It may not rank as the most compelling reason to curb greenhouse gases, but reducing our emissions might just save humanity from a pre-emptive alien attack, scientists claim.
Watching from afar, extraterrestrial beings might view changes in Earth's atmosphere as symptomatic of a civilisation growing out of control – and take drastic action to keep us from becoming a more serious threat, the researchers explain.
This highly speculative scenario is one of several described by scientists at Nasa and Pennsylvania State University that, while considered unlikely, they say could play out were humans and alien life to make contact at some point in the future.
Shawn Domagal-Goldman of Nasa's Planetary Science Division and his colleagues compiled a list of plausible outcomes that could unfold in the aftermath of a close encounter, to help humanity "prepare for actual contact".
In their report, Would Contact with Extraterrestrials Benefit or Harm Humanity? A Scenario Analysis, the researchers divide alien contacts into three broad categories: beneficial, neutral or harmful.
Beneficial encounters ranged from the mere detection of extraterrestrial intelligence (ETI), for example through the interception of alien broadcasts, to contact with cooperative organisms that help us advance our knowledge and solve global problems such as hunger, poverty and disease.
Another beneficial outcome the authors entertain sees humanity triumph over a more powerful alien aggressor, or even being saved by a second group of ETs. "In these scenarios, humanity benefits not only from the major moral victory of having defeated a daunting rival, but also from the opportunity to reverse-engineer ETI technology," the authors write.
Other kinds of close encounter may be less rewarding and leave much of human society feeling indifferent towards alien life. The extraterrestrials may be too different from us to communicate with usefully. They might invite humanity to join the "Galactic Club" only for the entry requirements to be too bureaucratic and tedious for humans to bother with. They could even become a nuisance, like the stranded, prawn-like creatures that are kept in a refugee camp in the 2009 South African movie, District 9, the report explains.
The most unappealing outcomes would arise if extraterrestrials caused harm to humanity, even if by accident. While aliens may arrive to eat, enslave or attack us, the report adds that people might also suffer from being physically crushed or by contracting diseases carried by the visitors. In especially unfortunate incidents, humanity could be wiped out when a more advanced civilisation accidentally unleashes an unfriendly artificial intelligence, or performs a catastrophic physics experiment that renders a portion of the galaxy uninhabitable.
To bolster humanity's chances of survival, the researchers call for caution in sending signals into space, and in particular warn against broadcasting information about our biological make-up, which could be used to manufacture weapons that target humans. Instead, any contact with ETs should be limited to mathematical discourse "until we have a better idea of the type of ETI we are dealing with."
The authors warn that extraterrestrials may be wary of civilisations that expand very rapidly, as these may be prone to destroy other life as they grow, just as humans have pushed species to extinction on Earth. In the most extreme scenario, aliens might choose to destroy humanity to protect other civilisations.
"A preemptive strike would be particularly likely in the early phases of our expansion because a civilisation may become increasingly difficult to destroy as it continues to expand. Humanity may just now be entering the period in which its rapid civilisational expansion could be detected by an ETI because our expansion is changing the composition of the Earth's atmosphere, via greenhouse gas emissions," the report states.
"Green" aliens might object to the environmental damage humans have caused on Earth and wipe us out to save the planet. "These scenarios give us reason to limit our growth and reduce our impact on global ecosystems. It would be particularly important for us to limit our emissions of greenhouse gases, since atmospheric composition can be observed from other planets," the authors write.
Even if we never make contact with extraterrestrials, the report argues that considering the potential scenarios may help to plot the future path of human civilisation, avoid collapse and achieve long-term survival.
http://www.guardian.co.uk/science/2011/aug/18/aliens-destroy-humanity-protect-civilisations (http://www.guardian.co.uk/science/2011/aug/18/aliens-destroy-humanity-protect-civilisations)
Post by: Kramer on August 18, 2011, 07:50:35 PM
1. Aliens
2. Man Made Global Warming
Scientists can't seem to prove either of them.
Post by: Religious Dick on August 18, 2011, 07:59:42 PM
Post by: BT on August 18, 2011, 08:07:07 PM
Post by: Kramer on August 18, 2011, 08:07:37 PM
This is NASA? Somehow, I doubt we'll be going to the moon again or anywhere else anytime soon....
One rocket ride creates more 'Global Warming' than 1 billion people using a wood stove to make dinner on a daily basis. We wouldn't want to upset the environment, now would we?
National
Alien
Spaceship
Administration
Post by: kimba1 on August 19, 2011, 01:18:31 AM
Ain't that the revamped movie " the day the earth stood still" ?
Post by: Xavier_Onassis on August 19, 2011, 10:17:10 AM
Post by: kimba1 on August 19, 2011, 11:59:57 AM
Post by: Kramer on August 19, 2011, 12:18:00 PM
I thought the exhaust of rockets was water? wouldn`t it be zero green house gases?
http://news.softpedia.com/news/Private-Spaceflight-May-Worsen-Global-Warming-162537.shtml (http://news.softpedia.com/news/Private-Spaceflight-May-Worsen-Global-Warming-162537.shtml)
http://www.msnbc.msn.com/id/39806493/ns/technology_and_science-science/t/new-climate-change-worry-space-tourism-soot/#.Tk5-Jl2rFRU (http://www.msnbc.msn.com/id/39806493/ns/technology_and_science-science/t/new-climate-change-worry-space-tourism-soot/#.Tk5-Jl2rFRU)
Here is one going back to 1991. http://www.nytimes.com/1991/10/18/us/study-calls-for-effort-to-limit-rockets-pollution.html (http://www.nytimes.com/1991/10/18/us/study-calls-for-effort-to-limit-rockets-pollution.html)
Post by: kimba1 on August 19, 2011, 12:34:51 PM
then I was mis-informed. I had the impression the feul was hydrogen and oxygen mixture .
