Stephen Hawking: Extra-Terrestrials Probably Exist

[coreybox]

Since when is it a stipulation that a single organism must survive the entire trip? It could be some kind of habitat on the vessel, that supports sustainable life. The generation that leaves may not be the one that arrives.

[VaughnC]

Originally Posted by abergdahl

The milky way is 90 000-100 000 light years in diameter.. still way to big for any life form remotely like us to travel from one end to an other...

Based on our current knowledge of physics...but we don't know everything.

However, for all we know, the universe may not even exist and all that we sense just might be part of some sort of pre-programmed group consciousness that allows us to interact as if everything we sense were real. And, from our perspective, we wouldn't know whether we're living in a reality or virtual reality.

[furry]

Originally Posted by VaughnC

Based on our current knowledge of physics...but we don't know everything.

However, for all we know, the universe may not even exist and all that we sense just might be part of some sort of pre-programmed group consciousness that allows us to interact as if everything we sense were real. And, from our perspective, we wouldn't know whether we're living in a reality or virtual reality.

hell, we don't really know the relative SCALE of anything either...

what we are calling 'universe' might just be a sub-atomic particle in another universe. and for that matter, what makes up what we consider sub-atomic particles might just be trillions of 'universes'.

[lharp]

Originally Posted by macheesmo3

While certainly not a brutality free century, I would hardly call what happened in all the wars more brutal than what went on for generations during the Crusades or the Inquisition. That's really brutal stuff!!! Not to mention what some of the Chinese rulers did to their own people....

I agree as far as quality. The Assyrians were the most hated people of antiquity; they depicted the torments inflicted on those who resisted them in frescoes in the royal palace walls, for foreign emissaries to see. They impaled with abandon and were utterly skillful at flailing people with a copper knife starting at the middle fingers. I'd say the Gestapo, the NKVD, and some of the competent jailers providing rendition services to the US were capable and have achieved similar levels of brutality, albeit less publicly. And then all in-between, including those you mention.

But in quantity, dear fellow -- that which separates a murderer from a serial killer, and massacre from genocide -- in quantity the 20 century stands unsurpassed, the old testament genocide of the Amalekites and Medianites: risible, the destruction of Carthage: a pittance, Godfrey of Bouillon: an apprentice, Temujin: an amateur, Cortez: a dabbler.

Originally Posted by macheesmo3

Problem is we don't really know how many people died during thos events... Nor de we really know what the worldwide populations were during those times, so per capita death.... kinda hard to get accurately.

True. But we have some idea. And we know that killing with edge weapons and wicked points is grisly butchery but SLOW. No earlier battle had the great dying of WWI with thousands of machine guns and carpet bombing of heavy artillery. What past war cost a nation 20 million people as Russia paid in the 40s? We had 16 million men in uniform.

Yep, our modern philosophy is still woefully inadequate to match our destructive power. Unthinking men ushered the atomic age to win a war that was already won, and we've been toying with self-annihilation since. That's the great achievement of political philosophy for you.

That other thing we are not supposed to talk about here, keeps millions of modern men and women incomprehensibly thinking the world is 6000 years old and lets credulity fester in their minds so unimpeded that they are easy prey to any charlatan that saunters by, not to mention eloquent politicians, faithless lovers, and disloyal friends. And we need armies of lawyers to keep each others greed in check. It's no good. And back on topic again, there is Area 51...

Originally Posted by macheesmo3

Now if you want to counter me with the Holocaust, I would say that this was the product of a disturbed regime not the product of any technological advancement. Ideas and prejudices exist, seperate from technology.( although sometimes technology itself is subject to prejudices)

The Holocaust cannot be counted out but it is by much not the worst dying of that century, though they most fuzzed about.

[MudPies]

Originally Posted by furry

hell, we don't really know the relative SCALE of anything either...

what we are calling 'universe' might just be a sub-atomic particle in another universe. and for that matter, what makes up what we consider sub-atomic particles might just be trillions of 'universes'.

I've always LOVED this thought.

[bobcs71]

http://www.theonion.com/articles/ste...-aliens,17343/

Quality, in-depth commentary on Mr. Hawking's announcement.

[lharp]

I generally agree with the rest I have not quoted.

Originally Posted by tonedaddy

My issue is when their estimates of such life are incorrectly elevated to something more than simply their beliefs to reflect evidence/fact

Any inference you make can be called a belief, supposedly a dirty word. You believe I am a person writing to you but it could all be in your head. That this is not the case is as difficult to prove as it is to belief that this is the case. And the same goes of every aspect of what we call reality.

What makes a belief worthy or unworty is how justified is the confidence with which we hold that belief. In the case at hand it is a reasonable inference to believe that we are not the only intelligent life, given (1) that we exist, and (2) the ordinariness of our station.

