effects of intelligence on the universe

[Metric]

The "last you heard" is still the current understanding. However, there are some weird cosmological models that have us accelerating now, and collapsing later -- but these require a lot more assumptions than a simple cosmological constant which already fits the data perfectly and predicts acceleration forever.

[Borodog]

This OP is Super-Hyper-Mega-Awesome(TM) and gets my Seal of Approval.

[Metric]

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Is it possible we could point a beam of light at a distant galaxy, and it never gets there due to the space in between expanding? Either from our frame of reference or theirs?

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Yep, this sort of thing can happen. If I travel sufficiently far away from the earth (in an accelerating universe), I won't be able to get back to earth or even signal back to earth.

[Piers]

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If you've got some specific idea for some limiting factor in galaxy colonization, you should say what it is

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The speed of light. Obviously. Any colonization would have to be at a snails pace and could easily peter out. Any particularly large chunks of empty space will pose a seriously big problem. Sorry I am not buying inter galactic travel, and absolutely not inter local group travel.

While I think you have greatly underestimated the frequency of intelligent life, I suspect you might of overestimated the frequency of life forms with the enthusiasm and technical expertise for unlimited colonization, plus adhering to the Dyson sphere approach to power conservation.

Dyson sphere’s and unlimited colonization appear to be to different solutions to the, not enough resource to support the species problem. Why employ both of them?

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The implication is that the universe may essentially become dark at this time, due to the fact that it's illogical to waste high-energy light.

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Illogical??

Perhaps the problem is that you are suggesting a uniformity that need not exist. While there might well be an infinite number of galaxies that disappear because of the effect you suggest, a much larger frequency will not do so because the necessary parley of events does not occur.

[Metric]

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If you've got some specific idea for some limiting factor in galaxy colonization, you should say what it is

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The speed of light. Obviously. Any colonization would have to be at a snails pace and could easily peter out. Any particularly large chunks of empty space will pose a seriously big problem. Sorry I am not buying inter galactic travel, and absolutely not inter local group travel.

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This kind of space travel would obviously be extremely difficult and expensive for biological beings like humans, but what emerges on the other side of the singularity may be able to engineer its own intelligence to easily withstand super-long duration space travel. The intelligence wouldn't have to be a massive collection of fragile biological brains with their massive and constant life-support needs. Once an initial push to some reasonable fraction of the speed of light has been achieved (say, 10%), there would be little to stop intergalactic space travel -- almost no intelligence needs to be active during the actual trip.

After colonization begins, the power of the exponential takes over -- if every new colony in turn sends out 10 new colonizers after some allowed initial build-up time, one can see that it doesn't take long at all to colonize an entire galaxy. (incidentally, this is part of the Fermi paradox -- once galactic colonization begins, it takes over so rapidly that we should expect to find our entire galaxy already colonized if we weren't the first technological life on the scene)

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While I think you have greatly underestimated the frequency of intelligent life, I suspect you might of overestimated the frequency of life forms with the enthusiasm and technical expertise for unlimited colonization, plus adhering to the Dyson sphere approach to power conservation.

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It doesn't exactly have to be a Dyson sphere approach -- all that has to be realized is that it's tremendously wasteful let the source of your life (the stars) simply burn out when it could instead be used to prolong the duration of your intelligence.

As for the other point, I agree that it's possible that technological intelligence is (and will continue to be) more rare than my estimate. However, even if I'm off by an order of magnitude, this should not stop the post-singularity intelligences that do emerge from continuing to expand. They certainly have a lot of time available to do this -- the stars are going to burn for a very long time.

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Dyson sphere’s and unlimited colonization appear to be to different solutions to the, not enough resource to support the species problem. Why employ both of them?

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If you want your intelligence to think the maximum number of thoughts and/or maximize its duration (and this seems like a reasonable motivation), you'll use both. Wasting energy by letting stars radiate their energy directly into deep space reduces drastically what any intelligence will be able to achieve, as does limiting the number of stars you wish to colonize.

As an analogy, if a new continent full of resources were discovered on the earth, do you think nobody would go there simply because we have plenty of resources as it is?

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The implication is that the universe may essentially become dark at this time, due to the fact that it's illogical to waste high-energy light.

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Illogical??

Perhaps the problem is that you are suggesting a uniformity that need not exist. While there might well be an infinite number of galaxies that disappear because of the effect you suggest, a much larger frequency will not do so because the necessary parley of events does not occur.

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My assumption is simply that there will be a low concentration (around one per supercluster or so) of post-singularity intelligence that thinks it a good idea to maximize its duration and/or number of thoughts. It could be a bad assumption, but it seems pretty reasonable to me that some of these will indeed show up on the scene in sufficient concentration for the "black out" effect to occur.

[speedfreek]

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Is it possible we could point a beam of light at a distant galaxy, and it never gets there due to the space in between expanding? Either from our frame of reference or theirs?

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Yep, this sort of thing can happen. If I travel sufficiently far away from the earth (in an accelerating universe), I won't be able to get back to earth or even signal back to earth.

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In addition, this is already happening. We don't have to point a beam of light at distant galaxy, our galaxy is already sending light towards distant galaxies that will never reach them (i.e. they will never see our galaxy as it is now, they can only see our galaxy as it was when the apparent speed of recession between us and them was below that of light).

That is unless the hubble constant changes over time (we have some evidence this has happened in the past). Simply put, if the expansion of space ever slows down enough, our light will then be able to catch up with them again!

We have some observations that lead us to conclude that the expansion decelerated early in the history of the universe, and then started accelerating more recently. We can see over a thousand galaxies that are receding from us faster than light, but when their light was emitted the hubble constant was different, (and thus so was the hubble distance - the threshold where we cannot see objects anymore) which has allowed their light to slip into our observable universe.

[MrMon]

If the universe is roughly 10^10 years old and will last 10^17 year, that means it has lived 1/10^7 of its lifetime, or .00001%. Given that 10^10 years is a freakishly long time and is barely a blip in the life of the universe, conserving the energy of the universe should generally be considered a non-problem.

Unless you're Al Gore.

[PairTheBoard]

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If you've got some specific idea for some limiting factor in galaxy colonization, you should say what it is

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The speed of light. Obviously. Any colonization would have to be at a snails pace and could easily peter out

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How long does it take for a beam of light to travel across a galaxy?

As I understand travel at close to the speed of light. Say you travel 1000 light years at close to the speed of light. To an outside observer it will take you 1000 years to get there. Not really that long in this scheme of things. But because of time dilation, the people in the space ship travelling close to the speed of light will only age maybe 1 year. So one way colonization becomes pretty feasible. You just have to go fast enough. How long would it take you to get up to that kind of speed at 1g constant acceleration?

PairTheBoard

[Sephus]

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How long would it take you to get up to that kind of speed at 1g constant acceleration?

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8.5 hrs i think.

[PairTheBoard]

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How long would it take you to get up to that kind of speed at 1g constant acceleration?

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8.5 hrs i think.

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More like 8500 hours or just under a year if you continued to get 9.8m/sec^2 acceleration from the 1g all the way up to the 300 million meters/sec light speed. Of course you can't exactly do this because you would exceed the speed of light in a year's time. But you can come close.

Here's a link to an article on 1g Space Craft

At 1g you could make the round trip of 2,480,000 light years to the Andromeda Galaxy and back in just 60 years onboard ship time. Of course, 5,000,000 years would have passed on Earth. But for one way colonization it's feasible. You just need a good matter to energy propulsion system.

PairTheBoard