Category Archives: Scientific American

New Biomarkers to Identify Possible Life in Space [Scientific American]

Important progress has been made in our understanding and use of biomarkers, the signatures astronomers use to search for life in space. The work is all the more important given budget constraints that have cancelled space missions complementing the biomarker work by identifying life friendly star systems; improved biomarker searches may make up for fewer supporting missions.

Astronomers still hope to revive some version of Terrestrial Planet Finder [artist’s rendering below], but it would take a decade for the mission to get back on track, Marcy estimates. In the meantime studies by exoplanet researchers including Sara Seager of the Massachusetts Institute of Technology and Victoria Meadows of the University of Washington in Seattle are honing—and expanding—the list of compounds that may serve as biomarkers for exoplanets orbiting stars of different sizes and ages.

With the chances of looking for chemical markers of life beyond the solar system initially few and far between, “we want to make sure we have the best possible understanding of bio-signatures,” Meadows says. “We don’t want to be fooled.”

Much of the new work focuses on planets orbiting M dwarf stars, which are about one-half to one-tenth the sun’s mass and account for about 75 percent of all the stars in the galaxy. Because M dwarfs are much cooler than the sun, their habitable zones are only about one tenth as far from them as Earth lies from the sun.

The recent work on biomarkers, as well information about the cancellation of and existing plans for relevant space missions, are covered in my latest feature article for Scientific American.

Credit: NASA Science Missions

Successfully Modeling Snowflakes [Scientific American]

My latest Scientific American article reports a major breakthrough in modeling…snowflakes:

Snowflake Growth Successfully Modeled from Physical Laws

Mathematicians have re-created the intricate patterns of ice formation, a breakthrough that could lead to new models of red blood cells, soap bubbles and other surfaces that evolve over time

Scientists as far back as Johannes Kepler have pondered the mystery of snowflakes: Their formation requires subtle physics that to this day is not well understood. Even a small change in temperature or humidity can radically alter the shape and size of a snowflake, making it notoriously difficult to model these ice crystals on a computer. But after a flurry of attempts by several scientists, a team of mathematicians has for the first time succeeded in simulating a panoply of snowflake shapes using basic conservation laws, such as preserving the number of water molecules in the air.

Read the article and find out why this is so important!

Image: Barrett/Garcke/Nurnberg
Image: Barrett/Garcke/Nurnberg

Crystalizing Perpetual Motion [Scientific American]

My article for Scientific American is out:

“Time Crystals” Could be a Legitimate Form of Perpetual Motion

The phrases “perpetual-motion machine”—a concept derided by scientists since the mid-19th century—and “physics Nobel laureate Frank Wilczek” wouldn’t seem to belong in the same sentence. But if Wilczek’s latest ideas on symmetry and the nature of time are correct, they would suggest the existence of a bona fide perpetual-motion machine— albeit one from which energy could never be extracted. He proposes that matter could form a “time crystal,” whose structure would repeat periodically, as with an ordinary crystal, but in time rather than in space. Such a crystal would represent a previously unknown state of matter and might have arisen as the very early universe cooled, losing its primordial symmetries.

Read the full article on Scientific American’s site!