Is there life in the universe, and if so has it visited Earth?

In summary: The argument is that if ETs could travel at the speed of light, it would not be practical for them to travel to our planet. However, if ETs have a billion years of advancements, they may be able to travel to our planet. However, we don't know if this is possible or not.

Has alien life visited Earth?

  • Yes

    Votes: 81 14.5%
  • no

    Votes: 201 35.9%
  • no: but it's only a matter of time

    Votes: 64 11.4%
  • Yes: but there is a conspiracy to hide this from us

    Votes: 47 8.4%
  • maybe maybe not?

    Votes: 138 24.6%
  • I just bit my tongue and it hurts, what was the question again? Er no comment

    Votes: 29 5.2%

  • Total voters
    560
  • #246
Here's my issue:

A super intelligent technologically advanced civilization constructs super advanced spaceships and traverses hundreds of millions of light years across stars and galaxies, finding their exact path to Earth through countless asteroids, dust, radiation, stars, black holes, etc, etc... Then, they crash in Roswell. Make sense to you?
 
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  • #247
Xori said:
Here's my issue:

A super intelligent technologically advanced civilization constructs super advanced spaceships and traverses hundreds of millions of light years across stars and galaxies, finding their exact path to Earth through countless asteroids, dust, radiation, stars, black holes, etc, etc... Then, they crash in Roswell. Make sense to you?

well, for one. Isnt there a star like 6.5 light years away? And maybe their just sending unmanned drones to test for life, Just like we do on mars. Also, You don't know how long they have been here for( if at all), so can't really judge their crash record.
 
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  • #248
Xori said:
Here's my issue:

A super intelligent technologically advanced civilization constructs super advanced spaceships and traverses hundreds of millions of light years across stars and galaxies, finding their exact path to Earth through countless asteroids, dust, radiation, stars, black holes, etc, etc... Then, they crash in Roswell. Make sense to you?

That's hugely suppositional. You suppose you know where they came from, how far they travelled, how they got here, why they came... the list is virtually endless.

But even granting all those suppositions, by that logic, no Spanish galleon who have ever foundered on the shores of the Western world.
 
  • #249
The Allen Telescope Array is online

The switch has been thrown on a telescope specifically designed to seek out alien life.

Funded by Microsoft co-founder Paul Allen, the finished array will have 350 six-metre antennas and will be one of the world's largest.

...On 11 October, the first 42 dishes of the array started gathering data that will be analysed for signs of alien life and help with conventional radio astronomy. [continued]
http://news.bbc.co.uk/2/hi/technology/7041183.stm
 
  • #250
...Astronomers reported Tuesday that there were at least five planets circling a star there known as 55 Cancri, where only four had been known before, making it the most extensive planetary system yet found outside our own. It is also the one that most resembles our solar system, with a giant planet orbiting far out from the star and four smaller ones circling closer in.

...Another team member, Geoff Marcy, a professor at the University of California, Berkeley, said the discovery had him “jumping out of my socks.” He said, “We now know our Sun and its family of planets is not unusual.” [continued]
http://www.nytimes.com/2007/11/06/s...em&ex=1194670800&en=9671413ac0ec230b&ei=5087
 
  • #251
Ivan Seeking said:

The star’s three innermost planets all circle more tightly than Mercury at distances from 22 million to 3.5 million miles. The closest of three is also the smallest, only 18 as massive as Earth and surely permanently scorched.

The new planet, which Dr. Fischer called “one of the more annoying planets” because it resisted being folded into their mathematical models for such a long time, basks in the lukewarm light of its star from a distance of around 70 million miles, taking 260 days to complete one orbit. Although too massive for life itself, Dr. Marcy said, the planet could harbor rocky moons, just as Saturn and Neptune in our own solar system do, and these would be warmed to the same lukewarm temperatures as Earth.
How do they determine when a planet is too massive "for life itself"?
 
  • #252
Are Aliens Among Us?

