Life Against All Odds: Are We Alone in the Galaxy?

[Gold Barz]

So, basically life is unlikely to arise and evolve on red dwarfs and binary or more systems, and half of the stars in the galaxy are in binary or more systems and 4 out of 5 stars are red dwarfs...seems like life is against all odds, I am startin to think we might actually be alone in the galaxy.

 

[Gold Barz]

Only 30-40 billion stars in the Milky Way are thought to be sun-like, that's a lot but I thought there would be more. Would there be more habitable stars other than that 30-40 billion estimated? that is the question.

 

[setAI]

I'm sure all the plasma-based life living in/on stars as well as complex biochemical life that evoved in the intersteller molecular clouds laugh at our concepts of 'habitability'

 

[Danger]

seems like life is against all odds, I am startin to think we might actually be alone in the galaxy.

Since this is the second thread that you've started on this topic, and you steadfastly refuse to pay attention to those of us who are saying that life is likely, why did you ask about it in the first place? You've already made up your mind despite the facts.

 

[Gold Barz]

Why do you say life is likely?

 

[Labguy]

Why do you say life is likely?

It is called statistics 101.

 

[Gold Barz]

show me the stats

 

[selfAdjoint]

Since this is the second thread that you've started on this topic, and you steadfastly refuse to pay attention to those of us who are saying that life is likely, why did you ask about it in the first place? You've already made up your mind despite the facts.

Maybe that's because some of us are telling him life ISN'T likely, at least not intelligent life. And "stats 101" doesn't make it; statistics doesn't work without input, and the only inputs we have are guesses and assumptions. Multiplying a bunch of WAGs together just gives you a shakier WAG, and the proportions can go either way.

 

[Nereid]

Why do you say life is likely?

I can only speak for myself ... we have (micro)fossils dating to, what, 3 billion years ago, and indirect evidence suggesting life was here on Earth before the oldest rocks we've found on Earth (so far) were formed. This suggests, but nothing more, that life on Earth got established pretty early on, perhaps as early as it could (i.e. after the end of the period of late heavy bombardment).

 

[Gold Barz]

Can someone who knows a lot about this calculate for me how many habitable stars there are in the Milky Way (star types A, F, G, and K)...you got to take out the red dwarfs and the binary star systems, my calculations ended up with 10 billion habitable stars, is it accurate?

Also, is it okay to assume that there is a habitable star in one out of a hundred light years?

I think there must be 50 or more alien civilizations out there. Even if it is very unlikely (like one in ten million) the galaxy is so massive that there must still be a pretty big number of alien civilizations out there.

 

[Danger]

Why do you say life is likely?

I'm just going to cut and paste my post from the other thread rather than repeat it.
It seems to me that there are very few conditions under which life can't develop. To start with, nothing is said about the basis of that life. It could use a sulphur metabolism, or be silicon based, or maybe even a plasma field with a coherent internal 'neurology' based upon charge exchanges. Just looking at Earth, who would suspect that one lifeform evolved living on the brink of undersea volcanic vents or that some lichen thingie is happy at subzero temperatures with no air? The life span of a red dwarf is so long that trillions of experimental attempts by random molecules to join into 'life' can take place. It's entirely possible that at least one of them is viable.
I stand by that statement. (Okay, the living plasma thing ain't too likely, but it's just an example of how much we don't know about the requirements for 'life'.)

 

[Chronos]

The stock for life in red dwarf systems has risen dramatically in recent years:
http://www.spaceref.com/news/viewpr.html?pid=3651

 

[amt]

Even though there are 9 major planets and a Star, along with several dozen smaller moons, life would not have been possible without the Moon orbiting the Earth. This is the miracle of life and we simply need to celebrate our presense.

The odds of life forming here in our solar system is very small. We could be alone after all...

 

[Gold Barz]

Chronos reply to my PM bud

and I thought it was generally believed that red dwarfs is very unlikely to harbor habitable planets? the link is from like 2001 too

 

[Labguy]

Maybe that's because some of us are telling him life ISN'T likely, at least not intelligent life. And "stats 101" doesn't make it; statistics doesn't work without input, and the only inputs we have are guesses and assumptions. Multiplying a bunch of WAGs together just gives you a shakier WAG, and the proportions can go either way.

Yeah, there is one stat we have. That is hundreds of billions of stars in a galaxy and billions of galaxies. That is a fair chunk of input. Besides, like Danger said, "life isn't just for us and our atmosphere, it could be any complex cellular structure that eats and passes gas...

