rsta223 t1_j9h1x24 wrote

The F-22 officially has a ceiling of 60k, and was apparently at 58k when it shot the balloon (which was at 63k, with the missile covering the 5kft difference).

(As stated by others, this is a U-2, but the 22 could actually get pretty close, and based on the flight envelope diagrams I've seen, even 60k is pretty conservative for the 22, and probably an artificial limit for pilot oxygen/pressurization reasons or something)


rsta223 t1_j1sq6jy wrote

Everywhere had superstitious and totally useless (and often actively harmful) doctors until very recently, with the advent of scientific medicine. Traditional Chinese medicine is just as useless as the four humours or the miasma theory of disease.

China is just holding on to theirs a bit longer.


rsta223 t1_j1km3l2 wrote

>Really depends on your climate.

Nah, all that determines is whether you need a fallback gas system or not. Even in cold climates, heat pumps can take up a significant chunk of the load on warmer winter days and in the shoulder season.

> The curve changes drastically.

Yes, which is why modern systems can choose whether to run the heat pump or the backup heat based on whichever would be more efficient based on current conditions.

>You can barely get parts for heat pumps just a few years old.

That's not a technological issue. In terms of parts and complexity, heat pumps are literally just air conditioners with a reversing valve, so they're not inherently any more expensive or difficult to fix than an A/C

>I live in New England and it’s just not the way to go. Plus good luck finding an A/C tech out here. Most guys just know oil/propane.

That just means that techs need to keep up with the times.

Similarly, if an area has a bunch of coal plant techs and no wind turbine techs, that's not an argument that the next power plant they build should be coal, it's an argument that they should start to train up some wind turbine techs.