... No planet is more Earth-like than Earth itself, so if life does emerge readily under terrestrial conditions, then perhaps it formed many times on our home planet. To pursue this tantalizing possibility, scientists have begun searching deserts, lakes and caverns for evidence of “alien” life-forms—organisms that would differ fundamentally from all known living creatures because they arose independently. Most likely, such organisms would be microscopic, so researchers are devising tests to identify exotic microbes that could be living among us.[continued]
http://www.sciam.com/article.cfm?id=are-aliens-among-us&print=true
 
  • #253
you assume that aliens have to physically visit earth. a "species" that advanced wouldn't have to visit us in material form. that much i guarantee.
 
  • #254
notagenius said:
you assume that aliens have to physically visit earth. a "species" that advanced wouldn't have to visit us in material form. that much i guarantee.
Do you think that any planet can sustain a single life form long enough for them to advance that far? The Earth hasn't been able to.
 
  • #255
Evo said:
Do you think that any planet can sustain a single life form long enough for them to advance that far? The Earth hasn't been able to.

well dude if they could come to Earth then who's to say that a single planet sustained them?
 
  • #256
Sorry! said:
well dude if they could come to Earth then who's to say that a single planet sustained them?
Good point.
 
  • #257
Sorry, Sorry, but Evo's not a dude. She's a dudess. :biggrin:
 
  • #258
Its tuff to say without really knowing how life on Earth first began. If we find life on Earth began simply as standard recipe that arises from a common set of conditions that are found throughout the universe, then it seems life would be found on any planet similar to earth. However, Earth life could be a one time thing that can not be replicated. Its all about finding how life was first created to see the likely hood of life being a universal thing. That is of course, unless aliens just show up at our doorstep or if we happen to ease drop on them using SETI :)
 
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  • #259
Sorry! said:
well dude if they could come to Earth then who's to say that a single planet sustained them?

exactly. as humans we see everything in terms of our world, observations from our solar system, etc. i think this stuff is largely beyond 21st century science.
 
  • #260
Interesting conflagration of posting:

"Sorry, Sorry, but Evo's not a dude. She's a dudess. "

"Its tuff to say without really knowing how life on Earth first began."


Eezekiel, you're taking your life in your hands... :rolleyes:
 
  • #261
we're going on a couple of assumptions, such as:

1. Life intelligent enough to travel to Earth will naturally approach us cautiously and monitor us for years to determine the situation.

2.They wouldn't just assess our inferiority and wipe us out if they perceived us as a threat.

3. Alien beings actually want to learn about us. That assumes they think like us, which we can't assume. The term alien doesn't just apply visually, but to overall existence. Trying to recreate the thought processes of a being whose existence you don't know, and possibly couldn't comprehend is like trying to imagine how a square thinks, if a square could think.

4. I think if life did exist, and it did come to us, the odds of us understanding (at least initially) their thought process, goals, motivations, or anything else, is about as likely as them speaking english.

Personally I think that if life DID exist, and somehow contacted us, it would be something beyond comprehension, possibly beyond understanding, because we know only what is on this earth. And 500 years ago we KNEW the Earth was flat. We know nothing. In the vast depths of all possible knowledge in the universe, we know the equivalent of 6 months on the know universal timeline. So close enough to nada;)
 
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  • #262
Zantra said:
And 500 years ago we KNEW the Earth was flat. We know nothing.
Not true. 500 years ago we did not have the Scientific Method. Things we "know" today are quantifiably, qualitatively and objectively more valid than things we "knew" prior to the SM. It's like night and day.
 
  • #263
DaveC426913 said:
Not true. 500 years ago we did not have the Scientific Method. Things we "know" today are quantifiably, qualitatively and objectively more valid than things we "knew" prior to the SM. It's like night and day.


The time frame is simply an example to demonstrate that our knowledge continues to expand every day, and that this is the beginning of knowledge. In other words, we can't make assumptions
 
  • #264
Zantra said:
we're going on a couple of assumptions, such as:

1. Life intelligent enough to travel to Earth will naturally approach us cautiously and monitor us for years to determine the situation.

