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Related: Culture Forums, Support ForumsDo you think there is life on other planets in the universe? I read a post on the main forum about
Last edited Thu Apr 27, 2023, 11:07 AM - Edit history (1)
people seeing UFOs.
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VMA131Marine
(5,270 posts)I’d even go so far as to argue that life is the default: wherever it’s possible for life to evolve then it will. I still expect we will find evidence of ancient life on Mars because we know it was covered in water after it first formed and cooled.
How much of the life that’s out there is intelligent is an open question; I’m still not sure it exists on Earth.
debm55
(60,612 posts)
Phoenix61
(18,828 posts)I have this theory that they won’t let us off planet earth until we learn to play nice with each other. Rather like a child who is confined to their own yard until they learn to play nice with the neighboring children.
debm55
(60,612 posts)
niyad
(132,440 posts)brewens
(15,359 posts)I'd say the odds keep improving. It seems like there are so many chances in the universe for life it would have to exist elsewhere.
brush
(61,033 posts)some close to them, like our Mercury and Venus, some far away like our gas giants and some in the habitable zone like our Earth, so of course there's life elsewhere.
What form it has taken, who knows? We may find out but the universe is so vast the chances of direct contact with us is very small.
It's a tremendous conceit to think that our little Earth is the one planet out of quintillions or more that has been touched with the spark of life.
debm55
(60,612 posts) 
ProfessorGAC
(76,703 posts)There are likely 200 billion galaxies in the observable universe.
The greater distant galaxies moving away from at superluminal speed, so we can never see them, make that 5 to 10x higher.
With a median star population of nearly 150 billion per galaxy, there are AT LEAST 3 million trillion stars. Could be 10x that!
So extend your logic to this much higher opportunity value & it makes even more sense.
PoindexterOglethorpe
(28,493 posts)away that even if we could develop FTL drive, they're already too far away to reach.
Interstellar distances are vast enough. Here's something I learned from My Son The Astronomer: as you may already know, our galaxy, Milky Way, is on a collision course with the next large nearby galaxy, Andromeda. Milky Way has about 300 billion stars, Andromeda about a billion. One day I asked My Son,m when the two galaxies collide in about 4.5 billion years, how many stars will actually crash into each other? He replied, "Well, we're not sure, but probably no more than ten." Many more will gravitationally interact, but actual star collisions? No more than ten.
That should give you a clue as to just how vast interstellar distances are.
As for intergalactic distances, forget about it. So it doesn't really matter if vastly superior alien civilizations are in other galaxies. We will never have an opportunity to meet with them.
Eventually, all of the galaxies in our local cluster will collide and form one extremely large galaxy. By the time that happens, every other galaxy in the universe will be so far away that we will no longer be able to see them. Granted, that's a long way down the road, about 150 billion years from now. Our sun and planet will long since be gone by then. But if there is some other intelligent life in that super galaxy, they will have no way of knowing that there are other galaxies out there, and might not be able to guess the actual age of the Universe.
ProfessorGAC
(76,703 posts)Cosmologists have consensus that at least 80% of all galaxies are so far away we can't see them. Or, they're so redshifted that any emissions are radio wave that can't be sorted from background.
The nearest galaxy is 8.2 billion billion miles away. Talk about the vastness of space!
PoindexterOglethorpe
(28,493 posts)My Son The Astronomer how far away something is, he gives me the red shift number. He REALLY is an astronomer.
ProfessorGAC
(76,703 posts)...physical organic chemistry, I know the feeling.
There was a thread here somewhere about the small of fresh mown grass.
I couldn't help myself. I did a short chem lesson of what it is we are smelling.
PoindexterOglethorpe
(28,493 posts)I'm very much a science geek.
When My Son was little, I had lots of books I read to him about dinosaurs, geology, volcanoes, earthquakes. You get the picture. I've told him I'm a bit sorry he wasn't identical triplets, maybe quadruplets, because then they each could have taken one of those other fields, and I'd be happily asking many questions of My Son The Geologist, or My Son The Paleontologist, or My Son The Vulcanist. And sharing them here, no doubt.
PufPuf23
(9,852 posts)there is a characteristic and pleasant smell.
The smell is from the bodies of Actinomycetes torn by the disturbance.
>>Actinomycetes are a group of bacteria that form thread-like filaments in the soil and have a high G+C base composition123. They are involved in recycling organic matter, especially resistant materials like cellulose, lignin, and chitin234. They also produce a chemical called geosmin that gives the soil an earthy smell35. They can inhibit some plant pathogens, fix nitrogen, and degrade pollutants in the soil3. They are aerobic, spore forming, and gram positive23.
ProfessorGAC
(76,703 posts)Terpenes are a huge class of aroma & flavor compounds found in plants & in some bacteria.
