this post was submitted on 10 Apr 2024
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I assume other life exists somewhere, because the universe is practically infinite in size, but I also assume that we will not meet them, because the universe is practically infinite in size.
Basically my thoughts. The speed of light, while the fastest thing we know, is as slow as smell on the scale of the universe. Any race of beings able to get here, check us out, and leave, would need technology that would break physics as we understand it. Not to say it's impossible, but we've now firmly stepped into beliefs, rather than anything based on observable data. Also, the notion of a race being so advanced they can travel faster than light accidentally crashing on our planet is pretty silly to me.
I like the space travel explained in three body problem. Soldering about folding up dimensions.
GET THIS MAN HIS VOTES
I mean, we could potentially see them if they're in any of the neighboring galaxies, and if they're in ours they should have arrived and turned Earth into a colony long ago. Space is big, but time is long. Loud aliens would have to be truly rare indeed for this.
I don't know, if this is worth arguing over. Depending on how far advanced you expect such a life form to be, obviously they might be capable of things that we currently consider impossible. But well, to illustrate what I mean:
The next galaxy is the Andromeda galaxy. It is 2.5 million light years away. There could be life over there right now, but we wouldn't know, until about 2.5 million years from now.
Compare that to the emergence of modern humans, which was 300,000 years ago. We didn't start sending out radio waves until some generations ago.
None of this means that it's not possible for life to have existed on some planet 2.5 million years ago, so we'd be seeing their radio waves right now, but even then, we might interpret them as background noise.
The next star is Proxima Centauri. It is 4.24 light years away. So, we could see things from there in 4.24 years, which is pretty good, although still absolute hell of a delay for exchanging messages.
But for them to actually visit us, even if they go at 1% the speed of light, that would mean they'd need 424 years of travel time. With little sunlight or other energy sources on the way.
And 1% of the speed of light is an insane 10,800,000 km/h. Compare that to the fastest man-made object, the Parker Solar Probe, which is expected to go 720,000 km/h, when it closely passes by the Sun.
Basically, we can be extremely generous with these examples and still see practically insurmountable time frames.
Worm holes could theoretically exist. Maybe a sufficiently advanced race could defy physics as we know it. But if they can't, that's a pretty good explanation why they're hiding.
Hey, I don't know if we even have to argue, your math checks out. But, is 425 years really insurmountable? The first Earth-like planets could be billions of years older than ours. IIRC Fermi himself estimated 3 million to settle the whole galaxy.
Let's go by light cones and local interval (clock time in one's own reference frame), if we are going to argue. This shit can get so confusing if we try to define "now", especially if a relativistically fast ship comes up.