While we dither on the planet, are we losing resources in space? Nick Bostrom has an article on astronomical waste, talking about the vast amounts of potentially useful energy that we're simply not using for anything:
As I write these words, suns are illuminating and heating empty rooms, unused energy is being flushed down black holes, and our great common endowment of negentropy is being irreversibly degraded into entropy on a cosmic scale. These are resources that an advanced civilization could have used to create value-structures, such as sentient beings living worthwhile lives.
The rate of this loss boggles the mind. One recent paper speculates, using loose theoretical considerations based on the rate of increase of entropy, that the loss of potential human lives in our own galactic supercluster is at least ~1046 per century of delayed colonization.
On top of that, galaxies are slipping away from us because of the exponentially accelerating expansion of the universe (x axis in years since Big Bang, cosmic scale function arbitrarily set to 1 at the current day):
At the rate things are going, we seem to be losing slightly more than one galaxy a year. One entire galaxy, with its hundreds of billions of stars, is slipping away from us each year, never to be interacted with again. This is many solar systems a second; poof! Before you've even had time to grasp that concept, we've lost millions of times more resources than humanity has even used.
So it would seem that the answer to this desperate state of affairs is to rush thing: start expanding as soon as possible, greedily grab every hint of energy and negentropy before they vanish forever.
Not so fast! Nick Bostrom's point was not that we should rush things, but that we should be very very careful:
However, the lesson for utilitarians is not that we ought to maximize the pace of technological development, but rather that we ought to maximize its safety, i.e. the probability that colonization will eventually occur.
If we rush things and lose the whole universe, then we certainly don't come out ahead in this game.
But let's ignore that; let's pretend that we've solved all risks, that we can expand safely, without fear of messing things up. Right. Full steam ahead to the starships, no?
No. Firstly, though the losses are large in absolute terms, they are small in relative terms. Most of the energy of a star is contained in its mass. The light streaming through windows in empty rooms? A few specks of negentropy, that barely diminish the value of the huge hoard that is the stars' physical beings (which can be harvested by eg dropping them slowly into small black holes and feeding off the Hawking radiation). And we lose a galaxy a year - but there are still billions out there. So waiting a while isn't a major problem, if we can gain something by doing so. Gain what? Well, maybe just going a tiny bit faster.
In a paper published with Anders Sandberg, we looked at the ease and difficulty of intergalactic or universal expansion. It seems to be surprisingly easy (which has a lot of implications for the Fermi Paradox), given sufficient automation or AI. About six hours of the sun's energy would be enough to launch self-replicating probes to every reachable galaxy in the entire universe. We could get this energy by constructing a Dyson swarm around the sun, by, for instance, disassembling Mercury. This is the kind of task that would be well within the capacities of an decently automated manufacturing process. A video overview of the process can be found in this talk (and a longer exposition, with slightly older figures, can be found here).
How fast will those probes travel? This depends not on the acceleration phase (which can be done fine with quench guns or rail guns, or lasers into solar sales), but on the deceleration. The relativistic rocket equation is vicious: it takes a lot of reaction mass to decelerate even a small payload. If fission power is used, decelerations from 50%c is about all that's reasonable. With fusion, we can push this to 80%c, while with matter-anti-matter reactions, we can get to 99%c. The top speed of 99%c is also obtainable if have more exotic ways of decelerating. This could be somehow using resources from the target galaxy (cunning gravitational braking or Bussard ramjets or something), or using the continuing expansion of the universe to bleed speed away (this is most practical for the most distant galaxies).
At these three speeds (and at 100% c), we can reach a certain distance into the universe, in current comoving coordinates, as shown by this graph (the x axis is in years since the Big Bang, with the origin set at the current day):
The maximum reached at 99%c is about 4 GigaParsecs - not a unit often used is casual conversation! If we can reach these distances, we can claim this many galaxies, approximately:
Speed | Distance (Parsecs) | # of Galaxies |
---|---|---|
50%c |
1.24x109 | 1.16x108 |
80%c |
2.33x109 | 7.62x108 |
99%c | 4.09x109 | 4.13x109 |
These numbers don't change much if we delay. Even wasting a million years won't show up on these figure: it's a rounding error. Why is this?
