At first thought, broadcasting ourselves to the universe in hopes of making contact with another intelligent species sounds amazing right? We all have a deep desire to discover other intelligent life like us. It just seems natural to reach out in hopes of contact. But is that really the wisest thing to do? Many astronomers and scientists have contemplated this scenario and many come to the same conclusion. We need to be very careful and should perhaps even hide our existence from the rest of the cosmos.
The reasons why are probably coming to mind now. Just think for a second about how our ancestors handled the discovery of new life when they reached new continents…genocide, slavery and the taking of land from what they considered to be “less intelligent” beings are just a few examples of how things went terribly.
Now imagine that we are happily sitting on our little water covered marble and sending out signals to distant space (as we did in 2008, sending The Beatles song ‘Across The Universe’ on a path for the North Star). Then a race of incredibly superior beings discover us and come to investigate. They realize that Earth is beautiful and habitable and they want it for their own…Now we’d like to think that they would come down nicely and make first contact. Shaking hands in a big grand gesture, kindly interacting and attempting to communicate. But that is incredibly far fetched according to scientists, including the esteemed physicist Steven Hawking.
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. – Steven Hawking
There is absolutely no way of knowing what these other intelligent life forms will be like. How they will function. What kind of emotions and thought processes they will have. They could be aggressive with a mindset only of colonization and expansion. They could be wary and careful, but slowly attempt takeover as they realize we are a weaker civilization. Just because they have the technology to travel large distances of space doesn’t mean they are all knowing, kind and perfect beings…It could in fact mean the exact opposite. If they truly do have a grasp on life and the universe as a whole, they might understand that a planet like ours is pretty insignificant in the grand scheme of the cosmos…They could destroy us without a second thought. As I said…we’re just a water covered marble floating around a ball of fire. If we disappeared, the universe would continue on without the slightest difference. That’s why Hawking suggests we hide ourselves. It will be much better to make contact with other intelligent life on our own terms; when we have the ability to travel to another species planet. Then we’ll just need to refrain from pulling another Columbus…
So the big question is, how will we cloak ourselves from extraterrestrial life? To understand that, we need to look at how we detect planets in the depths of space. When a planet orbiting a star passes between the star and someone observing it, a noticeable dip in light occurs. We are able to find distant planets by observing stars and detecting these dips in light, also known as a transits. We can assume that other intelligent life forms would know about and utilize this method to detect planets. If our star (the sun) were observed, intelligent extraterrestrial life would be able to detect a planet with optimal size and distance from it’s sun to sustain life.
Now that we know how a planet can be detected, we can understand how to prevent it. Astronomers at Columbia University suggested that large lasers can be used to hide the Earth from extraterrestrial civilizations. David Kipping and Alex Teachey released this proposal in Monthly Notices of the Royal Astronomical Society.
Kipping and Teachey suggest that emitting a 30 MW laser once a year for only 10 hours would eliminate earths transit signal by compensating for the drop in light caused by it’s transit of the sun. This would essentially make us “invisible” to any life forms attempting to detect us through visible light. To go even further, a chromatic cloaking laser (effective at all wavelengths) could be created by using a larger array of tunable lasers, requiring a power of 250 MW. It would even be possible to cloak just our atmosphere, making earth appear as if it cannot/never did sustain life.
Alternatively, we could cloak only the atmospheric signatures associated with biological activity, such as oxygen, which is achievable with a peak laser power of just 160 kW per transit. To another civilization, this should make the Earth appear as if life never took hold on our world. – Alex Teachey
The two astronomers also proposed that we could potentially use the lasers to deliberately broadcast our existence and technological capabilities by distorting earths transit signal into an artificial shape. In simpler terms, we could make our transit signal look obviously abnormal, blatantly telling other intelligent species we are here. This means it could function as an SETI (Search For Extraterrestrial Intelligence) beacon and even transmit data to distant planets. Knowing that we have the capability to distort transit signals, David and Alex also suggest we expand our search for aliens from radio signals to distorted transits as well.
There is an ongoing debate as to whether we should advertise ourselves or hide from advanced civilizations potentially living on planets elsewhere in the Galaxy. Our work offers humanity a choice, at least for transit events, and we should think about what we want to do. – David Kipping
Now we collectively must decide how to continue. Should we attempt to hide ourselves in hopes of discovering extraterrestrials on our own terms, or should we continue to broadcast ourselves and expand to distorting our transit signals.