Alan Alda says he's "all ears" for scientists to answer a question for him and 11-year-old children around the world: What is sound?

That's the challenge being posed in the 2016 "Flame Challenge" contest, which asks scientists to explain complicated concepts in ways young people can understand.

The TV and film star, who teaches at the Alan Alda Center for Communicating Science at Stony Brook University on Long Island, started the challenge in 2011, which has explained time, color, and of course, what is a flame.

Scientists have until Jan. 19 to submit entries in either written or video form. Eleven-year-olds will judge the entries. The winner in each format gets $1,000.

Fewer snowy Swedish winters

Snowy white winters are likely to become a thing of the past for most Swedes.

The national weather service released a new analysis of how climate change will affect the Nordic country — and it's bad news for skiing enthusiasts. It said the length of the snowy season is expected to shrink by 40-80 days by the end of the century, depending on what action governments take to fight global warming. That means the southern third of the country, where most of the population lives, would get very few, if any, days with snow cover.

How much of your brain do you use?

How many times do you have to be told? That line about humans using only 10 percent of their brains is not true. Yet, according to studies, about two-thirds of Americans still believe it.

So Popular Science magazine is debunking it again, as Myth No. 1 in "Brain Myths Busted," a roundup of misstatements. Having dispensed with that cliché ("we use every part of our brain, though not all regions are active at once"), writer Megan Scudellari goes on to challenge some other familiar beliefs. Adults can't grow new brain cells? In 1998, Swedish scientists showed that the hippocampus forms new cells throughout life; in 2014, Swedes learned to carbon-date brain cells and confirmed that the striatum, another brain region, also keeps regenerating.

Gaining insight into some Itches

Some kinds of itching can be caused by the lightest of touches, a barely felt graze that rustles tiny hairs on the skin's surface. This type of itch is created via a dedicated neural pathway, a study suggests.

The finding, in the journal Science, could help researchers better understand chronic itchiness in conditions such as eczema, diabetic neuropathy, multiple sclerosis and some cancers. The study also may help researchers determine why certain patients do not respond well to antihistamines.

"In the future, we may have some way to manipulate neuron activity to inhibit itching," said Quifu Ma, a neurobiologist at Harvard University and one of the study's authors.

In the study, Ma and his colleagues inhibited neurons that express a neuropeptide known as Y or NPY in mice. When these neurons were suppressed and the mice were poked with a tiny filament, they fell into scratching fits.

Rooftop view of insect migration

The Natural History Museum of Denmark has studied the insect population on its rooftop for 18 years, tracking 1,543 species of moths and beetles and more than 250,000 individuals. In a study in the Journal of Animal Ecology, museum researchers conclude that warming temperatures are affecting specialized insects that rely on a single food source. The nut weevil, for example, feeds only on hazelnuts; it appeared on the roof during the first half of the study but not the second. Scientists suspect that the nut weevil and other specialists are moving north, where the climate is cooler.

News services