The very small chance of it being aliens is the same as the very small chance of it being wizards, or angels, or the rogue appendages of extradimensional horrors, or glitches in the matrix. It's irrational to fixate on the technically non-zero odds of aliens when there are an infinite number of explanations with technically non-zero odds.
Our Galaxy formed 13,000 million years ago. We estimate any single technological civilization that developed the technology to build Bracewell/von Neumann probes during this time (perhaps minus a few billion years) could have colonized every star system in the galaxy with self-replicating tech in at most a few million years. Presumably if the probes were self-replicating they could also be self-maintaining and therefore a single colonization could effectively produce a permanent technological presence within a given star system. We can't know what a civilization would do with such a network, but we can guess that human beings would program it to investigate life and technological civilizations.
So the "could there be alien technology in our solar system" question breaks down to a series of technical questions around the feasibility and probabilities of the above events. I personally still think those probabilities are low enough that we can round them to zero, but the spec-fi fan in me very much hopes that they're not.
Also: for god's sake, these are Chinese balloons and not aliens. :)
I'm guessing, but is it because we'd see a big empty space with a large gravitional pull? Would light bend around it similar to a black hole, or is the behaviour different enough to be obvious?
Disclaimer, my knowledge extends to high school physics (which I've largely forgotten).
In an "infinite worlds, infinite possibilities" sense it's possible that something, somewhere in the universe is alive and/or magical. But there is no telling that 1) that's actually happening, and 2) that we'd ever encounter it before the heat death of the universe.
What bearing does the trajectory of humanity have on the reasonableness of explaining things by alien? I fail to see any connection.
On the other hand, it being extremely unlikely (because in every instance so far the answer has been "no" or "we don't know") seems pretty relevant.
you may feel this, but in reality these people might have heard "its aliens" for 50+ years and are fed up with people jumping to conclusions without actual evidence.
and no, shooting down unknown objects is not evidence.
That's the problem with considering the unlikely (especially when there is a lack of evidence for the phenomena prior to this). When you're that far down in the weeds, it's all noise. There are too many technically possible but extremely unlikely explanations to spend time on them all, and in the absence of evidence, there's no reason to single any one of them out.
I find that the two prior base scenarios, one with galactically widespread advanced civilizations and one with only us alone in the vastness of space, would very probably look practically identical to us. There’s no reason advanced civilizations would use radiowaves for communication, and little reason for them to interfere in the development of a primitive civilization. I find that we would see an empty galaxy in both priors with a high likelihood.
Given this, the core problem in assigning an actual probability for either scenario is that we don’t know how easy or difficult it is for intelligent life to emerge. At this point it is quite impossible to assign the probability, since our sample size is 1. It is no more true to assign a probability close to 0 than it is close to 1. This must then either be set to 0.5 or eyeballed by circumstantial info, which is never real proof to one direction or another.
I believe it to be sufficiently high that the scenario where the apparently-empty galaxy is full of life is far from vanishingly small - and far from certain.
I consider it vanishingly small because of the screaming lack of even moderately firm evidence that it's ever actually happened.
> I believe it to be sufficiently high that the scenario where the apparently-empty galaxy is full of life is far from vanishingly small - and far from certain
I believe it is likely to the point of virtual certainty that there are other intelligent forms of life in the universe. We don't disagree there.
But the universe is unimaginably enormous, and the chances of any two such life forms being within reach of each other is miniscule. In order for it not to be, the universe would have to be absolutely packed with such life, and if it were, we'd very likely have some sort of evidence of it.
But my point still stands. Of all of the very unlikely things that might be true, why fixate so hard on this one? My suspicion is because people want it to be true, and starting with that stance makes error and misunderstanding very likely.
Yes, this is where we differ. Even at sub-light speeds, an advanced civilization would take only a few million years to colonize the entire galaxy. Thus, distances within a galaxy are trivial for intelligent life. Observable-universe-tier distances, however, are not - if we stay within sub-light speeds. If we assume that intelligent life could have emerged only within the last billion years, the observable universe would need to have quite many intelligent lifeforms indeed for some to have reached us.
But then again, that's only a question of numbers. We have no idea of the probability of intelligence emerging and reaching space age. It could be very low or very high. We cannot make inferences about distances due to this. We can only consider evidence. If the universe and our galaxy was packed with life, and we assume they would not want to interfere with our development, what evidence would we have?
Personally I can come up with no other possible evidence than radio signals. We can't image other solar systems yet with our equipment. Detecting Dyson spheres under construction is a reach for a number of reasons. And radio signals may easily be phased out very quickly as means of communication - we have only been using them for 100 years or so. This is why I don't find it convincing to use lack of evidence as evidence - what evidence would there be which we could detect short of direct contact?
> Of all of the very unlikely things that might be true, why fixate so hard on this one? My suspicion is because people want it to be true, and starting with that stance makes error and misunderstanding very likely.
You may be right on this point. However, I also believe that the historical stigma on discussing the extraterrestial scenario as a realistic possibility clouds the judgement of many towards overt caution, using strawmen where steelmen should be used. Evidence we have on the general subject points to no direction. Thus it's a question of probability for a very simple event - an intelligence reaching space age in any given planet, which we (almost) know to be non-zero. Therefore things like pooling extraterrestials together with wizards further strenghtens the stigma which greatly inhibits assessment of probabilities for explaining unexplained phenomena.
This has zero (or to split hairs some nonzero probability that is so infinitesimally small as to be practically zero).
People, including respectable scientists, were perfectly willing to entertain the possibility of aliens there, with all the appropriate and huge caveats.
It’s not that people don’t want it to be aliens, it’s just that it never is.
According to who? How is that compatible with the history of physics?
There are a few cases where physicists found new capabilities which weren’t known before, like Faraday discovering induction, or Einstein discovering mass-energy conversion. But even then the basic principle of energy being conserved is respected, and physical limits obeyed.
The probability is so vanishingly tiny that there's little point to entertaining it beyond "sure, it's possible".
Keep your mind open, but not so open that your brains fall out.