Q. Over fifty years ago, a young woman was raped and murdered in the early morning in her quiet Queens, New York, neighborhood. Reportedly, some 38 witnesses failed to intervene, leading psychologists to propose “the bystander effect.” What exactly is that?
A. The bystander effect suggests that in a robbery or a stabbing, for instance, people are less likely to step in if there are other bystanders in the area, so the chances of intervention actually decrease, explains Grace Browne in “New Scientist” magazine. Now Richard Philpot and his UK colleagues are saying the effect may be just a myth. Looking at surveillance footage of violent situations in the UK, South Africa and the Netherlands, they found that “in 90% of the cases, at least one person, but typically several, intervened to try to help.” Also, the more people present, the greater the likelihood of intervention (“American Psychology”).
It was surprising, say the researchers, that “the likelihood of intervention was similar across all three nations, despite South Africa recording significantly lower perceptions of public safety, as well as higher levels of violence, on average.” Philpot hopes that these results will be reassuring to the general public, showing that people “have a natural instinct to help when they see someone in need.”
Q. Can plants hear?
A. There’s compelling evidence that the beach evening primrose hears the buzz of bees and welcomes the potential pollinators by rapidly increasing the sweetness of its nectar (“Ecology Letters”). Marine Veits and her colleagues at Tel-Aviv University studied hundreds of the plants over more than two years. They emptied flowers of their nectar, exposed them to various recorded sounds – including bees, pure frequencies, and silence – and then, three minutes later, measured the sugar concentration of any new nectar. They found that bee and bee-like sounds increased the sweetness, on average, by 20 percent compared to silence or other sounds. And using laser Doppler vibrometry, they confirmed that the flower petals resonate to the bee-like sounds, suggesting that flowers function as ears, tuned to the wingbeats of potential pollinators.
As the authors conclude: “Our results document for the first time that plants can rapidly respond to pollinator sounds in an ecologically relevant way. Potential implications include plant resource allocation, the evolution of flower shape and the evolution of pollinators’ sound. Finally, our results suggest that plants may be affected by other sounds as well, including anthropogenic ones.”
Q. Who is Alice, and how is “she” revolutionizing the airline industry?
A. Actually, the Alice is the first commercial all-electric, battery-powered nine-seat airplane that can fly up to 1,000 kilometers (620 miles) on a single charge, says Mark Alexander in “IEEE Spectrum” magazine.
Manufactured by Israeli-based Eviation Aircraft, it will be powered by a 900-kilowatt-hour lithium battery, compared to the 50-to-75 kWh battery pack in a Tesla Model 3 electric car. As Eviation CEO Omar Bar-Ohay explained, since no fuel is burned during flight, the plane’s take-off weight (6,350 kilograms, or 14,000 pounds) is more or less its landing weight, with the battery accounting for 3,700 kg. Also, each of the plane’s three motors has only one moving part, compared to 10 in a standard reciprocating engine, offering both reliability and low maintenance.
And since the Alice relies only on electric charge, “the cost of operating the plane is expected to be lower than for its petroleum-fueled counterparts.” The noise levels should also be lower, and the e-aircraft will be capable of varying its propeller speed to compensate for crosswinds and to lower cabin noise.
Watch for the Alice on the horizon in 2022.