New Doubts About Extraterrestrial Life??

Carl Sagan said that "extraordinary claims, require extraordinary evidence." In a stunning display of mathematical logic vs common sense, David Spiegel of Princeton University and Edwin Turner from the University of Tokyo have published a paper on arXiv that turns the Drake equation upside using Bayesian reasoning to show that just because we evolved on Earth, doesn’t mean that the same occurrence would necessarily happen elsewhere; "using evidence of our own existence doesn’t show anything" they argue, "other than that we are here."

What Bayesian reasoning overlooks, of course, is the inconvenient fact that there are some one trillion galaxies in the known universe and some 50 billion planets estimated to exist in the Milky Way alone and some 500,000,000 predicted to exist in a habitable zone.

Source: www.dailygalaxy.com...

Sorry if this has already been posted.

For so long, I personally, have been using the Drake Equation to try and convince myself that even though they might not be flying around and abducting farmers, extraterrestrial life should, technically, exist. The beauty that is life itself can't possibly be contained to this planet alone.

But with the use of Bayesian probability, some scientists are moving further and further away from the probability that life could exist elsewhere in the universe, and that just because life sprung up here on Earth, that doesn't mean it should exist elsewhere.

What does ATS think? I know full well that a lot of ATS members believe that they have seen/been contacted by/or are generally aware of the existence of life outside this planet. My question is a little more specific.

Does ATS think that it's a real possibility that life (Not specifically intelligent life. Microbial, cellular and so on) could be restricted to this planet alone. I have always been of the persuasion that life, even on a microbial level, should exist on other planets.

I'm not 100% sure if this should be in the Aliens & UFOs forum or here. So if this is in the wrong forum, could a mod kindly move it?

reply to post by SnedsDawg

What does ATS think? I know full well that a lot of ATS members believe that they have seen/been contacted by/or are generally aware of the existence of life outside this planet. My question is a little more specific.

I believe life is ubiquitous throughout the Universe.

===============================
New Estimate for Alien Earths: 2 Billion in Our Galaxy Alone
===============================

yeah right, guy probly a big skeptic evern if he seen one he would probly be saying oh thast man maid... even though though its not... some ppl just trying debunking stuff cause they dont wanna believe its real.. i in fact do believe its real . very real

reply to post by SnedsDawg


I think that Bayesian reasoning makes a good point but really only states the obvious. "We know we're here and that's what we know." Sure, okay. It makes perfect sense. No matter what any nut says, there's no actual proof of alien existence.

That said, I'm definitely inclined to believe life is abundant in the universe in many different forms. It's just a logical inference really. Not a big leap of faith in my opinion.


ETA: The rest of this thread is really just about casting votes. Sure, the occasional tin hat will pop in claiming he vibrates with them in the Crab Nebula or some other dude insisting that aliens couldn't possibly exist (lolwut) but what this comes down to is a vote right?

Anything else is mere speculation.

yeah right and all the government ppl coming forward are lieing too.. -_- gotta have evidence when pictures over all the past history isnt enough ? maybe do some more research? theres tons of evidence maybe not "physical" even though there has been proven artifacts left from crop circles to not be terrestrial origin...

reply to post by SnedsDawg
I think it's worth remembering that science isn't a broad church, but a segmented arena much closer to sports rivalry. Like in sports, they agree to abide by rules (Laws of Physics for example), but disagreement keeps them all going and some want to throw out the rule book.

In that light, as fast as some proclaim that life is unique to Earth, others are just as certain that it'll be everywhere. It's all a matter of perspective as far as I can see. The guys who make the most media-catching statements get the attention and the ones who quietly think 'maybe' get none.

Personally, I *believe* life will be found to be abundant; we've shown that it can survive in extreme conditions and even in the vacuum of space. If it's found on one other body in our Solar System...it's probably in any niche with suitable conditions..imo.

The way I see it is like this.

IF life exists elsewhere in space then there is a probable chance that life really did start by evolution and there may or may not be a divine Creator.

BUT if scientest are saying that life probably DOESN'T EXIST elsewhere then it almost certainly proves that life WAS created by a divine CREATOR/GOD.

MY reasoning for this is that with the amount of planets in space for one to think that there isn't one enough like earth to support a human type species like ourselves is simply asinine. Then you have to ask yourself if there is a planet that could support a species unlikel humans....

Would another species such as aliens NEED a planet just like earth? What do they breath? What do they eat? How do they function?

