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View Full Version : What is more probable to happen....Us finding aliens or aliens finding us?



AlphaCentauri
2014-Apr-24, 05:36 PM
Assuming aliens exist, which will happen first?

Swift
2014-Apr-24, 09:31 PM
Hi AlphaCentauri

I moved your thread from Q&A to Life in Space. Q&A is for "... astronomy and space exploration questions with straightforward, generally accepted answers". I doubt this question has either a straightforward or a generally accepted answer, so I think the debate will be better here.

John Mendenhall
2014-Apr-24, 10:44 PM
It will be difficult to answer your question, for today is yamaccizz day on my home planet, and one must tell the truth all day or lose one's entry to heaven. So, this is a lie.

SkepticJ
2014-Apr-24, 10:47 PM
Depends on what the aliens are like, doesn't it?

If they're technologically more advanced than us, they'll know about us first. If we're more advanced, we'll know about them first.

John Mendenhall
2014-Apr-24, 10:48 PM
More seriously, I vote for us. This primate curiosity we have built into us is just unstoppable.

KABOOM
2014-Apr-24, 11:09 PM
Way more probable that we will first discover alien life given that it is likely that 99%+ of all universal forms of life is less advanced than humans.

Noclevername
2014-Apr-24, 11:10 PM
No way to know, as there's no solid data to base an informed scenario on. Any speculation here would be unscientific, blue-sky guesswork.

Cougar
2014-Apr-25, 12:56 AM
Assuming aliens exist, which will happen first?

What will happen first is that we will detect some signature of life on some exo-planet. It will not likely be the signature of "aliens," but perhaps a more generalized detection of certain elements associated with the planet that would indicate, say, plant life....

Jens
2014-Apr-25, 02:31 AM
What will happen first is that we will detect some signature of life on some exo-planet. It will not likely be the signature of "aliens," but perhaps a more generalized detection of certain elements associated with the planet that would indicate, say, plant life....

I'm not sure if my logic is sound, but this is what I thought: Each ET race can only be discovered once (meaning by anybody, so once we are discovered by race A then race B discovering us no longer counts as a discovery). And each ET race can discover multiple other ET races. So I would conclude that the probability of us being discovered is much higher.

To add to that, we know we haven't discovered any other ET races, but we might have been discovered. So for that reason too, I would want to vote for "being discovered."

Noclevername
2014-Apr-25, 09:33 AM
I'm not sure if my logic is sound, but this is what I thought: Each ET race can only be discovered once (meaning by anybody, so once we are discovered by race A then race B discovering us no longer counts as a discovery).

Discovery is relative to your own knowledge. If you discover a cave, and I don't know about it, then I independently discover it, IMO it counts as a discovery for me. Hence the term "rediscovery".

Paul Wally
2014-Apr-25, 09:58 AM
It's a difficult question! My first guess was that we would be discovered by "them", but then again an advanced alien civilization would leave more signs of its existence meaning that they are more discoverable.

Jeff Root
2014-Apr-25, 10:00 AM
Jens,

I agree with Noclevername. Discovery is relative to your
own knowledge. I recently discovered romanesco in my local
grocery store, even though Strange has had a picture of one
as his avatar for quite a long time. If I had known the avatar
was romanesco, or even that it was a picture of part of a plant,
then it wouldn't have been the discovery of romanesco for me,
but just the discovery that my local grocery store has it.

* * * *

There could be a time lag such that we discover aliens and
they discover us before either of us communicates that fact
to the other.

Most likely, we will discover a very powerful radio or laser
signal in the sky telling us that they exist. They might not
know we exist until after they sent that signal. But they
might discover our signals before we discover theirs.

Alternatively, we travel to someplace that has alien bugs
that are too small to detect until you look at them under a
microscope. But they find our spacesuits tasty. So they
discover us slightly before we discover them.

-- Jeff, in Minneapolis

Colin Robinson
2014-Apr-25, 10:53 AM
Assuming aliens exist, which will happen first?

Does the word "aliens" include any form of extraterrestrial life, or intelligent life forms only?

I think there's a real chance we'll find extraterrestrial life in this solar system within the next few decades, perhaps on Titan or one of the other outer moons. We're more likely to find single-celled living things than multi-celled ones, and if we do find multi-celled things, they are more likely to be sessile (staying in one place, like plants, fungi, corals) rather than motile (swimming, crawling or running about).