2.They wouldn't just assess our inferiority and wipe us out if they perceived us as a threat.

3. Alien beings actually want to learn about us. That assumes they think like us, which we can't assume. The term alien doesn't just apply visually, but to overall existence. Trying to recreate the thought processes of a being whose existence you don't know, and possibly couldn't comprehend is like trying to imagine how a square thinks, if a square could think.

4. I think if life did exist, and it did come to us, the odds of us understanding (at least initially) their thought process, goals, motivations, or anything else, is about as likely as them speaking english.

Personally I think that if life DID exist, and somehow contacted us, it would be something beyond comprehension, possibly beyond understanding, because we know only what is on this earth. And 500 years ago we KNEW the Earth was flat. We know nothing. In the vast depths of all possible knowledge in the universe, we know the equivalent of 6 months on the know universal timeline. So close enough to nada;)
that's why we try to simplify things as much as possible when we consider interaction with other life forms... if they are 'intelligent' then we would assume that they would have a basic understanding of what we convey... if it they think it's wrong or beyond comprehension they should come to an understanding. hm?

and the reason we have those 4 assumptions runs on the same logic... we consider ourselves to be intelligent and it's what WE WOULD do if we could travel to study other life
And my bad Evo :D i just say dude to anyone :p
 
  • #265
Sorry! said:
that's why we try to simplify things as much as possible when we consider interaction with other life forms... if they are 'intelligent' then we would assume that they would have a basic understanding of what we convey... if it they think it's wrong or beyond comprehension they should come to an understanding. hm?

and the reason we have those 4 assumptions runs on the same logic... we consider ourselves to be intelligent and it's what WE WOULD do if we could travel to study other life
And my bad Evo :D i just say dude to anyone :p

Then I guess we should hope they approach things,have the same logic and value systems, and understand things eactly as we do
 
  • #266
This topic is always one of controversy. Regardless of how anyone believes life was created, I think it would be safe to assume there may very well be life outside of earth. With as many stars, planets, galaxies, etc. as there could be out there, it could be foolish to assume we inhabit the only one with life. It is exciting to think there could be others out there with a new kind of knowledge. Until solved, it will be the most inspiring question man has to answer. There will always be someone who can give us another piece to the puzzle.
 
  • #267
I voted YES.

I considered the research on

1) primitive life forms operating on similar or differing biochemical principles (Davies NASA)

2) alternative and fringe scientific arguments such as "animals from one planet became plants on another" (many science fiction stories t.b.x., apparently this idea also occurs in ancient Indian astronomy t.b.x.)

3) classical philosophical dissertations such as "theory of life eternal" (my received information from disscusion elsewhere - eternal refers to "Saturn beyond all existence", the Roman astronomers already considered that life originated on Jupiter, then it got to Mars, and finally to Earth! And so they believed! - t.b.x. although I'm not really up to searching through vast swathes of classical literature, I shall try...)

Of course, I am talking about primitive life, not advanced!

On advanced life, I tend to side with the reasonable mainstream scientists.

Perhaps we are the alien life itself, and would not exist in our present day form, were it not for the arrival of our primitive past form predecessors.
 
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  • #268
nicky nichols said:
it is also possible that animal life on one planet becomes plant life on another.

Could you explain what you mean?
 
  • #269
Schrodinger's Dog said:
http://video.google.com/videoplay?docid=-5594744703753734741

Bearing in mind this post by Ivan in the UFO stickied thread.

10,000,000,000,000,000,000,000 stars in the universe, a very conservative estimate but let's assume it's correct.

And the Drake equation is possible given the criteria and confirms there must be intelligent life: maybe in the galaxy, but definitely in the universe by the laws of probability.

http://www.activemind.com/Mysterious/Topics/SETI/drake_equation.html

And apply this to the universe, in a sort of what if way assuming this is fairly typical.

