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Futurology

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Astronomer: If Earth Is Average, We Should Find Alien Life Within 60 Light-Years (www.sciencealert.com)

submitted 11 months ago by [email protected] to c/[email protected]

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[–] [email protected] 17 points 11 months ago (4 children)

Sometimes I wonder if the reason we've not found any life might be because we just don't recognise it as such. It might be too alien; maybe it's such a large system that we don't fully comprehend it, or perhaps it moves at a timescale that we just cannot grasp.

We created gods in our image to explain existence. Anthropocentric as we are, we assumed that humanity was somehow special, distinguished from all other life on Earth. Now we're doing the same with the very definition of life. Life looks a certain way on Earth, so obviously it needs to look the same everywhere.

It makes sense as an outset though, you can only look for what we know to look for.

[–] sbv 14 points 11 months ago (3 children)

We're looking for high power radio signals leaking into space. With a structure that we recognize. Basically analog screams into the void.

But we're generating fewer and fewer of those, because it's more efficient to spread data across frequencies at low power. As we compress data and encrypt it, the signal begins to look more and more like random noise.

There were a few decades where our civilization was screaming into the void, but those are coming to an end. Because efficiency beats screaming into the void.

We're probably average. If alien technology follows a similar trajectory to our own, there will only be a brief window where it will be sloppy enough for us to detect.

[–] [email protected] 8 points 11 months ago (1 children)

That's assuming they develop technology like us. If they live in really short bursts they might never get to that point, or maybe develop something completely different. On the other hand, they might have really long lifespans, perhaps tens of thousands of years, and perceive time in a completely different manner.

[–] sbv 3 points 10 months ago

We're looking for (relatively) high powered radio signals. Regardless of how alien critters evolve, they're going to have the same constraints on their radio technology as we do.

It is possible they'd have some reason for pouring a tonne of energy into loud radio broadcasts, but if they are using radio for communications (as our SETI searches assume), then they will have lots of incentives to stop screaming into the void. At which point, our searches will not find them.

[–] [email protected] 2 points 10 months ago (1 children)

Is background radiation from space just some alien looking encrypted version of their pornhub?!

[–] sbv 3 points 10 months ago

That's why I have 16tb of background radiation recordings. When we figure out their video/audio/tactile/olfaction formats I'm gonna have a great time.

[–] [email protected] 1 points 10 months ago (1 children)

What about, rather than communicating with electromagnetic waves, they communicate with gravitational waves? Or something else? There's a lot of dark matter out there, what if it's alien telecoms?

[–] sbv 2 points 10 months ago

🤷 We're looking for radio signals. It seems unlikely we'd detect those.

[–] [email protected] 7 points 10 months ago* (last edited 10 months ago) (1 children)

If you think about it, looking for life that's very similar to us is the exact opposite of presuming we are special. It's presuming we are average.

[–] [email protected] 3 points 10 months ago

That's certainly one perspective! I'm a pessimist by nature, which I suppose is reflected in my view on humanity as a whole.

[–] Sethayy 3 points 10 months ago

Its more a statistical observation, life/knowledge could form complex patterns anywhere in the universe, but for sure exists in our cells. So we look for that similar to what's proven, otherwise we're just wandering blind

[–] [email protected] 2 points 10 months ago

We humans are made out of most basic atoms of the universe, so it does make some sense to assume most life to be carbon based. There could be more advanced silicon based life forms, but it would be much more complex.

Of course it might be that more advanced life forms would consider us as same level as we consider ants. How many conversations have you had with ants lately.

[–] [email protected] 9 points 11 months ago* (last edited 11 months ago) (1 children)

Reminder, that the furthest man made spacecraft right now is the voyager that started 46 years ago in 1977. it is 18 lighthours away. Not a lightday, not a lightweek. No a lightmonth. Not a light year. Not 60 lightyears. 18 lighthours in 46 years. One human lifetime is around 24-28 lighthours, in voyagers speed.

If we want to reach a system that is 60 lightyears away, we need to astronomically advance our technology for propulsion technology and long time human space flights. Bone and muscle loss is a real problem when staying in space even for relativity short time.

https://www.nasa.gov/missions/station/bone-and-muscle-loss-in-microgravity/

[–] [email protected] 2 points 10 months ago (1 children)

Yes.
Communication could happen though. A person could send and receive a message in a single lifetime.

[–] [email protected] 6 points 10 months ago

"hello"

"What?"

*dies*

[+] [email protected] 9 points 11 months ago* (last edited 10 months ago) (1 children)

[deleted]

[–] [email protected] 8 points 11 months ago (3 children)

Well statistically speaking you and me are probably both quite average....

But average here means just a rocky planet inside it's stars habitable zone. That is then shoved into the drake equation and that gives out that prediction for planet harboring at least microbial life within 65 light years, provided that 1% of planets with a chance to do so eventually develop life.

[–] [email protected] 4 points 10 months ago* (last edited 10 months ago)

The problem is, due to the anthropic principle, we cannot say that the occurrence of life is average, because there is an inherent selection bias there. If life didn't exist on earth, we wouldn't be here to observe it. We only come into existence where life already is, and so we do not have a true average planet. To have a true average planet, we would have needed the ability to come into existence on a lifeless world. The cosmological principle actually doesn't quite hold, because we are in a privileged position, as we, by definition, cannot come into existence where there isn't life. This includes the kind of universe we exist in, as well, if multiple universes exist.

So, from our existence we cannot form any conclusions on how common life is. At best only an educated guess. If we detect life on another planet, only then can we begin drawing conclusions, as in that case we avoid a selection bias.

[–] [email protected] 3 points 10 months ago

Speak for yourself. I've got higher than average number of hands, feet, fingers, toes, arms., legs, teeth, eyes, ears, hair, and more!