Intelligent life forms are another question. We might find them (though I doubt this will happen any time soon), or they might find us. If their technology was in advance of ours, it would be easier for them to find us than for us to find them. It would then be up to them to decide whether and when we humans would become aware of their existence.

Colin Robinson
2014-Apr-26, 02:15 AM
What will happen first is that we will detect some signature of life on some exo-planet. It will not likely be the signature of "aliens," but perhaps a more generalized detection of certain elements associated with the planet that would indicate, say, plant life....

If a familiar biological catalyst such as chlorophyll was detected, in conjunction with symptoms of photosynthesis (e.g. dioxygen, starches, sugars), that would be persuasive evidence for life... But I wonder how likely this is? Would evolution on a different world, light-years away, result in chemistries familiar enough to be recognizable by us at that distance? What if (for instance) photosynthesis on an exoplanet used something different from chlorophyll, to synthesize foods other than sugars or starches? Could remote observation of exoplanets distinguish signatures of unfamiliar biochemistry from those of an exotic non-living chemistry?

Distinguishing between living and non-living chemistries will be more feasible within our own solar system, where we can send probes with cameras and microscopes to look at morphologies (i.e. shapes and structures), as well as looking at what is happening chemically.

Jens
2014-Apr-26, 04:24 AM
Discovery is relative to your own knowledge. If you discover a cave, and I don't know about it, then I independently discover it, IMO it counts as a discovery for me. Hence the term "rediscovery".

I'm ok with that. I suppose my view would still be the same: we have never discovered ETs, but some ET race may have discovered us already, so I think the idea of being discovered seems more likely.

Paul Beardsley
2014-Apr-26, 10:01 AM
First a couple of thoughts on word meanings:

The verb "to discover" clearly has two meanings depending on whether we're talking about the point of view of the discoverer or the thing discovered. "Last Tuesday Polly discovered an old-fashioned furniture shop quite near her place of work." "In 1781, William Herschel discovered a new planet." The first example is about Polly; the second is about Uranus. Both are acceptable.

"Motile" - I thought that meant an organism that can move parts of itself but which isn't actually mobile A Venus Flytrap, for instance. But it doesn't mean that after all. Is there a word that does mean that?

As to the question, I think it is far more likely that aliens will discover us than we will discover aliens. (I take "aliens" to mean intelligent extraterrestrials, and not just the equivalent of seaweed.) The reason I think this is, space travel is hard, we've lost the will to do it, and with 7 billion people depleting the planet's resources, I think we will soon lose the ability, if we haven't already. Whereas aliens might not have lost the will and the ability and therefore will get to visit us.

I think achieving space travel is a bit like winning a gold medal at the Olympics - it's not something that just happens if you wait long enough or work out at the gym twice a year. There may be gold medal winners out there, but we didn't put in the necessary dedication, and now we're too old.

SkepticJ
2014-Apr-26, 07:05 PM
"Motile" - I thought that meant an organism that can move parts of itself but which isn't actually mobile A Venus Flytrap, for instance. But it doesn't mean that after all. Is there a word that does mean that?

Animate?

Noclevername
2014-Apr-27, 12:30 AM
By "finding" them, do you mean direct contact, long range communication, or inferring their existence from indirect evidence?

Paul Beardsley
2014-Apr-27, 07:27 AM
Animate?

I thought that covered all kinds of movement.

Paul Beardsley
2014-Apr-27, 07:30 AM
By "finding" them, do you mean direct contact, long range communication, or inferring their existence from indirect evidence?

I would take it to mean any of these as long as it's conclusive.

eburacum45
2014-Apr-27, 07:41 AM
A plant's response to touch is called thigmonasty
http://en.wikipedia.org/wiki/Thigmonasty
Thigmo- is a prefix meaning touch, added to the suffix -nasty
more nastic movements here
http://en.wikipedia.org/wiki/Nastic_movements

Animals that can move parts of their body but are fixed in place are referred to as sessile. as I'm sure you know.

Paul Beardsley
2014-Apr-27, 08:01 AM
Animals that can move parts of their body but are fixed in place are referred to as sessile. as I'm sure you know.

Thanks for all this, but I thought "sessile" also referred to living things that don't move at all.

So, is there a word for an organism that is capable of moving parts of itself at a visible rate (as opposed to, say, the slow opening of petals, or general growth) but which is not capable of travel?