They are hydrocarbons often with oxidative additions to -ols, -als, & carboxylic acids.
By convention (I don't know the history of why) if the acyl function is esterified they are no longer considered terpenes even though they are naturally occurring.
They are the principal taste & aroma compounds in pot.
brush
(61,033 posts)is just a guess as the vastness of the universe is unknowable to us.
Golden Raisin
(4,755 posts)of the Universe I find it hard to believe that there isn't some sort of life (intelligent or not) elsewhere in that great expanse.
debm55
(60,612 posts)Last edited Wed Apr 26, 2023, 08:47 PM - Edit history (1)
brewens
(15,359 posts)how can it be? To us, there is a beginning and an end to everything. A start and a stop. How can it just be and go on forever? If you tell me how it all started, what happened before that? "Hey, pass me the toad dude, I need another lick!" LOL
Phoenix61
(18,828 posts)the, please don’t laugh, Oprah Winfrey Show. He had interviewed people who said they had been abducted by aliens. He said their recounts were those of people recounting an actual experience. His belief was the “aliens” were from a different dimension. As we learn more and more about how time and space intersect this seems like a plausible answer.
Also, it’s incredibly ego centric to think we are the only life in the universe. The sheer number of planets suggests we are not.
debm55
(60,612 posts)
Omnipresent
(7,450 posts)Hell, some might have Dinosaurs, still roaming around on them.
debm55
(60,612 posts)
Mr.Bill
(24,906 posts)is the time factor which is often left out of the equation. The universe has existed for an unknown billions of years. Our life form has been here for a blink of an eye on that time scale. I would venture to say that the odds of a life form that would be recognizable to us evolving at the same instant of time would approach the odds of winning the lottery ten times in a row.
Now I'm sure there has been, may be or will be existing in the universe a life form similar to ours. But I doubt it may have happened right now.
And then there's the distance factor. Overcoming that would probably require violating the laws of physics as we know them, but I'm sure there is much we don't know about that, too.
PoindexterOglethorpe
(28,493 posts)a bit under 14 billion years. NOT unknown billions of years.
People also don't fully understand just how long a billion years really is.
Mr.Bill
(24,906 posts)Even science changes as new discoveries happen. None of us will live long enough to know everything.
PoindexterOglethorpe
(28,493 posts)has been a pretty stable number for a decade or so. Yes, I understand it might be refined, but I rather doubt it will change very much.
I think you'll like this. Sometimes I will ask My Son The Astronomer how far away something is (like some distant galaxy) and he will answer with a red shift number. I'm always blown away by that. And always ask him to convert that to a number of years.
Mr.Bill
(24,906 posts)how much a billion years is, we also seem to have politicians who don't understand how much a billion dollars is. 
PoindexterOglethorpe
(28,493 posts)Sigh.
JustABozoOnThisBus
(24,681 posts)... we're gonna need a bigger telescope.
PoindexterOglethorpe
(28,493 posts)but there won't ever be a telescope large enough to see before the BB.
Omnipresent
(7,450 posts)Right now! 
awesomerwb1
(5,103 posts)I don't think to this day with all these advances in technology, we can comprehend how big space is. There are probably trillions of "universes".
We're just forms of tiny tiny tiny bacteria in the vastness of it all.
debm55
(60,612 posts)
Walleye
(44,805 posts)He said, “I believe there is life on other planets, intelligent life is another story. For example, it has yet to be discovered here on earth.” Cracked me up. He had perfect comic timing with that artificial speech machine
debm55
(60,612 posts)Walleye
(44,805 posts)debm55
(60,612 posts)humor.
Walleye
(44,805 posts)It was a real measure of his intelligence, too.
303squadron
(820 posts)seems like an awful waste of space. " ~ Carl Sagan
debm55
(60,612 posts)WestMichRad
(3,254 posts)I like this one best!
Fla Dem
(27,633 posts)We may be unique in our physical form, intellect, and other attributes. But with the nearest solar system to our solar system, Alpha Centauri which is roughly 4.35 light years away from us, it's a question that probably will never be answered.
debm55
(60,612 posts)thought provoking.
PoindexterOglethorpe
(28,493 posts)My Son The Astronomer is doing exo-planet research. And while it appears that almost every single star out there has planets, we are yet to detect atmospheres on any of them.
There's also reason to think that for life to evolve beyond the most primitive point, a moon like ours may be crucial. Our moon stabilizes our rotation, and is responsible for the oceans' tides, which also seem to be crucial to life.