My question is two fold, we're fairly certain that probability indicates there must be life elsewhere in the universe, and assuming evolution works in simiilar if not the same ways elsewhere: it's fair to claim that their is intelligent life, so we accept life is out there? Yes/no?

Now given the conclusion is yes, do you think the intelligent life has visited Earth?

I would think in a very simple way : life on Earth demonstrates that there is life in the universe but can't demonstrate that it is the only one. About visiting the Earth by others it is not interesting over than for a pure curiosity.
 
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  • #270
quick theory of transevolution, an example in this instance would be that an animal which had evolved on a low gravity world wouldn't be able to move about properly upon its' arrival on a high gravity world, thus it stays still, turns itself upside down and buries its' head in the ground whereupon its' body becomes a plant...told you it was science fiction, however I suspect that there might well be the condensation of a yet to be elucidated bioevolutionary principle...
 
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  • #271
nicky nichols said:
On advanced life, I tend to side with the reasonable mainstream scientists.

And what would that opinion be?
 
  • #272
There is no peer-reviewed evidence that we have ever been visited by advanced aliens.
 
  • #273
It's interesting how so many people voted no. I had no idea that so many people on PF have been around since the creation of the Earth.
 
  • #274
hotcommodity said:
It's interesting how so many people voted no. I had no idea that so many people on PF have been around since the creation of the Earth.

It's a matter of probability. What are the odds of being found by an alien race, even if it is capable at moving at faster-then-light speeds? Almost nil.
 
  • #275
GleefulNihilism said:
It's a matter of probability. What are the odds of being found by an alien race, even if it is capable at moving at faster-then-light speeds? Almost nil.

We don't know that. Given a sufficiently advanced race [and tinkering with the assumptions], it could be that contact is a near certainty.

Already we on the planet of the apes are figuring out how to detect earth-like planets.
 
  • #276
We are not alone

Consider this...of all the planets, of all the starsystems in our wide infinite , uncharted universe...of all the millions of worlds that exists or existed before us...why are we the only one little mud ball in this plane of existence that can support life? I don't buy it. If this is the case...what a waste of space.
 
  • #277
I agree. With all the untold planets , stars and galaxies,why is our own little mud ball the only planet in the infinate , uncharted universe the only one that can sustain life? I don't buy it...If so, then it is n huge waste of space.
 
  • #278
hotcommodity said:
It's interesting how so many people voted no. I had no idea that so many people on PF have been around since the creation of the Earth.

That's a good one. Well said
 
  • #279
GleefulNihilism said:
It's a matter of probability. What are the odds of being found by an alien race, even if it is capable at moving at faster-then-light speeds? Almost nil.

"Probably no" wasn't one of the options. Additionally, your post assumes that there may be other life in the Universe, but that they wouldn't have the technology to reach us. I find this to be an even greater assumption than the assumption that alien life has never visited our planet. If there are indeed other races, you would have no idea what type of technology they've acquired. The human race remains primitive and crude on many levels, it wouldn't surprise me if they visited us and decided to turn right back around.
 
  • #280
hotcommodity said:
"Probably no" wasn't one of the options. Additionally, your post assumes that there may be other life in the Universe, but that they wouldn't have the technology to reach us. I find this to be an even greater assumption than the assumption that alien life has never visited our planet. If there are indeed other races, you would have no idea what type of technology they've acquired. The human race remains primitive and crude on many levels, it wouldn't surprise me if they visited us and decided to turn right back around.

You seem unable to wrap your head around the distances and timing involved. It would be like someone from Seattle, WA walking all the way to the African Savannahs to find a single blue ant. Even if that ant figured out how to click it's mandibles together rather loudly recently it still would only be a few fractions of a second ago and so far would not have done any good.

That's what the distances and duration of the universe turn the hunt for extraterrestial life into, we're the ant, the aliens would be the seattle resident, and the clicking would be our EM broadcast technology. Sure the odds of a more advanced lifeform existing somewhere are amazingly good but the sheer size and timescales involved make us finding each other amazingly bad.
 

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