Exploring the Possibility of Extraterrestrial Life: A Thought-Provoking Debate

[jonegil]

i think this is a complex question...what you guys think about this?

 

[marcus]

I think it is a waste of time to get bogged down in speculation about extraterrestrial life.

What is more interesting, in that department, is the discovery of earth-like planets and the development of methods to extend terrestrial life to them.

 

[jonegil]

how long do you think that it will take to detect an earthlike planet?

 

[marcus]

as a rough estimate I would expect there to be on the order of 10 good candidates, forming a short list to be studied in more detail, in on the order of 10 years.

a lot of orbital and ground-based astronomical instruments will be being used to find out more about conditions on them, by that time.

 

[jonegil]

yeah...da number of extra-solar planets' increasin as da number of telluric or somewhat teluriclike planets aswell...maybe in da next decade

 

[cristo]

What is more interesting, in that department, is the discovery of earth-like planets and the development of methods to extend terrestrial life to them.

I like this idea, however am not sure what the chances are of finding a planet suitable of sustaining life within traveling distance from the earth.

yeah...da number of extra-solar planets' increasin as da number of teluric or somewhat teluriclike planets aswell...maybe in da next decade

Firstly, I presume you mean "telluric" (earth-like). Secondly, it should be noted that when marcus used the term "in the order of ten years" he means within zero and one hundred years time, not in the next decade.

 

[jonegil]

telluric doesn't mean earth-like...it comes from latin and it means rock-like...and when i said "in the next decade" i was referring to telluric planets not planets with life...aight?

 

[cristo]

telluric doesn't mean earth-like...it comes from latin and it means rock-like...

Erm...

Of or belonging to the earth, terrestrial; pertaining to the Earth as a planet; also, of or arising from the Earth or soil.

I presumed that, since we are discussing extraterrestrial life, you would be using the first definition..

and when i said "in the next decade" i was referring to telluric planets not planets with life

Now correct me if I'm reading marcus' post incorrectly, but I'm sure he is talking about candidates to be earth-like planets also.

Aight?

 

[jonegil]

erm? lol...u look like george bush...but it's ok...the main subject here is ET life...let's talk about it

 

[wolram]

The only fact i know is that we have not detected extraterrestrial life.

Even if we did find life on a par with us at say, 10lys, 20llys, 50lys distant
what would the advantage be to us?

 

[neutrino]

We don't have evidence of ET(I). But I believe that it should exist...it would be really stupid to have a whole universe which just a bunch of nitwits.

 

[DaveC426913]

The only fact i know is that we have not detected extraterrestrial life.

Even if we did find life on a par with us at say, 10lys, 20llys, 50lys distant
what would the advantage be to us?

It would put to rest once and for all the question of whether we're unique. In this case, 1+1= way more than 2.

 

[BoomBoom]

Just playing the odds, given the number of systems out there, there really must be life all over the place. But also playing the odds, given the number of species on our planet that can do science/math, it is probably not so likely that "intelligent" life is very common.

 

[H8wm4m]

The mere existence of a UFO shatters the well protected dogmas of modern science. The extra-solar origins of UFO's suggest faster than light travel. Their right angle turns at extreme velocities, non-conventional propultion systems, and other oddities defy the laws of Newtonian and einsteinian physics.
This is why no amount of evidence, even if it is throughout mankinds history, will convince the bulk of the scientifc community of their existence.

 

[russ_watters]

That may be more of a topic for the S&D forum, but the quality of evidence currently available to show that UFOs are actually extraterrestrial spacecraft is very low. A large quantity of low-quality evidence is no substitute for a small quantity of high quality evidence.

Btw, Ivan - here's an example of an alien spacecraft proponent using the term UFO to mean "alien spacecraft ".

 

[jonegil]

The mere existence of a UFO shatters the well protected dogmas of modern science. The extra-solar origins of UFO's suggest faster than light travel. Their right angle turns at extreme velocities, non-conventional propultion systems, and other oddities defy the laws of Newtonian and einsteinian physics.
This is why no amount of evidence, even if it is throughout mankinds history, will convince the bulk of the scientifc community of their existence.

only the most conservative scientists...there are new scientific streams which tolerate the possibility of such travels

 

[cristo]

Why would alien spacecraft necessarily have to travel faster than the speed of light?

