Actually, i'm pretty convinced we do know, with very high probability of being right.
Our knowledge of physics is limited, but seems to be advanced enough (cfr relativity and astronomical distances) to make it likely that if there is someone else, they're just too far way, or else we're too uninteresting to be visited or else if we would be interesing enough, it takes so much technological advances to cross galactical distances, that humanity would be wiped out by the visitors before we even realise what's going on.
My dad worked for the military, as a civilian. He had an counterpart in the Air Force, a colonel, who told him in the late 70s that he knew for a fact there were aliens but he couldn't tell my dad how he knew those facts. My dad worked closely with this guy on military black box recovery and analysis.
Dad told me he believed there were aliens because he said the colonel made it a point to say that he knew this to be true, and I believe it to be true as well, because Dad trusted this guy. It goes without saying we typically believe our parents if they tell us things. None of this had anything to do with facts, and everything to do with trust, which is formed from a person to person exchange. Most of what Dad did for the Air Force remained a secret till his death, and I do know he was absolutely obsessed with airplanes and math. To believe a mistruth about something we care so much about is possible, but unlikely.
So, sometimes knowledge is what we have as stories and we can either choose to believe, or not. That is faith. We don't need facts to back up our faith in personally knowing a thing to be true or not. Besides, if there are aliens, it would probably be better if the general population didn't have hard facts to ensure it became general knowledge, because at that point the speculation faucet is wide open. It's far better to let people believe what they will, without it affecting civilization in a radical way.
Maybe there are aliens and maybe there aren't. As my local AI alien just said to me, "Ultimately, beliefs about extraterrestrial life often come down to personal perspectives and interpretations of available information, as well as the trust placed in sources of information, whether they be firsthand experiences, anecdotal accounts, or scientific findings."
or maybe telling people funny lies about aliens is just a strategy designed by government to help its employees deal with the stress of not being allowed to share "genuine" government secrets with their families and friends........
Alternative facts. No sale. There's no fucking aliens but there are a bunch of liars and bullshit artists who get a kick out of manipulating kids and other people.
> It goes without saying we typically believe our parents if they tell us things
No. It doesn't. I don't believe my mom when she says she saw angels and I don't believe my dad saw creatures that the cameras magically didn't pick up. I need to just stop reading this thread. People believing whatever they want is fine but this ad hoc delusional justification is killing my soul
You do realize people see things internally, right? Sometimes they see things augmented reality-like as well. Just because we can't see it doesn't mean they can't, or they are lying.
But don't you see the problem here? You don't know what you don't know. Radio communication wouldn't surprise e.g. Newton in the least once explained, but it's something he also would never have envisioned in a million years, because it was simply technology that he had no reason to even might imagine would be possible, outside of fantasy and fiction. He was actually skeptical of his own discovery of gravity because of the implication of some invisible force at work!
Or let's go back to ultra modern times. Nuclear warheads are shockingly small. Imagine telling something at the turn of the 20th century that soon a weapon the size of a small table would have a kill radius of multiple miles. I mean you can obviously imagine it, but it seems kind of silly to think about being actually real, until it turns out it is.
So there are two possibilities now. (1) Now we've finally reached that point, that we will only ever reach once, where our knowledge is advanced enough such that there will no longer any major revolutionary discoveries made. Or (2) we're just like every other generation throughout time who assumed that what they knew was, more or less, the peak of what's knowable (or at least not fundamentally wrong) only to have their own ignorance demonstrated with marked clarity in times yet to come.
Beyond the philosophical there are countless technical reasons to also think this is the case. Like you mention astronomy, yet so much of what's going on out there remains a complete mystery. Disharmony between the really big and really small aspects of the universe, whatever 'dark matter' and 'dark energy' truly are, the fact that observed galaxies are moving at rates far different than expected by relativity or Newtonian mechanics (including after factoring in whatever dark matter may be), that a big-bang would require a mysteriously convenient faster-than-light inflationary period to actually work, and countless other issues. So many things are breaking at scale, that it seems highly reasonable to assume that there remain yet many revolutionary and worldview-shifting discoveries to be made.
But we do know what is possible given the universe we can see. There is no magic left; the god of the gaps has been made so small that it can only live down in the quantum foam.
> Nuclear warheads are shockingly small. Imagine telling something at the turn of the 20th century that soon a weapon the size of a small table would have a kill radius of multiple miles.
Einstein published On the Electrodynamics of Moving Bodies in 1905, so that puts us close enough to the turn of the 20th century to state as a fact that at least a handful of well-read scientists would have no problem imagining what you proposed.
On the Electrodynamics of Moving Bodies has nothing, whatsoever, to do with nuclear weapons. Nuclear weapons are about nuclear fission, which was not even discovered until 1938. Nuclei weren't even discovered until 1932 for that matter! But getting back to the point here, do you not think every other generation thought exactly what you are saying? There's a really fun quote from Michelson (of the Michelson-Morley experiment) in 1894:
"...It seems probable that most of the grand underlying principles [of physics] have been firmly established and that further advances are to be sought chiefly in the rigorous application of these principles to all the phenomena which come under our notice. It is here that the science of measurement shows its importance — where quantitative work is more to be desired than qualitative work. An eminent physicist remarked that the future truths of physical science are to be looked for in the sixth place of decimals."
Notably Michelson was the first person to experimentally observe a shocking key fundamental of relativity, outside the scope of this post. But he was so convinced that there was "no magic left, etc, etc" that he (and everybody else) actually thought his experimental result was due to a miscalibration or lack of precision in his results. So convinced was he of this, that he casually rejected his own results which would only be explained decades later - coincidentally, partly in the paper you seemingly randomly referenced here!
The question was: could you expect to explain an atomic bomb and its power to someone at the turn of the 20th century? The answer is clearly: yes.
Knowing the specific structure of the atom is _not_ required for this. The point was to prove that something was not necessarily 'magic' and the example selected was a bad example, because we can actually show that people were on the cusp of figuring it out themselves and would not have a hard time following an ELI5 overview. Are you providing information they do not have at hand? Yes. Will a reasonably well-read person of the era understand your explanation of how such a device would work? Yes.
Don't be simple. You obviously know that's not what I said, it's like a quarter of a page above where you're posting! What I said:
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"Imagine telling something at the turn of the 20th century that soon a weapon the size of a small table would have a kill radius of multiple miles. I mean you can obviously imagine it, but it seems kind of silly to think about being actually real, until it turns out it is."
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So yes, give somebody from an era an absolute ton of information on things they had 0 knowledge of and 0 reason to think existed, and sure - they can begin to understand how a nuclear weapon might actually be viable. And that's the point. And the same will undoubtedly be true for countless other discoveries as we continue to advance our understanding of the universe. Something like e.g. faster than light travel is obviously easy to imagine today, but we still have 0 knowledge of anything* that might enable it, let alone how such things might work, and so it remains strictly in the domain of fantasy. Yet 50 years from now, it might simply be something everybody takes for granted. Because we don't know what we don't know.
* - not strictly true, but you probably think it is - and this is outside the context of this post in either case.
Actually, i'm pretty convinced we do know, with very high probability of being right.
Our knowledge of physics is limited, but seems to be advanced enough (cfr relativity and astronomical distances) to make it likely that if there is someone else, they're just too far way, or else we're too uninteresting to be visited or else if we would be interesing enough, it takes so much technological advances to cross galactical distances, that humanity would be wiped out by the visitors before we even realise what's going on.