The long view of science turns out to be both reassuring and daunting. Life on Earth turns out to be remarkably resilient. Within the story of our 13.5-billion-year old universe, our own lives — so crucial to us and to our families and dear friends — look fleeting, gossamer. These paradoxes overwhelm me.

For five years, I’ve immersed myself in geologic time while writing exhibit text for the new Natural History Museum of Utah. Again and again, mass extinctions sweep away millions of years of diversity, and we start anew.

One time period produces 6-foot-long arthropods that look like centipedes in a child’s nightmare. Another evolutionary interval yields a flightless six-foot-high bird whose head mostly consists of formidable jaws. The Mesozoic landscape teems with dinosaurs the size of commuter jets — and then the strange animals are gone.

I’ve become obsessed with fragility. We can take nothing for granted, from the air we breathe, to the value of our homes, to the well being of our loved ones.

In one recent week, I saw this tenuousness shatter four exceptional people. I attended memorial services for two friends, one who died in a freak accident at 41, a second who died of a disease with no treatment and no cure, at 63. In between, I visited a mentor living with the debilitating aftermath of a stroke and a legendary teacher paralyzed in a bike accident and fighting for breath, year after year.

Watch your step. On this day-to-day level, live every moment fully. Nurture resilience.

When we can define geologic time by our actions, we must think hard about consequences. When we have become connected to one-third of the people of the planet through our computers, our effects multiply; politics and social justice and human rights are no longer local issues. In the Internet-driven Anthropocene, we mightily affect our generation and those who come after us.

We can deal with this with hubris — why conserve when in a million years we will move on to a new evolutionary world? This might explain the Utah Legislature’s selfish attempt to turn over fragile public lands to the state for development, for management by the few and for the few, even though all Americans own the federal lands in question. Or the fossil fuel industry, intent on maximizing profits until we’ve drilled the last drop of oil, without regard for the people who live nearby.

Or we can deal with the extraordinary opportunity of our few decades on Earth with restraint, blessed by the fragile miracles of our health and acutely aware that we must act with care if our natural world is to flourish.

Stephen Trimble is a contributor to Writers on the Range, a service of High Country News. He is a writer and photographer in Salt Lake City.