What I don’t get is why the seemingly simple explanation is dismissed. Yes, it’s probable there were or still are other intelligent species out there, but the distances and times involved in interstellar, much less intergalactic, travel, are simply too vast to be overcome, even by technologically advanced civilizations. Unless there happens to be a solar system with two or more habitable planets or moons, it’s unlikely two different intelligent civilizations will ever meet. At least that’s my guess.
It’s not “dismissed”; the huge distances are an integral part of all discussions of the fermi paradox.
The part you perhaps are not getting, is that when you do the maths on how long it would take for, say, a Voyager-style probe to reach another star system, it’s a minute fraction of the galaxy’s age to date. And would take no more power than it took to get to the edge of the solar system. So it’s quite possible in fact.
And again, let me emphasize, the Fermi paradox is not only talking about face-to-face encounters in a Star treky way.
If intelligent species are common (and “common” here can be anything above, say, 1 in a billion stars), then some will be millions of years more advanced than us. Even if all these hyper-advanced species chose not to spread through the galaxy, how come they have not even made any detectable changes to their own star systems, or released any detectable signal?
Or, perhaps they don’t exist? We don’t know.
That is exactly the obvious that scientific minds are observing. I truly don’t understand what your objection is here. What scientific minds are you talking about, specifically?
Lotta maybe’s in there, and all to explain why we are unique, which gets us back to where we started, why are we unique?
Ever? You don’t think that, if we establish a self sustaining colony in space, that they would establish others? That they would not grow in number and push out? After a million years of this, that they would not have reached another star system, or ten or more?
A million years is a blink of the eye. Ten million years is not much longer. Even at an extremely leisurely pace, we’d have the galaxy brimming in a hundred million.
A hundred million years is less than 1% of the lifetime of the universe. If there is another civilization like ours out there that came about just 1% faster, they certainly would be detectable by now, as they would have already harvested our solar system and encased our star with solar collectors hundreds of thousands of years ago.
Right, some people think that it is saying more than it is, or that it is actually a “paradox”. There is no such thing as a true paradox, where two mutually exclusive things are both true, something is called a paradox when you come to different conclusions based on starting from different assumptions. The point of it is to call our assumptions into question, to determine which ones are not valid.
Right, the whole point of it is to ask the question as to why we do not have evidence of other civilizations. Which assumptions are not valid?
Why do you think that this is a more probable explanation? Wouldn’t a simpler explanation be that there are no other intelligent species within our local group of galaxies?
It’s just space. We’ve got plenty of time. Can you explain why we would not be able to reach other stars within a million years?
It would be quite unlikely that a human as we know them will ever meet and alien as we imagine, sure. But, if we start expanding out into the galaxy, our descendants, be the biological or entirely electronic, will eventually encounter anything that is out there to be encountered.
And it’s not just a question of meeting, it’s a question of detecting. It is entirely within our technology to become a K2 civilization, blocking out all the light from the sun, and that’s something that will probably happen in the scale of thousands, maybe tens of thousands of years if we are slow about it. Once we have done that, or even before we have completed that process, we would be doing the same to nearby stars, and spreading out from there. Dyson spheres would be detectable from a great distance away, especially during the building process.
If you remember Tabby’s star from a few years back, that was purported to be a possible site of the early stages of a Dyson sphere. It turned out not to be the case, that it is most likely a natural phenomena, but it does indicate that we would be able to detect that sort of astroforming from 1500 light years away.
And, if that is the case, that they chose not to spread through the galaxy, it is a good question to ask as to why? Why is it either impossible to do, when there is no actual barrier that we know of to do so, or why are we unique in wanting to do it?
One way or the other, there is either something about the universe that we don’t know that will prevent us from expanding into the galaxy, or that we are unique in some way, being the first with either the capability or the desire to do so.
Yeah it seems the word “paradox” has a different meaning in science, just like a word like “theory”.
If you look at this list of named paradoxes in physics, they are all basically of the format “Based on our current best model, we’d expect to see A, but we see B. Why?”
(There are two or three at the start of this list which are actually more philosophical, but the ones in the sections eg astrophysics are all of this format)
This is very different to the logical and philosophical paradoxes, and perhaps different to the colloquial use of paradox.
I’m not sure why you put it in GQ, since it obviously belongs in Great Debates. Rather than move this one, I refer you to an existing thread in that forum if you wish to discuss this.
Colibri
General Questions Moderator