Life, as we know it, may have just changed. We've been searching for extraterrestrial life, but aliens may have been here all along. Life is energy, and right now, there are bacteria in a laboratory at the University of Southern California living - breathing  electricity, according to Popular Science.

Microbiologist Kenneth Nealson made this discovery - right before he filed his retirement papers. "It really pisses me off that I discovered this when I was 70 years old, because it's important," he told Popular Science.

It sounds like science fiction.

"All the textbooks say it shouldn't be possible," he said, "but by golly, those things just keep growing on the electrode, and there's no other source of energy there."

Shewanella oneidensis, electric bacteria, deposits electrons via tiny chemical wires, according to Popular Science. In essence, Shewanella oneidensis exhales a solid. "We call this 'breathing rocks,'" Nealson said. The bacteria require no outside energy, like humans require carbohydrates.

"The glucose that we eat supplies the electrons, the oxygen we breathe receives the electrons, and that electron flow is what runs our bodies," Nealson explained to Popular Science.

Nealson discovered Shewanella oneidensis while he was a professor at Scripps Institution of Oceanography in 1982 when scientists realized something was eating up all the solid manganese oxide from Oneida Lake in upstate New York. In 1985, Nealson began his research after relocating to the University of Wisconsin-Milwaukee.

After two years, he found it.

"As soon as I saw what Shewanella could do, I just went wacky," Nealson told Popular Science. "I called all my students into the lab and I said, 'This is a very, very important organism to understand. Nobody's going to believe it. It's going to take us 10 or 15 years to convince the world it's true.'"

The retiring professor hopes to see more. "Before I kick the bucket, I hope that is proven to be true," he said.. "I mean, I don't. It's okay with me if it's not true, but I'll be really surprised. It makes so much sense, and life usually makes sense."