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Space => Life on Other Worlds => Topic started by: Quagnon on April 10, 2016, 12:01:18 am



Title: Can we mask the Earth from hostile aliens ?
Post by: Quagnon on April 10, 2016, 12:01:18 am
Can we mask the Earth from hostile aliens ?
Posted on Saturday, 2 April, 2016


(http://www.unexplained-mysteries.com/images/news_large/news-lightning-laser.jpg)

Lasers could be used to mask the Earth's presence. Image Credit: CC BY-SA 3.0 ESO/M. Kornmesser
A new study has suggested that it may be possible to stop alien civilizations from discovering us.
The hunt for extrasolar planets has been going from strength to strength in recent years with astronomers having so far identified more than 2,000 of them in orbit around distant stars.

We are able to detect the presence of these far-off worlds by looking out for the tell-tale dimming that occurs when a planet passes in front of its star, a technique that should in theory enable an extraterrestrial civilization to detect our planet as well if they happen to be looking in our direction.

But what if, for some reason, we didn't actually want to be found ?

In a recent study, Professor David Kipping and graduate student Alex Teachey from Columbia University determined that it would be possible to mask the Earth from being detected while it is passing in front of the sun by firing lasers out in to space.

The pair calculated that it would be necessary to shine a 30 MW laser for 10 hours straight, once a year to hide all the visible light from the Earth and a 250 MW laser to hide all wavelengths.

"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," said Teachey. "To another civilization, this should make the Earth appear as if life never took hold."

Source: Washington Post
https://www.washingtonpost.com/news/speaking-of-science/wp/2016/03/31/scientists-have-a-wild-idea-for-hiding-us-from-evil-aliens/?tid=pm_national_pop_b


Title: Re: Can we mask the Earth from hostile aliens ?
Post by: Quagnon on April 10, 2016, 12:02:28 am
Scientists have a wild idea for hiding us from evil aliens

The inside track on Washington politics.
(https://img.washingtonpost.com/wp-apps/imrs.php?src=https://img.washingtonpost.com/news/speaking-of-science/wp-content/uploads/sites/36/2016/03/lasercloakin-1024x711.jpg&w=480)

Do we really want to hide, though? (G. Hüdepohl/ESO)

Most of the time when we talk about silly scientific papers related to alien life, we're talking about crazy ideas for how to find aliens. But a new study in the Monthly Notices of the Royal Astronomical Society proposes a way of hiding from aliens. Humans are so fickle.


Title: Re: Can we mask the Earth from hostile aliens ?
Post by: Quagnon on April 10, 2016, 12:02:59 am
(https://img.washingtonpost.com/wp-apps/imrs.php?src=https://img.washingtonpost.com/news/speaking-of-science/wp-content/uploads/sites/36/2016/03/giphy.gif&w=540)


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A lot of our search for Earth-like planets (and, by extension, for life as we know it) hinges on transiting planets. These are planets that pass in front of their host star in such a way that the transit is visible from our perspective. The movement of the planet in front of the host star makes the light from that star dim or flicker, and we can use that to determine all sorts of things about distant worlds — including how suitable they may be for life.

[Study: Maybe we can’t find aliens because they’ve all died already]

Some scientists have suggested that we should hope that Earth is a transiting planet from the perspective of some other world that hosts intelligent life. In other words, our best shot at finding aliens might be hoping that they're using exactly the same methods of planetary detection that we are, and that they can see the passage of Earth in front of the sun with their telescopes. If we made a lot of noise in the direction of those theoretical planets, we might get their attention faster.

Or we could point lasers at them instead.


Title: Re: Can we mask the Earth from hostile aliens ?
Post by: Quagnon on April 10, 2016, 12:03:22 am
(https://img.washingtonpost.com/wp-apps/imrs.php?src=https://img.washingtonpost.com/news/speaking-of-science/wp-content/uploads/sites/36/2016/03/giphy-1.gif&w=500)


Title: Re: Can we mask the Earth from hostile aliens ?
Post by: Quagnon on April 10, 2016, 12:03:52 am
(giphy)

Professor David Kipping and graduate student Alex Teachey, both of Columbia University, decided to see how much laser light it would take to mask the dimming caused by our planet's transit. According to their math, it would take about 10 continuous hours of shining a 30 MW laser once a year to eliminate the transit signal in visible light. Actually replicating every wavelength of light emitted by the sun would take about 250 MW of power.

