Enrico Fermi was one smart guy. The Italian physicist is most famous for building the world’s first nuclear reactor at the University of Chicago in 1939, but he was also famous for his work in the development of quantum theory and for winning the Nobel Prize in Physics for his work on induced radioactivity in 1938. However, one of his more enduring theories came about as a result of a seemingly flippant remark that Fermi made one day at lunch.
The year was 1950. Fermi and some colleagues were sitting down and enjoying a nice lunch. The topic of the day was extraterrestrial life; professors and grad students eagerly traded theories about where alien life could be found and what it might be like. As the excitement level of the crowd continued to rise, someone noticed that Fermi hadn’t said anything. In fact, he was just sitting there quietly, eating his lunch. During a brief lull in the conversation, that person asked Fermi what he thought about extraterrestrial life. Fermi looked up, thought for a minute, then asked “Where is everybody?”
Now, that three word phrase might seem silly. Condescending. Flippant, even. But it was actually a very deep thing to say. And it would become the basis of the Fermi Paradox. The paradox is awfully complex, but in a nutshell it goes something like this: modern human beings (that is, humans that have left a physical record of their existence, such as writing or buildings) have been around for around 6,000 years. The universe has been around for around 14 billion years. Obviously, 6,000 years is a teeny, tiny fraction of the universe’s 14 billion total years, so isn’t it logical to assume that some other intelligent life has been around for longer than ourselves? And if so, why can’t we see any trace of their existence? We haven’t seen any evidence of their space probes, their battles to colonize other planets or their messages left in radio waves. Not only can we not find the alien equivalent of a Starbucks on Mars, we can’t find any evidence of their existence whatsoever.
The interesting question is why. Does intelligent life eventually get smart enough to destroy itself… and then do just that, as is the fear with nuclear weapons? Does the very process of gaining the intelligence necessary to colonize space ruin home planets, as is the fear with global warming? Is space simply so very vast that Wars of the Worlds are going on at this very minute, but humans lack the ability to notice it? Or is our greatest fear true: that we really are alone?