> How did Ethernet go from fat cables and vampire taps to RJ35?
Layers. The physical signaling is vastly different but the content that rides on it can remain the same. If you study the OSI model (https://en.wikipedia.org/wiki/OSI_model) you will know more about it than me.
I don't know how faithfully modern (or ancient) Ethernet follows this model - it might predate this work. Some layers might be blended for the sake of efficiency, but there are definitely layers.
There are a lot of L1 layers that have been used under Ethernet. There were several revisions of the coaxial cable used for ethernet before we switched to the rj45 terminated twisted copper cable everyone thinks of when you say "ethernet". Again, there are several iterations for the twisted copper physical layer.
More recently, we also run ethernet over optical fibers. The varience within the fiber family of cables is probably greater than the variance in either copper or coax.
Layers. The physical signaling is vastly different but the content that rides on it can remain the same. If you study the OSI model (https://en.wikipedia.org/wiki/OSI_model) you will know more about it than me.
I don't know how faithfully modern (or ancient) Ethernet follows this model - it might predate this work. Some layers might be blended for the sake of efficiency, but there are definitely layers.