How likely are we to find extraterrestrial life?

[otseng]

Many NASA scientists think we're on the verge of finding alien life.

Ellen Stofan, NASA's former chief scientist, said in 2015 that she believes we'll get "strong indications of life beyond Earth in the next decade and definitive evidence in the next 10 to 20 years."

Many astrophysicists and astronomers are convinced that it's not a matter of if we'll find life — it's when.

https://www.businessinsider.com/nasa-pl ... de-2019-11

Questions for debate:
- How likely are we to find extraterrestrial life?
- What empirical evidence is there that any extraterrestrial life exists?
- What are the implications if extraterrestrial life exists or do not exist?

[otseng]

To answer the second question, here’s a very interesting article.

Noting that the study has yet to undergo peer review, its conclusions nevertheless build on previous evidence of extraterrestrial amino acids. A logical inference is that life’s ‘building blocks’ exist elsewhere other than Earth.

That is interesting. It has a Wikipedia article on it here:
https://en.wikipedia.org/wiki/Hemolithin

But, as you mentioned, it has yet to go through peer review and the result in inconclusive.

But, they also note that there's a possibility what they found might not be protein. Although the team thinks it's the most likely explanation, it's also possible that their finding is actually a polymer - a broad class of molecules, of which proteins are only one.
So it's a little too early to get too carried away.

https://www.sciencealert.com/scientists ... -meteorite

But, it'll be interesting to see how this unfolds.

[otseng]

This past week, "Unidentified Aerial Phenomena" videos captured by the Navy were released.

The videos, released through the Freedom of Information Act, depict flying objects moving at incredible speeds and performing seemingly impossible aerial maneuvers. One of the videos was shot in November 2004; the other two were shot in January 2015. They have been circulating the internet since unauthorized leaks in 2007 and 2017. The three videos were code-named “FLIR1,” “Gimbal,” and “GoFast.” The 2004 video doesn’t feature any cross-talk, but in the 2015 videos, Navy pilots filming the aerial phenomena can be heard expressing their disbelief.

All three UFO videos were captured by Navy F/A-18 Super Hornets.

https://www.washingtonexaminer.com/news ... wing-leaks

Even politicians commented on the videos.

Trump - “I just wonder if it’s real,” he told Reuters. “That’s a hell of a video.”
https://people.com/politics/donald-trum ... -its-real/

Harry Reid - "I’m glad the Pentagon is finally releasing this footage, but it only scratches the surface of research and materials available. The U.S. needs to take a serious, scientific look at this and any potential national security implications. The American people deserve to be informed."

[William]

What do you think about extraterrestrial life if it exists?

[Swami]

- What are the implications if extraterrestrial life exists or do not exist?

This is the best question to ask. What good is a science that keeps probing ever deeper and farther into things "out there"? Has doing this led to the answers to life's biggest questions? Have we solved our differences?

I practice a science that shows that all I need to know is already in me. It is in all of us waiting to be realized. I do not bother with getting to know things that are outside of my immediate surroundings. Knowing your true Self is the most important truth.

[mgb]

I don't believe the argument that says there must be life because there are so many planets there has to be life in abundance. That is like two on Antarctica saying 'Look this place is huge so there must be millions of people here, just over the horizon maybe' But they may be the only two people on the Antarctic at that moment.

The universe seems to be mainly desert; ice deserts, heat deserts. We are nowhere near being able to calculate what percentage of planets have life, Drake's equation notwithstanding. It may be that the universe is a vast desert with only a few inhabited planets.

[Diagoras]

I don't believe the argument that says there must be life because there are so many planets there has to be life in abundance. That is like two on Antarctica saying 'Look this place is huge so there must be millions of people here, just over the horizon maybe' But they may be the only two people on the Antarctic (sic) at that moment.

An interesting simile. Those people are not (I assume) yet in a position to explore the entire continent and prove their claim one way or the other, so any claim of 'must be other people here' could be seen as being on somewhat shaky ground.

The universe seems to be mainly desert; ice deserts, heat deserts. We are nowhere near being able to calculate what percentage of planets have life, Drake's equation notwithstanding. It may be that the universe is a vast desert with only a few inhabited planets.

<bolding mine>

We have the Drake equation, therefore are in a good position to calculate what percentage of planets may have life. It's that one little word that makes the difference between an unfounded claim (which you're objecting to) and a more reasonable, and testable theory. The jury's still out, as we haven't yet ventured very far into the 'desert' (or across the ice fields) so we'll just have to wait and see.