Noclevername
2014-Apr-27, 08:39 AM
So, is there a word for an organism that is capable of moving parts of itself at a visible rate (as opposed to, say, the slow opening of petals, or general growth) but which is not capable of travel?

"Stuck"?

Jens
2014-Apr-27, 09:26 AM
Or "morbidly obese"?

Paul Beardsley
2014-Apr-27, 09:51 AM
Thank you people. Not. ;)

Jens
2014-Apr-27, 01:38 PM
Thank you people. Not. ;)

The honest answer is, I cant find a term for it. Maybe non-locomotive?

Colin Robinson
2014-Apr-27, 08:59 PM
Thanks for all this, but I thought "sessile" also referred to living things that don't move at all.

So, is there a word for an organism that is capable of moving parts of itself at a visible rate (as opposed to, say, the slow opening of petals, or general growth) but which is not capable of travel?

I don't know a single-word description for a organism like that, but I think the part(s) that move can be called "motile" even if the organism as a whole is not motile.

SkepticJ
2014-Apr-28, 06:28 AM
Thanks for all this, but I thought "sessile" also referred to living things that don't move at all.

Is there such a thing? All living things move, if you look closely, or long enough.

Paul Beardsley
2014-Apr-28, 06:52 AM
Is there such a thing? All living things move, if you look closely, or long enough.

Please see post 22.

Jens
2014-Apr-28, 10:14 AM
Is there such a thing? All living things move, if you look closely, or long enough.

The idea here is move in the sense of travel? Do trees move if you watch them long enough?

I think Paul is thinking of a being like a Venus flytrap, which cannot travel but can move some parts. Or perhaps a sea anemone?

Noclevername
2014-Apr-28, 10:20 AM
So, is there a word for an organism that is capable of moving parts of itself at a visible rate (as opposed to, say, the slow opening of petals, or general growth) but which is not capable of travel?

As far as I can find, subsessile (http://en.wiktionary.org/wiki/subsessile) comes closest in meaning. However it also has a completely unrelated botanical meaning having to do with leaf structure.

Paul Beardsley
2014-Apr-28, 10:36 AM
Yes, Jens, exactly right.

eburacum45
2014-Apr-28, 10:48 AM
All animals have moving parts, even the sessile ones. Plants, on the other hand, only have parts that move in response to stimuli, that is to say the nastic responses mentioned earlier. If we are considering alien species, they will not be members of either the animal or plant taxa, so it might be necessary to invent new words.

Paul Beardsley
2014-Apr-28, 11:03 AM
All animals have moving parts, even the sessile ones. Plants, on the other hand, only have parts that move in response to stimuli, that is to say the nastic responses mentioned earlier. If we are considering alien species, they will not be members of either the animal or plant taxa, so it might be necessary to invent new words.

But my point is, we don't seem to have a word for terrestrial life forms that can move parts of their bodies but cannot travel.

Noclevername
2014-Apr-28, 11:09 AM
Sessile tool-using intelligence might hypothetically exist, but it would take a very unlikely confluence of circumstances.

You'd need them to evolve in an area with enough food to support not only life but life with a large brain-equivalent. They'd need some materials to make tools out of, and not being able to go out and gather them, they would need some sort of fluid current capable of carrying significant amounts of materials to and fro.

Colin Robinson
2014-Apr-28, 10:34 PM
All animals have moving parts, even the sessile ones. Plants, on the other hand, only have parts that move in response to stimuli, that is to say the nastic responses mentioned earlier. If we are considering alien species, they will not be members of either the animal or plant taxa, so it might be necessary to invent new words.

I agree that aliens species will not be members either the animal or plant taxa. Words like sessile/motile will still be applicable, because they are about how an organism functions, rather than what it is related to genetically. That is why I used the terms sessile and motile earlier in this thread, when I suggested that the first multi-celled alien organisms we find are more likely to be sessile than motile. One reason for thinking this is that here on Earth, sessiles (including plants, fungi, corals) are easier to find than motiles. Presumably because of the energy costs of moving about.

Sea anemones are on the borderline of motile/sessile, because in an emergency they can actually detach themselves from the rock or coral they sit on and swim to a new position. Here is a video of one doing so:

https://www.youtube.com/watch?v=orFXn_pJONU&NR=1

AlphaCentauri
2014-Apr-30, 01:58 AM
Thank you everyone it all makes sense to me now. Its all depends on how advanced the aliens are. Thanks you :P