Do you think we are alone.

[LukeSkywatcher]

If you look at the Earth,there is an awrful lot of coincidences to allow life to develop

I dont think "coincidences" is the right word to use. Yes, it seems that way to us and how we think about things. I think its more a case of "conditions were perfect". Perfect for carbon based life forms, but not for any other type. We simply have no idea what type of life may exist elsewhere. Are we not naive in thinking ALL life in the universe has to be carbon based?

[Alien 13]

I think the answer might come in a few years (20 or so), if we can determine that life exists throughout our solar system on moons, comets even gas giants then it should be pretty much everywhere but as already stated conditions have to be right for a long time period to evolve intelligent life you only have to look at mars.

Alan

[Davey-T]

If there are other civilisations receiving our TV prog's then they have seen all those movies like "The Day The Earth Stood Still" etc etc, and seen how we welcome aliens so they will probably give us a wide berth

Dave

[Cath]

We are evidence enough. Earth is evidence enough. Any planet that is absolutely teaming with life (just like planet Earth) is evidence enough.

How much evidence do you need?

[jnb]

Of course as long as we are restricted to speed of light communications then given the distances between any two civilisations then by the time one sends a reply to another there's every chance that the first civilisation would no longer be there.

[Ryan1885]

Two possibilities exist: either we are alone in the Universe or we are not. Both are equally terrifying.

Arthur C. Clarke

I could not agree more. The universe is so vast and no object can be compared to another with so many variables needed to support life (as we know it) Take Europa for example. It is suggested that there is an ocean beneath 2km+ of ice. It will take billions of dollars, years of research, development and training in order to prove such a theory. Even if we discover single cell organisms then it will generate even more questions! I hope some of those questions will be answered within my lifetime but I have a feeling they won't.

If someone on a planet in the Andromeda Galaxy is looking at our sun and measuring the transit of our planet (like the Kepler mission) they would be looking 2.5 million years into our past and obviously were not home! So I propose another question...... Is the speed of light too slow to look for life??

[callisto]

Got to be.........right?

[Treeden]

Young Ellie: Dad, do you think there's people on other planets?

Ted Arroway: I don't know, Sparks. But I guess I'd say if it is just us... seems like an awful waste of space.

[stevepeverall]

If there are other civilisations receiving our TV prog's then they have seen all those movies like "The Day The Earth Stood Still" etc etc, and seen how we welcome aliens so they will probably give us a wide berth

They'll give Omicron Perseii 8 a wide berth too.

[JamesM]

I take a more progressive view on whether other life exists in the universe and suspect that in reality it is positively teeming with all kinds of life with varying degrees of intelligence and technological advantage. If there is at least one technologically advanced civilisation out there, there is a good chance that it is much older one than ours, perhaps even a million years older than our own history and if so, I'm sure they are very well aware of our existence and have as yet chosen not to make known there own existence. They will have witnessed many new life forms emerging into the galactic "safari park" and have a well established routine of when to avail themselves and how to do so. In addition I suspect our notion of life might need to take in account the possibility of a multi-dimensional universe in which some intelligent life forms might pass from one dimension to another and may themselves not be dependent on the carbon based model for their construction. One thing that I certainly hope for and that is that some confirmation of 'other' life will happen during my lifetime as that would be truly exciting and help move us on to the next big question.

James

[MrFinster]

Of course as long as we are restricted to speed of light communications then given the distances between any two civilisations then by the time one sends a reply to another there's every chance that the first civilisation would no longer be there.

One interesting theory is based around this communication method, 

Since humans have been about roughly 2 million years, we have only been broadcasting for just over 100 years by radio wave energy, thats only a very narrow window of transmission relative to human societal development. As technology improves, the use of wireless transmission will be increasingly replaced with faster systems as seen with rise of closed system data transfer such as fibre optics, this reduces the amount of signal broadcast  outwards into space. It is considered quite possible that radio transmission may well be obsolete in a small number of years hence.

If there was intelligent life elsewhere, then it would depend on their technology level as to whether they are actually listening with equipment that can receive any of the radio transmission we pump out into space, if they are behind our level of technology when our signals arrive, they wont hear them, if they are ahead, they may not be using radio transmission so they wont hear us.

This applies to us as well, by the time the signals from another world reach hear, we will probably not hear it as we will be using a technology different to the one that originated the signal, unless we are still using radio astronomy well into the future.

[Ptarmigan]

One last question.

Photon,s do not degrade over Distance,but I guess Radio Waves do?

Not quite.

radio waves are photons, photons do persist ( if photons had a lifetime they would have rest mass and that would have implications not least for the Standard Model )

The problem is with 'information' degrading.

Forget this business of "We have been broadcasting for 100y, so the aliens will be here in 100y(+a bit) time"

the further the ( our) radio waves carrying information travel the (relatvely) weaker they become until they get lost in the random noise*.

There are some ways to mitigate that effect, directional beams, coherent whatsits, and so on but all are eventually doomed to a noisy death far out.

