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Do Aliens Exist?
Posted: 11 August 2017 10:08 AM   [ Ignore ]
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I thought I’d start a thread in the Science section to seriously discuss the possibilities of extra-terrestrials. I find it an interesting topic that unfortunately also has alot of hogwash in it from movies, media, etc.

My personal belief is that ETs do exist and have visited earth. I believe they exist because of the law of large numbers. OR put this way, the chance that in this incredibly huge universe that we’re the only lifeforms has to be miniscule. From the movie Contact - it’d be an awful waste of space if we were the only ones here.

As for visiting earth. There are plenty of physical reasons why they couldn’t have visited. But I think those suffer from lack of imagination. A race even a thousand years more advanced than us might easily have technology enabling flight to earth. The downside as we see in the media or in documentaries, is that every imaginable being traveling in the most ludicrous ships evidently have visited earth. That I doubt. But a few species, maybe.

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Posted: 11 August 2017 11:41 AM   [ Ignore ]   [ # 1 ]
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I think it’s highly likely that intelligence life does exist somewhere else in the Universe and possibly our Galaxy given how many star systems there are with planets.

But I think the chance of us having being visited by intelligence life from another solar system is very unlikely.

That same vastness also comes into play as does the way nature itself seems to work. The speed of light and causality are powerful arguments against traveling at speeds that allow transit between star systems at anything less than many years of transit requiring vast resources.

Climbing into a little freighter and blasting off to the next star system makes for great fiction, in the real universe if you could somehow violate the speed of light you begin traveling back in time leaving the paradox of arriving at your destination before you even left your point of origin. Causality even applies to wormholes even if it is possible to create them and hold them open long enough to allow transit from one point in space time to another.

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Posted: 11 August 2017 03:58 PM   [ Ignore ]   [ # 2 ]
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I like Fermi’s paradox….

We are the only intelligent life in this galaxy - if any others existed we would know by now. Of course there might be spacefaring aliens in other galaxies, but we will probably never encounter them.

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Posted: 11 August 2017 05:58 PM   [ Ignore ]   [ # 3 ]
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Beltane - 11 August 2017 03:58 PM

I like Fermi’s paradox….

We are the only intelligent life in this galaxy - if any others existed we would know by now. Of course there might be spacefaring aliens in other galaxies, but we will probably never encounter them.

How would we know?

The Milky Way galaxy is 100,000 light years across, the fastest spacecraft we’ve ever produced takes years to just get to the outer regions of our solar system. There’s no indication of any means to travel faster than light speed which means that all interstellar travel is going to be on the scale of generations and be one way shots. Special relativity tells us that accelerating to the speeds necessary to reach even nearby systems within a single lifetime would result in all those left behind dying long before any traveler could return.

Space travel itself would be highly dangerous at relativistic speeds, interstellar gas would become high energy particles and any mass hit even dust particles would have tremendous force. Radios waves of the kind we’ve only been emitting for slightly over a century become rapidly attenuated as they spread out the further they are from the source, a receiver even at Alpha Proxima would be challenged to detect signals from Earth. There could be civilizations as advanced as we are 100 light years from Earth and we wouldn’t know it. That leaves room for thousands of advanced civilization in this galaxy alone.

There are limitation in where intelligent life might evolve, regions of the galaxy with large numbers of massive blue giants would be hostile to the formation of life as these stars quickly burn out and put out massive pulses of radiation when they die.

A much better possibility would be on the order of dozens of civilizations at our level in this galaxy at any one time.

But the distances and difficulty in travel between systems as well as the challenges of detecting signals at such distances are daunting.

There’s probably lots of life out there in a galaxy like ours with hundreds of billions of stars, but there are also huge hurdles in finding them and in spreading life from one star system to another. It’s not like in the movies.

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Posted: 12 August 2017 06:44 AM   [ Ignore ]   [ # 4 ]
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I tend to lean more toward DougC ‘s and Beltane’s pov here.  It’s more likely than not that life has evolved on other planets in the galaxy, and some of it may even be intelligent and civilized, but to the best of our knowledge, interstellar travel is not practical.  Sorry, that’s just the way physics happens to be set up.

I know the way I would LIKE things to be.  I would like for it to be like Star Trek, an entire Federation of intelligent, progressive aliens roaming the galaxy and looking out for one another, helping out their less enlightened brothers and sisters.  Maybe warp drive is possible after all.  Maybe there are starships passing by our star system all the time, and the reason we don’t know about it is that they stopped using primitive radio waves centuries ago, and communicate entirely through subspace.  That would be nice.  Unfortunately,  the way I would LIKE things to be holds no water with reality.

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Posted: 12 August 2017 09:12 AM   [ Ignore ]   [ # 5 ]
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Advocatus - 12 August 2017 06:44 AM

Unfortunately,  the way I would LIKE things to be holds no water with reality.

I like that.  The rationalist’s perspective.  Sadly too many in our society adhere to the

‘If I believe it hard enough, it’s got to be true!’

faith.

