> gravity at high energies

Not a physicist so excuse the ignorance, but do we understand gravity at all?

I mean afaik we can observe and predict it's behaviors but do we understand what underlying force causes it, and if it potentially has a counter force.

Well, at sufficiently low energies and sufficiently large length scales we can say gravity is how space time curves under the influence of energy (principly from gravitational mass; another mystery, why gravitational and inertial masses proportional to each other). This picture is called general relativity and it works very well in a wide range of regimes (from motion of planets and galaxies to merger of black holes). However, there should be an exchange of force carrier description (quantums of graviton) at small enough scales or very large energy densities where we fail to make the math work (because we expect certain properties/symmetries from gravitons).

So the word "understand" is a bit loaded. GR is a certain understanding of how gravity works, but it is not a "quantum mechanical" understanding.

The difference between the problems physicists were tackling at the turn of the 20th century and the ones we're trying to tackle today is that we don't have the technology or the resources required to build the kind of experiments that would allow us to study these phenomena at a meaningful scale and test out our hypotheses.

E.g. https://gizmodo.com/we-could-solve-the-mysteries-of-time-and...

"We Could Solve the Mysteries of Time and Space—If We Had a Particle Accelerator the Size of the Solar System"

That's the problem. Our collective civilization will need to move a few levels forward before we can afford to tackle these problems.

But the same was 100,200,300 and so years ago. Thete were always some sort of limitations, mostly technological. I'm not saying that we'll build solar system size colliders any time soon, however 50-100 more years and we should be much much more sophisticated in terms of what we can do in space and back on the earth.

Linear extrapolation is not always adequate. I tend to agree with GP that we may be close to a saturation point.

We're possibly within a few orders of magnitude of the saturation point, wielding the resources of a single planet.

Which leaves the obvious path forward...

This is not clear to me at all. I don't think "bigger particle accelerators" is what we need, and lots of the questions I posted are not necessarily solvable by particle accelerators. We do need new experiments, but probably in a sense of "new ways to observe the universe" rather than "old ways to observe the universe scaled bigger."

I personally believe a lot of that stuff cannot be further studied unless we are able to divert solutions to other problems in our society first. I'm saying that we need to have things like mass quantity sustainable energy, significant automation, global unification and standards, higher minimum education levels.

I'm saying that imagine 50% of the population works in blue collar general labor or semi-skilled labor fields. Now in this hypothetical worlds, all those jobs are managed by autonomous robots. Also we have a green power that is sustainable, storable, sufficient for even double the population, and can be held in high densities at low volumes. So there are now innumerable sectors within the economy that we don't need people themselves to learn. That leaves more time for people to take extended amounts of time to learn and study. I mean quite literally a Star-Trek "post-scaricity world" in a lot of ways. People use time to further themselves and expend time on cultural or scientific endeavors. Life is no longer about struggle and survival since money clearly would have no value if any and everything can be made or consumed for free. I mean it's really interesting to think that the only "conflict" that would exist is between people trying to min-max life in terms of achievement. There would be no achievement in religion, money, or ownership since everybody can do it.

Ultimately what I'm saying is that a lot of our advances are contingent upon other sectors becoming automated and allow for more people to get into academic sectors.

The 50% of the population who are blue collar workers aren’t going to retrain as particle physicist or theoretical computer scientists one they get their UBI.

I mean we could hash out all hypothetical all day. I'm just saying that the needs of the economy would shift to that where a PhD basically becomes the new High School Diploma. In essence, entry level jobs would be stuff that today would legitimately require a masters or higher.

I'm not saying that 100% of that 50% will be employable in this world. I'm saying that over time that 50% will inevitably become that bare minimum. The way I see it is 150 years ago, your idea would be that we couldn't possibly get all children to become educated at an 8th grade level, yet here we are, even making an HSD the bare minimum.

Eventually your masters thesis will be an area for you to study and pursue to make an attempt at furthering society.

I'm much more concerned about how we keep that portion of the population entertained enough to not cause trouble.

I am inclined to say the real problem is that smart people don’t have kids. But we’ll probably figure out how to make all babies intelligent before that becomes a problem. Incidentally, the problem you mention will also be solved in the same way.

genuine question - what do you mean by smart people? High IQ? Deep knowledge about mankind's place in the Universe / natural order? or their ability to maximise their own personal happiness over their lifetime? If the last point, then personal experience would suggest that having kids makes you happier person (once they are sleeping through the night)YMMV

Probably a high 'g factor' ( https://en.wikipedia.org/wiki/G_factor_(psychometrics) ).

High IQ.

The criticisms section in the Fertility and intelligence article on Wikipedia is interesting https://en.m.wikipedia.org/wiki/Fertility_and_intelligence#C...

Where does population control enter into this hypothetical?

Because that's the only way you get to post-scarcity.

Pretty much any study of the past century and any projection from reputable sources says that populations reach equilibrium and stop growing as the level of education, in particular education of women, rises.

This is a non-problem that has always taken care of itself in any developed country and we have no reason to believe it will not take care of itself in the developing world as well.

The UN for instance does not believe there will be 10 billion humans on earth ever (where "ever" means "as long as projections have any value").

I wouldn't quite call world population growth a non-problem, considering it is already a problem. The future predictions may well turn out correct, and have some solid reasoning behind them, but the numbers still look fairly crude to me. Plots of historic growth rates are bouncing up and down, while the prediction is they will suddenly turn a corner tomorrow and drop monotonically to zero and all will be peachy. How often has that happened? Considering the current record-breaking population numbers, the ultimate answer is it has never happened, at least not permanently. There's a lot of risk in betting on things to just work themselves out. Development can actually work against us in a sense, as new food production technology and cures allow faster-than-ever growth in new regions and populations.

The belief that world population will self-level at some point does not mean that it will self-level prior to resource exhaustion.

The fact that we're cooking the planet with ~8B does not bode well for what even 10B looks like.

Fertility is heritable. Population will probably continue to rise.

And yet, basically every developed country is below the replacement rate.

Below replacement fertility is a recent phenomenon (last couple of generations). Evolution works in multiples of generations. We’re at the very beginning of evolving resistance to modernity.

How many countries are "developed"? And how quickly will the remainder join them?

Education, quality of life and equal opportunities for women. As these increase, the birth rate goes down. Most countries that score highly in these areas actually have below replacement birth rates and only grow in population due to immigration.