Extraterrestrials

[polymath257]

First, if I were inclined to *bet*, I would bet that there at least has been other life in our galaxy. Given the number of galaxies, I would *bet* that there is other intelligent life out there.

But that is very much NOT the same as saying we have been visited by other intelligences. I find that to be rather unlikely.

Here's why.

Our species has been able to send radio signals for about 100 years. We have had agriculture for about 10,000 years. How much longer do you think we have as a species? Given how intent we ar at destroying ourselves, I'd say another 10,000 years is optimistic at best. That mens we have 20,000 years of being technological enough to have agriculture.

If that is typical, how likely is it that the 20,000 years for humans overlaps with the 20,000 years for another intelligent species in our galaxy? Remember that things like galactic rotation take 100 million years and star evolution takes billions of years. The sun is about 5 billion years old and it is only in the last 10,000 years we have had agriculture in our solar system.

So, my guess is that life (bacterial life, that is) is fairly common. But multi-cellular life, and intelligent life are, almost certainly, much less common and the likelihood of overlap and actual contact is low.

---

Correct me if I am wrong, but the first transmission to reach nearby stars was Hitler speech at Nuremberg.

Quite the vacation pamphlet. Babies soiling their own craddle, with no aim.

That was one of the first transmissions that was fairly powerful, yes. It was 80 years ago, which means it has reached places up to 80 light years away. Those are the *close* starts in our galaxy. Remember our galaxy is 100,000 light years across. We have signaled our presence to only a very small fraction of our galaxy.

And, like I said above, whether we even overlap with other intelligent species in our galaxy is a doubtful thing.

[vulcanlogician]

First, if I were inclined to *bet*, I would bet that there at least has been other life in our galaxy. Given the number of galaxies, I would *bet* that there is other intelligent life out there.

But that is very much NOT the same as saying we have been visited by other intelligences. I find that to be rather unlikely.

Here's why.

Our species has been able to send radio signals for about 100 years. We have had agriculture for about 10,000 years. How much longer do you think we have as a species? Given how intent we ar at destroying ourselves, I'd say another 10,000 years is optimistic at best. That mens we have 20,000 years of being technological enough to have agriculture.

If that is typical, how likely is it that the 20,000 years for humans overlaps with the 20,000 years for another intelligent species in our galaxy? Remember that things like galactic rotation take 100 million years and star evolution takes billions of years. The sun is about 5 billion years old and it is only in the last 10,000 years we have had agriculture in our solar system.

So, my guess is that life (bacterial life, that is) is fairly common. But multi-cellular life, and intelligent life are, almost certainly, much less common and the likelihood of overlap and actual contact is low.

There were a number of factors involved in allowing complex life to evolve on earth: our distance from the sun, abundance of water on the planet, luck regarding planet-destroying asteroids. In addition to that, only one kind of mammalian primate (us) seems to have lucked out enough to get opposable thumbs AND higher brain functioning. It was a fluke for it to have happened on our planet (we are the only intelligent/technologically capable species here) which suggests that intelligent life would be similarly anomalous on other planets.

[Brian37]

Billions of stars in billions of galaxies. We cannot be the only life out there.

Absolutely agreed my friend, but more to the point ...
are they here visiting Earth?

No.

Any life out there that is advanced, would still be stuck in the macro world like humans, and while they might have longer travel range, I'd bet they are stuck locally like we are. I am no fan of  the si fi crap that we can get warp drives or create worm holes or transporters. Star Trek was a show, not a documentary. AT BEST I could see us discovering communication from elsewhere. But no, I do not buy any Area 51 little green men, or ancient alien conspiracy crap.

It really pissed me off that si fi fans jumped the gun on the NASA article on the "warp drive". If hey had ACTUALLY read the damned article, they would have known it was ON PAPER ONLY, and the reality would be impractical in any case because of the energy required to do it.

The laws of science apply universally, so any life out there like us, is going to have to deal with the same macro world they are made of as well. 

I think our species needs to focus on climate change, and a meteor defense system in the short term. I am sure science will continue to create great advances, but I do get a lip twitch when we put the cart before the horse.

[polymath257]

First, if I were inclined to *bet*, I would bet that there at least has been other life in our galaxy. Given the number of galaxies, I would *bet* that there is other intelligent life out there.

But that is very much NOT the same as saying we have been visited by other intelligences. I find that to be rather unlikely.

Here's why.

Our species has been able to send radio signals for about 100 years. We have had agriculture for about 10,000 years. How much longer do you think we have as a species? Given how intent we ar at destroying ourselves, I'd say another 10,000 years is optimistic at best. That mens we have 20,000 years of being technological enough to have agriculture.

If that is typical, how likely is it that the 20,000 years for humans overlaps with the 20,000 years for another intelligent species in our galaxy? Remember that things like galactic rotation take 100 million years and star evolution takes billions of years. The sun is about 5 billion years old and it is only in the last 10,000 years we have had agriculture in our solar system.

So, my guess is that life (bacterial life, that is) is fairly common. But multi-cellular life, and intelligent life are, almost certainly, much less common and the likelihood of overlap and actual contact is low.

