Showing posts with label Search for Extraterrestrial Intelligence (SETI). Show all posts
Showing posts with label Search for Extraterrestrial Intelligence (SETI). Show all posts

Tuesday, August 23, 2011

Hoping to Contact Extraterrestrials? Think Again

(Didn't Hawking already do this bit? Perhaps they've already been here, found us to be ridiculous, and bolted toward greener petri dishes...--jef)

Monday, August 22, 2011

Astronomers who have been searching for extraterrestrial intelligence for decades are suddenly saying such an encounter might not be a happy one.

Aliens might destroy life on Earth or plan to eat or enslave humans if they sense our civilization was expanding too rapidly and could harm others, according to a latest study.

The scenario was brought up in a joint study by Seth Baum, Jacob Haqq-Misra and Shawn Domagal-Goldman.

Researchers say extraterrestrials might behave the way we humans have behaved whenever we have discovered other previously unknown intelligent beings on Earth, like unfamiliar humans or chimpanzees and gorillas.

"Just as we did to those beings, the extraterrestrials might proceed to kill, infect, dissect, conquer, displace or enslave us, stuff us as specimens for their museums or pickle our skulls and use us for medical research," according to the study, which was published in the journal Acta Astronautica.

Why should we worry about aliens? The simple reason is that if they can find us, they would be more advanced than humans.

"A core concern is that ETI will learn of our presence and quickly travel to Earth to eat or enslave us," the study says.

The authors speculate that extraterrestrials might try to spread their beliefs through evangelism or to use humans for entertainment.

Just because an ETI civilization holds universalist ethics does not mean that it would never seek our harm. This is because ETI may be quite different from us and could conclude that harming us would help maximize whatever they value intrinsically.

For example, if ETI place intrinsic value on lives, then perhaps they could bring about more lives by destroying us and using our resources more efficiently for other lives. Other forms of intrinsic value may cause a universalist ETI to seek our harm or destruction as long as more value is produced without us than with us.

Aliens also could harm or destroy us if they believe we are a threat to other civilizations. Rapidly expanding civilizations may have a tendency to destroy other civilizations in the process, just as humanity has already destroyed many species on Earth.

Though this scenario might seem unlikely given the likelihood of our technological inferiority relative to other civilizations, we would be at the receiving end if ET thinks that our resources could be used more efficiently to generate or retain other civilizations.

Perhaps ETI is observing rapid and destructive expansion on Earth and could become concerned at our trajectory.

ETI might prefer that our civilization change its ways to survive, but if it doubts that our course can be changed, it may seek to preemptively destroy us to protect other civilizations from us.

A preemptive strike would be particularly likely in the early phases of our expansion because a civilization may become increasingly difficult to destroy as it continues to expand.

"Humanity may just now be entering the period in which its rapid civilizational expansion could be detected by an ETI because our expansion is changing the composition of Earth's atmosphere (e.g. via greenhouse gas emissions), which therefore changes the spectral signature of Earth," the study's authors say, Human civilization affects ecosystems so strongly that some ecologists have begun calling this epoch of Earth's history the anthropocene, a new and unprecedented phase in the planet's history.

If the goal is to maximize ecosystem health, then perhaps it would be better if humanity did not exist, or at least if it existed in significantly reduced form. Since at least some humans believe so, invoking universalist ethical principles, then it is likely that ETI might agree.

But since we don't know what kind of aliens we will end up meeting, there are certain steps humans should take when making contact, the authors urge. Those steps include not sharing details of our biology and DNA structure, and not appearing as if we are rapidly expanding off the Earth.

Monday, July 5, 2010

It's too late to worry that the aliens will find us

05 July 2010 by Seth Shostak

STEPHEN HAWKING is worried about aliens. The famous physicist recently suggested that we should be wary of contact with extraterrestrials, citing what happened to Native Americans when Europeans landed on their shores. Since any species that could visit us would be far beyond our own technological level, meeting them could be bad news.

Hawking was extrapolating the possible consequences of my day job: a small but durable exercise known as SETI, the Search for Extraterrestrial Intelligence.

Although we have yet to detect an alien ping, improvements in technology have encouraged us to think that, if transmitting extraterrestrials are out there, we might soon find them. That would be revolutionary. But some people, Hawking included, sense a catastrophe.

Consider what happens if we succeed. Should we respond? Any broadcast could blow Earth's cover, inviting the possibility of attack by a society advanced enough to pick up our signals.

On the face of it, that sounds like a scenario straight out of cheap science fiction. But even if the odds of calamity are small, why gamble?

For three years, this issue has been exercising a group of SETI scientists in the International Academy of Astronautics. The crux of the dispute was an initiative by a few members to proscribe any broadcasts to aliens, whether or not we receive a signal first.

In truth, banning broadcasts would be impractical - and manifestly too late. We have been inadvertently betraying our presence for 60 years with our television, radio and radar transmissions. The earliest episodes of I Love Lucy have washed over 6000 or so star systems, and are reaching new audiences at the rate of one solar system a day. If there are sentient beings out there, the signals will reach them.

Detecting this leakage radiation won't be that difficult. Its intensity decreases with the square of the distance, but even if the nearest aliens were 1000 light years away, they would still be able to detect it as long as their antenna technology was a century or two ahead of ours.

This makes it specious to suggest that we should ban deliberate messages on the grounds that they would be more powerful than our leaked signals. Only a society close to our level of development would be able to pick up an intentional broadcast while failing to notice TV and radar. And a society at our level is no threat.

The flip side is that for any alien society that could be dangerous, a deliberate message makes no difference. Such a society could use its own star as a gravitational lens, and even see the glow from our street lamps. Hawking's warning is irrelevant.

Such considerations motivated the SETI group at the International Academy of Astronautics to reject a proscription of transmissions to the sky. It was the right decision. The extraterrestrials may be out there, and we might learn much by discovering them, but it is paranoia of a rare sort that would shutter the Earth out of fear that they might discover us.