Actually I think things like warfare will be a constant in the universe as no matter the species, scarce resources at their local area will always provide the excuse. The style and shape of that warfare though could vary a lot. But for species at around the same tech level as us, it's certainly possible they would have nukes, rockets, tanks ect as the laws of physics would be the same for them. The weapons though, especially smaller arms, would be more tailored to exploit their own weaknesses. For example some alien life might have an aversion to loud noise. So its likely you might see such a culture develop sonic based weaponry. God help us if an advanced species ever decides it likes the look of our mud ball. 😕 Mind you, perhaps their biggest weapon might be a massive water pistol! 😆

Speaking of war, lack of resource can be negotiated, but when you throw religion/faith into the mix, alien or not, war is the most likely result.

Well, then you add religion into the mix, all bets are off. This in itself has caused many horrible chapters to be written in our own history. 🙁

Scientists can't even get global warning facts straight so a guy that has analyzed data from 500 planets out of billions in our galaxy doesn't sound to dependable.

I am guessing that Howard Smith may have been mis-quoted. Only an idiot would claim that by looking at just a few (on a galactic scale) planets, with still un-proven methods, that we are alone. The universe is simply too big for us to be the only life within it. Such an idea of humanity being the universe's only attempt to look upon itself, is totally preposterous. So much so in fact, that we as a race should get out there asap and stake our claim before all the good stuff is taken by others! 😛

Incredulity is not a safe premise from which to form a position. Fact is, we don't know what the odds of life cropping up are like; we only have this one example, and the anthropic principle means that of course we'll always have at least one example, otherwise there could be no study.

Life itself, sentient or otherwise, is an amazingly counter-intuitive bit of chemistry. What we have is a localised patch of reversed entropy, where a chemical reaction tends from chaos to order, and spreads whilst doing so. It seems so obvious to us that it can happen, only because we (earth-evolved life) are the example of it happening. It does go counter to most of what's observed around the universe, though.

The universe is a huge place, so there might well be more of it. What we don't know is whether the odds of it happening are as long as the universe is wide. If the odds are hundreds of billions to one or longer, we might never see non-terrestrial life. It's all likely to be in other galaxies.

Of course, life is no guarantee of space faring life. For most of the history of life on this planet, the dominant species have not been big technology users. Remember, we didn't out-evolve the big reptiles; we only had the chance to evolve at all when they were smashed out of existence by some external force. They were remarkably successful, having lived on Earth for a statistically noticeable proportion of Earth's time. If they hadn't been wiped out, they'd still be here, adapted perfectly to the current climate and terrain. Large mammals wouldn't have shown up.

So, life might be unlikely, and technological life a complete fluke. It's by no means inevitable. We just won't know how likely it is until we find more. Until then, we appear to be alone and might have to face the fact that this might actually be the case.

My opinion. Well I disagree with this astro dude.

It's about chance and statisticks.

There something like goldylock zone.

we got one planet in it and most out side.

Wich means that most planets are indeed very extreem positioned. So exclude at least 95%

We discover first the most large and close to the sun gas giants.

Wich is very different then what we have. So there is extreem variation and most of them outside the goldylock zone.

But with many miljard of stars and factor 3 to 15 planets per star.

Wel most of them wouild be so extreem thus steril.

But the extreem numbers do great deal to chance.

we know that there can be life in extreem conditions. On vulcanic oceanic floor.

But there is a limit. So we curently don't even know if moons could have life. We only know that there is fluid water.

So the chance that there is life out there and inteligent is large.

but could be rare like 1000 or 10000.

Wich means not likely in the neighberhoud.

Our milky way 200miljard stars / 10.000. So per 20mil one alien race.

Also we are isolated by the extreem distances but also in what time the evolution come to be, but also could fade away.

In miljard of years planets can change to.

I don't expect life in the galacy core area. to much radiation

It boils down how many stars got somethin in that GZone.

And if how many are earth like 1 out a miljion with 1% in GZ means 2000

And with all those space game scifi stuff. That there is lot of interaction out there. NO.

That how we wish it could be. More brainwashed by hollywood.

It could be that aliens are mostly isolated. Not all barriers can be taken.

braking the sound barrier doesn't mean speed of light is breakable. We are now not sure it can be. Keep in mind it could not be broken even by a race with miljard years of evolution. If so. they are far far far awayyyyy......

So space trading would be something that isn't so posible . you need next to a broken FTL barrier a releative close group of aliens with a few lightyears.

It make no sense to trade with a race with no FTL means of travel. if your neigbure is 250 Light years away.

And with that war between races would be rare to.

Might be possible but not plausible.

It hard to commit to with the 25 Lightyears.

So if aliens are out there if more then I took as example. we don't see any because they are by extreem distances isolated for and likely to each other to.

