In a recent article by Space.com's senior editor, Tariq Malik, we learn that noted astrophysicist Stephen Hawking believes alien lifeforms may exist elsewhere in the galaxy - if only primitively.
However, Hawking doesn't believe advanced, intelligent forms of life are out there. He cites lack of success on the part of the SETI (Search for Extraterrestrial Intelligence) project to detect artificial signals from distant stars as prime evidence.
But Hawking, like so many other nuts-and-bolts astrophysicists seems to lack imagination. They can never seem to conceive of anything beyond their own frame of reference. This egoism has bitten Big Science on the rear before.
It seems beyond their grasp to envision an alien civilization with a mode of communication beyond that of various electromagnetic wavelengths. So, they theorize, if they aren't communicating in the way we would, then they must not be out there. How vain. Perhaps SETI is simply going about it all wrong. The old adage stands true: absence of evidence isn't evidence of absence.
Hawking does concede that IF an alien race were advanced enough to communicate, they would have developed weapons of mass destruction. Sadly, the thought ends there. Malik doesn't question further whether Hawking meant they would have long-ago destroyed themselves or they would be bent on dominating other planets. Either way, the argument is specious and likely born of too many movies. In my opinion, it is beneath speculation by such a "great" mind. While possible as a stand-alone hypothesis, it is puerile, anthrocentric, and, frankly, too obvious a conclusion from one who grew up in the Cold War generation.
Hawking also discounts sightings of UFO's. Although his rationale isn't given, one can assume it is that of all astrophysicists: space is too vast to be crossed effectively. This is an ironic statement from a leading scientist who should know better the quirky nature of space-time and is a proponent of the multiverse theory.
In this day and age, it should be obvious that the whole "traveling" across space in a rocketship model is wholly antiquated. It is more likely that any spacefaring civilization with ambitions to traverse the universe might have looked toward somehow manipulating space-time in some fashion, perhaps by utilizing abutting dimensions. Who knows? And that's the point. We cannot think conventionally about the unconventional. To do so is to merely bolster our own preconceptions to avoid anything we find distasteful.