 

[Ivan Seeking]

Btw, Ivan - here's an example of an alien spacecraft proponent using the term UFO to mean "alien spacecraft ".

Obviously if we knew a craft to be of extraterrestrial origin it wouldn't be a UFO, which is why we call UFOs, UFOs - as in "unidentified". Once identified, such as in the cases of ball lightning and Earth lights, they are referred to as such and not as UFOs.

I believe that virtually any interpreation of Drake's equation, when applied to the entire universe, yields a probability for life out there of [almost exactly] 1.
http://www.amazon.com/dp/0316648299/?tag=pfamazon01-20

From a statistical pov, we are certainly not alone.

late edit for clarity

 

[BoomBoom]

I believe that virtually any interpreation of Drake's equation when applied to the entire universe yields a value almost exactly equal to 1.
http://www.amazon.com/dp/0316648299/?tag=pfamazon01-20

From a statistical pov, we are certainly not alone.

Life...yes, but "intelligent" life? I think the odds are still against it. Think of all the billions upon billions of species on our planet. How many of those are capable of space travel? Just one.

Especially if our universe is really as young as it is supposed to be. Considering the amount of time it must take to build the elements that make up life and the amount of time for that life to evolve into something like us, we may very well be the first "intelligent" life in the universe. :uhh:

 

[Ivan Seeking]

Life...yes, but "intelligent" life? I think the odds are still against it. Think of all the billions upon billions of species on our planet. How many of those are capable of space travel? Just one.

Estimates of global species diversity have varied from 2 million to 100 million species, with a best estimate of somewhere near 10 million, and only 1.4 million have actually been named.

http://pubs.wri.org/pubs_content_text.cfm?ContentID=535

And many species differ very little so this is somewhat misleading. But again, only the most conservative interpretation of Drakes equation leaves anything but a very large number when multiplied by the number of galaxies in the universe. [Earlier I was stating it as a probability, which was somewhat confusing.]

How many species might have become intelligent but went extinct due to random events? For all we know, with time, intelligence as you define it may be inevitable anywhere that life exists.

 

[Ivan Seeking]

Also,

...Neanderthals have typically been thought of as incapable of innovation, as it was assumed to be something unique to Homo sapiens, says Hopkinson. "With this evidence of innovation it becomes difficult to exclude Neanderthals from the concept of humanity."

http://www.newscientist.com/channel...85.400-neanderthals-bid-for-human-status.html

And let's not forget what appears to be another intelligent species in our world's history, homo floresiensis, who apparently had fire and used tools and weapons.
http://news.nationalgeographic.com/news/2004/10/1027_041027_homo_floresiensis.html,

 

[Chronos]

Neanderthal practiced ritual burial, built fires, used tools, and created artistic works. I'm curious to whom Hopkinson attributed the 'incapable of innovation' assertion. There is at least a fair chance homo erectus used fire:
http://anthro.palomar.edu/homo/homo_3.htm

 

[BoomBoom]

http://pubs.wri.org/pubs_content_text.cfm?ContentID=535

And many species differ very little so this is somewhat misleading.

I think that estimate is very conservative since there could be as many as 50 million insect species alone while recognizing my estimate was grossly high. But you also make a good point about diversity.

I guess all life needs to do is get to the point where they can do some "higher" communication and start dealing with mathematical concepts and the rest comes quite swiftly (thousands of years). Given the number of galaxies, I guess I can see the probability being high, but constrained to just our galaxy (since inter-galaxy travel seems impossible), I still bet it's pretty low chances that aliens are out there flying around in spaceships.

 

[russ_watters]

I believe that virtually any interpreation of Drake's equation, when applied to the entire universe, yields a probability for life out there of [almost exactly] 1.
http://www.amazon.com/dp/0316648299/?tag=pfamazon01-20

From a statistical pov, we are certainly not alone.

That interpretation assumes that the universe is spatially infinite. Regardless of whether or not it is true, it isn't a terribly useful assumption. Besides potentially yielding a $(1/ \infty) * \infty$ situation, it doesn't provide us with an answer that has any meaning. The Drake equation was designed for our galaxy only and it is speculative enough as it is! It may be a catchy title for a book, but it doesn't have any meaning beyond that. And, in fact, the book wasn't written for that purpose anyway, but just uses it as teaser and a jumping-off point to discuss the actual purpose of the drake equation: We already know that the probability of life existing in the universe is exactly 1. The point of the Drake equation is to guestimate how much life there is in the universe.

