I think that resource constraints and environmental damage are real, but I don't think they're the cause of collapse.
It seems to me that complexity itself is the cause of collapse. The problem with human societies is that there's no mechanism for reducing complexity. Each feature of a complex society has a stakeholder, someone who would lose out if that feature were reduced or abandoned. So societies grow in complexity without bound until the complexity collapses under its own weight.
A similar effect is very familiar to every engineer, especially in software. Systems grow in complexity until they are unmaintainable. Then you have to trash them and start over. Removing complexity is difficult, because there is a "reason" for every piece of complexity you have.
I don't think inventing Mr. Fusion would stop this cycle.
The problem with human societies is that there's no mechanism for reducing complexity. Each feature of a complex society has a stakeholder, someone who would lose out if that feature were reduced or abandoned. So societies grow in complexity without bound until the complexity collapses under its own weight.
A key here is that we don't have an ethic of just buying these people out.
New York City taxicabs operate on a medallion system where there are always a limited number of licenses to operate a cab and the right, once granted, is permanent. If the city could buy out every medallion holder and charge a fee set every year, it could control the number of cabs and gain more revenue in the long run. But it is politically impossible to persuade the public to pay a million dollars each to buy a medallion back that was given away for free. So the insane permanent-medallion system continues.
The same sort of thing happens with local municipal monopoly franchises, subsidies, agricultural supports in unsustainable regions, water rights, and some public employee deals.
Eventually accumulated special privileges can strangle a state.
It seems to me that complexity itself is the cause of collapse. The problem with human societies is that there's no mechanism for reducing complexity. Each feature of a complex society has a stakeholder, someone who would lose out if that feature were reduced or abandoned. So societies grow in complexity without bound until the complexity collapses under its own weight.
A similar effect is very familiar to every engineer, especially in software. Systems grow in complexity until they are unmaintainable. Then you have to trash them and start over. Removing complexity is difficult, because there is a "reason" for every piece of complexity you have.
I don't think inventing Mr. Fusion would stop this cycle.