(excepting maybe quantum entanglement but we have not yet found a way to broadcast that, but anyway it needs a prior visit to get things arranged right in the first place)

* so the aliens will be spared Hancock and Steptoe

[Enlightened Consciousness]

I don't believe we're alone in the cosmos and I most certainly think we never were. All the ancient remains/hieroglyphics etc all point towards extraterrestrial contact and even inter-breeding. This is all around the world, believe what you like but this is fact and it's exciting to know we could possibly contact extraterrestrials one day, they say with technology advancement we could be looking toward contact in 2040. We shall see.  

[LukeSkywatcher]

One thing to consider when thinking about "are we alone", is the simple fact that right here on planet Earth..................life exists in every single nook and cranny. Life exists on the surface,life exists in the oceans and life exists in the atmosphere..

Our planet is teeming with life in environments that to us humans seem impossible. They are called "extremophiles'". They happily exist in boiling water,in low oxygen environments and they even exist inside what we think as solid rock.

Granted they are uni-cellular organisms, but they are life. So why the hell can similar life forms not exist elsewhere in the universe..............if they manage to do so right here on Earth?

I do know that here on earth, they are all STILL carbon based life and need water/moisure to survive, but why cant similar life exist elsewhere and maybe they need methane,silicone,sulphur (blah blah blah) to survive.

I'm sure they can and do, but us carbon based life forms wouldnt know them as life forms if they slapped us in the face with a wet fish.

Intelligent (as we deem that to be) or not, if mankind ever found living bacteria,microbes or a big pink flying elephant in the universe (or even our own solar system).................it would be the story of all time and would answer the biggest question we have/ever had as a species.

[LukeSkywatcher]

I don't believe we're alone in the cosmos and I most certainly think we never were. All the ancient remains/hieroglyphics etc all point towards extraterrestrial contact and even inter-breeding. This is all around the world, believe what you like but this is fact and it's exciting to know we could possibly contact extraterrestrials one day, they say with technology advancement we could be looking toward contact in 2040. We shall see.  

We all are our own "extraterrestrials". The building blocks for life on Earth came from space/the cosmos. We are "aliens" on this planet.

I often wonder what Earth would be like today if the dinosaurs didnt go through the mass extinction event that they did. Would they have evolved further over time and develop technology and get to where us humans are today. Then again, small mammals survived the same event (because they  could burrow underground)...............and thats where our own evolution kicked in.

Just makes me think.

[Ptarmigan]

One thing to consider when thinking about "are we alone", is the simple fact that right here on planet Earth..................life exists

But then the question arises - what do you mean by being 'alone'

There is no evidence, umm,, that I have yet seen he says defensively , that any of the life that we see all around us or that may be out there posesses the intelligence to have tried to say "hello" !

Ok ok, I know what they say about dolphins and chimps,,

maybe we are too dumb to understand them, but we have given Nim Chimpsky et al every opportunity to say hello to Noam Chomsky and so far they have not obliged.

[brantuk]

We are alone - so are whatever aliens that are out there. The distances are so vast we're never destined to meet (except in sci fi films where aliens look like humans in costumes anyway) lol

[LukeSkywatcher]

But then the question arises - what do you mean by being 'alone'

There is no evidence, umm,, that I have yet seen he says defensively , that any of the life that we see all around us or that may be out there posesses the intelligence to have tried to say "hello" !

Ok ok, I know what they say about dolphins and chimps,,

maybe we are too dumb to understand them, but we have given Nim Chimpsky et al every opportunity to say hello to Noam Chomsky and so far they have not obliged.

If you are going to quote me, please post my full comment. I said that here on Earth, life exists in extreme conditions (as we see them to be), so why could life not exist elsewhere in the universe in similar such extreme conditions.

Here's my full comment:

One thing to consider when thinking about "are we alone", is the simple fact that right here on planet Earth..................life exists in every single nook and cranny. Life exists on the surface,life exists in the oceans and life exists in the atmosphere..

 

Our planet is teeming with life in environments that to us humans seem impossible. They are called "extremophiles'". They happily exist in boiling water,in low oxygen environments and they even exist inside what we think as solid rock.

 

Granted they are uni-cellular organisms, but they are life. So why the hell can similar life forms not exist elsewhere in the universe..............if they manage to do so right here on Earth?

 

I do know that here on earth, they are all STILL carbon based life and need water/moisure to survive, but why cant similar life exist elsewhere and maybe they need methane,silicone,sulphur (blah blah blah) to survive.

 

I'm sure they can and do, but us carbon based life forms wouldnt know them as life forms if they slapped us in the face with a wet fish.

 

Intelligent (as we deem that to be) or not, if mankind ever found living bacteria,microbes or a big pink flying elephant in the universe (or even our own solar system).................it would be the story of all time and would answer the biggest question we have/ever had as a species.

 

I never said that we are alone. The thread title is "Do You Think We Are Alone".

 

I didnt even say that any life out there could be intelligent enough to say "hello". I just pointed out the fact that life exists here on Earth in extreme environments, so why not elsewhere.

 

Nothing more.............nothing less.