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Posted: 12 August 2017 11:18 AM   [ Ignore ]   [ # 6 ]
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Good discussion. When it comes to physics limiting the means to travel to visit earth everyone seems to forget they’re only considering physics as we know it today. A mere, and by universal timescales extra-super mere, 500 years ago notions of relativity and speed limits were unknown. Flight was unknown. Flight into space, well, ridiculous.

So by analogy, I have to believe physics will evolve as well, especially now that there’s advanced technology behind it. Again, we can’t even imagine what known physics will be like in, again, a mere say 1000 years.  Given that, and the idea that there might be millions of civilizations at all levels out there, I have to believe that at least some of them are not just a thousand years more advanced, but five or ten thousand, a hundred thousand years more advanced. Again, I blink of the universal eye so to speak. And so they would have the technology.

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Posted: 12 August 2017 12:07 PM   [ Ignore ]   [ # 7 ]
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We can’t discount new advances in physics that may allow much faster travel times between star systems. What our current best models indicate - Special Relativity - is that by traveling faster than light speed we violate causality. If we do live in a causality based universe where A causes B then traveling FTL would violate that in some frames of reference. An objective observer could see B occurring before A, the effect happening before the cause.

We exist in a four dimensional universe - on the macro scale - 3 of physical dimension and 1 of time. As an object accelerates relative to other frames of reference it elongates along its axis of movement and the time dimension decreases in relation to those other frames. At lightspeed the time dimension reaches zero which means that zero time passes for a photon. Traveling faster than light would mean the time dimension reversing into the negative, an FTL drive would also be a time machine.

The faster an object travels in relation to other frames the more massive it also becomes. As it nears lightspeed the amount of energy required to accelerate it further increases to the point of requiring infinite energy to take it to lightspeed. It is theoretically impossible to accelerate an object with mass to lightspeed.

The reason we don’t see evidence of other intelligent life having visited us yet could be due to the fact these barriers are in fact insurmountable.

That doesn’t prevent travel to other star systems, it just dramatically increases the time require for the travelers. Laser power lightsail craft or rockets that collect and burn interstellar hydrogen are candidates for long range travel. But that means decades at least to get to the nearest star systems for the travelers and centuries passing for those left at home. The moment they began to accelerate away from the Solar System they would enter a difference reference frame and time would slow for the travelers compared to those left on Earth.

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Posted: 12 August 2017 02:05 PM   [ Ignore ]   [ # 8 ]
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Re: Long distance space travel - if it turns out the limits of physics are what they seem, another possibly is developing the ability to extend our lifespans to the point where a few centuries of travel isn’t that insurmountable, e.g. transhumanism or something similar.

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Posted: 12 August 2017 02:20 PM   [ Ignore ]   [ # 9 ]
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Or develop the ability to transfer human consciousness into artificial non-organic “brains”. In the not too distant future the pilot of an interstellar craft could be an integral part of the craft. It would remove the need for extensive life support systems and scale down the size of the craft.

To seed other planets in distant systems with terrestrial life it could be carried in the form of digitized genomes that are then rebuilt on site.

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Posted: 12 August 2017 04:46 PM   [ Ignore ]   [ # 10 ]
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If the universe is 13.9 billion yrs old and the solar system is 8ish billion yrs old.  It’s unlikely that even if there is a civilization out there somewhere that it’s much more advanced than we are.  We usually see the small picture; how much we’ve advanced in such a short amount of time.  But they forget that we are a link in the chain of life that took billions of yrs to get this far.  I don’t think there is conclusive evidence as to the date that other solar systems formed, so even if say it took only 2 billion yrs for another solar system to form, and only another 3 billion for life to evolve on a planet in that solar system, they would only be making advances like interstellar space travel right now if at all.  If our own experience has any bearing, there very well maybe life, but incredibly advanced, not likely.  Let alone that a civilization in this hypothetical solar system, their sun would be burning out if not already supernova.

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Posted: 12 August 2017 04:52 PM   [ Ignore ]   [ # 11 ]
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CuthbertJ - 11 August 2017 10:08 AM

I thought I’d start a thread in the Science section to seriously discuss the possibilities of extra-terrestrials. I find it an interesting topic that unfortunately also has alot of hogwash in it from movies, media, etc.

My personal belief is that ETs do exist and have visited earth. I believe they exist because of the law of large numbers. OR put this way, the chance that in this incredibly huge universe that we’re the only lifeforms has to be miniscule. From the movie Contact - it’d be an awful waste of space if we were the only ones here.

As for visiting earth. There are plenty of physical reasons why they couldn’t have visited. But I think those suffer from lack of imagination. A race even a thousand years more advanced than us might easily have technology enabling flight to earth. The downside as we see in the media or in documentaries, is that every imaginable being traveling in the most ludicrous ships evidently have visited earth. That I doubt. But a few species, maybe.

Hey my 1500th post. Is there a prize? Free totebag?

No totebag. The most you can expect is a symbolic punch to your solar plexus.

