in 1959, RCA took their tube-making expertise and made this micro miniature tube almost as small as a 1950s transistor

RCA developed all new equipment to make it. this machine seals a batch of Nuvistors automatically!

in the 1950s, tubes still had advantages over transistors -- they even lasted longer!

so how did they miniaturize the Nuvistor? time to cut one in half. check out the cross section!

i'd annotate my photo, but RCA published a really nice cutaway diagram, so i will show you that instead.

Nuvistors found their way into some high end applications but transistors surpassed them in a few years, and they just faded away.

fascinating to imagine an alternate reality where transistors never worked and people figured out how to miniaturize vacuum tubes, etching arrays of them on metal wafers and building computers. In fact, they could even have built the entire Internet using a series of tubes.

@tubetime the Vacuum Transistor allows fabrication of chip-scale vacuum tubes on normal CMOS process. These devices switch in the terrahertz range and require neither a heated filament nor a vacuum, since the source-to-drain distance is shorter than the mean free path (which means electrons won't hit any other atoms along the way): https://spectrum.ieee.org/introducing-the-vacuum-transistor-a-device-made-of-nothing

@th @tubetime The article from 2014. I suppose it's a little younger than promises of energy from nuclear fusion.