YouTube lecture on this by the discoverer, Ryan Williams
Ryan Willaims's paper, "Simulating Time With Square-Root Space
This appears to be based partly but largely on Tree Evaluation is in Space O(log n * log log n)" by James Cook and Ian Mertz (2023 colloqium, STOC 2024 conference).

I'm just a programmer who has spent an hour or so looking at this, so please take the rest of this post with a grain of salt.

I get the impression that Professor Williams's result so far, already a tool for making progress about which computational complexity classes are the same and different, has the limitation of relying on how slow Turing machines are at accessing memory, based on the mention at 18min:50sec into that YouTube Video of how the space savings degrades for a Turing machine with tapes of more than one dimension. If I understand correctly, for such Turing machines, an algorithm with running time bounded above by time T(n) for any input of length n, the space used by this potentially much slower space-saving simulation is bounded by O( ( T(n) + log T(n) ) ** ( 1 - (1/(D+1))) ). I'm using "**" as exponentiation, so the exponent means square root (that is, exponent 0.5) for a one dimensional (linear) tape, two thirds power (exponent 0.66...) for a tape that is a two dimensional surface, 0.75th power for a three dimensional tape, and, so far, no known savings for a tree shaped tape, although I suppose that that three dimensional limit does ultimately apply to real world data storage systems.

More seriously, I wonder if subways currently store some of that kinetic energy by putting the passenger platforms at a slightly higher elevation (not as deep in the ground) in comparison to the other portions of the track. If I have my math right, the kinetic energy of moving at 30 meters per second ( ~67 miles/hour) is approximately the potential energy of an elevation of 45 meters in 1 Earth gravity (0.5mv^2 = mgh --> 0.5v^2 = gh --> h=0.5v^2/g --> h = 0.5(30m/sec)^2/(10m/sec^2) = 45 m/sec). I imagine that that would be much too rollercoastery for a local train, and you wouldn't want to have the train fly off the track so easily for arriving a little too fast, but it wouldn't surprise me if a dip of a meter or two is engineered into subway lines for a bit of energy savings.

They need to weight individual MPs votes by their local approval rating.

Interesting, although the devil is in the details of how approval ratings would be measured.

You might want to consider what other improvements are politically and technically practical. Australia already has a relatively sophisticated vote counting system (instant runoff voting, which is not my favorite, but still pretty good in my opinion). So, perhaps the most universally understandable improvement in responsiveness would come from having more frequent elections. Lowering the stakes in elections and reducing the time that a losing politician needs to wait to run for reelection would encourage them to be slightly more honest in stating their opinions and would give them more accurate feedback about what the public really thinks.