Readers were curious about a new depression drug and more

What’s the matter?

The source of matter’s dominance over antimatter in the universe might be revealed by tiny subatomic particles called neutrinos, Emily Conover reported in “Mounting evidence suggests neutrinos are key to why antimatter is rare” (SN: 12/21/19 & 1/4/20, p. 12).

The story stated that matter and antimatter existed in equal measure in the early universe, and that when they come together, they annihilate each other. “No problem there,” reader Eric Brunner wrote. If nothing intervened to disrupt the balance between matter and antimatter, the universe would have been left with nothing but energy. Based on Albert Einstein’s equation E = mc², Brunner thought that for energy to survive, matter must also survive. “Is my logic incorrect?” he asked.

It is incorrect, Conover says. In Einstein’s special theory of relativity, the equation E = mc² indicates that the energy contained in the mass of an object is equal to that object’s mass multiplied by the speed of light squared. The equation indicates the possibility of converting the energy of that mass into other forms of energy, Conover says. “That’s what happens when a particle and its antiparticle annihilate. The annihilation typically results in two particles of light called photons. Photons have no mass and therefore are not typically considered matter particles, but they do have energy,” she says.

Promise for PTSD

The U.S. Food and Drug Administration approved a ketamine-based nasal spray for treatment-resistant depression in 2019, Laura Sanders reported in “In 2019, a ketamine-based antidepressant raised hopes and concerns” (SN: 12/21/19 & 1/4/20, p. 33).

Reader Barbara Wilson asked if ketamine could help people diagnosed with post-traumatic stress disorder, or PTSD, which may be accompanied by depression. “Flashbacks might be relieved, if memory of violent events is muffled,” she wrote.

Researchers are studying whether ketamine can help ease PTSD symptoms, Sanders says. Already there have been some positive signs: One small study, for example, found a dose of ketamine reduced the severity of people’s PTSD symptoms after 24 hours, she says. Those results were published in 2014 in JAMA Psychiatry.

One reason to suspect ketamine might work for PTSD has to do with the drug’s possible effects on memory. “Memory is slippery,” Sanders says. “Each time we remember something, that memory is vulnerable to being changed, scientists suspect. Ketamine might be one way to alter memory.” But there will need to be a lot more evidence of this effect before we really understand how ketamine interacts with PTSD. “This is a fast-moving field that I’m eager to follow,” Sanders says.

Whiskey business

Evaporated droplets of different American whiskeys leave behind unique patterns not seen in other tested liquors, Maria Temming reported in “American whiskeys leave unique ‘webs’ when evaporated” (SN: 12/21/19 & 1/4/20, p. 44).

A Reddit user noted that scientists didn’t test how chill filtering may have affected the patterns. The process cools and filters whiskey, forswearThinPotation says. “I’m guessing it has an impact on the physiochemical properties during e­vaporation.”

The patterns are very sensitive to anything that can influence the whiskeys’ chemical composition, says fluid dynamics researcher Stuart Williams of the University of Louisville in K­entucky. “Factors like temperature, humidity, chemical additives and filtration will impact the final pattern,” he says.

Williams’ team has yet to conduct a study looking at how all of these factors affect the patterns. “There are thousands of chemicals in whiskey, and it would be difficult to systematically isolate each one,” he says. “We are currently working on creating s­ynthetic liquids that create similar structures