Perhaps we don't want to know - there's one argument that suggests finding extraterrestrial life would be a bad sign.

[brunumb]

[Replying to post 55 by mgb]

I don't believe the argument that says there must be life because there are so many planets there has to be life in abundance. That is like two on Antarctica saying 'Look this place is huge so there must be millions of people here, just over the horizon maybe' But they may be the only two people on the Antarctic at that moment.

Your example awkwardly conflates the known with the unknown. We know about Antarctica, the two people you reference presumably do not. They do not know the extent of the continent and, from what they are observing, it might be more logical to conclude that there is unlikely to be anyone living in that harsh environment.

Similarly, two people standing on the edge of an island confronted with nothing but sand and scrub might conclude that the place could not possibly support life, Yet, on climbing a massive dune, they might be confronted with a thriving oasis teeming with life.

There are trillions of planets in the universe all essentially made from the same limited building blocks of matter. The probability that there are environments similar to those on Earth are high. Life exists on Earth in even the harshest of environments. I do not find it unreasonable to consider that life has arisen on many other planets in the universe. Whether the life forms have developed to the same level of intelligence as those on Earth is another matter. The direction that evolution takes is governed a lot by chance events affecting the environment. Dinosaurs ruled our planet for millions of years until a chance asteroid altered everything. Humans have only dominated for around 200,000 years and their continuation is not a certainty either.

[mgb]

There are trillions of planets in the universe all essentially made from the same limited building blocks of matter. The probability that there are environments similar to those on Earth are high. Life exists on Earth in even the harshest of environments. I do not find it unreasonable to consider that life has arisen on many other planets in the universe.

The assumption that life "is likely to arise" is implicitly based on the assumption that life arises spontaneously from matter. This is where many materialists and theists would part ways. If life does not arise spontaneously from matter but requires intelligence to evolve it, life only arises where it is meant to arise. So we're back to the ole evolution argument, again.

Perhaps we don't want to know - there's one argument that suggests finding extraterrestrial life would be a bad sign

Some say they have found us already. Maybe the question should be 'How likely are extraterrestrials to find us'!

[DrNoGods]

[Replying to post 58 by mgb]

If life does not arise spontaneously from matter but requires intelligence to evolve it, life only arises where it is meant to arise.

That is a very big "if." With no evidence that such intelligence exists (removing humans from the prospect list as we clearly haven't figured it out yet ourselves), it makes sense to go with a process that does not rely on an unidentified intelligence of some sort.

Things like gods would be a prospect for such intelligence, but none of the thousands of gods that humans have imagined have ever shown themselves, or been demonstrated to exist by some other means. So we're left with the options of (yet unidentified) mechanisms for origin of life that do not require intelligence, or purely speculative ideas that some intelligence exists that is responsible.

If I had to bet on which would come first ... unambiguous confirmation that a god entity of some sort exists, or life being found outside of planet Earth, I'd put my money on the latter. God hunting has a substantial head start in terms of time spent on the effort, but it has yet to produce a single positive result. No reason to believe this will change any time soon.

[William]

[Replying to post 58 by mgb]

If life does not arise spontaneously from matter but requires intelligence to evolve it, life only arises where it is meant to arise.

That is a very big "if." With no evidence that such intelligence exists (removing humans from the prospect list as we clearly haven't figured it out yet ourselves), it makes sense to go with a process that does not rely on an unidentified intelligence of some sort.

Things like gods would be a prospect for such intelligence, but none of the thousands of gods that humans have imagined have ever shown themselves, or been demonstrated to exist by some other means. So we're left with the options of (yet unidentified) mechanisms for origin of life that do not require intelligence, or purely speculative ideas that some intelligence exists that is responsible.

If I had to bet on which would come first ... unambiguous confirmation that a god entity of some sort exists, or life being found outside of planet Earth, I'd put my money on the latter. God hunting has a substantial head start in terms of time spent on the effort, but it has yet to produce a single positive result. No reason to believe this will change any time soon.

As I have pointed out in the past, the planet itself appears to be intelligent, since it is the planet which creates the life-forms.

That is at least a strong indication of agency, so it becomes a matter of perspective in relation to whether a planet can be intelligent and self aware.

Of course that is on a whole other level, through which scientific process has no particular interest in scaling since no one knows how one might find a way of figuring it out.

Nonetheless the notion is not without merit due at least to the evidence already available. Yes there is a planet teaming with intelligent life forms and yes, these appear to all derive from the one source and yes, there appear to be no other known planets which are like our own.