There were a number of factors involved in allowing complex life to evolve on earth: or distance from the sun, abundance of water on the planet, luck regarding planet-destroying asteroids. In addition to that, only one kind of mammalian primate (us) seems to have lucked out enough to get opposable thumbs AND higher brain functioning. It was a fluke for it to have happened on our planet (we are the only intelligent/technologically capable species here) which suggests that intelligent life would be similarly anomalous on other planets.

Exactly. Although, the big obstacle seems to be multicellularity. There has been life on Earth for around 3.8 billion years. Oxygen generation killed off many of the obligate anaerobes about 2.5 billion years ago. Multicellularity is within the last 1 billion years. So there was 2.8 billion years of only single celled life on Earth.

Once that happens, it was another half a billion before hard structures (bones, shells) became common. Then another half billion years before humans showed up. We have been around about 100,000 years, but have had agriculture for only 10,000 of those and radio for just over 100 years. I don'tknow of many who are optimistic about our prospects for another 10,000 years.

if this is a common progression, the chance that we are around at the same time as another intelligent, technological species in our galaxy is very, very low. Not impossible, but I wouldn't bet on it.

[GUBU]

Yes, this is about Aliens from outer space. (Not border-crossing aliens for all you so eager to post a meme you just found on Google images)



UFO sightings around the planet now number in the tens of thousands since the 1940s and there's an overwhelming amount of compelling cases for extraterrestrial life visiting this planet. Oddly enough, I have found that many atheists scoff at the notion of intelligent life visiting and/or residing here on Earth.
One would think that the religious right would be far more inclined to this position (as many are), but I have found that despite the overwhelming evidence and the fact that the topic itself is based in science and reality rather than magic and superstition, that many open-minded people will not even consider the possibility.

So...

What are your thoughts on the matter?
Is it all a hoax? 
Do you think extraterrestrials have or are possibly still visiting this solar system?
Roswell?
Abduction?

Discuss.

Let me save you all the time ...

I voted no. I'm going to caveat that vote with the line "unless life on earth was as a result of panspermia".

On UFO sightings, I'd like to point out the resemblance of many said sightings to medieval sightings of witches and succubi. Sleep paralysis is a very good explanation for the vast majority of these occurrences, much better at our current level of evidence than genuine alien visitations.

[Gawdzilla Sama]

1. There never was any other life in the Universe.
2. There never will be any other life in the Universe.
3. There was life elsewhere in the Universe, but not now.
4. There will be life elsewhere in the Universe, but not now.
5. There is/was/will be life elsewhere in the Universe, but we'll never meet it.
5a. Because they won't find us.
5b. Because they will find us, but won't interact with us.
6. There is/will be life elsewhere in the Universe, and we'll meet it.
6a. Because they will want to come here.
6b. Because they will stumble upon us.
6c. Because we will stumble upon them.

Okay, which ones did I miss. :lowcoffee:

[Brian37]

1. There never was any other life in the Universe.
2. There never will be any other life in the Universe.
3. There was life elsewhere in the Universe, but not now.
4. There will be life elsewhere in the Universe, but not now.
5. There is/was/will be life elsewhere in the Universe, but we'll never meet it.
5a. Because they won't find us.
5b. Because they will find us, but won't interact with us.
6. There is/will be life elsewhere in the Universe, and we'll meet it.
6a. Because they will want to come here.
6b. Because they will stumble upon us.
6c. Because we will stumble upon them.

Okay, which ones did I miss. :lowcoffee:

Huh?

I bet before long scientist will prove that microbial life can exist and survive on other planets. Knowing the shear size of the universe, it should not surprise anyone if we find this to be the case elsewhere, where water exists even on the other planets and or moons in our solar system.

What I object to isn't the idea that life exists elsewhere. What I object to is conspiracy crap, not real science.

Wave functions build up to particles, particles make up atoms, atoms make up matter, and you CANNOT skip that buildup to become macro. Once matter is macro, it will be subject to the limitations of motion in a macro state.

I only see QM explaining things on paper. I see it helping us improve communication, and maybe increase speed a little. But I do not see a day where we can shrink an entire human, break down every atom to the wave function, keep track of the spin and momentum of every particle in that atom, in our bodies, copy it, and or move it, and reconstitute it elsewhere. I do not see life anywhere being able to bend space and time to move the universe while we stay still. I only see QM being able to improve technology, and explain the universe in natural terms. 



I think all life out there is still stuck with the macro state we are.

[Gawdzilla Sama]

Sorry, but why the "Huh?"?

[Brian37]

Sorry, but why the "Huh?"?

Not sure why you posted that, that's why the "huh".

I get a cringe reaction to threads about the topic of "visitors". 

My position is we should expect to find life elsewhere considering the size of the universe. But no, if you are basing that on si fi or X-File Area 51 pop culture, not going to buy that.

If that is not what you were advocating in your response, great.

[Gawdzilla Sama]

It was a list of possibilities. Some more likely than others. I'm on record as saying they most likely won't be interested in Earth even if they were close enough (in time and space) to get here.