With no explanation, label text_A→text_B with either "not_related" or "related".
text_A: Black Sabbath formed in May of 1968.
text_B: Neal Hooker Williams -LRB- 1870 -- 1956 -RRB- was a physicist notable for the very first spectroscopic measurements at microwave frequencies .. physicist. physicist. spectroscopic. spectroscopic. microwave. microwave. He carried this out with a magnetron and investigated the spectrum of gaseous ammonia together with his student Claud E. Cleeton .. Claud E. Cleeton. Claud E. Cleeton. magnetron. magnetron. spectrum. spectrum. ammonia. ammonia. This formed the groundwork for the later inventions of the radar and the gas laser .. radar. radar. laser. laser
not_related.