that are comparable to the dimensions of elementary particles,” write physicists Valeria Sequino and Mateusz Bawaj. Nature | 7 min readReference: Nature paper