Post by: Kramer on August 19, 2011, 01:11:10 PM
hydrocarbon-fueled orbital rockets
then I was mis-informed. I had the impression the feul was hydrogen and oxygen mixture .
Don't believe what I posted. I just Googled up some stuff. Likely made up information so scientists, at NASA, can justify us not traveling in space anymore due to causing so-called man-made Global Warming.
Post by: Amianthus on August 19, 2011, 03:39:50 PM
I thought the exhaust of rockets was water? wouldn`t it be zero green house gases?
Water vapor *is* a green house gas. It's worse than carbon dioxide.
Post by: Amianthus on August 19, 2011, 03:45:23 PM
then I was mis-informed. I had the impression the feul was hydrogen and oxygen mixture .
For the shuttle, the main engines used a hydrogen / oxygen mix for fuel, releasing heat and water vapor (plus trace amounts of other stuff). The SRBs however used ammonium perchlorate, aluminum, iron oxide, a polymer, and an epoxy curing agent.
Post by: Xavier_Onassis on August 19, 2011, 04:07:22 PM
==============================
I never do.
It would be surprising if NASA scientists did NOT speculate about what cultures on alien planets might think of us, if they actually knew of our existence. They also surely know how improbable it is that they do know that we exist.
Post by: Kramer on August 19, 2011, 04:13:10 PM
Don't believe what I posted.
==============================
I never do.
It would be surprising if NASA scientists did NOT speculate about what cultures on alien planets might think of us, if they actually knew of our existence. They also surely know how improbable it is that they do know that we exist.
Nobody should believe what you post, most of it is fantasy. Just like your fantasy about what you think NASA is doing, believing, or not doing.
Post by: Xavier_Onassis on August 19, 2011, 10:06:48 PM
I can't imagine that anyone in NASA has not thought about life on other planets. There are very few people who have not.
More so than most, people in NASA are aware of the huge distances between stars and planets in the universe and the unlikelihood that travel during a human lifetime will ever actually be possible.
I don't see where that is fantasy at all. I have heard the same thoughts from NASA and other scientists, and I am pretty sure that I am hardly the only one.
Post by: Plane on August 19, 2011, 10:27:26 PM
Perhaps this is another reason to develop a space elevator as soon as possible.
Post by: Xavier_Onassis on August 19, 2011, 11:20:47 PM
===============================================================
Before doing this, it needs to be proven that it is actually possible, I would think.
Post by: Plane on August 19, 2011, 11:43:42 PM
Perhaps this is another reason to develop a space elevator as soon as possible.
===============================================================
Before doing this, it needs to be proven that it is actually possible, I would think.
There doesn't seem to be anything wrong with the theroy, but as yet there is no cable strong enough to support even its own weight over such a long distance.
Everything elese seems to be simple to solve problems.
Carbon tubes promise the potential for cable of monomolecular strength, now if only we can learn how to make them more than an inch long.
Post by: kimba1 on August 20, 2011, 02:11:55 AM
Post by: Xavier_Onassis on August 20, 2011, 10:54:59 AM
I would think that the weather and aircraft could present many problems as well. I am not against the idea, simply in favor of making sure it is possible before starting on it.
Post by: kimba1 on August 20, 2011, 12:13:08 PM
Post by: Xavier_Onassis on August 20, 2011, 12:50:30 PM
The legend is based on the ziggurats built by people in Anatolia, which is a very bad place to build towers because of the earthquakes. Dubai, Taipei, and Kuala Lumpur have had no major problems with their tall buildings yet, and the Sears Tower is still standing as tall as ever. I don't think that Al Qaeda was acting on divine authority, but perhaps they did.
If reaching into the sky actually god God's drawers in a knot, then why didn't he smite Yuri Gagarin when he was floating about in orbit and said that he saw no God up there? It barely made the papers in the US.
Post by: Plane on August 20, 2011, 09:40:02 PM
So it is a great idea, but sort of like making a jet engine out of cheese: there is nothing available to make it out of.
I would think that the weather and aircraft could present many problems as well. I am not against the idea, simply in favor of making sure it is possible before starting on it.
Actually making a rocket motor out of cheese is pretty easy, and cheese would not be difficult to utilise as Jet fuel.
Rockets useing asphalt , balona , wood, plastic as fuel grain have been made to work.
Just how much structural strength can one find in cheese rind?
Post by: Xavier_Onassis on August 21, 2011, 12:48:29 AM
Post by: Plane on August 21, 2011, 08:20:15 AM
You could CARVE a jet motor out of cheese, of course, but to would not function for any length of time. Cheese dires out and shrinks with heat, and of course it melts and catches fire.
It would be dead easy to build a jet that used cheese as fuel.
Perhaps a ramjet could be built of cheese entirely , provided (as you point out ) that the duration of thrust need not be long.
Post by: Amianthus on August 21, 2011, 12:33:24 PM
You could CARVE a jet motor out of cheese, of course, but to would not function for any length of time. Cheese dires out and shrinks with heat, and of course it melts and catches fire.
Mythbusters made a rocket out of salami.
http://dsc.discovery.com/fansites/mythbusters/db/food/salami-rocket-fuel.html (http://dsc.discovery.com/fansites/mythbusters/db/food/salami-rocket-fuel.html)
Post by: Henny on August 22, 2011, 02:39:09 AM
I see where one of the authors does work for NASA, and i see where it was published in Acta Astronautica, but i don't see where NASA commissioned the work, so maybe the Guardian misled a bit. If so, my bad.
Quite right. One of the authors NASA as his professional affiliation, that is all. In the world of STM publishing (I work for the company that published this paper), affiliation to does not mean approved by.