have they found anything?

[Radrook]

The difficulties of contacting intelligent life has been recently made even more daunting by the idiea of multiple universes and dimensions.

 

[JoeTheJuggler]

Gas giants have been discovered, I forget the number, is it 200? But they all seem to orbit their star at close proximity. Any rocky planets that may exist there are probably too far from their star to produce animal life.

Not all of them are close orbits. The fact that we've mostly found gas giants in close orbits is because with the techniques we've used, that's what we were looking for.

There is no reason to think that rocky planets like the earth are unusual.

And another point to remember is that most stars in our proximity are too large or too small, or produce far too much ultra violet rays for animal life to evolve. And of course, a large number of these stars are binary systems. Not suitable for animal life of any kind.

Says who?

And how big exactly is "our proximity"?

I'll happily cede that there probably is no life form that's been capable of using radio communication within about the last 30 years or so within 30 light years of us. Beyond that, we simply don't know. And that's an awfully tiny slice of the universe.

At any rate, I'm certainly not arguing that we're likely ever to encounter life forms anything like us. I'm just saying that that statement is not incompatible with there being many such life forms in the universe spread out over space and time.

Here's what Carl Sagan had to say on the topic:

I'm often asked the question, "Do you think there is extraterrestrial intelligence?" I give the standard arguments--there are a lot of places out there, and use the word billions, and so on. And then I say it would be astonishing to me if there weren't extraterrestrial intelligence, but of course as yet there is no compelling evidence for it. And then I'm asked, "Yeah, but what do you really think?" I say, "I just told you what I really think." "Yeah, but what's your gut feeling?" But I try not to think with my gut. Really, it's okay to reserve judgement until the evidence is in.

And about the only new evidence we have since Sagan wrote that is something like 30 years of not finding a signal in the SETI radiotelescope scan of the skies. Absence of evidence is not evidence of absence, so about all we can say is that SETI has yet to find a signal from an ET intelligence.

If I had to bet, I'd say it's very unlikely there's anything in our neighborhood right now. (Again, in the history of life on Earth, we've only had an intelligence capable of communicating by radio for the most recent eyeblink of time. In our sample size of one, we can say that this kind of intelligence arose, but not for most of the time. We, of course, have no idea of how long it will endure.)

ETA: Sagan quote is from the introduction to The Outer Edge: Classic Investigations of the Paranormal edited by Joe Nickell.

 

[amb]

I don't buy the argument that intelligent life is widespread. If a study of how life evolved on this planet, and the number of coincidences that occurred to make animal life possible,
the chances of it happening as a law of the universe suggests a designer. I don't believe in a designer. Granted, microbial life may be widespread in the cosmos. Animal life may be as rare as hens teeth. As for intelligence, we may well be alone in the galaxy, and in eons to come, it may be us that colonisers the galaxy and beyond if we don't meantime become extinct.

 

[JoeTheJuggler]

I don't buy the argument that intelligent life is widespread. If a study of how life evolved on this planet, and the number of coincidences that occurred to make animal life possible,
the chances of it happening as a law of the universe suggests a designer. I don't believe in a designer. Granted, microbial life may be widespread in the cosmos. Animal life may be as rare as hens teeth. As for intelligence, we may well be alone in the galaxy, and in eons to come, it may be us that colonisers the galaxy and beyond if we don't meantime become extinct.

I don't understand your reasoning (especially the bit I highlighted). Sounds like an argument from ignorance. If we can't explain something or don't understand something, then there must be a designer?

And that's aside from the fact that the way evolution through natural selection works is that the life forms end up adapted to the environment, not the other way around. So the "fine-tuned" argument is all backwards. In other words, these "coincidences" didn't happen with animal life in mind. Animal life evolved in the environment that existed. So saying that animal life couldn't have evolved if things were different than they are is pretty meaningless.

But I agree animal life and intelligence might be extremely rare. The question is, what is "rare"? If it turns out that there are earthlike planets around one of three single stars, and the "coincidences" needed for animal life as we know it (which isn't really the question of ET intelligence anyway) only happens one in a million times, then it's still likely to happen at least thousands of times in our galaxy alone.

