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Existing laser tech could be used for “porch light” to attract alien astronomers (news.mit.edu)
37 points by rodneyrdx 2787 days ago
7 comments

I prefer a Dark Forest strategy for approaching the universe.

If anything, we should be thinking about how to emit less radiation that can be traced back to Earth into space.

Best case: aliens send us technology via morse code.

Worst case: relativistic projectile from advanced civilization destroys Earth.

https://en.wikipedia.org/wiki/The_Dark_Forest

At this point I think I would rather take our chances with the aliens since we are going to destroy ourselves anyway.
For being such a cynic about humanity you're awfully optimistic about aliens.
I think there might be some reasons to be optimistic. Any civilization that might notice our signal and decide to interact with us has with us has existed much longer than our own civilization with high probability. Thus, there is more evidence of long-term stability in such a civilization than our own. With stability comes the potential for experience, with experience the potential for wisdom.
How would you expect a society that is extremely stable would deal with an incohate civilization? I think it's at least plausible they would want to stifle potential problems in the cradle, so to speak.
Why would you believe they’d have our extremely temporary set or morals? Human empires have lasted for thousands of years and the one thing that binds 99% of human history is soul crushing enslavement of each other.
Old movie spoilers ahead

I watched a short movie (an episode from the Outer Limits? It was ~20 years ago) about some army rangers who stumble upon, track and ultimately kill an alien.

When observing it closely afterwards, they realized it was an alien child sent to Earth on some kind of children camp.

The primitive livings on that planet killed the child. The parents were not happy, blew up the camp (and our planet).

So yes, I also favor the Dark Forest approach

A relativistic kill shot would take out a lot more of Earth's biosphere than humans are likely to. If we kill ourselves, bacteria and cockroaches will live on. Not so much, if Earth is vaporized to make way for a hyperspace bypass.
On the upside, the bypass is very splendid and worthwhile. Even ignoring something as extreme as the Dark Forest theory, it still seems like a questionable policy. A more conservative aim would be to want to maximize development time against the risk of discovery, ideally ultimately finding yourself in the role of observing without being observed. The history on our planet of first contact between disparate groups of humans should be illustrative. Even when people had good intentions, the unforeseen impacts could be enormous; I’m thinking of smallpox, and even the history of coexisting Neanderthals and Homo Sapiens. Maybe aliens are totally different, but it’s a hell of a thing do, assuming they would be more benevolent.
Quoting the link

> Like hunters in a "dark forest" ... where any two civilizations cannot communicate well enough to relieve mistrust, making conflict inevitable. Therefore, it is in every civilization's best interest to preemptively strike and destroy any developing civilization before it can become a threat, but without revealing their own location, thus explaining the Fermi paradox.

What was the Greek story (Plutarch? Idk) where some guy being hunted by some army captain crashes on some island and the local pseudo intellectual sophist says they need to kill him before the army captain comes or else they’ll be punished for either aiding him or letting him go. Then the army captain finds out they killed his target for no reason so he kills all of them for being corrupt idiots
I think the explanation of the Fermi paradox is the fact that without a natural predator and add technically superior intelligence we populate the entire planet, while also having little care for the environment causing global warming which is then a problem handled too little too late (or even denied) by our politicians around the globe. This can eventually cause conflict, especially when food prices become too high. Besides that we are also are still fighting like toddlers (USA, Russia, China, Middle East) though it is hard to tell how serious those conflicts are.

I think we are before the gap, that might also be because I'm pessimistic about the current state of the world.

That said, if I'm wrong I would rather have any aliens find us. If you're advanced, you probably resolved various issues regarding limited resources, so why would you kill us as being primitive species?

Why would you kill an ant? Would you care if one died while workers were building an orphanage?
I just finished reading the series a few days ago. That's how I look at our universe now.
This seems to be based on the premise that alien civilizations can only find us if we broadcast and doesn't account for them sending out probes

Even in that universe, we know they could easily send probes out to the galaxy and it would solve the whole "chain of suspicion" thing that makes destroying alien civilizations the best option.

was thinking exactly this when I saw the title.
especially if those astronomers live in nearby systems, such as around Proxima Centauri, the nearest star to Earth, or TRAPPIST-1, a star about 40 light-years away that hosts seven exoplanets, three of which are potentially habitable. If the signal is spotted from either of these nearby systems, the study finds, the same megawatt laser could be used to send a brief message in the form of pulses similar to Morse code.

“If we were to successfully close a handshake and start to communicate, we could flash a message, at a data rate of about a few hundred bits per second, which would get there in just a few years,”

40 light years in "just a few years"? So this laser beam travels faster than the speed of light?

In any case, I don't open my front door and flash my lights to invite strangers off the street, and I don't think we should be doing the same thing to strangers from outer space, you never know if it's an interstellar axe murderer and if they meet us at our planet, then they are already known to be far more technologically advanced than we are so there's nothing we can do to stop them.

