These trains use superconducting magnets, which allow for a larger gap,
and repulsive/attractive-type Electrodynamic suspension EDS.
Ampère also provided a physical understanding of the electromagnetic relationship,
theorizing the existence of an"Electrodynamic molecule"(the forerunner of the idea of the electron)
that served as the component element of both electricity and magnetism.
Duplex transmission was essential for telephony and the problem was not satisfactorily solved until 1904, when H. E. Shreeve of the American Telephone and Telegraph Company improved existing attempts at constructing a telephone
repeater consisting of back-to-back carbon-granule transmitter and Electrodynamic receiver pairs.