The problem here is that to go down this path you need to violate quite a few fundamental aspects of physics that we have. Several of which have stood the test of millennia despite many serious attempts to disprove.
We've greatly increased the amount of things that can be done, but I wouldn't be so confident about the things that can't be done.
I'll let Asimov speak on this because he says it better than I can. But this is not even remotely accurate. We've become less wrong over time.
I was quite precise in my wording and didn't say what you are responding to.
My opinion (and it's just that, I'm unprepared to defend it) is that we've always been [less and less] wrong on everything.
And since we can't know what the boundaries of knowledge are, and it could easily be some insane unbounded fractal existence, it seems rash to me to decide that we know enough to say that there can't exist civilizations whose technology is magic to us.
See my comment in the sibling subthread.
https://www.sciencealert.com/study-shows-how-the-universe-wo...
Sure, and that's not a problem so as long as self-consistency is preserved.
> But to rewrite how a sequence of events happens, well that's a big fundamental change.
Depends how you look at it. There are retrocausal explanations of quantum mechanics, for instance.
You break the lightcone...
> Depends how you look at it. There are retrocausal explanations of quantum mechanics, for instance.
Let me save people the time, there's critiques at the bottom but there is no actual evidence for retrocausal explanations: https://plato.stanford.edu/entries/qm-retrocausality/
The point is you can't. Existence would be a static 4D structure. No matter how you tried to change the past, your attempts are already part of your own history and clearly all failed.
> Let me save people the time, there's critiques at the bottom but there is no actual evidence for retrocausal explanations: https://plato.stanford.edu/entries/qm-retrocausality
There is no evidence for any interpretation of QM. That's what makes them interpretations and not distinct theories.
You never know, when this advanced technology is revealed by the US military it could just be some kind of physics hack that fits in neatly somewhere and doesn't require any rewriting, just a footnote.
As I see it. Let's say that human civilization does not turn Earth to a nuclear wasteland but rather resolves its social issues and proceeds with colonization of Solar System. We already sent probe out of our Solar System. It does not look for me to be impossible technology to build a probe with AI and robots smart enough to reach another star system, decelerate there, build some factories on asteroids and copy itself sending copies to further star systems. Of course at the same time exploring its "home" star system and transmit information they got to Earth.
So very quickly (in universe scale) our sphere of knowledge will expand limited only by some fuel tanks capacity required to accelerate and decelerate.
Yes, there will be years, decades, centuries and millenniums for this information to reach Earth. That's the nature of cosmos (according to our current knowledge) and we will have to deal with it.
Eventually probe will find planet with life. May be life is more abundant than we imagine now. May be not. Surely there will be protocols for the probe to investigate life. It's hard to imagine what those protocols would be. May be explore freely until certain technology advances are observed and then hide. So may be our ancestors saw alien probes on a regular basis and just didn't care. But now those probes observe that we've got quick airplanes so they hide better.
My point is that developed civilization inevitably will expand its sphere of influence at speed limited by speed of light. Probably slower than that. But billion of years at 0.1c is still huge chunk of universe. Are we sure that no civilization born within this radius billion years ago?
I'll bring up another point that I didn't in my longer post though. Maybe these lifeforms solved things like longevity and so such time constraints aren't meaningful to them. What's a few hundred years when you live millions?
> But billion of years at 0.1c is still huge chunk of universe. Are we sure that no civilization born within this radius billion years ago?
That's 1,000,000ly fwiw. That does cover the entire Milkey Way (but doesn't get us half way to Andromeda). But also consider that the Milkey Way is 13.6bn years old and life on Earth is 3.7bn.
I'm not saying that your idea is crazy, it is definitely possible (and has been proposed by others, in quite high detail). I just think there isn't any evidence for this and there's reason to believe that this would be quite difficult to pull off. But we'll see as time goes on.
Sure, if we would find crashed space ship, that would be good evidence. We don't have that (or it's not public knowledge anyway).
Anything less than that would be hard to consider evidence. Especially if those things are trying to minimize encounters.
As to mining planets. I think that it makes more sense to mine asteroids. You don't need to overcome gravitational well and asteroids are quite rich when it comes to resources. Asteroid belt is huge. You can build lots of stuff there without fear to be noticed. Also it's not really clear how far can you go with minituatirization. We think about big ships but if you can operate on molecular level, may be you can stay small. Think about robots size of bacteria, size of ants and stuff like that. Alien anthill in some asteroid pit might be never noticed.