Something else to know: about 70% of all the stars in our galaxy are red dwarfs. That will make a difference in what kind of life might possibly evolve on their planets. Yet another consideration: just as there's a Goldilocks Zone for a star (the correct distance for a planet so it's not too hot, like Venus, nor too cold like Mars) there's also a Goldilocks Zone for the galaxy. Too close to the center where the stars are much closer together, and cosmic radiation will keep meaningful evolution from happening.
Time is another issue. The Universe is not quite 14 billion years old. Our planet is 4.5 billion years old. While the earliest and most primitive life occurred relatively quickly, after about the first billion years, it wasn't until about 600 million years ago that multi-cellular life happened. And technological civilization is incredibly new. So, even if life evolves readily in the first place, the chance of technological civilization happening seems highly unlikely. And even more unlikely that we'd overlap in time.
Interstellar travel is another issue. It is simply not possible to travel faster than the speed of light. Which means that going to another star will take years. And no, being thousands of years more advanced than we are won't change this. The rules of physics apply to everyone.
Perhaps more to the point, is that despite the vast majority of people having cameras with them all the time in the form of cell phones, we are not seeing lots of good pictures of the UFOs.
For what it's worth, My Son The Astronomer tells me that the consensus in astronomy is that we may very well be the very first technological civilization in our galaxy.
debm55
(60,612 posts)believe that there is life out there --somewhere.
PoindexterOglethorpe
(28,493 posts)but how advanced it might be is the real question.
These are the kinds of things I talk about all the time with My Son The Astronomer.
nevergiveup
(4,815 posts)they are watching us for entertainment 
debm55
(60,612 posts) 
MiHale
(13,032 posts)to me. UFO’s do not necessarily mean life or aliens…we have absolutely no idea what is the cause for the appearance of UFO’s. The pure distances needed to travel between worlds is mind boggling. Using the only form of physics we know it is impossible to travel at speeds faster than the speed of light. It takes us three days to just go to the moon. 30 days for the James Webb telescope to get only one million miles away. The Pioneer and Voyager spacecrafts have been traveling outbound of the solar system for over 40 years they are barely out of the system and into interstellar space.
Life on other planets now that’s a great discussion, problem is most times we have no idea about what we’re looking for. Carbon-based, silicon/mineral-based, gaseous or plasma in form, energy-like? If we can physically see it we’ll we recognize it as a life form or file it under “unknown”?
Is it beyond our species bias to even consider non-humanoid life, could we accept reptilian intelligence, plant intelligence?
Panspermia is a likely candidate for the way life may spread throughout the cosmos but with the distances it would be a long process.
But what do I know? I did stay at a Holiday Inn Express the other night. 
debm55
(60,612 posts)PoindexterOglethorpe
(28,493 posts)life on other planets and UFOs are two very different things.
What kind of life, even what kind of intelligent life might be out there, is a huge question.
What if an intelligent species of some kind has evolved on Jupiter? I seriously doubt they would ever get close enough to the edge of the gas giant to see stars. So for them, the entire Universe is going to be their planet. Same for Europa, which is ice covered and could possibly have liquid water beneath that rock. There's a lot of hope that some kind of life may have evolved there.
As you've asked, would we even recognize a very different form of intelligent life? Maybe not. That's why, science fiction person that I am, I was singularly unimpressed by the movie Arrival which has a linguist deciphering an alien language in under a century. Honestly, it happens absurdly fast. Yeah, I realize the essential point of it and the original short story had to do with perceptions of time, but it still didn't work for me.
Because I am a science fiction person (go to cons, hang out with writers) I love stories that involve travelling to other stars, time travel, all sorts of impossible things. But it's important not to confuse good fiction with reality.
I wonder what a Holiday Inn Express of interstellar travel might look like. 
MiHale
(13,032 posts)Took me a little to remember the book series about very different life forms but one of the Swiss cheese holes started closing and “Saga of The Seven Suns” by Kevin J. Anderson popped out before complete closure. It’s the book(s) that opened an entirely new way of thinking about different life forms.
David Brin’s “Uplift” series is another. Then for the genetic manipulation of the human species, Iain M. Banks Culture series will twist your mind. Love this guy.
I feel that to be able to enjoy most good sci-fi an open mind is essential.
https://en.wikipedia.org/wiki/The_Saga_of_Seven_Suns
https://en.wikipedia.org/wiki/Uplift_Universe
hunter
(40,690 posts)We're just too primitive and dim-witted to recognize it.
trof
(54,274 posts)It probably won't look anything like humans.
We might not even be able to see it/them.
LudwigPastorius
(14,725 posts)...probably even intelligent life.
But, it is rare enough, and the universe is so mind-bogglingly vast, that our species may never make any kind of contact with it.
There is almost no chance that UFOs are visiting aliens.
Tikki
(15,140 posts)Possible by the circumstances of anything else out there in the Universe.
