this post was submitted on 10 Apr 2024
109 points (92.2% liked)
Asklemmy
43742 readers
1095 users here now
A loosely moderated place to ask open-ended questions
Search asklemmy ๐
If your post meets the following criteria, it's welcome here!
- Open-ended question
- Not offensive: at this point, we do not have the bandwidth to moderate overtly political discussions. Assume best intent and be excellent to each other.
- Not regarding using or support for Lemmy: context, see the list of support communities and tools for finding communities below
- Not ad nauseam inducing: please make sure it is a question that would be new to most members
- An actual topic of discussion
Looking for support?
Looking for a community?
- Lemmyverse: community search
- sub.rehab: maps old subreddits to fediverse options, marks official as such
- [email protected]: a community for finding communities
~Icon~ ~by~ ~@Double_[email protected]~
founded 5 years ago
MODERATORS
you are viewing a single comment's thread
view the rest of the comments
view the rest of the comments
The chances of extra terrestrial life to have visited earth is very, very small.
The chances of life to occur are small enough,
The chances of evolution to pass through multiple extinction events and producing a being capable of higher intelligence is even smaller,
The chances they have done this faster than humans is smaller still,
The chances they have evolved close enough to us to have visited is near impossible.
The universe is huge, there's almost certainly life elsewhere - but to ask whether they visited earth is like speculating on whether ghosts exist.
Also the universe is expanding at such a fast rate that unless we develop faster-than-light tech, we will never reach another solar system.
This is a valid reading of the Fermi paradox. But just for balance I'm going to devil's advocate all over it.
Not known. At the moment the data set is one habitable planet = one occurrence of life, so the odds might be very high indeed, even approaching 1:1
They are smaller, but how much smaller is impossible to tell. What if extinction events are less frequent than they are here? What if 100% extinction events are as rare as they are here? What if intelligence is a natural point of evolution everywhere?
This one's not true. The earth is relatively young at 4 billion years compared to 15 billion for the universe. A billion year headstart is completely plausible
Agreed that the earth's position in the milky way is a bit of a galactic backwater. At 25000 light years from the centre, stars are more sparse here than they are at the centre. But our nearest star is 4ly away. We could have a probe there within half a century with our current technology if we wanted to. So I disagree on the "near impossible" part.
Can't really argue with that. Until we see some evidence, ghosts and galactic visitors are in the 'conspiracy nut' bin. But it doesn't mean life on other planets doesn't exist. There are many theories why we wouldn't have seen or met alien life if it does exist. Absence of evidence isn't evidence of absence.
Hubble expansion isn't a big factor at the galactic level. Galaxies are traveling away from other galaxies at relative speeds faster than light, but for stars within the galaxy, the scale is infinitely smaller and the expansion is so small it's difficult to even measure.
There's actually a fairly decent argument that life may have developed literally everywhere in space in the first few hundred million years of the universe, since yes it started insanely hot and compressed, but as it expanded there had to be a time period of up to a hundred million years or so, that everything outside of stars was at the proper temperature for water to be liquid. The end result being that you'll find single cellular life existing literally anywhere it possibly can.
I have coined a theory I call "Galactic spring." It's that the emergence of intelligent life is a manifestation of and synchronized by some underlying phenomena - perhaps just the natural growth in informational complexity in a galaxy-wide entanglement network. Perhaps just a matter of sufficient amounts of the needed elements being available. The specific underlying mechanism isn't that important, unless we have an understanding about the initial emergence of life to compare it to. But the theory is that there is a larger synchronizing factor.
Like spring, there are some species that may emerge early. But also like spring, the emergence of one heralds the emergence of others. Every other "the earth is the unique snowflake of the universe" theory has failed. We are simply emerging. The conditions are occurring that generate intelligent life, and there's no strong reason to believe that our circumstance in that regard is unique.
Jeremy England proposed a while back that life is just an expression of entropy increase. Interestingly, if this could be verified (I don't think it can) it would point to life being universally abundant.
That we're not special is one of the ~~founding~~ foundational principles of astrophysics, the Copernican Principle. It goes that we aren't special, we don't have a privileged viewpoint, and therefore the universe should look the same in every direction. It does get applied in other fields of science in one form or another, since it's more a way of thinking than a theory as such. Again, it's not falsifiable but it does seem reasonable.
Interesting, but i have to disagree with "and therefore the universe should look the same in every direction."
Everywhere we look, we see asymmetry and variegation, along with instances of homogeneity and monoculture, as one thing wins out in a small domain.
So, yes, in some sense, same in all directions, but that "sameness" sure has a heck of a lot of play. And not being special, per se, doesn't mean lack of uniqueness. Even cloned plants on the same shelf have differing viewpoints, though perhaps not "privileged", unless one happens to be closer to a sunny window. But that happens.
I've also thought about life being an expression of entropy increase, but I can't say I fully agree. There are aspects of that at play - somewhat more noticeable in thought and consciousness, and the efficiency of organizing thought - but I think that an assumption of universal entropy is just another local-phenomena-first issue. Although it applies in systems we isolate from the universe as a whole, the broad tendency for substance clumps (i.e., organization) and variegation is also universal.
