Zany measurements and theories

I suspect that the vinyl that deflects from friction heat returns quickly to its
original form and is back to room temp before the record is finished playing.

For all this talk about a 24-hour cooling off period, is there any resarch to
verify this--with electron micrographs and temperature measurents with a
cooling-off timetable? No? Then a dogma has once again risen out of worst-
case speculation of a theoretical scenario with no verification.

Pressure is force/unit of area. For a phono stylus the force is small but the contact area is very, very small. Result, high pressure.

For another example,consider ice skates. Ice occupies more volume that liquid water, hence high pressure lowers the melting point (Le Chatelier's principle). Since the contact area of the skate is small, the pressure is high. High enough to melt the ice temporarily and lubricate the skate.

"Then a dogma has once again risen out of worst-
case speculation of a theoretical scenario with no verification."

It's not speculation. The contact point does get very hot. I did list 2 publications in my last post that dealt with this topic.

If you want some type of scientific explanation, look at it this way: How could there not be heat generated when playing a record. There's friction. I has to heat up.

Most estimates for stylus surface temps range between 300-
500 degrees(F). The temperature of your record will be
at(or close to) room temperature, except at the point of
contact with the stylus. Much will depend on VTF and
RPM(higher numbers there=higher temps). You're only talking
about milliseconds of contact, between the sylus and any
given point in the groove. Maybe a few molecules of vinyl
will be heated and the surrounding vinyl acts as a
heatsink(ice skate example, on a much smaller scale). I've
got a number of test records, that I used in my shoppe, for
setting up turntables. They were, of necessity, played
multiple times, during a setup. They are still as pristine
in function & sound as when I purchased them. Even the very
high velocity, "Tracking Torture Test Tracks." My
favorite demo record tracks, were often played numerous
times, within a few minutes, to compare my various speaker
models to customers. That was in the 80's and I'm still
enjoying those vinyls, with no loss of presentation.

All of us who play records, at some point, have seen a little buildup of dust on the stylus while a record plays every now and then. I'm not sure what the combustion temperature is of dust, but I think it'd be safe to say that those grooves aren't getting hotter than what it would take for dust to smolder or even ignite.