Although it now seems as if that was massively inaccurate, things were very near to turning out completely differently in the first days of the war: https://www.youtube.com/watch?v=QlttS0N7uVA
"A study using a complex mathematical technique claiming to cleanly isolate the effect of X and Y. I can't really follow what it's doing..."
This is a frustrating type of issue. Dismissing something with "I don't understand this, but I don't believe it" isn't the sort of thing I want to be doing. However, I don't have any desire to waste time trying to understand what someone has done (and did they really understand what they were doing themselves?) when it's clear that the effect isn't cleanly isolated in the data and no amount of mathematics is going to change that.
Yeah, I'm always a bit suspicious of apparently effective dietary changes which result in a calorie reduction - often different people report completely different dietary changes helped them, but one thing they all have in common is being in calorie deficit.
There are plenty of studies showing that caloric restriction calms inflammatory responses which are responsible for the majority of common diseases. Without balancing the energy intake, I'm always slightly suspicious that any improvements with changing what I eat are actually caused by the change in how much I eat.
I don't see why that means there's anything off. Just because most of us can't produce enough energy per unit time to maintain this pace doesn't mean that it's not the most efficient pace per unit distance.
Anecdotally, when I start (or re-start) running I find the pace I can run at increases quite rapidly. That makes sense with this data - although my fitness is only increasing slowly, being able to produce slightly more power actually gives a disproportionate increase in pace because the higher speed is more efficient per km.
Yeah, the potential loading is annoying.
I remember wondering why predestrian/cycle bridges were always so annoyingly narrow despite having low loads.
The issue is of course that they have to be strong enough to support being crammed with hundreds of people when everyone is there to watch the local fireworks/rowing race/anything else that's happening, even if that happens almost never.
I can recommend this film from one of the last commercial sail ships rounding Cape Horn in 1928 during some big storms, narrated by an experienced captain.
https://www.youtube.com/watch?v=ZLzBDhilDL0
That sounds massively expensive. Being very generous and assuming that the piston is the length of the hole and can rise out completely, then the energy storage is still only a few times that required to pump all the water out of the hole. It doesn't start to compare to the volume behind a hydro dam (which may then have a large vertical drop to the generator further down-river), but is still much more complex.
Another proposed idea for places that have deep seas or lakes is pumping air down into a storage at the bottom of the water. This storage can even being a flexible plastic - there isn't any high loading on it because the pressure balances out. The issue with that tech is that it's not that efficient, as compressing the air going down generates a lot of heat - some of that could potentially be recovered, but there's a trade-off with simplicity. Also if the containment fails then a lot of air bubbles to the surface, potentially sinking any ship on the surface at the time.
It's surprising how well these ships sail; although square sails are often thought of as only being effective going down wind, they sail somewhat into the wind fine. And of course, you don't have to worry about a bad gybe removing your rigging.
I was in Norway a few years back and took a tourist trip in a 2/3 replica of a Viking boat found in a burial mound - the crew took us up the lake, turned round and came straight back - it was remarkably nippy and seemed to handle very well. I'd be interested to read how the much larger ship here performed under sail.