Between the Rocks and the Stars

Narratives in Natural History

Stephen Daubert

• Publisher: Vanderbilt University Press
• Year: 2020
• ISBN:
  9780826522764
• Topic: Ciencias biológicas
• Subtopic: Historia natural

These stories take readers where they cannot go, be it out into space, back in time, deep under the ocean, down to microscopic scales, or out onto the geologic overview. Squid turn themselves inside-out when disturbed by predators hunting through the darkness with sonar. Beneficial microbes spend their summer living in nectar and being transferred between blooms by the bees, then spend the winter living within those bees. Ecological stories are seen through the eyes of squirrels, birds, fish, ants, butterflies, and beetles. Between the Rocks and the Stars dives deep into the relationships that shape the natural world. The book presents a collection of vignettes from the wild, each of which describes the natural advantage of a particular organism. These true-to-life accounts are then posed in particular circumstances that illustrate the principles—commensalism, speciation—that shape the place of these organisms in their living environment. Some stories cover topics in geology and cosmology, describing the physical world context in which natural history progresses across the eons. Underlying themes in the book include the network of connections that link all these organisms together and the adaptations they make to the physical world in which they must find themselves a home.

24

Photon

The photon awoke with a bang. It had spent the previous ten billion years as part of a hydrogen atom. Inside of a young star, the atom had been stripped of its electron. It was left as a bare proton, surrounded in the star’s core by other protons. They were compressed to densities far greater than metal, and boiling at white-hot temperatures in the millions of degrees. There, half a million miles below the star’s surface, the proton crashed head-on into a proton/neutron pair. The collision fused the two particles into a helium nucleus. As a byproduct, the fusion produced the photon—which was born flying at the speed of light.

The newly born light wave traveled less than a picometer before it collided with another proton. The photon’s energy was there converted into matter—one electron and one positron, particles with equal masses, but opposite charges. The two particles instantly destroyed each other in an antimatter annihilation, recreating the photon, which took off again in a different direction. It was then absorbed by an electron, which recoiled in the opposite direction and re-emitted the photon at a lower energy. The photon repeated interactions like these millions of times in the first second of its existence. Even though it always travelled at light speed, its course was a tight clump of zigs and zags. Its net movement was only inches per hour.

A million years after its creation, the photon’s random path had taken it to the uppermost layer of its star. Its switchback course had finally spanned the star’s radius. In air, it would have covered that linear distance in a few seconds. By now, its total travel distance was equivalent to halfway to the nearest galaxy.

The photon had been born as a high-energy gamma ray. But over the course of its travels, it had given away most of its energy to its surroundings as heat. Its own energy was now only that of a photon of visible light. It would be perceived as yellow. The number of collisions it suffered per second had decreased as the ...