The Year 2512

Regarding material scarcity, I think space mining becomes a lot more economically viable once you have not only extraordinarily cheap energy, but also super light, super strong materials. Ralph Merkle talks about a diamondoid space shuttle (composed of perfectly arranged carbon atoms) weighing a few hundred pounds and getting to orbit with only a hundred dollars worth of fuel: http://www.youtube.com/watch?v=cdKyf8fsH6w

Also, people have been talking about space elevators forever, once we crack economically viable carbon nanotube production, reducing the cost to orbit by something like 99%.

Most importantly, when people talk about molecular manufacturing and molecular assemblers, they never seem to see the other side of the coin - molecular disassemblers - essentially "just in time" goods. When you can assemble and disassemble atoms at will, you essentially have programmable matter, and therefore you can do much more with less material.

As I mentioned below, you could also make the case that highly realistic VR systems would drastically reduce our demand for materials. After all, who needs to buy an actual Porsche when they can just close their eyes and have an experience much better than the real thing.

Regarding longevity, it seems to me that this is a cognitive bias because of the audacity of the idea, similar to the widespread skepticism towards human flight a hundred years ago. The idea is just so outlandish, and goes against thousands of years of philosophical and theological thought on accepting the inevitability of death, that people (myself included) instinctively recoil from it.

Assuming a 500 year time span - or even a 100 year one - and assuming that humans have developed the capability to manipulate matter at will, can scan and monitor the human body at extraordinarily high fidelity, model and simulate the body in great detail, and can experiment and iterate on those experiments at light speed with the aid of AI and neural interfaces - the death of death seems inevitable.

I don't think this is a real issue. Expensive metals are recycled extremely efficiently even today. This is only going to get easier as we go on.

> You can recycle iron to a degree but a certain amount is lost through corrosion/rust. Rare earth elements are harder to replace.

Iron is the metal that least needs recycling. There are deposits for essentially unlimited amounts at prices not absurdly higher than the present market conditions. Also, should energy get cheaper, iron would be greatly substituted with aluminium in construction. (And the aluminium supplies of the surface of the earth are essentially infinite.)

The talk about REE is largely misguided. REE are not rare. There are exploitable deposits pretty much in every country that's larger than Luxembourg and has exposed rock. The world deposits are greatly larger than any reasonable use we have for them.

The reason REE is in the news is that extracting it is an extremely dirty process, and if you want to do it in a first-world country, you have to pay very much to clean up after you. China captured nearly all of the world production not because they have a large share of a limited resource, but because they allowed miners to dump their separation waste in rivers. This makes REE extraction cost a fraction what it would be if you had to rebury all those unwanted heavy metals, and so the Chinese mines so depressed the market price that all the non-subsidized mines elsewhere in the world shut down. As the Chinese started restricting exports (which is only shrewd of them, considering the massive societal cost they bear of the cheap production), the market price rose again and mines elsewhere started to open. The Mountain pass mine is now finally entering large-scale production, and will very soon make the US a net exporter of REE.

The cost of the raw material used to make fuel is absolutely trivial in all nuclear power plants. The market price of uranium would have to increase by more than three orders of magnitude to increase the cost of produced electricity by 10%. At that point, we have unlimited supplies in seawater.

The capital costs of power plants have trended up as safety and monitoring requirements have risen. Given sufficient automation, AI, and simpler and fundamentally more safe designs (which do not need as much active safety), these costs can probably be brought down.

Assumptions: I think a lot of what we "know" is going to be wrong. It's just a thing which seems likely to me. Not in a "things fall up now" sort of way, though a little of that, since the laws of physics have been revised quite a bit, and I don't see that trend stopping. But more in a "We were pretty much crazy to think these things" way. You know about alchemy's position politically today, and how some of the church's actions were perceived? Some things which we consider important today are going to be treated like that.

History: We'll be better at this. Assuming historians haven't mysteriously vanished as a profession, I think we're going to know more about history in the future, and knowing more about the present in the future. As a collective, I mean, not every individual.

Screwing the world up: Will happen a lot less. We gained raw power in the last 500 years, we're going to learn wisdom now. Or die. That's a possibility, its been discussed. But I'm assuming we survive.

Culture: Will have finally recovered from British expansionism. There will be lots of strong local cultures again.

Government: Will be competent. And not vitriolic. I'm predicting a break from history again.

Population: Will be ignored. Won't be a problem.

Tech: People will get what they want here. Even if what they want is something they've never heard about. And if they don't want it, that will stop it. We got the atom bomb because we wanted to kill people. That will happen less. No flying cars, but maybe hover-boards. Lots of the stuff that we usually relegate to philosophy, or say that is impossible to know, and won't affect anything even if we know it will be known and become part of science. And we'll be better, way way way better, at biology and ecology.

Intelligent Aliens: Will be found, will be relevant to some people's careers, but won't be all that important. Not the main driver of events.

Planet: Will be better, much better. Things will turn around here. People will care about it. The majority doesn't really care about it now, except in a kind of abstract way as it relates to government. But they will care about it later.

Intelligent Aliens: Will be found within a hundred years, won't be important until at least 200 years in.