I would venture a guess that all so-called intelligent life seeks make use of anything that it can get its hands on and order it according to its will. If this is true, then you really don't ever want to meet other intelligent life. At best they would integrate you into their economic system, just like we integrate people with lower intelligence into our economic system... or underdeveloped countries for that matter. A bit worse would be making us into slaves, which might appeal to their humanity. Most likely is simply to eliminate us and take the planet for their own colony and keep us as pets.
I like the idea that when an old and powerful Galaxy ranging alien race discovers a planet that has life, they place that solar system off limits to any settlement and only observations are allowed. It does not seem that unlikely, unless life is just not rare at all. If 1 in 1000 or 1 in 100 or even 1 in 10 systems were set aside in this way, that would leave plenty of solar systems to continue to expand into.

In the US, we got rich and powerful enough around the 1880's that nature was basically conquered and we wanted to start preserving places for their natural beauty. By the 1970's we had set aside huge amounts of land for National Parks, State Parks and wilderness areas. Wilderness areas alone in the lower 48 is about 64.4 million acres, or about the same as cities and towns (urban areas are 69.4 million acres)[1].

[1]https://www.bloomberg.com/graphics/2018-us-land-use/

If there is life in the Proxima Centauri system, and it has the technological capability to get to the Earth, I think they already know about us.
Serious question: how could they already know about us?

Are you simply assuming they have advanced signal detection technologies that match their space fairing capability?

We can observe a lot more in the cosmos than we can physically reach. We are mapping out and tracking far more stars and planets than we could hope to reach for a long time. Even within our solar system, we have gained and will gain much knowledge of the outer planets from probes well before we set foot on them. I would expect this property to hold for other civilizations, it's just much easier to observe far away things than to transport complex life forms to them.
Perhaps they periodically send probes like Oumuamua that report on nearby systems.
That’s a closed minded view of intelligence. There’s a level above exploitation where you value other intelligent life and cherish it.
It's well established that fish feel pain[0]. It's also possible to kill them far more humanely that we do now, e.g. by electroshock or by eugenol anesthesia. Despite this, out of the 1+ trillion fish killed by humans every year, almost all of them die slowly and painfully. We choose to do this simply because it's more convenient. Why would aliens treat humans any differently?

Intentionally signaling to aliens is one of the stupidest ideas I can think of. The Killing Star by Charles Pellegrino and George Zebrowski has a good analogy (longer quote here: http://www.projectrho.com/public_html/rocket/aliencontact.ph... ), describing a thought experiment of surviving the night in a crime-ridden Central Park:

"How do you survive the night? The last thing you want to do is shout, "I'm here!" The next to last thing you want to do is reply to someone who shouts, "I'm a friend!"

What you would like to do is find a policeman, or get out of the park. But you don't want to make noise or move towards a light where you might be spotted, and it is difficult to find either a policeman or your way out without making yourself known. Your safest option is to hunker down and wait for daylight, then safely walk out.

There are, of course, a few obvious differences between Central Park and the universe.

There is no policeman.

There is no way out.

And the night never ends."

[0] https://www.hakaimagazine.com/features/fish-feel-pain-now-wh...

> Why would aliens treat humans any differently?

There's no obvious reason why aliens should perceive humans as either a threat or a resource. There may be non-obvious reasons, or they may be irrational about it. But unless interstellar travel is a lot easier than we think it is, it's unlikely that aliens would assume visitation is likely in either direction.

There might be a policeman but you don't know how to recognize one.
>There’s a level above exploitation where you value other intelligent life and cherish it.

That sounds like a hope/belief, not a fact.

There may be levels of regard for intelligence that are below pets. See, for example, "To Serve Man". [1]

[1] https://en.wikipedia.org/wiki/To_Serve_Man

edit for misspelling

I haven’t seen much of that from available examples.
Humans cherish their pets. Aliens will cherish humans. Can intelligent life however leave things that they know about alone to do as it wishes without any interference whatsoever? No. In the short term maybe, but in the long term it's impossible. Why? Because either it's under control or it's a threat. Either you are a beast, in which case you become a beast of burden. Or you a barbarian, in which case you should be subdued. Or you are an ally in which case you must be integrated. Or you are food which must be farmed and eaten.

Heck maybe in the long run aliens have more to fear from humans than humans have to fear from aliens. But it's not going to end well for one of them in the long run.

Humans cherish their pets. Aliens will cherish humans

Who says they'll see us as pets? Humans also gather horseshoe crabs by the thousands and suck the blood out of them ("only" killing 10 - 30% of them)

https://www.iflscience.com/plants-and-animals/how-horseshoe-...