Put a little more formally...

1) We live in a planet inside a system of planets, and as close as within this system we can't rule out that life has existed outside Earth, Mars being the best candidate.

2) There is nothing stringkingly special about our system, it's an average star in the boonies of an average galaxy.

3) The basic elements that led to life are far from exclusive to our planet. They came from supernovas in the universe and there is no reason why the same elements can be found elsewhere with regular frequency

4) The factors that permit life on a planet, like distance from the start, geological stability, etc. are not necessarily unique to our planet. More and more multiplanet systems are being detected suggesting an iceberg's tip

5) The visible universe seems to be composed of structures similars to those that surround us, mainly: galaxies, stars, and planets, And their number it's vast enough to have also a vast variety of star systems in combinations where in some life could exist.

Therefore, it is reasonable to infer that in a number of galaxies there may be a number of systems where planets have the right orbit, and then the right environment, and then the right active processes for life, and so on with Sagan's reasoning for Drake's parameters. Conversely, it is unreasonable to infer that the rest of the universe is just fill so that we, the only intelligent life, can look up at a starry night.

I invite me to show that any of the premises above are false or that the conclusion is invalid or unsound.

Originally Posted by tonedaddy

If it's just as valid to use a value of zero as any other number, [...] from from zero on up.

And every single one of those values is as valid as any other.

I disagree.

A zero value outright asserts with absolute certainty, and accepts no doubt, that we are the only intelligent life in the universe. It's a notion not only chauvinistic but unreasonable once you consider the argument above and contemplate the vastness of the universe containing structures similar to that we inhabit in number so great that boggle the mind.

If you have a tree with ants on it, and look around and see similar trees as far as the eye can see and beyond, it is unreasonable to infer that not other tree has ants, and that is what a zero value does.

Originally Posted by tonedaddy

But when using Bayesian approximations, one must be certain to clarify if any of the factors used may be zero, and if the values are observed or simply reflect one's belief and

????

Why would anyone need to bother with Bayesian probabability if (a) values can be objectively obtained by observation, or (b) the best reasonable value for a multiplier is zero?

The whole point of Bayesian probability is the ability to do something with a bunch of related estimates, and the only requirement is that their values are reasonable and none of the multipliers best estimate is zero.

Of course it is possible that there is no other life and that all Drake parameters are zero, but that is not the point, the point is whether knowing what we know zero is the best estimate we can give. It is not.

Inference must be understood. The chicken infers that the same hand that fed it everyday and yesterday will feed him today, but instead it wrings its neck. Well, there are no guarantees, but that doesn't mean all inference is as useless as an unjustified belief. Reasonable inference leads to justified expectation, and the usefulness of having been prepared when expectations are fulfilled far outstrips the waste of times when expectations aren't fulfilled

Originally Posted by tonedaddy

So yes, Sagan tosses in "if"s.
But rarely do he or others using Drake acknowledge that there is just as much validity in assigning zero values in Drake.

Again, he doesn't because it is not reasonable to do so. If it was we'd have no use for the equation.

Originally Posted by tonedaddy

Try using classical (not Bayesian) statistics to develop a probability with a degree of confidence when you only have one observed outcome (say the existence of life on only one planet), and tell me what the probability of the next outcome is going to be (say the probability of extraterrestrial life).

It's impossible.

???

Impossible? If that was true the following would not make sense and I think it does.

The odds in favor of life arising on a planet are surely the ratio of the probability of it occurring to the probability of it not occurring. Nothing stop us from using 1 in the numerator of that ratio and the number of planets solar and extra-solar we know of in the denominator to get a pretty good non-zero probability.

That is, if we know of Earth and 99 other planets the odds are 1%, for planet 101.

The fact that we cannot extrapolate that probability to the entire universe is not because we have only 1 positive data point, but because the sample size is too small and because this simple example leaves out important elements, like the frequency of life-friendly planets.

Originally Posted by tonedaddy

For Bayesian approximations, you can use a consensus of anything you want, from a range of values based on observations, or forget the consensus and just use whatever you believe

This "anything-goes" attitude towards Bayesian statistics tells me you don't really understand what they are. You cannot forget the consensus. It's not a case that shit must taste great because one million flies can't be wrong, but it is the case that one good way we have to reduce error is to cross-check our reading of the data with those of others: a consensus from proper authority takes us closer, if not affirms, correctness. What would be the point of peer reviews if we can forget consensus?

Originally Posted by tonedaddy

"Bayesian statistics uses the word probability in precisely the same sense in which this word
is used in everyday language, as a conditional measure of uncertainty associated with the
occurrence of a particular event, given the available information and the accepted assumptions."

And of course, when the available information is zero or none, then there is complete uncertainty, and the "probability" is zero.

