"Time" is the most commonly-used noun in the English language, according to the Oxford English Dictionary. Time's prominence in communication speaks to its supremacy in nature. All living systems follow the same cycles – birth, life, and death – with one stage distinguished from another by the arrow of time. There's no going back; that arrow is decidedly one-way. Even nonliving systems, from geologic formations to the expansion of the universe, change with time.
Though every system bows to time, researchers have long recognized the existence of a range of rhythms and timescales. Houseflies live for 28 days; red blood cells live for about three months; redwood trees can live for hundreds of years; the sun will expire in about five billion years. But how do these timescales emerge?
That's the question behind an upcoming SFI workshop. “The Origin and Implications of Time in Adaptive Systems,” to be held June 18-20. It will bring together thinkers from around the world, in disciplines ranging from cosmology to chronobiology to neuroscience.
The meeting will begin with an exploration of the most elemental understanding of time known to scientists – namely, relationships among time, entropy, and the second law of thermodynamics. With that discussion as a foundation, participants will talk and share research on the emergence of time at varying scales in diverse systems. At the end, they'll return to where they started, asking whether the relationship between time and entropy differs among systems.
“We want to know how time connects what happens in physical systems with social systems, and biological systems, and how those systems are related,” says Caltech physicist Sean Carroll, who is participating in the workshop. Other organizers include SFI President David Krakauer, SFI Professor Jessica Flack, and External Professor James Hartle (UC Santa Barbara).
The workshop kicks off “Aging, Adaptation, and the Arrow Time,” an SFI research program that will continue with a series of workshops and working groups over the next five years. Geophysicist Amy Chen, who manages the program, says its ultimate goal is not only to understand time, but find ways to mitigate loss – like the loss of neurological function that comes with aging.