By
Madeleine Kando
Common sense tells us that the idea of being alone in the universe is infinitesimally small. There are thousands of solar systems in the Milky Way alone, and in the visible universe there are trillions of galaxies. And that is just the observable Universe. The real universe is quadrillions of times bigger, because it is constantly expanding.
Therefore, it is statistically improbable that we are alone. A human’s chances of being born are one in 400 trillion, but if life on earth is the only form of life in the Universe, that chance becomes unbelievably small.
The size of the Universe is not the only variable that determines whether there is life out there. How many other planets could support life? If there is other life somewhere out there, is it intelligent? Is it near enough to us that we could ever make contact?
In 1961 American astrophysicist Frank D. Drake devised a simple equation that could determine whether extraterrestrial intelligence is possible.
The equation is made up of seven variables, each of which represents an unknown quantity. When combined, they produce an estimate of the number of civilizations we might be able to make contact with in our galaxy. Here’s a breakdown of all the factors:
In the Milky Way, stars form at a rate of R*. Some (fp) of those stars have planets, but a smaller percentage (ne) of those planets are capable of supporting life, and an even smaller percentage (f1) of those actually develop at least basic life. A fraction (fi) of those planets with any life may develop intelligent life. And of those intelligent life forms, an even smaller fraction (fc) will have the technology to communicate with us.
The final factor in the Drake equation accounts for how long (L) these intelligent, technologically advanced civilizations will exist before they self-destruct or otherwise disappear.
The Fermi Paradox: Where is Everybody?
The Fermi paradox emerged from a conversation between physicists Enrico Fermi, Edward Teller, and Emil Konopinski in the summer of 1950. Fermi argued that when considering various probabilities such as those of Earthlike planets, intelligent life, and the lifetime of intelligent civilizations, Earth should already have been visited many times by aliens. If that’s the case, Fermi asked: “Where is everybody?”
Scientists have given hundreds of explanations for the Paradox: Perhaps life is too fragile to survive for long. Habitable environments are difficult to maintain long enough for intelligent life to evolve. Civilizations may tend to extinguish themselves soon after becoming technologically competent. The universe is enormous and incredibly old. Humanity has been around for just 200,000 years, and we've been listening for possible radio signals from E.T. just since 1960 (70 years?). So the odds that we overlap in time and space with a detectable alien civilization don't seem great.
Frank and Sullivan find that human civilization is likely to be unique in the cosmos only if the odds of a civilization developing on a habitable planet are less than about one in 10 billion trillion, or one part in 10 to the 22nd power.
We keep making the same anthropocentric mistake in our search for little green men. This new interpretation of the Drake equation is by far the most sensible explanation of the famous Fermi paradox. leave comment here
Sources: Fermi Paradox: Where are the aliens?
Scientists have given hundreds of explanations for the Paradox: Perhaps life is too fragile to survive for long. Habitable environments are difficult to maintain long enough for intelligent life to evolve. Civilizations may tend to extinguish themselves soon after becoming technologically competent. The universe is enormous and incredibly old. Humanity has been around for just 200,000 years, and we've been listening for possible radio signals from E.T. just since 1960 (70 years?). So the odds that we overlap in time and space with a detectable alien civilization don't seem great.
Revisiting the Drake Equation
In new research, Professor Adam Frank and Woodruff Sullivan offer a new equation to address a slightly different question. Rather than asking how many civilizations may exist now, they ask: how often in the history of the universe has life evolved to an advanced state?
In other words, how low would the probability have to be for us to be the ONLY civilization the Universe has ever produced? It’s called the pessimism line. If the actual probability is greater than the pessimism line, then a technological species and civilization has likely happened before.
In new research, Professor Adam Frank and Woodruff Sullivan offer a new equation to address a slightly different question. Rather than asking how many civilizations may exist now, they ask: how often in the history of the universe has life evolved to an advanced state?
In other words, how low would the probability have to be for us to be the ONLY civilization the Universe has ever produced? It’s called the pessimism line. If the actual probability is greater than the pessimism line, then a technological species and civilization has likely happened before.
Frank and Sullivan find that human civilization is likely to be unique in the cosmos only if the odds of a civilization developing on a habitable planet are less than about one in 10 billion trillion, or one part in 10 to the 22nd power.“One in 10 billion trillion is incredibly small,” says Frank. “To me, this implies that other intelligent, technology producing species very likely have evolved before us. The universe is more than 13 billion years old,” said Sullivan. “That means that even if there have been a thousand civilizations in our own galaxy, if they live only as long as we have been around—roughly ten thousand years—then all of them are likely already extinct. And others won’t evolve until we are long gone. For us to have much chance of success in finding another "contemporary" active technological civilization, on average they must last much longer than our present lifetime.”
So the problem is a matter of time scale. A mayfly lives only one day. Were it to look for another mayfly during that one day, but cannot find one, it might conclude that it is the only mayfly in existence. But a Ming Clam*, who lives 500 years, which is 4 million times longer than a mayfly, would have the opportunity to see thousands if not millions of mayflies over its lifetime and would conclude that mayflies are abundant.
We keep making the same anthropocentric mistake in our search for little green men. This new interpretation of the Drake equation is by far the most sensible explanation of the famous Fermi paradox. leave comment here
Sources: Fermi Paradox: Where are the aliens?
