I started reading Josephine Quinn's book "How the world made the west" and I can recommend it. It goes quite into detail and is not of the sort "coffee-table"-style picture book. It explains the origins of technologies, trade between groups and challenges the common view how civilizations evolved.
Based on reading the Guardian review (that predictably praises it and seems to be written by someone who doesn't know much history) and a much better review on a website run, weirdly enough, by Christians (written by someone who does know history), I would agree.
The first half of the quality review praises the good parts of the book, the second half is where the meat is.
It is probably a useful book if you don't know much about the classical world but it doesn't seem like one should take one's politics from it.
The author is a professor of ancient history at Oxford University. What makes you think it is political? A book can specialise in Western history without having a hidden agenda.
Most relevant part: “By applying a total of 950 square meters of AeroSHARK riblet film to the fuselage and engine nacelle surfaces of a Boeing 777, fuel savings of approximately 1.1 percent can be achieved.”
Seems hardly worth it ? 1.1%? What about the cost of application and maintenance ? I’m guessing it’s plastic too, which will pollute the environment somehow.
Expectation of success or profit = P(success)reward - P(failure)penalty - opportunity cost (TCO)
Supposed these panels were $100k/plane.
Jet fuel costs $0.36/lbs and a 777 burns about 30 lbs/nm in cruise. Suppose a 777 averages 14,000 nm/day. That's 420,000 lbs/day or $151,200/day. 1% savings would be $1,512/day, so the break even point would be roughly 2 months and would be profitable from then on. Suppose a 2 year lifecycle. That a savings $500k per year per plane.
Put a little more thought and data into your comments if you would be so kind.
The plane can carry 45,000 gallons of fuel. 2.1 bucks a gallon. So probably 500 bucks of savings a flight since most flights arent full capacity. 130k flights in '23. So ez 65 million in savings a year.
Worth doing for the environment even if it's cost neutral probably.
That provides more information (and visuals) on the technology itself.
I've spent a few minutes looking for imagery of the film itself, sufficient to show details. There's surprisingly little, and I suspect the manufacturer doesn't want visual details of the skin itself available.
There's a schematic in the link below, which also shows the contrast of the AEROShark film to actual shark skin. The film is more grooves than scales, for those curious.
The Swatch brand was founded 1983 by ETA CEO Thomke and his Engineers. ETA is a watch movement manufacturer.
Speaking of Swatch and mechanical watches: the Sistem51 is an interesting watch, since it's the only mechanical watch ever fabricated in a 100% automated production line. The parts are welded together and held by a single screw.
https://www.swatch.com/en-us/sistem-51.html
"Near Ticino" is relative. ;) This article is about a famous rocky cirque in the french part of Switzerland, so a completely different region, in Swiss scales. However, around 150 km and some high mountains apart.
Interesting article, thanks!
From the article: "The reason grottos worked so well as natural fridges is due to their excellent ventilation. Since they usually occurred on rockfall or on an accumulation of scree, they have a porous foundation that guarantees internal air circulation and results in a year-round stable temperature..."
Maybe rocks in the scree cool down the air in the pores between them. Cool air is denser so it sinks and flows out at the bottom of the porous layer, and new warm air is pulled into the ground towards the top of the scree pile. People found the places that cool air was flowing out and built these grottos there. Not saying I knew anything about these before 10 minutes ago, but that seems plausible to me.
IANAGeologist, but my understanding is that when a steady wind blows from underground it's often due to a naturally occurring trompe: water flowing underground entrains air bubbles which collect in caverns and leak back to the atmosphere. Trompes can be quite large.