(And that's leaving off the possibility of "earth-like" moons around gas giants capability of sustaining life.)

Granted, that's a lot of "ifs", but if that's the case, is animal life "rare"?

I think for the purposes of SETI it is still likely to be spread out enough in space and time as to make contact or communication extremely unlikely--especially out here in the galactic suburbs.

 

[amb]

Billions of years ago this planet was void of any life. It was the start of life that transformed the planet. For example, there was no oxygen which aided the beginning of life as oxygen was toxic to many elements. It wasn't until microbial life transformed the atmosphere to something like we have today that made animal life possible.
Another furphy is that it is often said that the sun is a typical star, but this is entirely untrue.
The mere fact that 95% of all stars are less massive than the sun makes our planetary system quite rare.
Stars less massive than the sun, the habitual zones are located farther inward. but all gas planets so far discovered are roughly orbiting their star in this habitual zone. Which means the rocky planets may be too far form their sun to make animal life possible.
The giant rocky planets in your link could not possibly support animal life of any kind. Can you imagine the force of gravity on such a planet. And if they orbit their sun at such close distance, means the water [if any] would have escaped into space as vapour.
No water, no life.

 

[Radrook]

Wht did Isaac Asimov continually refer to Earth as the impossible planet in his pro-atheist arguments?

 

[JoeTheJuggler]

The mere fact that 95% of all stars are less massive than the sun makes our planetary system quite rare.

Do you have a source for this? I thought Sol was a main sequence star, which is what most stars are.

At any rate, the search for ET life (and ET intelligence) is not the same as the search for conditions similar to those of the Earth.

but all gas planets so far discovered are roughly orbiting their star in this habitual zone. Which means the rocky planets may be too far form their sun to make animal life possible.

Well I know for a fact that the highlighted part is not true. Extra solar gas giants have been found at a range of distances from their primary. That most of the planets (not "all" by any means!) have been found are massive gas giants close to their primaries is due to a bias in the techniques we use to find extra solar planets. (A point that was already made.)

See this list of confirmed extra solar planets and note the range in values of the semimajor axis.

It really seems that as we develop techniques for detecting extrasolar planets of a given mass, we have found them in abundance. The study I linked to above estimates that 1 in 3 single stars will have earth-like planets (or "super-earth" like--that is, rocky planets as opposed to gas giants).

We really don't know where we might find the "sweet spot" in a lot of circumstances. I already pointed out that gas giant satellites might provide good places too.

The point I keep making, though, is terms like "common" and "abundant" or "rare" are all relative. I reject that there is anything about the Earth that is "unique". In the history of science, that way of thinking has led us astray too often.

 

[Radrook]

To be honest, the only life that really would interest me would be the reasoning kind.
Animal life we already have right here.

 

[my_wan]

"Simple," they'll say, "just use the sap of the common elibo tree which grows in most pod-stalk forests."

"uh, we don't have those" we'll say.

(75 years later)

"LOL! you guys are screwed then!" they'll say.

Only 75 years? That practically puts them in our driveway.

Why do you assume they would be millions of years more advanced than we? Even if they are, they weren't always that advanced. At some point in their development, they may have used radio. Those signals would still be traveling through space.

Very simple. If we assume the Universe is 15 billion years old and you pick two civilizations at random what are the chances their technological development is within a million years of each other?

Notice that a one terawatt signal transmitted from a Arecibo sized antenna is required to reach a range of 150 light years.So you not only have to envision an advanced civilization. You have to envision an advanced civilization that decides to construct a vastly powerful transmitter, a massive antenna and the desire to use them to engage in what is likely to be only one way communication with a fellow advanced civilizaton.Seems like a long shot to me.

Yes and the odds get even worse if their signals passed us a few hundred thousand years ago before they give up trying.I wouldn't support any great amount of money spent on this but we should keep looking and listening.

Is it possible for impossibility to be inevitable?

