Physics Buzz

A fraction of a second after birth, before his eyes were even open, my son was pooping. Now a six-year-old, he tells the story of his first act proudly whenever the subject of babies comes up. We laugh at the memory, and the event is documented in photographs and highlighted in his baby book. It’s part of his story. Without witnesses, photos, and written records, the universe’s first few fractions of a second are much harder to unravel. Scientists look at the current state of this 13.8 billion-year-old and try to work backwards, creating models that begin somewhere, somehow, and bring us here. The successful models make predictions that match astronomical observations , indirect records like the cosmic microwave background , and the physical laws of the universe. Modern cosmology is a well-established field, but many unknowns remain.

Lightning detector in the foreground with a cosmic ray detector in the background. Credit: William Hanlon, University of Utah There’s a chance that the mystifying phenomena we call lightning would not exist without cosmic aid. The same high-energy particles that light the night sky with colorful auroras, scientists think could also explain a longstanding problem in the process of lightning production. When you shock yourself after reaching for a metal doorknob, you’re experiencing a similar process that leads to lightning. As long as the extra charge you accumulate from, for example, rubbing your feet across a carpeted surface reaches a minimum value, called the breakdown voltage, a shock will travel from you to the doorknob. Storm clouds can also build up extra charge, which must go somewhere. Often times it will either strike the ground or branch outward across the sky in the form of a lightning bolt. However, scientists have yet to find a way to explain how storm clouds bu