Let's hope human blood isn't useful to the aliens.

> such as around Proxima Centauri, the nearest star to Earth, or TRAPPIST-1, a star about 40 light-years away...

I don't think they are asserting that the laser beam travels faster than the speed of light. I think they are referring to Proxima Centauri being about 4 light-years away from Earth [0].

[0] https://en.wikipedia.org/wiki/Proxima_Centauri

That may be what they meant, but that's not what they said, they mentioned 2 systems, one is 40 light years away, and said "...If the signal is spotted from either of these nearby systems..."
They're talking about interstellar communication, not how long you've lived in your house. 40 years is just a few years.
"Few" has a specific meaning when applied to something countable. 40 is not "a few" in any common use of the word.

You don't say "It took the settlers 180 days to ride a wagon across the country, but today it only takes a few hours to drive across the country" when you meant "40 hours".

If you want to use "few", you'd use a different unit like "and now it only takes a few days". Or "And you can send a signal to that star system in a few decades".

Your example sort of fell apart there. It took 180 days at some hypothetical moment in history. Now it takes a few days.

There are a few words in English the meaning of which is absolute, regardless of context. "Few" is not among those words.

Are they fucking crazy? Turn out that light!

Our first encounter with space faring aliens will probably go about as well as native Americans first encounter with Europeans.

The value that Earth provides is the fact that it hosts millions of living species.

Mere geological resources can be gathered from asteroids or other planets with lesser gravity wells.

The Alien species would have to determine if Human technology, economy and culture holds any value to them. If it does, they will conduct a cost-benefit analysis of the various billions of humans inhabiting the planet, and eliminate the least-productive in order to improve average genetic quality and bring the overall species back to within the carrying capacity of the planet.

For example, 56% of the Earth's population from the least-productive countries could be eliminated, for only a 6% decrease in scientific output, and 17% decrease in GDP. Doing so would also result in a 23% decrease in carbon emissions.

Of course, if they find that humanity holds negative value, they will simply eliminate all humans, and turn the planet into a giant nature park.

If we're talking about intelligences that can travel between stars, there is no 'carrying capacity' aside from space on the surface for radiative cooling towers to stop the planet from boiling from the heat generated by the trillions of humans and machines. Seriously, you can probably put all the nonhuman processes of an ecosystem into a bottle that takes in air, energy, and wastewater and puts out food/crops/etc, and you can just dismantle some asteroids for the materials needed for as many fleets of solar panels as you need to put around earth, assuming they don't want to use what's powering their rockets. Really, the limiting factor is cooling the earth. You'd probably want to block all infrared from the sun for convenience.

Implying these beings would likely have any need to worry about 'decreasing' carbon emissions is ludicrous. It's like humans going to a beehive and worrying about killing some bees to stop honey wastage when the humans poke a hole in the hive to collect honey- no, they'll just completely reconstitute the hive. There's a chance it's some first-interstellar-travel thing we might do right now, but it's more likely it's from the time a civilisation is kardashev-2, given that time would be longer. Fermi paradox's still a problem, though.

They could treat us like we treat dogs, lab mice, or beef cattle too...
...sport.
This seems to me like shining a laser pointer randomly up into the sky and hoping someone from a passing plane sees it?

Is this practical given the vastness of space and the directionaality of this laser?

Let's hope that there are no interstellar laws against shining lasers at other star systems.
The Vogons may come by and destroy Earth.
I'll knowingly violate HN's rules to say that's a Vogon conclusion.
Is there a rule against humour? Or puns? I thought it was just a sect of users who are also Wikipedia editors.
There is a rule against anything that doesn't make Sam Altman richer or more acutely aware of the startup landscape.
Well not just a plane passing overhead, a plane passing overhead 200 years from now.

Maybe we should be aiming the big laser at Oumuamua. With a big HEY COME BACK HERE message.

I've wondered if that was the purpose of the "probe". To see if anyone follows it, or otherwise interacts with it. Let's say you know there is a habitable planet, but you don't want to land there first, instead send a probe and see if the planet reacts to it. If they do, it would indicate a rather advanced civilization.
I bet aliens love it when you shine a pointer in their eyes
How we would agree on a handshake? Aliens don’t know English let alone Morse code.
But any alien that can build a receiver knows math, and understands physics, and probably has come to similar conclusions about computation. They might be so different from us that communication would be impossible, but it's not likely.

If nothing else, you can draw simple two-color pictures by sending pixels in a NxM grid, where N and M are both primes. Enough minds thinking about the problem will eventually figure it out.

What would we do if we detected a big glob of binary? Try and look at it in everywhich way. And we would as well if it was stranger.
What’s the worst that could happen?
What's the best that could happen? No such thing as a free lunch.
Probably extermination via a similar-yet-higher-powered laser, as the worst case scenario