Can someone who knows a lot about this calculate for me how many habitable stars there are in the Milky Way (star types A, F, G, and K)...you got to take out the red dwarfs and the binary star systems, my calculations ended up with 10 billion habitable stars, is it accurate?

Why just the Milky Way? Like I said, we already know of billions of galaxies, maybe more?

 

[Moonbear]

Yeah, there is one stat we have. That is hundreds of billions of stars in a galaxy and billions of galaxies. That is a fair chunk of input.

But no matter how many stars and galaxies we can count, the relevant data to address his question is what is lacking, and that is sufficient examples of planets that have life on them to calculate any probability of other planets having life. So far, we have N=1. But, Gold Barz didn't ask about planets, he asked about life on stars. For that, we have N=0 data of such a thing existing. Now, what statistics are you going to use to predict how many other stars will have life on them?

We can resort to the stock answer, "anything is possible," but in order to determine if it is probable or likely, we need data. What percentage of the planets and/or stars in the universe do we need to examine for signs of life before we can determine we've tested a sufficient sample size for statistical analysis? And what percentage have we actually examined? Even with my limited knowledge of astronomy and cosmology, I'm going to venture the guess that the latter falls far short of the former. Do you know of stars with life on them that I haven't heard of? If so, I don't know why it isn't making headlines and the cover of Science.

 

[turbo]

Chronos reply to my PM bud

and I thought it was generally believed that red dwarfs is very unlikely to harbor habitable planets? the link is from like 2001 too

Jeez, Gold Barz! Are you trying to agitate all of us who think that 100G stars in 100G galaxies can't possibly be home to more than one sentient race?

You can't take the argument back to "x many forms of life" because no matter how you slice it, Earth already contains a whole lot more life-forms than sentient life. Life already seems a lot more likely (nay, required) than your model might have contemplated.

Pose your argument from the other end of the spectrum. Pretend you are a competitor in a debate competition and take the other side for a while... Check back when you've done that, or perhaps pose an opposing post and let us bash you from the other side.

 

[amt]

From what we know now, there is no other life forms. We are alone in this Universe. Any counter debate is purely speculative.

This is where believers in creation Triumph.

 

[Danger]

This is where believers in creation Triumph.

The only place that believers in Creation triumph is in their own minds.

By the way, Moonbear, I'd love to find out what you as a biologist think of Robert L. Forward's speculative life-form evolving on the surface of a neutron star. Check out "Dragon's Egg" (if you like it, there's a sequel called "Starquake").

 

[Labguy]

But no matter how many stars and galaxies we can count, the relevant data to address his question is what is lacking, and that is sufficient examples of planets that have life on them to calculate any probability of other planets having life. So far, we have N=1. But, Gold Barz didn't ask about planets, he asked about life on stars. For that, we have N=0 data of such a thing existing. Now, what statistics are you going to use to predict how many other stars will have life on them?

If he actually meant life on stars, and not on planets around them, then this whole thing is a waste of time. I think he must have meant life on other planets, just a bad choice of wording.

As far as enough statistical examples, we will never have enough; we are too small and remote to even make a tiny dent in anything ever to happen in our galaxy, much less the universe.

 

[Gold Barz]

I wasnt actually talking about life on stars

 

[Chronos]

The Drake equation gives a basis to make a prediction. We cannot assign any supported probabilities to some of the variables, but we can to most of them. And given the huge number of possibles that still remain after eliminating the known impossibles, the numbers are still staggering. I'm siding with the principle of mediocrity - there is nothing unique about our little niche in the universe.

An aside, I wouldn't put too much stock in a large moon as being a necessary precondition for life [and once that arises, anything is possible]. We still have tantalizing evidence life that suggests life may have existed [or may still] on Mars. It's not the odds on bet, but is not so remote a probability that it can be dismissed.

 

[cDimino]

The Drake Equation is as follows:
N = N* fp ne fl fi fc fL

N = Stars in Milky Way

fp = Fraction of stars with planets around them

ne = Number of planets per star capable of sustaining life

fl = fraction of planets (of ne) where life evolves

fi = fraction (of fl) where intelligent life evolves

fc = fraction (fi) that communicate

fL = fraction of the planet's life of which this intelligent communicating civilizations evolve.


The value of the drake equation is not the number that comes out of it, but more so the questions raised when trying to come up with the appropriate data with which to plug into the equation. There is so much we don't know, and so much guesswork involved right now, that it is impossible to accurately predict the number of planets with communicating intelligent life on them in our galaxy.

As for life on STARS, I'm not sure how that would work, but anything is possible!