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Once we can see them, it’s too late

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Re: Once we can see them, it’s too late

#71

Post by ndjtjgkglf »

tzs wrote: post #67
ivalm wrote: post #18

This kind of assumes that a “maxed out” civilization can expand at speed of light, but I don’t think it is given. It may very well be that meaningfully massive transport cannot exceed even a small fraction of c . After all, propulsion has to make energetic sense. 1. There is energy to get to speed 2. Mass of fuel to decelerate (and you have to accelerate that fuel in the beginning!) 3. Highly blue shifted CMB (that a…

Sometimes I wonder if a prerequisite to becoming the kind of civilization that could span a large volume of space is becoming the kind of civilization that has solved the problems that might drive a civilization to need that kind of expansion. Consider Earth. If we set T=0 at one year ago, and assume that there really is no way around the speed of light, then it follows that by year N, every human alive must be withi…

You might want to read about matroska brain - star and then galaxy sized sentient computer.

Meaning a single individual would be and use the whole galaxy.

Re: Once we can see them, it’s too late

#72

Post by Terr_ »

tzs wrote: post #67
ivalm wrote: post #18

This kind of assumes that a “maxed out” civilization can expand at speed of light, but I don’t think it is given. It may very well be that meaningfully massive transport cannot exceed even a small fraction of c . After all, propulsion has to make energetic sense. 1. There is energy to get to speed 2. Mass of fuel to decelerate (and you have to accelerate that fuel in the beginning!) 3. Highly blue shifted CMB (that a…

Sometimes I wonder if a prerequisite to becoming the kind of civilization that could span a large volume of space is becoming the kind of civilization that has solved the problems that might drive a civilization to need that kind of expansion. Consider Earth. If we set T=0 at one year ago, and assume that there really is no way around the speed of light, then it follows that by year N, every human alive must be withi…

> Sometimes I wonder if a prerequisite to becoming the kind of civilization that could span a large volume of space is becoming the kind of civilization that has solved the problems that might drive a civilization to need that kind of expansion.

Or we may just discover new risks to avoid. Our ancestors created new villages because the river dried up, we might want other planets due to extinction-level asteroids, and our descendants may need to sidestep The Interstellar Ooze or whatever.

Re: Once we can see them, it’s too late

#73

Post by 5nlight »

If you look carefully enough at the implications of our situation through the lens of the 2nd law of thermodynamics, the Fermi paradox becomes a lot less paradoxical.

Edit: Apparently I have violated a HN taboo in even daring to mention that bothersome little law.

Understanding it and its implications and applying that knowledge to our IRL situation on earth might not be fun, however IS fundamental to making plausible statements about perpetual motion and related topics (i.e."von Neumann probes.")

Now, all that remains to be seen, this being HN, is: Will this comment be downvoted into oblivion without a good reason being proferred?

Re: Once we can see them, it’s too late

#74

Post by lebuffon »

Or... is it possible that we are not supposed to meet the "others?

Consider: If you wanted to build a "terrarium" for sentient evolving life forms how would you keep them from escaping?

1. Make the distances really really big 2. Put a speed limit in the environment

Rolled up with the Fermi paradox this simulation has "smelled fishy" to me for some time. :)

Re: Once we can see them, it’s too late

#75

Post by kurthr »

ivalm wrote: post #18

This kind of assumes that a “maxed out” civilization can expand at speed of light, but I don’t think it is given. It may very well be that meaningfully massive transport cannot exceed even a small fraction of c . After all, propulsion has to make energetic sense. 1. There is energy to get to speed 2. Mass of fuel to decelerate (and you have to accelerate that fuel in the beginning!) 3. Highly blue shifted CMB (that a…

If you can seed enough intelligence with self replicating "nano-machines", which seems reasonable, then you can accelerate clouds of that material at quite close to the speed of light with high power lasers, much like diffuse solar sails. No need to carry large payloads, reaction mass, or energy... those are at the endpoint where you find them (and convert them into grey-goo?).

It's more of a viral mode of expansion where (virus) seeds carry the operational commands to new worlds (cells) which host them until they are consumed by the continued expansion. The intelligence and power consumption are concentrated where it's available, while passive catalytic action and stored knowledge is transported at speed.

Re: Once we can see them, it’s too late

#76

Post by bob33212 »

AnimalMuppet wrote: post #66
bob33212 wrote: post #39

Earlier quoted context omitted.

We are within 500 years of creating millions of self sustaining spaceports. We are within 500 years of AGI. We are within 500 years of understanding quantum gravity. We are within 500 years of fixing biological death. The order we get to those and how they interplay and change the world matters so much that it doesn't make sense to worry about making predictions.