For science to even remotely think they have enough evidence to say there is no life in space is absolute madness. Once we are able to visit a ton of other galaxies and planets and find NOTHING I will consider there is no life in space until then science is wrong......

Besides they found single cell organisms in space already........ wouldn't that be life technically?


Matt

also do u guys remember saying the laws of physics isnt on a ufo. so that right there tells you physics doesnt know everything... just saying

They have a very valid argument. So many people use the argument well its pretty dumb to think that we could be the only ones here in the vast universe. Well, think about it. There may be trillions of stars and planets but they are not the perfect distance away from their sun, or the sun is too small or too big etc.

The planet may be too small or too big as well. We may have evolved, YES evolved, you religious twits, simply because our conditions were perfect, nothing more.

The simplest explanation is usually the right one.

I just simply cannot get over the wide spectrum of human arrogance......

if WE can't travel that far, than surely no other species or civilization can.

if WE can't live too close to our star, than surely no other species or civilization can.

if WE can't live without water or oxygen, than surely no other species or civilization can.

and so on and so on.....

PEOPLE

WE are not the center of the universe, both physically or figuratively.

Originally posted by shadowreborn89
yeah right and all the government ppl coming forward are lieing too.. -_- gotta have evidence when pictures over all the past history isnt enough ? maybe do some more research? theres tons of evidence maybe not "physical" even though there has been proven artifacts left from crop circles to not be terrestrial origin...

Now I'm quite open to the existence of intelligent extraterrestrial life. This thread is not about saying that there is no possible way the life outside Earth could exist, I was just looking for ways in which ATS members personally justify their position, whether for or against intelligent extraterrestrial life.

But you're making some pretty extraordinary claims, and as Carl Sagan said, "extraordinary claims, require extraordinary evidence."

A lot of these Government People that you say have been coming out and claiming to have knowledge of extraterrestrial life, where are their credentials? Where are their medals? Where's the proof that they were ever employed by any Government body? They might be able to talk the talk, but there's no proof to back up their claims (About extraterrestrial life, or that they ever worked at the installations they claim to have).

And where are these artifacts that have been left behind in crop circles? This is the first I've ever heard of it.

As I've said. I'm quite open to the existence of extraterrestrial life, but this is the one thing that bugs the hell out of me when it comes to the UFO community in general. A lot of people will make these broad claims with no evidence whatsoever, and it makes the rest of the reasonable UFO community look like tin foiled hat idiots. Almost all UFO videos and picture have been proven to have quite normal, reasonable and logical explanations.... And the rest are Chinese Lanterns

humans can't even construct roads and highways that aren't in constant gridlock between 8-9 am to 4-5pm.

so if the best and the brightest can't even fix rush hour traffic how can anyone claim to know what is out there.

reply to post by illusion987


So out of curiosity YOU know for a FACT that aliens do not exist? Its not a religious twits argument. It a simple FACT that no one knows if they do or not. Being close or not close to a sun is not even a relevant fact, just because WE AS HUMANS need to be where we are in the universe to exist does not mean any alien life form would as well.

Your ignorance lies in the fact that you assume/believe that aliens would be exactley like the human species or Earthbound creatures as far as our planetary needs go.

Also your point about our conditions being perfect is a moot point and invalid as well. It still is suggesting that aliens would be identical to us. We exist the way we are because of our planetary conditions. That is not saying that aliens couldn't have evolved to match there's as well.... ya know....... since your so big on evolution and all.....

In my opinion its nothing more than ignorant to think we would be the only rock in all that exist to harbor life. If you can think logically then its not hard to get to the point, life exist everywhere. Point is, we are looking for life just like we are, chances are that we are the only species like we are, but that does not rule out any possebillity that we are the only living creatures. If there are more stars/suns/planets in the universe then there are grains of sand on this planet alone. Its just like thinking today the earth is flat! Its just stupid and really ignorant/arrogant to think like that, and can only be explained as an ego driven person who cannot comprehend the idea that we maybe not the most intelligent species alive.. We like to think that we are all that and special etc etc, well oke i agree we are special, everything is special. But to rule out the possebility's of life elsewhere to me really says allot about a person.