Tikki
Skittles
(171,710 posts)I mean, how fucking depressing a thought would THAT be??? 
ZoltarSpeaks
(100 posts)I originally posted a version of this in that UFO thread but pulled it when I felt it veered too far off topic. But this thread is a little more appropriate, so here goes:
I read these alien life /UFO threads on DU from time to time and have noted the wide variety of opinions, some of which are often based on personal experience and others based on belief laid down as fact. But generally opinions are all over the map and range from total (sometimes bordering on derisive) dismissal, to belief based on common-sense or scientific probability, to belief based on some isolated personal experience or encounter. This is not unusual, but when I see certain misconceptions promoted repeatedly (often by the same individuals) I feel the need to stick my nose into the fray.
The probability of the existence of intelligent alien life is to some degree quantifiable, and in scientific circles that probability is considered to be quite high. And whether we like it or not, or whether we choose to believe it or not, it naturally follows that the chance that we have been visited by alien life at some time, perhaps frequently, is not zero.
Alien Life?
The Drake Equation attempts to answer the seemingly unanswerable question of whether intelligent life could exist elsewhere in the universe. It is a simple mathematical product of terms that are individually more estimable than the larger question, and the resultant solution is an estimated number of intelligent civilizations that could have evolved in the universe, provided the individual estimated factors were valid. For example, one factor might be the number of new stars created in the entire universe in one year. Another multiplying factor would estimate the fraction of those stars that develop planetary systems, and another factor would represent the fraction of planets that exist in a habitable region for life as we know it. And so on. Many of the factors are based on scientific observation, but some have to be guesses.
But even using very conservative estimates of all the factors, and given the unimaginably large number of known star systems, the Drake equation calculation results in a number of intelligent alien civilizations that is potentially in the tens of thousands.
You can carry the Drake equation a step further and multiply in your own factor estimating what percentage of alien intelligent life has mastered the limitations of traveling through time and space to reach Earth. That probability also would be low but probably not zero; if we've made it this far there is a good chance that others have advanced further. While the true frequency of occurrence of alien intelligent life unknown, the probability is estimated from a number of factors that are known to science, and the final result is almost certainly not zero.
The Unconquerable Distance Myth
One argument that often shows up here on DU is that the vast distances to other star systems preclude the possibility of alien visitors. The argument is based on the premise that even the nearest star outside our own solar system, a red dwarf named Proxima Centauri, is 4.25 light-years from us. The assumption is that even this closest star, if it has any "inhabitable" planets that are inhabited, would take us 4.25 years to get to it even if we could travel at the speed of light, which we most certainly cannot. Indeed, at the speeds at which we can currently travel through space, it would take a nearly a hundred generations to reach it. Therefore it is assumed that any alien travelers would be bound by the same limitations.
But a curious thing happens to travelers as speed increases, thanks to Einstein's Special Relativity and the very real effect of time dilation. And this is nothing new to anyone with entry-level college or perhaps even high school physics. If, as an intelligent civilization you master the more tangible problem of accelerating a spacecraft to high speeds, say half the speed of light or greater, the fast-moving traveler no longer ages at the same rate as those left behind. As you travel ever closer to the speed of light, your clock and aging processes slow down to the point that you are able to cross vast distances of spaces in your lifetime while eons pass on the planet you left behind. And ultimately you may be able to travel thousands of light-years distance in just a few months or years of your life. Space comes within reach even when bound by the celestial limit of the speed of light, c. Just figure out how to produce the energy required to accelerate to high speeds approaching c, and you will be able to reach distances far greater than the mathematical relationship of speed times time would suggest.
The ultimate example demonstrating this effect is to consider a photon of light that that impacts your retina as you gaze at a star, say Polaris, A.K.A. the North Star. This star is about 430 light-years from earth, and yet this photon, massless and traveling at the speed of light over this vast distance, by its own frame of reference arrived at your eye instantaneously, the same instant that it left Polaris. If the photon had some kind of onboard clock, or if it had any measurable aging process, no time would have passed, nor would it have aged one bit.
That's the Theory of Special Relativity. It's not a "theory" in the common sense, because it is highly tested and verified, and time dilation is a reality that enters into physics and celestial calculations to some degree even at the lowly speeds that we are able to attain these days. But overcome the problem of traveling at velocities near the speed of light, and the universe is within your reach.
So yeah, don't rely on your assumption that we can't have visitors because it would take them too long to get here.
Emile
(42,289 posts)niyad
(132,440 posts)inhabited one in the entire multiverse, and have thought so since some ridiculous sermon I heard about the time I was eight.
The scene in the ending credits of "Men In Black" expresses it perfectly.
debm55
(60,612 posts)of the answer are well beyond me. But I feel interested it what they are saying.