You state these "we are within 500 years" as if they are certainties, but you show no evidence for any of them. The only one I consider even slightly likely is that we are within 500 years of understanding quantum gravity. So... evidence? Argument? Just stating baldly that it is so is not very convincing.

I don't have a time machine so no I cannot prove what will happen in the future

Re: Once we can see them, it’s too late

#77

Post by thesteamboat »

Pazzaz wrote: post #23

An interesting paper that I don't see brought up often enough is "Dissolving the Fermi Paradox" by Anders Sandberg, Eric Drexler and Toby Ord[0]. They show that it isn't a surprise that we are alone in the universe if we consider the uncertainty inherent to parameters of the Drake equation. Their analysis estimate that there is (at least) a 39% chance that we are alone in the observable universe. [0]: https://arxiv.o…

From a previous discussion of this paper I took away the following clarifying insight:

The Drake equation is usually turned into the Fermi paradox via some estimations that show the average (mean) number of alien civilizations we expect to see is large (>1).

However, just because the mean is large does not imply that seeing 0 is low probability.

More concretely, suppose there were 10 possible 'parallel' universes. In 9 of them humanity is alone and in the tenth there are tens of millions of alien civilizations. The probability of appearing to be alone is 90% even though the number of alien civilizations we'd expect to see is in the millions.

Re: Once we can see them, it’s too late

#78

Post by krapp »

thesteamboat wrote: post #77
Pazzaz wrote: post #23

An interesting paper that I don't see brought up often enough is "Dissolving the Fermi Paradox" by Anders Sandberg, Eric Drexler and Toby Ord[0]. They show that it isn't a surprise that we are alone in the universe if we consider the uncertainty inherent to parameters of the Drake equation. Their analysis estimate that there is (at least) a 39% chance that we are alone in the observable universe. [0]: https://arxiv.o…

From a previous discussion of this paper I took away the following clarifying insight: The Drake equation is usually turned into the Fermi paradox via some estimations that show the average (mean) number of alien civilizations we expect to see is large (>1). However, just because the mean is large does not imply that seeing 0 is low probability. More concretely, suppose there were 10 possible 'parallel' universes. In…

You don't even need to invoke parallel universes. Look at the Hubble Deep Field photo[0]. Our observable universe has hundreds of millions of galaxies. It's entirely feasible for tens of millions of alien civilizations to be spread about and not visible to us in the narrow window of space and time in which we've been looking.

[0]https://en.wikipedia.org/wiki/Hubble_Deep_Field

Re: Once we can see them, it’s too late

#79

Post by PeterisP »

amelius wrote: post #15
larsiusprime wrote: post #5

This seems like a variant of a hypothesis I've heard before: "The universe is old enough, and the rate of expansion of a spacefaring civilization is fast enough (relative to the age of the universe, even at sub-light speeds) that either the aliens should already be here since long ago, or we're the first (or among the first)." ?

How do you determine who was "first" when simultaneity doesn't exist on a cosmic scale?

Well, at any given point of reference (e.g. a star or galaxy) there's a clear ordering of events, who is first there. And the relative velocities between different stars and galaxies aren't that large; if we're speaking also about cosmic time scales (e.g. not days or years, but millions of years) then there's no need to involve relativistic reasoning about who's first.

Re: Once we can see them, it’s too late

#80

Post by gmuslera »

TeMPOraL wrote: post #59
lisper wrote: post #41

Earlier quoted context omitted.

But first you have to deliver the printer to the destination somehow.

Here's an idea. Imagine you have a way to build von Neumann probes that can boost themselves to some high fraction of c (say, 0.9). You start pumping them out in your home system, and send them towards some stars - not necessarily the closest ones. You keep sending them . There's now a shell expanding at 0.9c that's shaped by your production capabilities. Of course, the probes will spend time accelerating and then de…

Suppose that there is no need to have in the equation living beings. So you have your von Neumann probes assimilating all the matter in their path into new von Neumann probes, lets call them Borg von Neumann. And they are nodes of a collective /distributed "computing" scheme called Alien Civilization 3.0.

Still you need time to stop, make your conversion, pick next target, accelerate and deaccelerate. And you may be turning everything into nodes, i.e. suns, exoplanets, etc. As we find stars pretty far away and exoplanets in far away solar systems, we are safe for some million years at the very least, even with relativistic speeds.

And still, it is about what we think with the wrong mindset and a lot of unknown unknowns to properly understand the problem. Expanding may be obviously wrong for advanced enough... something.

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