Some good common sense points there in my opinion SuperG.

We are making some headway, slowly on traveling in space. Do I think we will travel the speed of light in the next 100yrs, hell no. We are still using gasoline powered cars so no way.

But the 'New Horizons' spacecraft was launched in Jan 2006 and it reached Mars by April 2006. Granted we did use a slingshot effect to propel the craft faster and it is going at about 33,000+ mph currently and should make Pluto in 2015.

This is why your points are so valid. It's because I don't think we could sustain a crew that long without cryosleep, they would go insane or food and/or power would pose a problem.

My point is that we are just at the front door wenn about talkin of exploring.

the funding is done on scientific exploring nature and is very expensive.

this fase far away of a interstellar trading economics.

The problem is with this is the technology.

First fase.

Orbital reach

orbital satelits.

orbital station.

Moon walk

Moon exploration

Moon base

Moon mining

Moon city.

Moon space port.

Space mining of close astroids.

With all those fases thenology need to leapfrog to higher level also make it more economical feasable and not just traveling time.

Still far away of trading because the resources and funding need the collective support of severel big countrys.

not big corporations.

Wenn technoligy comes wen going to orbit is economical and commercial feasable more fases are doable with less financial support.

And single big country can handle that and coporations.

But the one man company space trucker is still far far away.

The technolohgy and economical commercial feasability must be the same for one man company similar to own a truck on earth like a 18 weehler. but then the same runtime and higher tech to support something like that in space.

this also need a high level of space kolonisation. On earth lot of regions to do bussnes for a trucker. But in pre trading local space not.

a mars base and moon distric is not much for a fleet of corporations and lot of small companys.

So you need 10.000 places to trade and that can only be wenn kolonising also other stars with nations in multi miljion people with lots of space stations and space mining in suroundingh stars and FTL is a must.

My response is small, but I must just say that 500 planets is simply not enough considering the scope. Since we now estimate 1,000,000,000,000,000,000,000,000 stars in the universe (and no that number is not just made up by me), I would have to say 500 planets is sort of a laugh in comparison.

Always reckon there's a good chance of some thing out there.

Was it carl sagan or arthur c clarke who said that there was three possibilities.

1 The galaxy is teaming with life.

2 No one out there.

3 We are the fist ones.

My hunch and that's all it really is = life is rare but we are not alone...

No idea what rare means though.

But if you think about it if there's only one earth in every galaxy that's literally millions of earths.

Sad thing we won't get to see a single one..

Space is big guys..

I agree that a 500 planet sample may be a bit small to make such a sweeping declaration. I personally find it very hard to believe that there is not some other planet somewhere in our universe if not within our galaxy even that has conditions capable of supporting some form of life. As others have pointed out, our galaxy is enourmous and it is only 1 out of billions of galaxies in the universe.

I think with the number of other galaxies in the universe its quite likely there exists other planets just like Earth. Probably many of them. So there is a reasonable chance that one or some of them have life.

Its most likely that the life that exists there will work the same way as our world. There wont be the same animals or plants, but unless there is an entirely different way of constructing a living cell to the ones on our world, then the process of life will progress in a similar way to on our planet. The life on any Earth "clone" could be at any stage of evolution. The very nature of "living things that can die" creates the evolutionary cycle.

One way to find out how likely there will be life on an Earth clone, would be to figure out how it spontaneously appeared in the first place. A question I have never found a satisfying answer for.

.. how it spontaneously appeared in the first place. A question I have never found a satisfying answer for.

Thereby hangs a tale!

Thereby hangs a tale!

Um......what does this button do again? <presses button> Oh!

There are 2 methods one wobble and passing in front of star. But that not relevant.

His observation that solar systems are very diverse. And most planet are due to these extreme condition lifeless.

On that point he right. Life might be very rare but not impossible. The chance to find a intelligent life form close like within 1000 LY is very small. And still out of reach. But that's following the goldilocks zone.

Then there is these primitive one cell life things. As lot of discovery documentary's point out. Life can exist in extreme conditions. Earth is example. where there is life where other life can' t exist.

I think it could be possible to find life forms on planets with ellipsoidic orbits, where a winter would last 300-500 years and a life-prosperous summer will occur for only 1 or 2 years when the planet comes near to the sun, the ice transforms in ocean, the top crust of landscapes lose ice consistency etc, etc. There is a pleiade of possibilities that is difficult to define by statistical means, the more elements considered, the more the whole response could swing in one direction or the exact opposite that would - or not - favor life. For Earth, such elements are:

- presence of a large gas planet that deviates bigger asteroids from earth, thus making evolution possible

- right distance from the sun for oxigen in gas form and liquid water

- magnetic field than keeps the atmosphere from burning away

- no continental discreapencies (like on Venus)

I could tell about at least 20 more such "uncommon" elements that all have a very small overall probability - all at once would be the more smaller if you multiply them. That's the essence of the reasonning that says "no other life in the immediate vicinity", but there's a central flaw with all that: it doesn't take account of the possible laws that may build a solar system, or a single planet. Observation alone is not science but empirical data only.