[symesie04]

I first saw this equation demonstrated by Carl Sagan.  To be honest I thought it was his work, but it turns out to be 'The Drake Equation'. 

Here's the link: http://science.howstuffworks.com/space/aliens-ufos/extraterrestrial-life-odds1.htm

The problem with the Drake equation is a) it is out dated and it is so variable.

When the Drake equation was written in the early sixties we knew very little about the existence of other planets. We had no idea if any planets existed outside of our solar system at all.  Now of course we now that the majority of stars are likely to host planets. We are also beginning to get the idea that rocky planets and planets in the "goldie locks zone" maybe quite common as well. If you couple this to our greater understanding of the conditions needed to support life the Drake equation begins to look shaky at best. We now know that organisms can live to miles down in solid rock, we know organisms can survive the freezing radioactive conditions of space, we know that organisms can tolerate high levels of arsenic (previously assumed to kill all living organisms). As a result our search for life is no longer dependent on those rocky goldie locks zone planets and has instead turned to the moons of outer gas giants. And that's our solar system alone.

Then you have things like the rate of star formation which was based on our own milky way and at the time it was assumed that that was the norm for all galaxies. Well surprise surprise not so. Star formation varies a fair amount on a whole host of factors throughout galaxies in the known universe. If the conditions required to sustain life aren't complicated enough the conditions required to create life are totally unknown at this stage, and there may not be a uniform set of rules required but more likely a whole interchangeable set of variables. As a result the determining fraction of the equation associated with the formation and emergence of any life form are nothing more than pure guess figures, therefore making the likely hood of any accuracy as probable as a quad trillion lottery draw. Just a thought

Do we need a large tidal moon? probably not, it stabilises the earth's rotation but so does the sun.

Not sure "probably" can be used as a loose form of certainty. Along with stabilising orbits and controlling spin rates it is also thought the moon played a major part in mixing together the early soup of RNA. Without its huge early tidal forces this it would seem would "probably" have not happened. Is a large tidal moon required for life to take hold? Totally unknown.

As far as THIS dimension is concerned, I have seen no reason, thus far, to think life exists anywhere but on the ball we occupy.

20-30 years ago we had no reason to think that life existed 2 miles down in solid rock, or that life existed 9000 metres down in the darkest depths of the sea gathered around black and white smokers spewing what would seem poisonous gasses into the surroundings. 20 years ago we had no reason to believe planets existed anywhere but our solar system. Please don't take this the wrong way, no offence intended here but that seems a rather closed view.

[symesie04]

Blimey when I started typing that there was just one page on this thread! what just happened???

[Mike Hawtin]

Of course we will never know for absolutely sure until we come into contact for the first time but the chances are so overwhelming that intelligent life is out there that it is just a matter of time.  I'm surprised nobody has posted a link to the Kepler mission findings (apologies if they have and I've overlooked it), it seems there are billions of earth analogues in our galaxy, check it out:     http://newscenter.berkeley.edu/2013/11/04/astronomers-answer-key-question-how-common-are-habitable-planets/

[GuillermoBarrancos]

The problem is the distance. If distant aliens With super massive technological Advanced power telescopes were able to zoom in to our planet. They would see the dinosaurs roaming around. Or even earlier time.

Add to that Einstein´s Law of General Relativity.

If that ends up being the final Law that really cannot be broken and no one can achieve speeds beyond lightspeed, yet alone even close to it.

Then things become very dissapointing. Star Trek then trully will always be that. Entertaining Science Fiction.

[todd8137]

Makes ya wonder ,is there isn't there ,I think use in the radio wave spectrum is useless ,I think there could be all those galaxies ,it's not life as we no it Jim

But I think the distances are just to vast for us to send or receive any thing and we may not have the tech we base every thing we no on earth we looking for radio signals ,and think others might be use in that ,just like we say ,all life in the solar system needs,light and water that's because we do ,it does not mean other life forms will

I think if there is they should stay well clear of humans and earth we can not even get on country to country imagine trying to get on with another life form !

Pat

[astro mick]

But we don't have to send to receive!!!!

Just by listening in,we still here absolutely nothing.

I dony know if radio waves degrade with distance,but if like photons they don't,they would have enough time to reach here,regardless of us sending a message.

We see Supernova,s from millions of years ago.

I have to assume that any alien life will be similar to us because of the elements of the Universe.

A alien race must communicate as well,so their  signals must be out there,must.nt they?

[ChrisLX200]

But we don't have to send to receive!!!!

Just by listening in,we still here absolutely nothing.

I dony know if radio waves degrade with distance,but if like photons they don't,they would have enough time to reach here,regardless of us sending a message.

We see Supernova,s from millions of years ago.

I have to assume that any alien life will be similar to us because of the elements of the Universe.

A alien race must communicate as well,so their  signals must be out there,must.nt they?

True, but no alien race will be using supernovae as a semaphore, extreme distance is the problem (as always) for detecting remote signals. An advanced alien race I should imagine would use communication a system a bit more efficient than to broadcast it all over the universe, but at a lower level (like radio) it would be so faint as to be detectable only over short distances.

ChrisH