Harvard astronomer Abraham Loeb says that life may be almost as old as the universe, originating as early as 10 million years after the Big Bang. The science behind his theory is rock solid, and it introduces the intriguing possibility that we may be surrounded by extraterrestrial life that we're not even in a position to recognize.
Loeb begins by taking the basic values that scientists believe need to exist in order for life to form without looking at the conditions under which those values are supposed to arise. Traditionally, astronomers have looked for planets that exist in a habitable zone—close enough to a star to be warm, far enough away to be livable. But Loeb suggests that we forget about stars themselves, and look specifically at the issue of temperature.Is there anything, other than stars, that could create a habitable temperature?
As a matter of fact, there is: cosmic background radiation. As Minute Physics explains, the early universe's energy kept it uniformly warm:
Loeb's theory wouldn't account for intelligent life—the universe didn't stay habitably warm for very long, in evolutionary terms—but what makes it interesting is the way it undermines the idea that life elsewhere in the universe will develop under conditions similar to those of life on Earth. If even the early universe could have accommodated life, Loeb seems to suggest, then maybe there are other nooks and crannies in our cosmos that could unexpectedly accommodate it today.