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I often have a lot of sympathy for the Lame Stodgy Sensible Center-Left types, but - it is hard to maintain much of that sympathy when I see them posting sneering takes about how only an idiot could fail to support important ideas like (ahem) "teen curfew zones."

Matt Yglesias in recent weeks, notably.

I am aware that DC has an actual current crime problem related to teenagers doing terrible shit. I am in favor of the city finding effective ways to deal with that problem, some of which might be uncomfortably harsh (at least in theory). "Making public spaces inaccessible to people solely on the basis of age" should be about as acceptable a solution as "making public spaces inaccessible to people solely on the basis of race."

The release of Portal was closer to the release of the Game Boy than to today.

Of the people I have least sympathy towards are Little Old Grandmas who just Can't Pay the Property Tax and has to move out of her Sentimental Family Home with only several million dollars of appreciation to tide her over. Just the worst ratio of whining to suffering among the gentry. Spend a week sleeping on the streets and then explain why you need lower property taxes

The blades are moving faster near the tip so the apparent direction of the air (which is the sum of the plane’s linear velocity and the blade’s tangential velocity) changes, meaning the blade actually has to twist to maintain a constant angle of attack. The same thing is true for normal turbofans, the blades are just smaller and enclosed so it’s harder to see.

so do they look different to a regular propeller, like on a Cessna or something, because they have to spin faster?

Pretty much. Conceptually, a propfan is just a turboprop designed to operate in the same performance envelope as a traditional turbofan (30,000 ft, >0.8 Mach). Even regular propellers have a bit of this twist too, but since they spin much slower it’s way less pronounced. One of the big qualitative differences is that traditional props are subsonic whereas to reach the aforementioned performance figures propfans have to be designed for the majority of the blade to be supersonic, and aiui that’s responsible for most of the obvious differences between the designs (more, thinner, bendier blades). Regular turbofans partially get around this by using the cowling inlet to slow the incoming air, so the majority of the blade sees a subsonic airstream. The tips are still supersonic, but being right up against the cowling helps suppress a lot of the noise and inefficiency that would otherwise produce. The fact that propfans are exposed to the full unmitigated airstream and have nothing to help suppress the tip shocks is most of what makes them challenging, I believe.

I see, lots of tiny little sonic booms, sounds like the cavitation difficulties that afflict fast water props.

Ok am I the one who has to be juvenile and note the positioning of the two planes in the preview image and the phrase "it's really coming"

#the reason that lab safety regulations are the way they are is because literally all chemists are like this #as in 100% of them #no exceptions (via @prokopetz)

My grandfather got the GI bill after the war and decided to become a chemist. He was a year into his degree when he spilled something on himself in the lab. The way he told it, he watched whatever it was start to dissolve the leather apron he was wearing, thought about what it might be doing to his lungs, and after calmly removing the apron, became an architect instead. I think chemists are Like That because the sane ones all self-selected out of the pool.

cocktail recipe