Btw - I answered with the last poll option.

 

[Ivan Seeking]

Just out of curiosity, have you read the book?

The point of the drake equation is to estimate how much life might be in the galaxy, not the universe. So when we extrapolate this to the entire universe, any Drake result larger than zero yields a very large number.

The poll asks if there is any extraterrestrial life, so the "probability 1" seemed appropriate to mention. He uses the Drake equation in his reasoning.

 

[Ivan Seeking]

Neanderthal practiced ritual burial, built fires, used tools, and created artistic works. I'm curious to whom Hopkinson attributed the 'incapable of innovation' assertion. There is at least a fair chance homo erectus used fire:
http://anthro.palomar.edu/homo/homo_3.htm

I just happened to notice the story in the news yesterday.

 

[Ivan Seeking]

...but constrained to just our galaxy (since inter-galaxy travel seems impossible), I still bet it's pretty low chances that aliens are out there flying around in spaceships.

I see it this way. We don't know if ftl travel is possible. Right now we think it's probably not possible based on what we know, but we don't really know; without a complete theory of physics we can only guess. And even then it may take a century or two to fully understand the absolute limits on speed imposed by a grand theory of physics. Consider that even today, almost one-hundred years after GR was published, the debate about ftl and time travel persists within that context alone.

If it is possible for sufficiently advanced beings to make ftl ships, then depending on the real values for the Drake variables, it might be inevitable that we encounter ETs at some point in time - nearly a 100% chance. On the other hand, there may be some, little, or no chance at all of an encounter. So at this point we can't even talk about the odds of an encounter; only the odds of the odds. At this time I see no way to have any confidence about any answer here.

 

[BoomBoom]

So at this point we can't even talk about the odds of an encounter; only the odds of the odds. At this time I see no way to have any confidence about any answer here.

Question: who knows?

Answer: Nobody.

All I know is that I will be happier than a clam if we find a bacteria or anything from some other planet or moon. I would love to see how it's sequence data (assuming it would also have DNA) compares to life on Earth.

 

[russ_watters]

Just out of curiosity, have you read the book?

No, just a handful of the reviews and summaries...

The point of the drake equation is to estimate how much life might be in the galaxy, not the universe.

Yes, that's what I said.

So when we extrapolate this to the entire universe, any Drake result larger than zero yields a very large number.

No. Not if the number is only infinitessmally larger than zero. My math is a touch thin on this, but I think infinity/infinity is undefined.

The poll asks if there is any extraterrestrial life, so the "probability 1" seemed appropriate to mention. He uses the Drake equation in his reasoning.

I understand that. I'm just pointing out that it isn't a very meaningful thing to do - or to discuss.

I'm trying to think of an analogy - I guess it would be like picking 3 numbers in a 7-digit number lottery (or even a lottery where you don't know how many numbers there are.

At this time I see no way to have any confidence about any answer here.

Well, that's my point as well - you seemed to have a great deal of confidence in the "1" you posted, which is why I was arguing that we can't have any confidence in that number.

 

[Ivan Seeking]

No, just a handful of the reviews and summaries...

I see. So you dismiss a book that you haven't even read. Got it.

Yes, that's what I said.

No, it isn't.

The point of the Drake equation is to guestimate how much life there is in the universe.

Not if the number is only infinitessmally larger than zero.

True. But if the number from the Drake equation is less than one, we wouldn't be here.

you seemed to have a great deal of confidence in the "1" you posted, which is why I was arguing that we can't have any confidence in that number.

You said earlier:

We already know that the probability of life existing in the universe is exactly 1.

 

[Kurdt]

While people have been speculating about life from other solar systems there is the possibility that there may be extra terrestrial life in our own back yard. Europa has a very good chance of harbouring some sort of primitive bacterial life similar to those found round undersea volcanic vents on Earth.

 

[lightgrav]

not to mention Titan, etc.

These environments are enough different from Earth that
detailed investigation of their (bio/organic) chemistry
might test the "anthropic" expectations that many seem to have.

I just hope our investigation doesn't contaminate these worlds
before we can accomplish the necessary studies.