Politics in the Milky Way

What's your perfect profession? If you could pick out of every job that has existed or will exist, what would you do? I know my answer. I would be an archaeologist.

That may seem odd since the profession already exists and I am in an apprenticeship to become a physicist, but give it a few thousand years. The job is going to become infinitely more interesting.

What empires ruled or perhaps still rule the stars? What insane monuments are out there in the dark. I don't know so I decided to simulate my own political history of the Galaxy!

I made a cellular automata, a model where the value of each cell updates according to the values in the cells around it, and have concluded that the Galaxy is probably divided and in a state of technological stagnation.

Here are the rules of the game:

1. No breaking the light barrier. We assume there is no workaround. The speed of light remains a limitation on life forever.
2. Civilisations spread at a large fraction of the speed of light. Although the speed of light remains a barrier, technology that allows races to move and communicate at close to the speed of light is developed relatively quickly.
3. Innovation slows with time. It becomes harder and harder to develop technology that gives a strong advantage to one civilisation over another as time progresses.
4. There is a fixed likelihood that members of a culture will drift away from that culture and become something entirely new.
5. When two civilisations meet the one with the superior technology will always either replace the other civilisation or share its technology with them.

Nobs we can turn on the model:

1. The probability that alien civilisations arise in the time it takes for the first civilisation to spread across the galaxy.
2. The probability that innovation will be made.
3. The probability a civilisation will share its technology with an alien one.
4. The probability part of a civilisation will drift away and form an enclave.

We can consider these 4 probabilities either high or low. This gives us 16 possibilities for how, qualitatively, history might go. Don't click off yet! It turns out this can be reduced down to 3 cases and every case has the same solution in the limit.

Case 1: Tapestry of life

If the probability of cultural drift is very high then even as a civilisation spreads it loses its identity and becomes a collection of thousands or even millions of empires.

Case 2: Grabby Aliens

Robin Hanson and colleagues recently proposed that “Grabby Aliens” could be the reason why Humanity seems to have arrived cosmically early. In the Grabby alien model there is no conflict between aliens.

Since war is so rare the probability of innovation is irrelevant to the politics as it is almost always instantly shared. If Grabby alien civilisations are very common then something resembling the tapestry case will form quite quickly. If they are rare then a few cultures, or even a single one, will dominate early history before the galaxy tends to the tapestry case as cultural drift occurs.

Case 3: Cosmic war

If the expansionist civilisations are rare then a single culture will come to dominate the galaxy.

If they are common then the early history of the galaxy is dominated by war. The higher the rate of innovation the more stable this warring state is. Innovations that lead to territorial gains for one side will quickly be matched by the opposition. As the probability of innovation decreases this state will become unstable and rivals will either eliminate each other or make peace.

If peace prevails then cultural borders stretching across the Galaxy could persist for long eons (depending on the rate of cultural drift).

Conclusion

With the assumptions I have made, my model always tends to a semi-stable tapestry state. In other words, a Galaxy divided where no culture can gain an advantage over the others due to a homogenous distribution of technology.

What do you think those future archaeologists will find in the stars?

Hanson, R., Martin, D., McCarter, C., & Paulson, J. (2021). If Loud Aliens Explain Human Earliness, Quiet Aliens Are Also Rare. The Astrophysical Journal, 922(2), 182.