"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," Teachey said in a statement.

This assumes, of course, that the aliens in question haven't already figured out more sophisticated (or just very different) methods for detecting a planet's habitability. It's possible that they'd catch on to our little laser show pretty quickly.

[Looking for alien civilizations? Check these star clusters, scientists say.]

https://www.washingtonpost.com/news/speaking-of-science/wp/2016/01/06/looking-for-alien-civilizations-check-these-star-clusters-scientists-say/


Title: Re: Can we mask the Earth from hostile aliens ?
Post by: Quagnon on April 10, 2016, 12:04:24 am
But we could use our lasers to be even louder. Instead of cloaking ourselves, we could make our transit signature so darn weird that aliens would have to take notice.

There's a big, interdisciplinary debate about whether we should try to contact intelligent life from other planets. To be fair, it's possible that we'd really, really regret it. Humans are kind of the worst, so intelligent life has a pretty bad track record so far.

"Our work offers humanity a choice, at least for transit events, and we should think about what we want to do," Kipping said in a statement.

But it could also be really great. And hey, the chances are slim anyway — especially now that we know it's pretty easy to hide from our best method for detecting Earth-like planets. I already worry that people are ignoring my texts because they hate me. Now I get to wonder if aliens might be pointing lasers at us because they think we're gross, and they just can't even.

Read More:

The hunt for extraterrestrials turns to the ‘dim bulbs of the universe’

Stephen Hawking announces $100 million hunt for alien life

Why NASA’s top scientist is sure that we’ll find signs of alien life in the next decade

Study suggests a new trick for finding alien civilizations

A new way of calculating distant stars’ gravity could help us find alien worlds

This broken space telescope keeps spotting new planets

https://www.washingtonpost.com/news/speaking-of-science/wp/2016/03/31/scientists-have-a-wild-idea-for-hiding-us-from-evil-aliens/?tid=pm_national_pop_b


Title: Re: Can we mask the Earth from hostile aliens ?
Post by: Manetho on April 10, 2016, 02:53:04 am
I don't agree with the 'vast distances' argument. Our space exploration is in its infancy, and our current propulsion method (pushing the air behind the craft) will one day be laughed at, in the same way that we chuckle about 1980's cellular phones.


Title: Re: Can we mask the Earth from hostile aliens ?
Post by: Manetho on April 10, 2016, 02:54:00 am
I'm very sure advanced beings who can space travel would be able to see us. Any beings that galaxy travels should have unspeakable technology.


Title: Re: Can we mask the Earth from hostile aliens ?
Post by: Manetho on April 10, 2016, 02:55:09 am
And in any case, many exoplanets have been discovered by variations in radial velocity - i.e. the star "wobbles" - as opposed to dimming due to transits.


Title: Re: Can we mask the Earth from hostile aliens ?
Post by: Katie Wondrash on April 10, 2016, 03:05:33 pm
Why would we even want to..? How do we know if they're even hostile until they contact us?


Title: Re: Can we mask the Earth from hostile aliens ?
Post by: Katie Wondrash on April 10, 2016, 03:24:01 pm
Obama: 'no direct contact with aliens yet'

http://blogs.wsj.com/washwire/2016/02/12/president-obama-will-let-you-know-when-humans-contact-aliens/


Title: Re: Can we mask the Earth from hostile aliens ?
Post by: Katie Wondrash on April 10, 2016, 03:24:43 pm
Could alien life have already gone extinct ?

http://www.dailymail.co.uk/sciencetech/article-3410524/Have-aliens-EXTINCT-Experts-claim-extraterrestrial-life-formed-planets-died.html#ixzz3xtyoxBUS


Title: Re: Can we mask the Earth from hostile aliens ?
Post by: Katie Wondrash on April 10, 2016, 03:25:26 pm
"The chances of finding out what’s really going on in the universe are so remote, the only thing to do is hang the sense of it and keep yourself occupied."