Although much scientific knowledge was lost in the Dark Age after the Catastrophe, ponykind’s knowledge of science increased greatly during the Golden Age. Today, pony science consists of both conducting novel experiments and recovering the writings of Golden Age scientists.
Theoretical knowledge is considerably ahead of any practical development due to the lack of infrastructure. See Technology. (As a rough rule of thumb for game purposes, current pony scientific knowledge is about as advanced as that of human western civilization around 1890-1910.)