There are 2 fundamental problems to all that, to be divided in 2 generic formulas:

- The Antropic Principle (we would all not be there to discuss if the universe was not at least in part life-friendly)

- The limits of Science: What we discover and analyze by scientific means is not totally independent of our (human) self-satisfaction.We generally find what we are searching, a larger rule of quantic physics that we just start understanding. This is to say our searching and analyzing FORMS  the universe.

But what is life on a planet? One definition could simply be a system of mutual dependencies, intelligent or not. If considered such systems, the stats change dramatically.

Greets,

XenonS

My take on this: Drake equation

Ok, it is not mine :p. Anyway, a 500 planet sample - and bound to be planets easier to find from outside the solar systems, is not much of a sample compared to the .. ahh .. trillion+ planets of this galaxy alone. 

Who knows...

I took one look at the personal homepage of http://en.wikipedia.org/wiki/Howard_Alan_Smith (see "External links" section), and all my alarm bells started to ring. (Other stuff already covered by others.)

So ... After a bit of searching. As short headline-articles from papers like The Telegraph are never a good source. Especially not as only source.

- http://www.americanscientist.org/issues/id.91/past.aspx (just short of the article in question.)

- http://www.americanscientist.org/issues/feature/2011/4/alone-in-the-universe (synopsis)

- http://lettherebelightbook.com/wp-content/uploads/On_living_alone_AAAS.pdf (not sure, but this might be the article in question)

- http://melpor.hubpages.com/hub/Evidence-That-We-Are-Alone-In-The-Universe (Way better than that "The Telegraph" page.)

- http://www.psychologytoday.com/blog/world-wide-mind/201104/are-we-alone-in-the-universe (other one on the same subject.)

Seems to me the issue was not that we are factual alone in the Universe, but that from a practical point of view we probably going to be. (well ... for at least a long long time.)

Neil DeGrasse Tyson answered this question.

After seeing a documentary about the SETI project, I noticed that the most important question has not been asked during all the interviews and explanations of the very interesting work of this group.

This question is: how can we interprete the Silence in the past 40 years? I mean the absence of any intelligent signal, be it laser, radio or any wave that propagates with the speed of light and has its origin from a technological and space-oriented life form. I dare to say that this silence should give us information about the absence of such life forms.

What I don't understand is: how strong is a radio signal after propagating in space for 500 years ? How has it been affected - if at all - by the space evironement?

Not sure about the exact year, but we have roughly started sending signals in space in the year 1900. All sort of radio stuff.

Now let's assume that there is a high-tech civilization at exactly 500 light years distant from us, and let's further assume that they will reach our exact current tech level of 2015 in the year 2400. Let's also make the adventurous assumption that they have the same radio and telescope equipment that we have (a 2nd earth let's say). So, from 2400 and past, are they going to hear all our radio stuff, our first radio signals, the song of Lili Marleen, communications about World War II, the Kennedy speach for the moon project, etc. etc. all in the exact chronology? Or are the radio waves so distorted or just absent due to space environment (magnetical fields etc..) so that they wouldn't hear anything ?

My point is: If such a 2nd earth would in fact hear everything from us in 2400, then we should already be bombarded by such signals from other such distant high tech civilisations, it doesn't matter if they have already disappeared. Our galaxy is old enough to allow for the transit of many such radio stories from past civilizations.

But no, we are not bombarded, we don't receive anything, or we don't realize it for some obscure reason, which I don't  believe. So, it's very simple: such high tech civilisations do not exist, period.

On other planets there may be a lot of fishes in the water, creatures living in some clouds around gaz planet giants or anything else we could imagine, all maybe intelligent but clearly not sending signals into space, and surley no creatures like human kind.

So, where is the lag in all this reasoning? Does this silence mean anything? What will happen with our own radio signals in 500, 5000 or 80.000 years (the limit area of our galaxy if our waves pass around the center) ?

Greets,

XenonS

Why would aliens communicate through radio signals? Why would they even be carbon based? Why would they have aural senses in the first place? Who's to say they don't communicate through phermones? Or light? Maybe we have been getting bombarded and we call it radiation?

My point is this. Look at humans. Now look at Jellyfish. We have such a rediculously large variety of life here on earth, and you are going to try and convince me life in the rest of the universe is ANYTHING like us? Its silly.