The alien species we invite to Earth - and which actually reaches us - may not be warm, fuzzy and benign like "ET".
I said it before in numerous newspaper articles as well as other (academic) papers, that if we humans have any sense at all we will keep our galactic location a secret and not actively attempt to advertise our presence to whatever alien civilizations might be out there (and there are probably thousands in our Milky Way galaxy alone).
For example in one article I did for the Barbados NATION newspaper back in 1978, e.g.
I cited Sir Martin Ryle's warning that any advanced aliens out there could already have assembled a complete picture of our technological and defense capabilities simply from the electromagnetic waves already dispatched, incidentally, as part of our media broadcasts.
Earlier, in 1972 - at a conference on potential interstellar contact- physicist Freeman Dyson warned that the first species we are likely to encounter is going to be technologically advanced and also highly aggressive - not ready to merely become easy friends- but more likely our worst predators.
More recently, Stephen Hawking has sounded similar warnings comparing the aliens that are most likely to visit Earth (because of stupidity on our part, i.e. in actively beaming messages) to the first colonizers of the New World - who decimated native populations for resources and territory.
All the above bears on some current plans by a group of astronomers (many connected to the SETI project) that we should no longer just sit passively at radio telescopes waiting to hear from "ET" but instead "actively beam messages into the void and invite the closest few thousand worlds to chat or visit." ('Calling the Cosmos', Denver Post, Feb. 15, p. 10A).
TO which I and others (e.g. Stephen Hawking) reply 'bad idea'. Hawking goes so far as to call it 'crazy' (I say it's irrational) and that "instead of sweet and gentle ET we might get the aliens from Independence Day.)
This isn't as far fetched as it seems. Any race able to mount the technological ability for interstellar travel is likely to be aggressive and possibly even conspicuously territorial and warlike. Look no further than the conquering empires on Earth which developed the most advanced tech abilities - say for space travel and going to the Moon, or Mars - they are also the most aggressive. The U.S.- which actually landed men on the Moon, has also engaged in 248 armed conflicts in 153 locations since the end of World War II. It is also responsible for 41 percent of the world's military spending according to a paper in the American Journal of Public health available as a free PDF here.
So there is good preliminary evidence using examples from our own world that high tech and aggression go together. We would be foolish to believe it's any different in the stellar void at large, and believing in fantasy motion pictures as an alien template is as foolish as believing human virgins can give birth or that Lee Harvey Oswald killed JFK.
Some astronomers like Douglas A. Vakoch - director of interstellar message composition at SETI- don't buy this hesitaton or the arguments for exercising an abundance of caution. They're convinced that actively "calling out" may be the only to find out if we are alone. Hence, we need not fret about too many negative speculations, particularly just "letting sleeping aliens lie". But those of us adhering to the precautionary principle would remind these contact Pollyannas of the monstrously aggressive sorts that Freeman Dyson once described as a "technological cancer in the galaxy".
Believe me, these characters will find us soon enough, so why press our luck? Haven't we enough to worry about with climate change now on the verge of the runaway greenhouse effect - without adding aggressive, voracious aliens to our troubles?
SO it was good that this dispute broke out last Thursday and Friday in San Jose, CA at a convention of the American Association for the Advancement of Science. We need to get this out in the open and hope to hell that cooler, more rational heads prevail. Thanks also to Elon Musk (of Space X fame) and Geoff Marcy for starting a petition cautioning against actively sending out such messages since it's impossible to predict whether extraterrestrial life will be benign or hostile.
The idea they oppose is one called "active SETI". While it is true we've been passively , incidentally sending out radio and TV messages for 70 years - these lacked the strength and power that a directly beamed and focused message would possess as part of active SETI.
Vakoch has described this potential coordinated, sustained million dollar a year effort as "an attempt to join the galactic club". Fair enough, but what if that "club" is only composed of the most territorial and consumptive species in the galaxy - who give no quarter - and might regard planets like ours as fodder for their machines? (They might even argue that given how we're wrecking the planet anyway with fracking we don't deserve to have a say in how or whether it is preserved).
My pessimism is shared by astrophysicist David Brin (also a scifi author) who thinks inviting aliens here is a bad idea. Even if there's a low risk of nasty creatures arriving (see image) the consequences would be horrific if in fact they do. As he puts it:
"I can't bring myself to wager my grandchildren's destiny on unreliable assumptions about benevolent aliens".
Well put, and I agree!