Author Alan Weisman's new book, The World Without Us, is a long query on that theme. His premise: If humans disappeared, what would happen to the Earth and all of the embellishments human hands and minds have added to it during their 10,000 years on Earth? Their art, their nuclear plants, their arsenals, their oceans, their shopping bags and Mount Rushmore, to name a few.

Weisman will read from his book and speak at Weber State University and Sundance Resort this weekend.

For the book, he spoke with ecologists, art curators, structural engineers, miners and even religious leaders to probe how and when the human creations would disintegrate.

He tells how and when nature will take over once again, wrecking steel bridges with corrosion, carving new streams into the skyscraper canyons of Manhattan, foresting the concrete sidewalks and streets with opportunistic trees.

Author Bill McKibben calls The World Without Us "one of the grandest thought experiments of our time, a tremendous feat of imaginative reporting."

Weisman bases his observations in science rather than opinions of how people have improved - or some might say destroyed - the planet.

The book "doesn't preach," said Weisman, interviewed by phone from his Massachusetts home. "It simply shows all this interesting stuff and doesn't comment on it."

That's not to say The World Without Us is dry or monochromatic.

There are moments of magic, for instance, when he talks about the ruin of cities, thanks to the freezing and thawing of tiny water molecules, "pushing apart slabs of sidewalk" and exploding carbon-steel water pipes built to withstand 7,500 pounds of pressure per square inch.

His most surprising finding? Plastic will enter the geological record, since the environment has no way to break it down.

"There are rafts of this stuff floating around," said Weisman, who also has written about ecology and his family. "The mass of plastic out there is greater than the mass of plankton."

He finds cause for optimism, too.

"Nature has all the time in the world," he said. "I came out of this book less concerned about the future of the Earth than when I went in."

fahys@sltrib.com

Book readings

Alan Weisman, author of The World Without Us, has two scheduled appearances in Utah this week. He will read from and talk about his book in a free, public appearance at Weber State University's Stewart Library, 6 p.m. today. For more information, call 801-626-6006. He also is speaking at the Sundance Tree Room Author Series at noon Saturday in the Tree Room Restaurant, State Road 92 in Provo Canyon at the Sundance Resort. Tickets for the event, which includes brunch, are $95; more information is available at 801-223-4567.