I’ve been using Fastmail for years now. Easy to use, reliable, and consistent. No major extra features but that’s exactly what I want for an email provider! I see it recommended here sometimes, so I’m happy to be that guy today
IIRC the original bolts were opaque in the middle and hazy around the edges. It felt like they were blinding even to cameras and visors. New ones were thinner and evenly transparent, as if someone overlaid some cheap translucent plastic
Depending what kind of reading material you're looking for (e.g. high level details or mathematically/jargon dense papers) look for things discussing "Rosseland optical depth" and "grey atmosphere approximation".
At a high level, the common convention is to define the radius by finding where the optical depth is 2/3 when using Rosselands clever way of calculating a weighted mean of the opacity from that layer in the star to space across different wavelengths of light. 2/3 being a clever derivation from Eddington where, in an idealized model of a star, that's when the actual temperature of the star should equal its blackbody equivalent temperature.
Pedantically, this distance to the point of equality is an ever so slightly different value than the "distance from the center where there is a 50% chance a photon traveling directly outward will escape the star without another interaction" rule of thumb (in the same idealized grey model). Practically, that the difference is so small is why it's a fantastic rule of thumb explanation.
Jesus Christ on a pogo stick, execution for stealing 12 pence worth of stuff? That's crazy! Adjusting for inflation[1][2], that would be the same as nowadays being executed for stealing £5!
reply