Well, a typical probe will be flying through space, at quasi-constant velocity, for several billion years. Gains in speed make an immense difference, as they compound over the whole duration of the trip; gains from an early launch, not so much. So if we have to wait a million years to squeeze an extra 0.1% of speed, we're still coming out ahead. So waiting for extra research is always sensible (apart from the closest galaxies). If we can get more efficient engines, more exotic ways of shielding the probe, or new methods for deceleration, the benefits will be immense.
So, in conclusion: To efficiently colonise the universe, take your time. Do research. Think things over. Go to the pub. Saunter like an Egyptian. Write long letters to mum. Complain about the immorality of the youth of today. Watch dry paint stay dry.
But when you do go... go very, very fast.
I think there are two potential problems with this argument, given below.
For these reasons, I think in practice everyone will keep dividing resources between both research and launching probes with existing technology, as soon as we have technology good enough to launch colonizing probes at all, even extremely slow ones at (say) 0.01c to neighbouring stars. Of course there'll be different tradeoffs depending on the balance of costs: perhaps research is hard but probes are cheap. As a result, there will be some waste of resources as later, faster probes overtake earlier slow ones.
Competition:
If you were alone in the universe, or could speak for everyone even when they're spread out across a galaxy, then your analysis would work. But if, deciding for yourself, you wait and research, then others could launch first. Since others generally have different values, and because people want things for themselves and their own clans, this is undesirable. So people will launch first to get first-mover advantage.
Suppose your research will eventually develop fast probes that can overtake their earlier, slow probes (though you can't be certain ahead of time, when deciding not to launch). The sphere of space right around you will have been taken by others, which is not a good position to be in. They might be able to stop you from spreading your probes through their occupied space, if they choose. Or they could use their resources to interfere directly to stop you from launching probes.
Even others who are generally friendly may prefer to lose some time copying your fast probe technology, to having most of the universe settled by you instead of them.
In fact, it might be much easier to buy, copy or steal new technology than to develop it in the first place. Then if I know others are working on research, I may decide to launch early and try to free-ride on their research later. In particular, if people wno do research aren't guaranteed to share the results with all of humanity - if not everyone is offered to be a part of the research project, or has resources to contribute to pay their way in, or lightspeed limits prevent cooperation across star systems - then those excluded will launch slow probes if they can, and hope to acquire the fast probe technology later.
Competition and value divergence may be prevented by a singleton AGI. Fear of such a singleton appearing will drive people to colonize other stars before it happens, and to keep expanding instead of slowing down to research. Some people believe that the only probably futures in which we colonize other stars at all, are ones in which a Friendly AI singleton is created first. This sounds probable to me, but not the only possibility.
Acquiring more resources:
(HaydnB already suggested the first part of this.)
Suppose it's expected to take a long time to develop faster probes, compared with the time it takes to settle and develop new nearby systems with existing, slow probes. Then it would be worthwhile to divert some resources to expanding with slow probes, and then use the acquired resources - new settled systems - to speed up the research. This might lead to the same balance of "always send out probes of existing technology, and divert some percentage of resources to research for faster probes."
Why would that be possible? If the research is expected to take a long time despite big investments, there is probably a limiting factor that can be raised by adding resources of some kind. Like matter/energy/space for building things and running experiments. Or like more sentient minds to do research.
Also, if new star systems can become highly developed quickly enough - compared with the time you need for your research - then it's more likely faster probes will first be developed on one of the many worlds first settled by slow probes, than by those who stayed behind, simply because there are many new worlds and few old ones. For reasons of competitino, people will want to settle new worlds to increase the chance that they or their descendants will first develop new faster probes and colonize even more worlds.
Differences of distance:
Matter is clumped on different scales: as stars and planets, then star systems, then galaxies, then groups and clusters, superclusters, sheets and filaments. At each transition there is a jump of many orders of magnitude in the distances involved. So if expansion is going to stop temporarily, it will probably be at one of these points. (We've stopped for a long while after colonizing the entire planet.)
I really want to read Stuart's response!
p.s. Thanks for the HT