The world is full of mysteries, contradictions, and questions that are seemingly impossible to answer. Paradoxes, for instance, are great examples of thoughts that can leave you scratching your head. What is a paradox, anyway? A paradox, sometimes referred to as antimony, is a statement that has a logically sound premise but comes to a conclusion that appears to be senseless, absurd, self-contradictory, or the opposite of the expected outcome. It could be a situation that produces two opposite but entirely possible outcomes. Or, it could be as simple as a sentence that contradicts itself, such as “This statement is a lie”. Paradoxes are some of the most unusual quirks of human logic. To better understand them, we’ve compiled a list of some famous paradoxes that will surely blow your mind.
The liar paradox or liar’s paradox statement is one of the simplest yet most famous paradoxes out there. The statement “this statement is a lie” or “this statement is false” is a paradox because if that statement is indeed a lie, then it would be saying the truth. If the statement is the truth, however, then it would counter the premise that the statement is a lie. This statement contradicts itself and indicates that the statement is both true and false. Weird to think about, isn’t it?
Different forms of this paradox have been around for centuries. The Epimenides paradox, for example, existed since around 600 BC. Epimenides, a semi-mythical Cretan seer and philosopher, famously said that “all Cretans are liars.” This would mean that as a Cretan himself, Epimenides is a liar as well if this sentence were true. If Epimenides is lying when he said that statement, however, then it would follow that Cretans would be truthful — but that would mean that Epimenides, a Cretan, would be lying. This again confirms that Cretans are liars, making the statement true and Epimenides would not be lying. The cycle continues. Scratching your head yet?
Another popular version of the liar paradox is the Pinocchio paradox. In this version, the dilemma arises when Pinocchio says “My nose grows now.” Pinocchio’s nose only grows when he is lying, however, so if the sentence is true, then Pinocchio’s nose will not grow. However, this would mean that Pinocchio is lying, which causes his nose to grow. As Pinocchio’s nose grows now, then Pinocchio would not be lying… which means his nose will not grow, and so on without end. Some have sought solutions to this problem and claim that Pinocchio was not inherently being dishonest — he was simply making a prediction that would turn out to not be true. The prediction that his nose will grow wouldn’t count as a lie, so Pinocchio would not be lying even if he says his nose will grow and it doesn’t.
The Fermi Paradox
With the vast knowledge we have of the observable universe, scientists say that the Sun is a pretty common star and there are billions of stars similar to it in the Milky Way alone. There’s also a good chance that those Sun-like stars have Earth-like planets orbiting around them. It’s also pretty likely that these stars and planets have been around for much longer than our solar system, so the evolution of intelligent life and civilizations more advanced than us would likely be possible. These advanced civilizations may have developed interstellar travel already or at least launched probes to study other planets from far away. However, even with the likelihood of all of these circumstances, why hasn’t anyone made contact with us yet? Shouldn’t their presence be obvious to us by now?
The Fermi paradox presents this problem. If Earth is just one of the billions of planets that have similar conditions, why is it that sentient life seems to be unique to us? The paradox takes its name from the Italian-American physicist Enrico Fermi. While he wasn’t the first one to raise the problem, the paradox has ties to his name because of his conversation with fellow physicists Edward Teller, Herbert York, and Emil Konopinski in 1950. In this conversation, while they were talking about UFO sightings and faster-than-light travel, Fermi reportedly asked, “But where is everybody?”
The conflict between the scientific estimates that sentient life is likely common in the Universe and the fact that we don’t have any solid evidence of sentient life on other planets still baffles scientists to this day. Some have tried to explain this paradox by arguing that intelligent life outside of Earth is extremely rare and civilizations like these have short lifetimes. Others have suggested that alien life could be so alien that it’s completely unrecognizable to us.