Readers question photons colliding, black sea snakes and more

Your letters and comments on the September 16, 2017 issue of Science News

Brain boost

It’s possible that therapies such as external brain stimulation and neurofeedback, as well as some drugs, may one day boost brain flexibility. A new line of research suggests flexibility is important for learning, Laura Sanders reported in “Learning takes brain acrobatics” (SN: 9/16/17, p. 22).

Online reader Glenn wondered if drugs for Parkinson’s disease and Huntington’s disease that help with movement problems could also remedy learning difficulties that accompany these conditions.

“Currently, there are no drugs that can stop or reverse the neural damage from either disease, though some drugs help with symptoms,” Sanders says. “But scientists are studying whether the Parkinson’s drug levodopa, which can ease movement symptoms, can also influence brain functions such as memory, quick thinking and learning.”

The skinny on sea snakes

Polluted waters may be driving more sea snakes to go all black, a sign of an evolutionary phenomenon called industrial melanism, Susan Milius reported in “Polluted reefs may favor dark snakes” (SN: 9/16/17, p. 14).

“Is it possible that increased melanin production in sea snakes is a sign of arsenic poisoning as it is in humans?” Mark Moberg asked. He also wondered if an observed increase in algae that adhere to the snakes’ skin might also be a sign of arsenic poisoning.

The higher frequency of black-bodied snakes seems to be due to genetics, not arsenic poisoning, says Rick Shine, an evolutionary biologist at the University of Sydney. Shine points to genetics because “a snake doesn’t change its color from the time it is born until it dies,” he says. And the higher incidence of algae on dark surfaces doesn’t just apply to the snakes. The researchers found that algae also congregated on painted pipes in the snakes’ environment. “It’s a simple attraction to the color, not an effect of the poison,” he says.

Hit and run

Scientists spotted evidence of two photons ricocheting off one another at the Large Hadron Collider, Emily Conover reported in “Normally aloof particles of light seen ricocheting off each other” (SN: 9/16/17, p. 7).

Online reader David Laing wondered how photons, which are theoretically massless, can transform into particles with mass that may interact.

Massless particles with enough energy can convert some of that energy into mass, Conover says. “Remember Einstein’s equation E=mc2! But photons can briefly convert into massive particles even if they don’t have enough energy thanks to Heisenberg’s uncertainty principle.” A photon can convert into an electron and a positron for a brief instant before those particles revert back into a single photon. “These so-called ‘virtual’ particles allow light to scatter off of other light,” she says.

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