The lack of evidence does not support a claim. Otherwise we'd make arguments about ghosts, invisible unicorns, and flying spaghetti monsters. Just to be clear. You're right that it is hard to consider evidence when it doesn't exist. So my believe of aliens visiting earth is in the probability ranges of these other things.
To give an idea of the scale involved, Voyager 1 is only 0.058% of the way to the nearest star system, and that took 45 years. Granted it wasn't built for speed but given that the best hypothetical plans for a spaceship we have allow travel at ~.1c it'll take 50 years not counting acceleration / deceleration.
> Eventually probe will find planet with life. May be life is more abundant than we imagine now. May be not. Surely there will be protocols for the probe to investigate life. It's hard to imagine what those protocols would be. May be explore freely until certain technology advances are observed and then hide.
Even assuming that some set of automated probes have been travelling our galaxy for millions of years, and reached earth in the last few thousand years, where are they now? By what mechanism could they even be hiding? Every inch of the planet is being watched by satellites.
> My point is that developed civilization inevitably will expand its sphere of influence at speed limited by speed of light. Probably slower than that. But billion of years at 0.1c is still huge chunk of universe.
As an aside, I'm not sure you could meaningfully have one civilization spanning hundreds of millions of light years, the ends are just too spread out for there to be a single cohesive or web of cultures. Imagine if an email took longer than our entire species existence to reach you.
> Are we sure that no civilization born within this radius billion years ago?
I personally am certain that there are many other forms of life throughout our galaxy, and at least some of them must be technological. As much as would like for it to be false, I also believe there is no realistic mechanism for travel between stars and we are all effectively doomed to stay in our little corner of creation, maybe spying on each other through telescopes, assuming we can even spot a neighbor.
As well as ground based cameras, radar systems, infrasonic, particle detectors, scientific instruments, etc. And how would these ships power themselves for so long. To be able to do so while being hidden from xray, visible light, infrared, and radio? Except for maybe a few of these random sightings? Sure, it is possible, but doesn't sound likely.
The most obvious way to hide is stay small. I don't know what physical limits would be to build small robots with advanced technology. Build main base somewhere in asteroid belt. Build some intermediate bases for refilling or something like that in moons. Or may be just rock somewhere in the space with small solar panels which collects electricity and can charge robot of size of sparrow which will travel further to Earth. Can we notice sparrow landing Earth and intelligently hiding e.g. in the sea?
Surely the protocol wouldn't be "show a tic tac in the sky and disappear foerver"
Consider the following aspects of the observed phenomena:
- Intelligent characteristics (chasing / following / loitering behaviour)
- Ability to generate and withstand extreme G-forces
- Ability to expend/sustain extreme bursts of energy
- Lack of visible exhaust
- Bizarre aerodynamic characteristics
I'm not an aerospace engineer, but I am a technologist and I took some aerospace-related courses in university. The first two aspects combined seem to rule out control by a human in the cockpit, and given the history of AI I would say autonomous control by a computer as well. Although not altogether the possibility of remote control by a human.
But the last three aspects transcend not only everything I think I know about existing technology, but also my understanding of:
- Newton's Third Law of motion and the rocket equation
- Fluid mechanics/Navier-Stokes equation
- Thermodynamics
i.e., it exceeds our current science by such an enormous margin that I couldn't even begin to approach how to analyze it. Therefore, I think that if we rule out the possibility of a delusion/hoax, it's far more likely that these objects are alien than a secret skunk works project.
As for within our solar system, I'm fairly certain this isn't true. There would be a crazy amount of effort to hide all that. Like you're hiding an entire civilization from x-rays, visible light, infrared, and radio. A civilization that would be constantly monitored (we pay a lot of attention to local objects). Possible, but these aliens clearly spent a lot of energy and resources to undertake this but have also hidden that resource collection (there's a feedback problem here). Combined with that we aren't sure for mechanisms for life. I'm not going to hold my breath.
Also, I don't think we can rule out aliens within our solar system. An alien civilization beneath the ocean of some moon?
To... what? Study a civilization and do nothing with the data?
> Also, I don't think we can rule out aliens within our solar system. An alien civilization beneath the ocean of some moon?
Yeah, we pretty much can. Odds are extremely low. Now, life might exist, but not advanced space fairing life. Those civilizations produce a lot of noise and make drastic changes to their planets (/moons).
Arguments like this neglect the relative inscrutability of even human motivations, with which we ought to be intimately familiar, yet can nevertheless perplex us.
Humans undertake spectacular projects as jokes, religious activities, and as art. There's really no speculating about equivalent, befuddling alien motivations, and certainly nothing to rule out autonomous devices that travel unfathomable distances, and then play hide and seek when approached directly.