But it is not zero in our case. Life on Earth is not a zero. An universe filled with like structures is not zero information, and complete uncertainty can exist only for those who are certain that we are alone. Are you one of them? You must be with so much talk of zero.

[lharp]

Originally Posted by coreybox

Since when is it a stipulation that a single organism must survive the entire trip? It could be some kind of habitat on the vessel, that supports sustainable life. The generation that leaves may not be the one that arrives.

Pardon me for assuming that that a civilization that has mastered galactic travel, may, just may value life a little more, and define "the good life" differently than spending life, not in single life-spans but in entire lineages, inside spacecrafts on angling expeditions.

But you are right.

[lharp]

Originally Posted by The Guy

obviously hawking is an idiot.

TGP is where the magic, er. . . meticulously conducted science. . . happens.

Somebody give guy a cookie.

[dzo]

We better use up all of our natural resources quickly so the aliens don't bother us.

[macheesmo3]

Originally Posted by lharp

I agree as far as quality. The Assyrians were the most hated people of antiquity; they depicted the torments inflicted on those who resisted them in frescoes in the royal palace walls, for foreign emissaries to see. They impaled with abandon and were utterly skillful at flailing people with a copper knife starting at the middle fingers. I'd say the Gestapo, the NKVD, and some of the competent jailers providing rendition services to the US were capable and have achieved similar levels of brutality, albeit less publicly. And then all in-between, including those you mention.

But in quantity, dear fellow -- that which separates a murderer from a serial killer, and massacre from genocide -- in quantity the 20 century stands unsurpassed, the old testament genocide of the Amalekites and Medianites: risible, the destruction of Carthage: a pittance, Godfrey of Bouillon: an apprentice, Temujin: an amateur, Cortez: a dabbler.




True. But we have some idea. And we know that killing with edge weapons and wicked points is grisly butchery but SLOW. No earlier battle had the great dying of WWI with thousands of machine guns and carpet bombing of heavy artillery. What past war cost a nation 20 million people as Russia paid in the 40s? We had 16 million men in uniform.

Yep, our modern philosophy is still woefully inadequate to match our destructive power. Unthinking men ushered the atomic age to win a war that was already won, and we've been toying with self-annihilation since. That's the great achievement of political philosophy for you.

That other thing we are not supposed to talk about here, keeps millions of modern men and women incomprehensibly thinking the world is 6000 years old and lets credulity fester in their minds so unimpeded that they are easy prey to any charlatan that saunters by, not to mention eloquent politicians, faithless lovers, and disloyal friends. And we need armies of lawyers to keep each others greed in check. It's no good. And back on topic again, there is Area 51...



The Holocaust cannot be counted out but it is by much not the worst dying of that century, though they most fuzzed about.

I meant per capita. There were(and are) a heck of a lot more of us now than there were then. The fact that technology has improved may have made us more efficient at killing each other, but it has also made us a lot more resistant to use it....(hence no nuclear war...yet).

My whole point is that technology is a good thing. The primitive nature of man is the "problem" ( and I don't think it's a problem at all, but rather a natural result of our increasing population. We don't see Lions killing Hyeanas as a "problem" it's nature. So are we. Tribalistic, protectionistic animals with big brains).

[7StringJazz]

Originally Posted by Zero G

Right, because when astrophysicists don't have answers to important questions like these, they turn to Hollywood for answers.

My point is you need to find a better algorithm. Any approach based on pushing a rock is problematic given what we think we know about astrophysics. You could argue that we are one breakthrough away from solving this. But I suspect the solution will come from outside of the current box of physics.

I'm one who believes that if we can conceive it, its already in the realm of possibility. YMMV.

[7StringJazz]

I recall a sci-fi book from Vernor Vinge called 'A Deepness in the Sky' in which he speculates on a non-uniform universe, where there are portions which do not obey the laws of physics. The part where we are was called the slowing because we are limited by c, but he speculates on the possiblity of other areas where the c constant does not exist. It won the Hugo award for sci-fi.

Which just goes to show you what happens when you change the paradigm and how constrained our current thinking is with respect to star travel. Perhaps that is just the step required to be recognized by the ETs. If you can bridge the gap, you are worthy. If you can't you are not worth recognition and you pose no threat. Just a thought.

[phoenix 7]

Originally Posted by furry

hell, we don't really know the relative SCALE of anything either...

what we are calling 'universe' might just be a sub-atomic particle in another universe. and for that matter, what makes up what we consider sub-atomic particles might just be trillions of 'universes'.

Good point. I suppose there could be living, intelligent entities thousands of times larger than us who live for a hundred thousand years and for whom a trip across the Milky Way is a walk around the block. Heck, dramatic differences in the scale of living creatures exist on our own planet -- organisms hundreds of times smaller than us that live for a day or two.

[dividedsky]

Don't blame me. I voted for Kodos.