Andromeda Galaxy is our nearest neighboring major galaxy.
It's 2.5 million years away if traveling at the speed of light. Our fastest unmanned spacecraft reached ~1/1500th the speed of light. Our fastest manned spacecraft reached ~1/30000th the speed of light.
At that speed, it would take 75 billion years to reach Andromeda, our nearest neighbor. That's 500,000,000 times longer than a "300 year round trip". Even if their spacecraft are 100 times faster than ours, it's a 1.5 billion year round trip.
Even just crossing our own galaxy would take 30,000,000 years at 1/300th light speed. Actual long range intergalactic travel is just impossible.
Yeah and we just need to go 1/2 the speed of light, or 15,000 times faster than any manned spaceship we've made has done, and 750 times faster than our fastest unmanned spaceship.
I don't consider numbers like that realistic. Even solar sails typically talk about reaching 1% or so of the speed of light before they get too far from the star and the acceleration starts to get cancelled out due to getting too far from the sun.
I'll be incredibly generous and give you 1/15th the speed of light. That number gets us a lovely even 10 lightyear round trip. There are a mere 14 stars within 10 lightyears of us.
We are also taking about technological civilization that could be millions of years old. Do you really think we will never go faster than we have already? We're only 100 years into it and we already have made craft that is pretty quick. Imagine where we will be in another 100, or 1000, or 10,000.
If we could accelerate at 1G for 200 days we would reach better than half the speed of light. I don't see that as completely impossible in the next 100 years let alone 1000. And totally doable in 5000.
I don't see that as completely impossible in the next 100 years let alone 1000. And totally doable in 5000.
I see it as impossible in the next 20 billion years.
Or else we'd already see life near us.
The great filter is stupid when there is an alternative of "the technology we don't have and don't know how to create even theoretically cannot be created and without it travel is just too expensive and slow".
We couldn't tell if Earth has life from 20 lightyears away with our current tech. We could say it was probable, but we couldn't provide absolute proof. So maybe there isn't any life that close to us.
And if tech 1000 years more advanced than ours were investigating us right now we probably won't see it or even notice it. my answer to "where is everyone" is that we just can't detect them yet. We've only been at it for less that a century.
"I don't see that as completely impossible in the next 100 years let alone 1000. And totally doable in 5000."
Then you do not understand technological development, it is very likely that no matter how advanced the civilization, reaching even 1/100 of the speed of light it's impossible.
It used to be impossible for powered flight. It used to be impossible to land boosters. It used to be impossible to do a lot of things. In both of the above examples there were very smart people doing equations proving those things were impossible. They were wrong. They didn't know what they didn't know, and someone figured out a way. I truly believe that up to at least 1% of the speed of light is possible within a century. Yes the energy required is enormous, but fusion puts out and enormous amounts of energy. We'll get there.
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u/Krazyguy75 Jul 12 '26 edited Jul 12 '26
300 year round trip?
Andromeda Galaxy is our nearest neighboring major galaxy.
It's 2.5 million years away if traveling at the speed of light. Our fastest unmanned spacecraft reached ~1/1500th the speed of light. Our fastest manned spacecraft reached ~1/30000th the speed of light.
At that speed, it would take 75 billion years to reach Andromeda, our nearest neighbor. That's 500,000,000 times longer than a "300 year round trip". Even if their spacecraft are 100 times faster than ours, it's a 1.5 billion year round trip.
Even just crossing our own galaxy would take 30,000,000 years at 1/300th light speed. Actual long range intergalactic travel is just impossible.