This of course was a loaded question here as creationist often quote really outrageous odds against abiogenesis. Suppose the odds was 4*10^46 to 1. Would that make it practically impossible? Consider that this is roughly how many water molecules are on Earth each interacting with other molecules many times a second. That means a particular reaction given those odds will happen at least a few million times while you read this post. Life would have to be far more rare than that. Big numbers and tiny odds do not equate with impossible. Impossible only applies when the odds are 0 to infinity. In practical terms we can say long odds are essentially impossible only when we restrict those odds to relatively few interactions and/or a sufficiently short period of time.If you want some impossible odds consider God. He is supposed to be infinitely complex yet wasn't created. That makes the odds of his existence 0 to infinity. The complexity of God suggest a creater of God by the logic of creationism.

 

[I Ratant]

SETI has already made a discovery...
In every manner they've looked, we're alone.

 

[JoeTheJuggler]

Very simple. If we assume the Universe is 15 billion years old and you pick two civilizations at random what are the chances their technological development is within a million years of each other?

I have no idea, and neither do you. We don't know anything about the longevity of a technological civilization. Ours is only about 100 years old (using radio technology as a measure of "technological civilization").

It could be that such civilizations don't often survive their own technology. It could also be that large meteor strikes tend to wipe out such civilizations before they're capable of protecting themselves from such a disaster.

We just don't know.

SETI has already made a discovery...
In every manner they've looked, we're alone.

That's drawing a conclusion far beyond the dataset. We've only been looking for a radio signal in our sky for a fairly short time. At best you can conclude that there is no other civilization broadcasting radio waves in our vicinity in recent years. 30 years' searching is a very tiny slice of time, and the distances we'd be able to detect a signal such as the ones we've been broadcasting are similarly small.

Again, ET intelligence could be relatively common, but two such species might not ever encounter one another. Stuff is just so spread out in time and space.

And even if it's a "rare" thing, like one single star in a million (or even 1 in ten million or a hundred million) that ends up giving birth to an intelligence, there would still be lots and lots of them.

 

[Radrook]

If they are out there why all the silence? Given the age of the universe we should at least here a couple of indentifable beeps. Yes I know. They are supposed to have blown themselves to smitherines before they could beep. Strange that they can blow themselves up without beeping. I mean., even after they blew themselves up the beeps would still be around. Yet nothing. After all, considereing all the molecular interactions out there a beep or two from at least one of the thousands of civililizations that must have surely emereged from the primordial slime isn't too much to expect. Is it?

 

[davefoc]

If they are out there why all the silence? Given the age of the universe we should at least here a couple of identifiable beeps. Yes I know. They are supposed to have blown themselves to smithereens before they could beep. Strange that they can blow themselves up without beeping. I mean., even after they blew themselves up the beeps would still be around. Yet nothing. After all, considering all the molecular interactions out there a beep or two from at least one of the thousands of civilizations that must have surely emerged from the primordial slime isn't too much to expect. Is it?

This post seems to not take into account vastness of the universe and the limited range of known forms of communication between sentient entities .

The milky way galaxy in which our solar system exists is estimated to be 100,000 light years across. The estimates that were put forth earlier in this thread suggest that based on very optimistic assumptions it might be possible to detect a transmission made in the direction of the earth from as far away as 150 light years. But the distance that two planets with earth like technology and inclinations could detect each other at is actually substantially less.

My own guess is that based on recent pessimistic estimates of how common the conditions for habitable planets are and the very limited range of the ability to detect them and the failure up to now of SETI to detect signs of intelligent life and other arguments that humans will never detect signs of life from beyond the earth.

But that is a hugely different guess than that intelligent life is unique to the earth throughout the universe. The Wikipedia estimate for stars in the Milky Way was 200 to 400 billion. And the Milky Way is just one of 100's of billions of galaxies in the observable universe. My guess is that there are many planets with civilizations with sentient entities in similar states of advancement as the earth's but I think it is likely that it is beyond the limits of any possible technology to ever detect them.