Maybe aliens don't breathe, don't need light, don't need an atmosphere like we have. If scientist can find living creatures aroud underwater vulcanoes and underneath the icecaps in the artic area, then why would it be so hard to imagine life on an other planet. I for one would'nt be surprised really if there is other life in our solar system, what about cock-roaches, they can even withstand nuclear fallout and all that. But i don't go around screaming hey, there must be life believe me.. Its mostly a personal opinion. If you don't want to believe in life outside of our planet then fine, if you do believe, also i say fine. I'm not forcing people to believe what i believe, sometimes i just try to explain it in simple facts to consider not to force a opinion on someone. That's how science should work to imo..

Also to add, i'm not the kind of person who relies on his believe in the hope it will save us. I'm more for doing it ourselfes because we are the creators of our own problems, and without a sollution problems will never dissappear. (The Problem isn't the Sollution).

Edited to add:
If you just even consider the amount of living creatures and the diversity on this planet alone, and with that understand that life here on this planet has addepted to EVERY possible condition here on Earth, Why would it then be so hard to believe for one there is life elsewhere if not everywhere..

There is no way this guy is right. Just look around you. Have you ever read anything in history that identifies a precursor to DNA. NO, because it doesn't exist. DNA is one of the most complex molecular structures on the planet (organic). If this extremely complex molecule evolved on this planet wouldn't there be some fossil evidence of it, oh, rna is not a simple enough precursor to dna. Wherever DNA evolved/was created I can tell you it wasn't here. I would agree that once DNA made it to earth, earth may have been able to form brotobionts in early earth conditions but the complexity of our genetic material is present in every species and virus on the planet. There is no evidence of its evolution anywhere on earth. If there is then link it and show me but make sure you know that whatever the precursor is its quite simple and could form in early earth environments. I doubt you'll find anything.

Eta: yes DNA changes over time and these changes are visual in speculation but I'm talking about the evolution of the actual molecular structure of DNA.

Originally posted by XJMatt
Besides they found single cell organisms in space already........ wouldn't that be life technically?

Matt

I'm not sure a single cell organism has been found in space, what Stardust Mission returned to earth from comet Wild 2 was an amino acid compound glycine that contained more carbon-13 than glycine in amino acids found on earth, that they say proves it originated extra terrestrially. Spectroscopic observations of other bodies in space indicate signatures of organic compounds, but without samples, one has to be a little skeptical.

Once the building blocks of RNA arrive I don't think its a huge leap to believe in DNA evolution from there. In the molecular world things work very fast, if you've ever seen videos of DNA replication in Mitochondria. To me the numbers of probability are staggering to suggest impossibility.

Our solar system is known to be relatively young comparatively. When one thinks of billions of years, possibilities become staggeringly infinite. One also has to be open to life forms unlike us, I myself don't entertain extra dimensional entities but organismic life unlike ourself has to also come in a myriad of basal compound structures, it would b arrogant to close one's mind to consider extreme alien chemistry.

Here on earth it took 2.8 billion years for the evolution of a single cell organism to evolve to the lofty life form similar to a common earthworm. What if a habitable solar system out there is twice as old as ours, one can't close consideration of the possibilities of continued evolution there.

Originally posted by illusion987
They have a very valid argument. So many people use the argument well its pretty dumb to think that we could be the only ones here in the vast universe. Well, think about it. There may be trillions of stars and planets but they are not the perfect distance away from their sun, or the sun is too small or too big etc.

The planet may be too small or too big as well. We may have evolved, YES evolved, you religious twits, simply because our conditions were perfect, nothing more.

The simplest explanation is usually the right one.

Your conclusion indicates that we are created by God, which is far more of a simple concept than evolution.
The name calling isn't justified on a grown up board such as ATS.

reply to post by SnedsDawg


There are most probably millions of planets that support life and a few are probably copies of the earth.
You can only assemble molecules in certain ways, yes you could have trillions of different ways but eventually you would run out of different ways of combining them and inevitably you would repeat.
The chances of other planet’s having life are better than no other planets having life.
If you took one million Lego pieces and put them together in every configuration you could, you eventually would start where you began and copy what you have already done.
The universe is most probably a multi verse thus every form of life will inevitably exist somewhere.
I believe there are planets out there that will be very hostile but have some kind of life and planets that would look very much life earth. Perhaps even a carbon copy.
The universe is so vast it would inevitably repeat it’s self. Even if only 1 in 100 trillion can support life, it’s out there.
Imagine us in I million years from now. We wouldn’t recognize ourselves we would seem like mystical beings to us.

If we are the only ones, what an incredible waste of space that would be...