The noun ken means "range of vision or comprehension." If quantum mechanics is beyond your ken, you don't understand it, or it is beyond your scope of knowledge.
imp. & p. p.
of Ken
Usage Examples
Kenned, Kenned, enned, Kenned, Kwenned, K3enned, K4enned, Krenned, Ksenned, Kdenned, Kwnned, K3nned, K4nned, Krnned, Ksnned, Kdnned, Kewnned, Ke3nned, Ke4nned, Kernned, Kesnned, Kednned, Kebnned, Kehnned, Kejnned, Kemnned, Ke nned, Kebned, Kehned, Kejned, Kemned, Ke ned, Kenbned, Kenhned, Kenjned, Kenmned, Ken ned, Kenbned, Kenhned, Kenjned, Kenmned, Ken ned, Kenbed, Kenhed, Kenjed, Kenmed, Ken ed, Kennbed, Kennhed, Kennjed, Kennmed, Kenn ed, Kennwed, Kenn3ed, Kenn4ed, Kennred, Kennsed, Kennded, Kennwd, Kenn3d, Kenn4d, Kennrd, Kennsd, Kenndd, Kennewd, Kenne3d, Kenne4d, Kennerd, Kennesd, Kennedd, Kennesd, Kenneed, Kennefd, Kennexd, Kennecd, Kennes, Kennee, Kennef, Kennex, Kennec, Kenneds, Kennede, Kennedf, Kennedx, Kennedc.