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Posted: 12 August 2017 09:30 PM   [ Ignore ]   [ # 12 ]
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WaylonCash - 12 August 2017 04:46 PM

If the universe is 13.9 billion yrs old and the solar system is 8ish billion yrs old.  It’s unlikely that even if there is a civilization out there somewhere that it’s much more advanced than we are.  We usually see the small picture; how much we’ve advanced in such a short amount of time.  But they forget that we are a link in the chain of life that took billions of yrs to get this far.  I don’t think there is conclusive evidence as to the date that other solar systems formed, so even if say it took only 2 billion yrs for another solar system to form, and only another 3 billion for life to evolve on a planet in that solar system, they would only be making advances like interstellar space travel right now if at all.  If our own experience has any bearing, there very well maybe life, but incredibly advanced, not likely.  Let alone that a civilization in this hypothetical solar system, their sun would be burning out if not already supernova.

Our Solar System and Sun are about 4.6 billion years old.

Stars are constantly being created and dying, the larger the star the quicker it burns its fuel and dies. Our Sun will likely last for another 4 billion years and is located between two spiral arms of the galaxy where massive stars that soon go supernova are much less common. That is a likely place to search for other intelligent life as the less hazardous conditions allow life the time to develop for long periods.

Also in the young universe there was a lack of heavier elements which are necessary to the formation of life so we may be at a time when the conditions favorable to life are good. Or there could be areas of the galaxy where conditions were right for life billions of years ago, we don’t know for sure.

As for incredibly advanced life being present, there’s no guarantee that we will ever reach that level. We are likely the cause of the latest and sixth mass extinction event - that we know about - that is now underway that we may very well become part of.

Intelligent is a relative term and it’s not very intelligent to kill off the biosphere you’re an intrinsic part of.

So the question of where all the intelligent life is may also be answered by the possibility that when life reaches the level of development we’re currently at it usually kills itself off.

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Posted: 13 August 2017 06:55 AM   [ Ignore ]   [ # 13 ]
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DougC - 12 August 2017 09:30 PM
WaylonCash - 12 August 2017 04:46 PM

If the universe is 13.9 billion yrs old and the solar system is 8ish billion yrs old.  It’s unlikely that even if there is a civilization out there somewhere that it’s much more advanced than we are.  We usually see the small picture; how much we’ve advanced in such a short amount of time.  But they forget that we are a link in the chain of life that took billions of yrs to get this far.  I don’t think there is conclusive evidence as to the date that other solar systems formed, so even if say it took only 2 billion yrs for another solar system to form, and only another 3 billion for life to evolve on a planet in that solar system, they would only be making advances like interstellar space travel right now if at all.  If our own experience has any bearing, there very well maybe life, but incredibly advanced, not likely.  Let alone that a civilization in this hypothetical solar system, their sun would be burning out if not already supernova.

Our Solar System and Sun are about 4.6 billion years old.

Stars are constantly being created and dying, the larger the star the quicker it burns its fuel and dies. Our Sun will likely last for another 4 billion years and is located between two spiral arms of the galaxy where massive stars that soon go supernova are much less common. That is a likely place to search for other intelligent life as the less hazardous conditions allow life the time to develop for long periods.

Also in the young universe there was a lack of heavier elements which are necessary to the formation of life so we may be at a time when the conditions favorable to life are good. Or there could be areas of the galaxy where conditions were right for life billions of years ago, we don’t know for sure.

As for incredibly advanced life being present, there’s no guarantee that we will ever reach that level. We are likely the cause of the latest and sixth mass extinction event - that we know about - that is now underway that we may very well become part of.

Intelligent is a relative term and it’s not very intelligent to kill off the biosphere you’re an intrinsic part of.

So the question of where all the intelligent life is may also be answered by the possibility that when life reaches the level of development we’re currently at it usually kills itself off.

  Thank you for the correction, I was reading recently of another star system, Trappist and I may have confused the numbers.
  That does widen the range, but like you said and I think this is a Hawking idea, once a civilization reaches its pinnacle it begins to self implode.  So this may be the reason we have never seen any other life. 
  I believe we could potentially overcome this coming extinction, but we need to have a serious conversation about eliminating the cancer that has formed on our world.  Politicians and corporations.

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Posted: 13 August 2017 01:28 PM   [ Ignore ]   [ # 14 ]
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If there is intelligent life anywhere they would take one look at the US and turn tail and speed off. They wouldn’t be intelligent if they came to earth considering the godawful mess it’s in. I’m not worried about aliens. i’m worried about earthlings, especially the ones in the US. What kind of intelligent life would choose to tangle with us?

LL

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Posted: 14 August 2017 07:13 AM   [ Ignore ]   [ # 15 ]
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I’m certainly not saying that it’s “not possible”.  If we use enough imagination, we can come up with all kinds of scenarios.  Someone once speculated that if the dinosaurs hadn’t been driven extinct, the velociraptors had the capacity to evolve big brains.  What if they had developed a civilization 60 million years ago?  So there could potentially be civilizations that far in advance of us.  Or scratch the idea of warp drive.  Maybe it’s more like “Independence Day”—the aliens used up all the resources of their own planet and destroyed the ecology, so they were forced to build massive generation ships and seek out other planets to exploit.  It’s possible.  All I’m saying is just because it’s possible doesn’t mean it actually happened.  My attitude toward aliens is similar to my attitude toward the existence of God—I’m not hostile toward the idea, but I’ll believe it when I see it.

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