<p>The experimental data only shows that there is no life and no intelligent life in the parameter space where we could detect it.</p>

<p>The experimental data doesn't explain the cause.</p>

<p>That we are alone in the Universe, it is still a possibility.</p>

CC BY-SA 4.0
2019-01-15T05:03:39.133Z
2019-01-15T05:03:39.133Z
peterh
<p>There are a number of questions here on the <a href="https://astronomy.stackexchange.com/search?q=fermi">Fermi Paradox</a> with answers ranging from an Infinite Universe, the parameters for the Drake Equation and others. Well worth having a read through them.</p>

<p>But my favourite is author Cixin Liu's theory outlined in The <a href="https://www.amazon.co.uk/Three-Body-Problem-Cixin-Liu/dp/1784971553" rel="nofollow noreferrer">Three Body Problem</a></p>

<blockquote class="spoiler">
  <p> Civilisations which are noisy draw attention to themselves, and are extinguished by civilisations thinking long term who don't want to have competition for resources in the far distant future.</p>
</blockquote>

<p>Obviously that theory is not easily proven or disproven in any useful way, so currently it may be as valid as any other. Well worth a read in any case!</p>

CC BY-SA 4.0
2019-01-15T05:00:12.813Z
I think a civilization which is capable to destroy another from many light years away, don't need to think so long term - transferring a lot of nukes to a distant planet is probably not much more harder than transferring a colonization ship.
peterh
CC BY-SA 4.0
2019-01-15T13:25:10.480Z
You need to read the book. Also, no, the solution is much easier than trying to transfer nukes anywhere.
Rory Alsop
CC BY-SA 4.0
2019-01-15T13:26:00.707Z
You've made me curious! I'll do that.
peterh
CC BY-SA 4.0
2019-01-14T17:26:12.393Z
2019-01-14T17:26:12.393Z
Rory Alsop
<p>I assume you mean "civilization", not "life".</p>

<p>It's a pure speculation that an advanced civilization would emit a "cacophony of noises".</p>

<p>Even our civilization on Earth is already working on reducing the amount of electromagnetic noise it produces. We are reducing light pollution, we are moving communications from radio waves into fiber optic cables and into low-power cellular networks, a lot of our equipment is shielded to avoid unwanted electromagnetic emissions. The general push to conserve energy means less and less will be emitted into space.</p>

<p>So based on our own recent historical experience, a civilization is unlikely to generate an electromagnetic signal noticeable at interstellar distances.</p>

CC BY-SA 4.0
2019-01-15T23:22:58.843Z
2019-01-15T23:22:58.843Z
cuckoo
<p>It would seem that if life were relatively common in the universe that there would be a cacophony of noise somewhere in the electromagnetic spectrum. Is life so rare and distant that the waves haven't reached us yet, or have they attenuate out, or are they unintelligible, or are we the first, or are we alone?</p>

CC BY-SA 4.0
2019-01-15T07:55:51.170Z
Jake, your question has been flagged for closure as it's likely to generate *opinions* rather than scientific answers. Could I suggest you [edit] the question to focus on a specific "problem"? For example, it's 2.5m ly to the next galaxy: at that distance, how powerful would a radio transmission need to be for us to detect it? (If we can't detect it from there, what hope have we got to detect anything from the billions of other galaxies?). That's just a suggestion, but hopefully gives you an idea of the kind of question that's ok here. See also [ask], and take the [Tour]. :-)
Chappo Hasn't Forgotten
CC BY-SA 4.0
2019-01-15T18:21:14.957Z
Well, that depends if you ask about finding "life" - something we might not recognize even if we literally stepped into it, or you're asking why we didn't find some creatures dumb enough to scream with radiowaves in all directions?
Mithoron
<life><origin-of-life>
Why haven't detected life in the universe?
Jake Geo
# Why haven't detected life in the universe?

(Asked by: username_0 on 2019-01-14)

It would seem that if life were relatively common in the universe that there would be a cacophony of noise somewhere in the electromagnetic spectrum. Is life so rare and distant that the waves haven't reached us yet, or have they attenuate out, or are they unintelligible, or are we the first, or are we alone?

**Tags:** life, origin-of-life
> **Comments:**
> **username_1**: Jake, your question has been flagged for closure as it's likely to generate *opinions* rather than scientific answers. Could I suggest you [edit] the question to focus on a specific "problem"? For example, it's 2.5m ly to the next galaxy: at that distance, how powerful would a radio transmission need to be for us to detect it? (If we can't detect it from there, what hope have we got to detect anything from the billions of other galaxies?). That's just a suggestion, but hopefully gives you an idea of the kind of question that's ok here. See also [ask], and take the [Tour]. :-)  
> **username_2**: Well, that depends if you ask about finding "life" - something we might not recognize even if we literally stepped into it, or you're asking why we didn't find some creatures dumb enough to scream with radiowaves in all directions?  

---

## 3 answers

### Answer by username_3 on 2019-01-15. Score: 2

The experimental data only shows that there is no life and no intelligent life in the parameter space where we could detect it.

The experimental data doesn't explain the cause.

That we are alone in the Universe, it is still a possibility.


---

### Answer by username_4 on 2019-01-14. Score: 1

There are a number of questions here on the [Fermi Paradox](https://astronomy.stackexchange.com/search?q=fermi) with answers ranging from an Infinite Universe, the parameters for the Drake Equation and others. Well worth having a read through them.

But my favourite is author Cixin Liu's theory outlined in The [Three Body Problem](https://www.amazon.co.uk/Three-Body-Problem-Cixin-Liu/dp/1784971553)

> Civilisations which are noisy draw attention to themselves, and are extinguished by civilisations thinking long term who don't want to have competition for resources in the far distant future.

Obviously that theory is not easily proven or disproven in any useful way, so currently it may be as valid as any other. Well worth a read in any case!

> **Comments:**
> **username_3**: I think a civilization which is capable to destroy another from many light years away, don't need to think so long term - transferring a lot of nukes to a distant planet is probably not much more harder than transferring a colonization ship.  
> **username_4**: You need to read the book. Also, no, the solution is much easier than trying to transfer nukes anywhere.  
> **username_3**: You've made me curious! I'll do that.  

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### Answer by username_5 on 2019-01-15. Score: 0

I assume you mean "civilization", not "life".

It's a pure speculation that an advanced civilization would emit a "cacophony of noises".

Even our civilization on Earth is already working on reducing the amount of electromagnetic noise it produces. We are reducing light pollution, we are moving communications from radio waves into fiber optic cables and into low-power cellular networks, a lot of our equipment is shielded to avoid unwanted electromagnetic emissions. The general push to conserve energy means less and less will be emitted into space.

So based on our own recent historical experience, a civilization is unlikely to generate an electromagnetic signal noticeable at interstellar distances.


---

