Wind turbines are currently over 100 meters high and installed into places that see lot of wind. It's a rule of thumb that you should keep the natural frequency of any large steel building above 20 hz. Swiching to heavier magnets will increase the mass of the generator which is mounted on top. That in turn will make the whole thing more wobbly (ie lower the frequency). To combat this you need thicker frame. Which in turn will cost more and weight more.
It's completely possible that current windmill designs are only possible with neodymium magnets. We would need to ask turbine designer.
>Education doesn't lead to social mobility, redistribution of wealth does.
I cannot name a single example that would prove this. Having little education and redistribution of wealth has led to whole nation simply getting poor in every example I can think of.
Social mobility != wealth and doesn't even necessarily correlate. Some countries have high mobility and are rich (Germany, Sweden, Canada). Some countries have low mobility and are still rich (US, UK, or maybe for a more extreme example, Saudi Arabia). Some relatively poor countries have low mobility (Brazil, Argentina). Some poor countries have high mobility where the topline is still poor.
Education does help the total wealth of a nation. But education doesn't necessarily help anyone change their social standing within a single country.
My understanding is that you claimed that education does not help one bit to social mobility. On national level, to big groups of people. I still think that is false and I still have not seen any one example that would even rise a suspicion that your claim could be sometimes true.
Doesn't high mobility actually mean that outcomes aren't correlated to inputs, which doesn't seem like an obviously good thing? Low mobility would also mean the same thing. Somewhere in between would be where the actual difference between generations equals the difference in outcomes.
If you use the formula for thick walled cylindrical pressure vessel, you hit practical limit with outside diameter being twice the inside diameter. When this happens and you also take into account fatigue, usually about half of the yield strength of the material is usable.
Your best bet is using thin shells of maranging steel wrapped around each other with thin layer of pressurized non-compressible fluid in between. The pressure control of the fluid is then absolutely critical. Alternate with 0,5mm thick fluid and 1mm thick steel sections. Rinse and repeat. The total thickness would not be all that crazy, but the pressure control would be incredibly expensive.
EDIT: Did some calculations. Using roughly that system I described earlier you would only hit 10 GPa with roughly 50 meters thick piping system, that would have 75 alternating layers of pressurized oil. And each layer would have different pressure from all the other 74 layers of pressurized oil. So not possible.
If you try using single thick wall in your cylinder, increasing the wall thickness means that your max stress gets closer to the internal pressure reading. So you would need material that can deal with 200 GPa of stress.
The real problem was the Marian reforms. With professional army the imperium was able to expand to a size that was impractical to rule. Also success was so thorough that there were no strong enemies left to practice your troops against. And no enemies that would weld the society into single cohesive nation. War protects from despotism, as Kant said. When you don't have to fear war, the wannabe despots start to rob what they can.
Hadrian only saved what he could. And giving the empire some 400 years more life as he did so. And the walls of Constantinople lasted still thousand years after Hadrian had led the way of wall building.
Now if you wish to connect dots to possible downfall of U.S. Then the critical things would be instituting selective service after Vietnam war. And then collapse of soviet union and now U.S. is also lacking credible enemy. With any luck China will quickly rise as competitor.
I think the problem is totally different for those who live to see their projects finished. Then there are people like me who have no such urge.
If a person like me can get into the routine of writing (which would be very difficult trick) then the writing itself would probably be quite easy. There is no fear of blank page, no depressive thoughts of "am I ever going to finish" etc. But there is no reward in the other end of the tunnel either. The writing itself would have to be fun enough.
What you describe seems more akin to why people write diaries rather than write books.
I'm sure I'm over-generalizing but anyone who sets out to write a book has publishing it in mind--and, if they're using a publisher, the publisher certainly does.
Things like blogs blur the boundaries to be sure. But I still view blogs as discrete published items rather than a process I enjoy for sake of the process.
For me, photography is probably more in the enjoying the process camp although I do publish it as well.
You get exactly the same benefit if government only backs 70% of each student loan. Then it's not profitable loan if the student cannot pay back.
But if you keep significant government backing, then the student loans would get lot lover interest rates. Which is probably good for absolutely everybody.
The old school "production lines" are pretty much automated away these days. Most production requiring human labor is custom or small batch jobs. And as a result the real amount of work done is relatively small.
