Scientists who have been looking for intelligent — or any other type of — life in the galaxy have assumed through various models that there might be as many as 10,000 tech savvy civilizations out there looking for us while we look for them.
But a new report, published on LiveScience.com today, suggests the number may be closer to zero.
Astrophysicist David Spiegel at Princeton University and physicist Edwin Turner at the University of Tokyo debunk the models, based on taking the fundamental laws that established life on earth and calculating that they apply elsewhere, too. The pair argues that the laws don’t translate to the rest of the galaxy.
“Although life began on this planet fairly soon after the Earth became habitable, this fact is consistent with … life being arbitrarily rare in the Universe,” the authors state. In the paper, they prove this statement mathematically.
Their result doesn’t mean we’re alone — only that there’s no reason to think otherwise. “[A] Bayesian enthusiast of extraterrestrial life should be significantly encouraged by the rapid appearance of life on the early Earth but cannot be highly confident on that basis,” the authors conclude. Our own existence implies very little about how many other times life has arisen.
In other words: The genesis of life in other worlds is not inevitable.