I suppose that's fair, since "looks the same in every direction" is a bit of an oversimplification. The principle is an assumption, rather, that we are not privileged observers, and therefore the universe should look the same in every direction. It then follows that we should be very interested to understand why when it doesn't.
I can't agree with you that the assumption of universal entropy increase is at all unreasonable. The laws of thermodynamics appear to hold everywhere, therefore entropy must be increasing everywhere. England's extrapolation to presume that life is an expression of this law might be tenuous, but the law is pretty much ironclad. That's not to say that structure can't arise; it clearly can because: hello. But the tendency of the universe as a closed system with a one directional arrow of time is heat death. That's just a result of thermodynamics. Eventually.
What caused the initial imbalance, and what prevents it from happening again?
Nothing. It's happening, and has always been. Anything that claims the universe as a whole is deteriorating is absolute bollocks, as it requires a creation myth, just as it postulates destruction.
If the universe is anything that we currently have theories for, the universe is a strange loop.
Now you're talking about some of the biggest unsolved problems in physics :)
I don't know if it necessitates a creation myth, though. The big bang theory doesn't imply a creator, but also doesn't require a steady state.
What's this about a strange loop? I don't know if I've heard of this before.
I meant a strange attractor, but I think it also has ~~prostitutes~~ properties of a strange loop.
A strange loop is a hierarchy, or heterarchy, where as you proceed 'up' the hierarchy, you eventually arrive where you started.
A strange attractor is a system which, although never quite having the exact same state, cycles around the same general set of states. One way of thinking of this is "a loop which never quite mets up with itself". An interesting example of this would be a three+ body gravitational system where the bodies are of comparable mass, and no stabilizing elements are present. Odds are very against them actually striking each other, but orbits are virtually completely unpredictable. Nevertheless, they won't eject any of the bodies, so they will always be in the same general region.
As applied to the universe, you could set the 'laws' of the universe as values on a manifold, and these 'laws' would flex and shift as the overall state of the universe changes, but the universe would cycle around within a probability niche - a strange attractor. There's also a potential it could leave that probability niche and 'fall' into, or enter into, another. One such probability niche would be the very strong tendencies of the universe - the 'laws' of the universe - as we know them.
My training is in applied mathematics, so I'm only conceptually aware of strange attractors. It's my understanding that they are chaotic systems that tend towards a stable state. As such I'm a little skeptical of the claim that the universe itself is a strange attractor, since it is broadly predictable and hence not chaotic, and it's expanding and thus not tending towards stability!
I'm referring to the laws of the universe, which have not always been consistent. A strange attractor can form states that are temporarily dynamically stable - and for something like the universe, we may not notice any small changes to 'constants,' as we are directly subject to them (including our tools of measurement). Aside from that, change is likely so slow that we may not even notice it.
Nevertheless, if the big bang is in any form to be believes, we must accept that the universe's basic laws can change, and yet they enter states where they do not noticeably change. If the pattern of the rest of nature holds (massive numbers of similar forms and structures distributed over time and space, where rough repetition along a common theme is a common theme), the universe will probably do similarly.
What would be incredibly odd would be:
Or
Either of those seem unlikely. But, of course, I live in this universe, so I could be biased. :-)
I'm pretty much on board, though how much anyone can agree is a matter of relativity.
We know about the closest stars and the planets within them, and based off spectrometry, we're confident the planets "close" to us haven't had life, though they might be capable.
The chances of there being no mass extinction events in the millions of years following abiogenesis is arguably smaller than surviving the five or so we've had. Given everything we know about astrophysics, we owe the asteroids a few clean hits, we have been astronomically lucky, and that's not even taking into consideration every other cause of mass extinction.
15 billion years is still considered early in the grand scheme of things, it's likely that we are the early ones. A billion years head start is plausible, sure, but it's certainly less plausible than our existence.
All of this is to say that life is rare enough without them being a stones throw away.
And this is all disregarding any possible intent behind a visit. Any being capable of space travel does not need our resources.
Unless they're sex tourists, which would explain all the anal probing.
On second thought, I choose to believe.
I'm incredibly fascinated by the ghost comparison. Is the probability that ghosts are a real physical phenomenon higher or lower than the probability that aliens exist or have visited us? That's an extremely interesting question, and I'm sure someone could do a statistical meta-analysis comparing the incidence of, say, UFO sightings with the incidence of paranormal experiences (if such an analysis doesn't already exist). Both questions seem like the things that should be generally empirically falsifiable (and indeed, specific instances certainly are), but humanity's curiosity about both has proven remarkably durable despite centuries of curiosity and myriad efforts to settle (negatively) both questions once and for all.
They're both so near zero as to be hardly worth considering.
The thing to think about is the fact that, in either case, ghost or alien are in any way especially indicated by the evidence. People don't see something strange and conclude aliens because they have good reason to believe from the evidence that something traveled vast distances across space, but rather they simply don't have anything good to believe right now.
Having unusual evidence that doesn't seem to point at the simple, mundane explanation isn't the same as having evidence that does point at a supernatural or extraterrestrial explanation
Wouldnt have to do it faster, just first
Wait, what?
That's like saying you don't have to drive faster to win the race, you just have to cross the line first.
Maybe more like saying "you don't have to be fastest to finish first if you get enough of a head start"?
Yupyup