 

[JoeTheJuggler]

If they are out there why all the silence? Given the age of the universe we should at least here a couple of indentifable beeps. Yes I know. They are supposed to have blown themselves to smitherines before they could beep. Strange that they can blow themselves up without beeping. I mean., even after they blew themselves up the beeps would still be around. Yet nothing. After all, considereing all the molecular interactions out there a beep or two from at least one of the thousands of civililizations that must have surely emereged from the primordial slime isn't too much to expect. Is it?

As has already been noted, they could have beeped for thousands of years, then blown themselves to smithereens or died of off "natural" causes long before we started listening. Remember, things are spread out in time. In the 4.5 billion years (or so) of our solar system, we've only had the ability to communicate by radio waves for about 100 years. That's what? About 0.000000002% of the time?

And then there's the distance. How strong does a signal have to a significant portion of the way across the galaxy and still be strong enough for us to detect it? I'm pretty sure SETI would only be able to detect signals in our neck of the woods.

So again, intelligent life could be "out there", yet it might still be reasonable to think that no two forms of it would ever encounter each other.

ETA: I just read davefoc's post. He said much the same thing I meant to say, but he did a better job of it.

 

[davefoc]

Hi JtJ,
On a totally unrelated subject my brother in law gave me juggling balls and a juggling instruction video for Christmas.

It happens that I can juggle a bit and decided to demonstrate my juggle and eat the apple trick. It was the only time in my life that I have ever gotten a significant round of applause. I kind of liked it. Anyway I've been practicing a bit over the last few days, but I suspect that I have already reached the limit that my talent and my inclinations about juggling are going to produce. I think consistency with four balls will elude me. It is hard for me to imagine that I am a member of the same species that includes people that can juggle more than four balls.

 

[arthwollipot]

To be honest, the only life that really would interest me would be the reasoning kind.
Animal life we already have right here.

Really? Are you absolutely sure you wouldn't be interested if microbial (or even plant or animal) life was found on another planet?

I think this would be one of the most groundbreaking, world-changing discoveries ever.

 

[I Ratant]

Hi JtJ,
On a totally unrelated subject my brother in law gave me juggling balls and a juggling instruction video for Christmas.

It happens that I can juggle a bit and decided to demonstrate my juggle and eat the apple trick. It was the only time in my life that I have ever gotten a significant round of applause. I kind of liked it. Anyway I've been practicing a bit over the last few days, but I suspect that I have already reached the limit that my talent and my inclinations about juggling are going to produce. I think consistency with four balls will elude me. It is hard for me to imagine that I am a member of the same species that includes people that can juggle more than four balls.

.
I suspect the true origin of anyone that can fly r/c helicopters... These people cannot be of this earth!
http://www.vimeo.com/463570

 

[shadron]

Wht did Isaac Asimov continually refer to Earth as the impossible planet in his pro-atheist arguments?

The only references I could find relating Asimov to "impossible planet" are the jacket blurb on Foundation's Edge and a short story by the name by Philip K Dick in an Asimov anthology. Better luck next time.

 

[amb]

I will stick to my theory and predict that microbial life will be widespread in the universe, as we can see on our own earth that such life is capable of existing in the most hostile regions of our planet including inside a volcano, hot vents in the bottom of the oceans where there is no sunlight, or light of any kind, including oxygen. Even Ice has uncovered life in Antartica.
But animal life is a complete different kettle of fish. The chances of animal life ever occuring again a extreemley rare.

 

[Radrook]

The only references I could find relating Asimov to "impossible planet" are the jacket blurb on Foundation's Edge and a short story by the name by Philip K Dick in an Asimov anthology. Better luck next time.

Better luck in reference to what? Just because you couldn't find what I repeatedly read in one of his books doesn't mean I made it up. Actually I read Foundations Edge and don't recall coming across that statement. The statement wasn't made in one of his sci fi books. If memory serves me right, it was a book about religion where he was hell-bent on proving the Bible is drivel in terms of scientific descriptions. Asimov has, I believe. approximately three-hundred books in print. So finding a single expression as the one I referred to is a daunting task. Unfortunately I can't recall the exact book I read it in some twenty years ago. However, I'll start a search of my own and see if I can track it down.