Student Media Cell
Is Earth the only place with life in the universe? Are we really alone? Have we ever asked ourselves this question? I bet most of us have. It has and continues to be one of the most fundamental questions in astronomy that are yet to be answered. Yes, there is no definite and conclusive evidence of life elsewhere as of now. But let’s just first consider some basic facts.
The Earth is a small part of the Solar System, which itself is part of the Milky Way galaxy. According to NASA, the Milky Way has more than a 100 billion stars. 100 billion! To put that in perspective, the total length of one hundred billion currency notes laid end-to-end measures more than 9.6 million miles. That would be enough to extend around the earth a total of 387 times. The Sun is merely one of these one hundred billion stars out there in our galaxy.
NASA, by virtue of the Hubble Space Telescope, estimated in 1995 that the universe contains at least 100 billion galaxies. Further research in 2016 has indicated that the number might be ten times as thought before, that is, the number of galaxies that human made technology can detect now is up to a trillion. “It boggles the mind that over 90 percent of the galaxies in the [observable] Universe have yet to be studied,” said Christopher Conselice, the astrophysics professor at Nottingham who led the research. “Who knows what interesting properties we will find when we discover these galaxies with future generations of telescopes?”
It is but a matter of time before humans can peer still deeper into space, with much more clarity. In the context of this grand design, it’s difficult to imagine Earth as anything more than a tiny speck of sand in a beach that extends for hundreds of miles. It is believed that there is at least one planet orbiting each star, which means that there are trillions of planets out there in the universe. But inspite of all this, we know of only one that contains life. Is that really possible? Are we really alone?
This is the problem that has puzzled scientists for decades, and the intrigue continues to grow deeper with time. This paradox of the lack of contact or signals from any other civilizations in the universe was first proposed by Enrico Fermi, and has since been labelled as the Fermi Paradox. Is life on earth a galactic fluke or a consequence of natural progression in the life cycle of a planet? Or is there something extremely special about the Earth, and Earth has won some kind of lottery? Or have we not looked far enough yet? The answer is – we simply don’t know.
It is evident that any civilization ahead of us by only a thousand years could have shockingly advanced knowledge and technical capabilities. We would be merely medieval in comparison to them. In cosmic terms, a thousand years is less than the blink of an eye. The universe is estimated to be 14 billion years old, and the Earth’s age has been calculated to be about 4.5 billion years.
“Fermi realized that any civilization with a modest amount of rocket technology and an immodest amount of imperial incentive could rapidly colonize the entire galaxy,” the Search For Extraterrestrial Intelligence (SETI) Institute in Mountain View, California, says on its website.
There have been multiple hypotheses proposed to suggest possible solutions to the Fermi Paradox. One of them is that maybe there are higher civilizations all around us, but we’re too primitive to perceive them. As Michio Kaku said: “Let’s say we have an anthill in the middle of the forest. And right next to the anthill, they’re building a ten-lane super-highway. And the question is “Would the ants be able to understand what a ten-lane super-highway is? Would the ants be able to understand the technology and the intentions of the beings building the highway next to them?”
Or maybe an advanced species knows about our existence, and is observing us. Any super-intelligent civilization which has had millions of years more than us to evolve could have developed the capabilities to do that. Just like a baby is born into a world regulated by those born before it, similar could be the case for us humans born in the intergalactic neighbourhood. They might have developed the abilities for interstellar travel, and might choose to establish contact when they deem fit.
It could also be that we are listening for the wrong things. As Carl Sagan has pointed out, it could be that our minds work exponentially faster or slower than another form of intelligence out there—e.g. it takes them 12 years to say “Hello,” and when we hear that communication, it just sounds like white noise to us.
It is also possible that there are several predator civilizations in the galaxy, and most intelligent life has realized that broadcasting their signals and location could be disastrous for survival. This is an alarming explanation, but it would help explain the lack of any signals being received by the SETI (Search for Extra Terrestrial Intelligence) satellites. It also implies that humans are being highly irresponsible and risky by ever broadcasting outward signals, which reveals our location. There’s a debate going on currently about whether we should engage in METI (Messaging to Extraterrestrial Intelligence—the reverse of SETI) or not, and most people say we should not. Stephen Hawking warns, “If aliens visit us, the outcome would be much as when Columbus landed in America, which didn’t turn out well for the Native Americans.”
Regardless of the possibilities, the Fermi paradox is a simple but incredibly powerful question, with no satisfactory answers as of yet. It is a question that has deep implications for the future of mankind as a whole, and might well lead to even more fundamental questions. But till then, we just keep searching, and waiting….