In her latest column, Catherine Heffner asks if there’s anyone out there in the big wide universe…?
The concept of extraterrestrial life has been infused in our culture for decades. With the development of space programmes throughout the 20th century, interest in outer space sky-rocketed (if you will pardon the pun). “Extraterrestrial” was first used as a noun in the 1950s, during what is known as the Golden Age of Science Fiction. There seems to have been an explosion of interest which was reflected in our movies, books and television, and it wasn’t just in fiction. Sightings such as the Roswell Unidentified Flying Object provoked both panic and excitement from the public. Government agencies were set up. Space law started being discussed. And yet we still have no hard evidence that there is anything out there at all.
Image credits: Adam Baker
Historically, we’ve behaved as though aliens exist. For instance, when Armstrong, Aldrin and Collins of the Apollo 11 crew returned from the moon they were immediately quarantined for 18 days. This was to prevent “backward contamination”; the transfer of extraterrestrial life into Earth’s biosphere. In the past, the US government heavily funded the organisation SETI (the Search for Extraterrestrial Intelligence). SETI has constructed a ‘Declaration of Principles Concerning Activities Following the Detection of Extraterrestrial Intelligence’ in the event that alien life should decide to pay Earth a visit. Given the lack of formal government policies in this area, it has been noted that the US government would be likely to follow these protocols in such an event.
But really, aliens? C’mon. This is a science column!
Granted, the cartoon vision of little green men seems a tad improbable. But perhaps we shouldn’t be so sceptical. Astronomer Jill Tarter of the SETI institute notes that statistics argues against the notion that humans are the singular life form of the universe. Let’s look at some numbers…
The Sun is one of up to 400 billion other stars in our galaxy.
There are at least 100 billion other galaxies.
Altogether, there are about 1022 stars in the universe.
To top it all off, we know that other stars have planetary systems like ours. In fact, over 350 have been found in the last 14 years.
There’s still no denying that that Earth could be unique as the only life-sustaining planet in the universe. But, with a universe so vast, it makes you wonder how alone we really are.
Given the possibility that extraterrestrial life could exist, we need to figure out what that means for us here on Earth. Do we contact them? Can they already hear us? Well we’ve been sending signals out for decades. Both intentionally and non-intentionally; our “noise-bubble” from escaping radio and TV signals increases by one light-year every year. It’s even possible that we’ve been receiving signals from extra-terrestrial life but we just haven’t been able to detect them. Who knows what advances in technology will allow us to hear…
However, at the same time as our ‘noise-bubble’ is growing, our universe itself is also expanding. While it was once thought by scientists in Einstein’s day that the universe is expanding at a decreasing rate, recent research has shown that this expansion is actually speeding up. If this theory turns out to be correct, sometime in the future, we won’t be able to see the stars in the sky. Regardless of the strength of our telescopes or the power of our satellites, the laws of physics dictate that the light they emit will no longer be able to reach us, and the stars will no longer be visible.
What will the people under this starless sky think? Will they look back at our work and believe the findings of such ancient astronomers? Perhaps not. More likely, they would reject our research as primitive knowledge and with it, all possible ideas of a lifeform existing outside of earth. Now, wouldn’t it be a surprise for them, if those humans finally encounter an extraterrestrial species, when they couldn’t even see what the universe held beyond their inky black sky.
Catherine Heffner, Features Columnist
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