(2023-07-10) Could An Industrial Civilization Have Predated Humans On Earth

Could an Industrial Civilization Have Predated Humans on Earth? Schmidt and Frank write that a “species as short-lived as Homo sapiens (so far) might not be represented in the existing fossil record at all.” Today, less than 1 percent of the Earth’s surface is urbanized, a tiny proportion that hardly stands a chance of being re-exposed millions of years in the future

At least 1,000 dinosaur species existed on Earth for 180 million years, yet for all the billions of dinosaurs that ever lived, we have only uncovered a few thousand nearly complete fossils. “We estimate that we have one dinosaur fossil for every 10,000 years—which is a tiny fraction of the ones that lived,” Schmidt said.

Even if a human fossil is discovered in the future, xenoarcheologists would need to find it accompanied by technological artifacts—otherwise, they might think that Homo sapiens were just another unremarkable species of ape.

Fifty-five million years ago, the Earth warmed abruptly by more than 5 degrees Celsius. At the same time, the ratio of carbon-13 to the most abundant carbon isotope, carbon-12, sharply fell. Was this event, known as the Paleocene–Eocene Thermal Maximum, a natural occurrence brought on by exuberant volcanoes, or the demise of an industrial civilization that overheated the globe?

Schmidt admits that his and Frank’s thought experiment has been met with a few good counter arguments. “The best one is probably the issue of deep mining,” Schmidt said. “We are mining very old deposits for metals and ore, and if these had been depleted by a prior civilization, it might have been noticed. These place limits on the scope of a prior civilization, but don’t eliminate the possibility.”

A second argument asserts that if a terrestrial civilization before humans achieved technology comparable to our own, we would find it in space. A civilization with rocket technology might leave artifacts beyond Earth, like the conspicuous alien monolith that astronauts uncover on the moon in 2001: A Space Odyssey.

our moon, which might be tectonically active but has no atmosphere. Without much of the conventional erosive processes that would chisel away at human artifacts on Earth, the Apollo landing sites will probably remain as monuments to human presence for ages.

“In human terms, it may seem like forever, but in geologic terms, probably there will be no traces of the Apollo exploration in, let’s say, 10 to 100 million years.” While there is no wind or water erosion on the moon, the naked landscape lies vulnerable to UV radiation, micrometeorites, and occasional macrometeorites that wear away at artifacts.

Although the Paleocene–Eocene Thermal Maximum is ambiguous, a faster and more violent civilization-ending catastrophe would leave a clearer signature. (Silurian Hypothesis)