E.t.

[Ophiolite]

I think life will arise everywhere there is a possibility' date=' not just by chance.

 

To have the Earth as the only place in the hole Universe with the correct circumstanses for life to arise [b']must[/b] have lower odds than the opposite.

How do you justify 'must'?

[psikeyhackr]

The Drake equation has already been mentioned.

 

If you want to look at it from a more metaphysical perspective. The universe is a REALLY BIG place, to use an understatement. If some God created this big place, then whatever reason HE/SHE/IT had for putting what passes for intelligent life here, that same reason should apply elsewhere in the universe. What kind of incompetent God would just put aliens here?

[Thomas Wood]

i belive there is e.t's. Iff the big bang created us, theres potentionaly millions more life forms

[dsjgenius]

Thomas Wood:

i belive there is e.t's. Iff the big bang created us, theres potentionaly millions more life forms

 

what do u mean by potenially millions more life forms, how are u corerelating the big bang with life origination.

[Dapthar]

YT can u give and explain the drake equations i read the equation but i only found one.

are there more than one eqaution?

well could u explain the equation and how they are credible

As fara as I know' date=' there is only one Drake equation, namely: ([i']This is largely copied from http://www.activemind.com/Mysterious/Topics/SETI/drake_equation.html[/i])

 

[math]N_{civ}=N_{star}\cdot f_p \cdot n_e \cdot f_l \cdot f_i \cdot f_c \cdot f_L[/math]

 

Where:

 

[math]N_{civ}[/math] = The number of intelligent, communicating civilizations there are in our galaxy.

 

[math]N_{star}[/math] = The number of stars in the Milky Way Galaxy.

 

[math]f_p[/math] = The fraction of stars that have planets around them.

 

[math]n_e[/math] = The number of planets per star that are capable of sustaining life.

 

[math]f_l[/math] = The fraction of planets in [math]n_e[/math] where life evolves.

 

[math]f_i[/math] = The fraction of [math]f_l[/math] where intelligent life evolves.

 

[math]f_c[/math] = The fraction of [math]f_i[/math] that communicate.

 

[math]f_L[/math] = Fraction of the planet's life during which the communicating civilizations live.

 

There is also a very nice calculator at the bottom of the following webpage (same page as above) that lets one plug various numbers into the Drake equation and see how many civilizations one gets.

 

Link: http://www.activemind.com/Mysterious/Topics/SETI/drake_equation.html

 

Finally, regarding the poll, I voted yes, for probabilistic reasons.

[dsjgenius]

Oh i've seen this eqaution before in one of my astronomy books

[Spyman]

isn't this a contradiction by itself

I meant the odds of having Earth as the only place in the hole Universe with the correct circumstanses for life to arise must have lower odds than having at least one more place and the Earth.

 

BTW: Half Your post is inside the qoute of my post.

[Spyman]

How do you justify 'must'[/b']?

I started my post with "I think" which means I am not going to try to justify it = It's just my thoughts.

[JohnB]

Sorry if this upsets anyone, but the Drake equation is a crock....

 

An equation where the answer is the result of 7 variables, the values of which are left up to the person doing the maths? The equation itself is logical, but since it can give any answer between 1 civ around 1 star to every star having civs, it is essentially meaningless.

 

Would anyone care to fill in the blanks in the equation and provide proof of the accuracy of their inputted values?

 

Also, what is the big deal about primates? If ET exists, there is no guarantee they are bilaterally symmetrical, let alone primates. They could be trilaterally symmetrical crabs for all we know.

 

Early multicellular lifeforms on Earth tried a number of different designs, trilateral symmetry amongst them. For some reson, these forms died out leaving the bilaterals dominant. There is no reason to believe that this would be true elsewhere.

[Ophiolite]

I started my post with "I think" which means I am not going to try to justify it = It's just my thoughts.

Damn. I was looking forward to an intriguing debate. Never mind.

[YT2095]

YT can u give and explain the drake equations i read the equation but i only found one.

are there more than one eqaution?

well could u explain the equation and how they are credible

 

sorry for the delay, I`ve been busy as this thread progressed, but I`ll happily accept Dapthars answer in post #'30 as my response also.

[Ophiolite]

Sorry if this upsets anyone' date=' but the Drake equation is a crock....

 

[/quote']Your assessment is due to ignorance. (i.e. you have misunderstood its purpose.)

 

An equation where the answer is the result of 7 variables, the values of which are left up to the person doing the maths? The equation itself is logical, but since it can give any answer between 1 civ around 1 star to every star having civs, it is essentially meaningless..

Only meaningless because you are ignorant of its function.

 

Drake laid out the equation to provide a framework for discussion at the first ever conference on extra-terrestrial life. Each term in the equation identified some aspect, astronomical, biological or cultural, of the problem that would have to be understood before we could accurately estimate the number of extant civilisations.

 

It was not meant to provide a vehicle for making this calculation, other than as an intellectual exercise.

 

It achieved its initial goal so effectively that it has acquired an unlooked for longevity.

 

Would anyone care to fill in the blanks in the equation and provide proof of the accuracy of their inputted values?

As I hope you see, the equation now focuses attention on our uncertainties and consequently on the range of possible results. It's not about proof, it's about stimulating investigation and providing a framework within which results may be placed.

 

Also' date=' what is the big deal about primates? If ET exists, there is no guarantee they are bilaterally symmetrical, let alone primates. They could be trilaterally symmetrical crabs for all we know.

 

 

 

Early multicellular lifeforms on Earth tried a number of different designs, trilateral symmetry amongst them. For some reson, these forms died out leaving the bilaterals dominant. There is no reason to believe that this would be true elsewhere.[/quote']Is this a separate topic? The Drake equation has nothing to say on the matter of primates.

 

As a separate topic, who is making a big deal about primates? I do agree bi-lateral symmetry is not necessarily a given. Were there tri-laterals amongst the Burgess Shale fauna? I can't recall. Certainly we still have the five-fold symmetry of the echinoderms. I suspect bi-lateral will turn out to have inherent advantages, but that may just be geo-chauvinism.

[JohnB]

Your assessment is due to ignorance. (i.e. you have misunderstood its purpose.)

Only meaningless because you are ignorant of its function.

Are you calling me higgerent???? Because you would be totally correct in this case. Many thanks for the explanation.

 

As a stimulus for debate the equation is certainly useful, but I have seen it misused in magazines and articles over the years to "prove" that life must be incredibly rare in the galaxy.

 

Personally, I believe that we are not alone. However, as we cannot even begin to fill in any of the blanks, any estimate (even mine) of the number of ETs must be nothing more than an ill informed guess. I accept that as a reality.

 

My comments about primates stemmed from what appears to be the idea that if there is an ET, they will have the same basic form as us. I just can't see why this should be.

 

I don't know if there were tri-lats in the Burgess shale deposits. I remember seeing a doco some years ago with reconstructions of some extremely early fossils. The one that stuck in my mind was one with 14 legs in 7 pairs, with 7 mouths along it's back. This was still a bi-lat of course, but the 7 pairs of legs was very unusual. IIRC it was around 20 cm long.

[Ophiolite]

I agree with you completely that the equation has often been misused by persons trying to prove their view of the frequency of intelligent life. I think if you had said 'the common usage of the Drake equation is a pile of crock' I would have nodded vigorously.

I subscribe to the view that intelligent life is very rare and I use the Drake equation to arrive at that conclusion. But, and this is a huge but, I do so by selecting a set of parameters that tend to the pessimistic end of the spectrum available from our current understanding. I would not be surprised if, when those parameters narrow, the probability of ETI was markedly higher than I currently rate it. Equally, I wouldn't be surprised if it was lower.

I've generally thought that the preference for humanoid aliens stemmed from the accountants overseeing Hollywood costume departments. That said, one of the movers and shakers of evolution theory - whose name has run off to hide in some secluded group of neurons - has put forward some plausible arguments for why ETI would be bi-lateral, bi-pedal, sighted, with a brain at the top, and look like a comic book alien. If and when I remember I'll post his name - I think he's at Oxford.

There were some weird critters in the Burgess shale. They had been known since the early 1900s, but it wasn't till the 70s that geologists realised quite what they had.