Carbonado compared to carbon‑12, relative to typical diamonds). Carbonado exhibits strong luminescence (photoluminescence and cathodoluminescence) induced by nitrogen and by vacancies existing in the crystal lattice. Luminescence halos are present around radioactive inclusions, and it is suggested that the radiation damage occurred after formation of the carbonados, an observation perhaps pertinent to the radiation hypothesis listed below. The origin of carbonado is controversial. Some proposed hypotheses are as follows: None of these hypotheses for carbonado formation had come into wide acceptance in the scientific literature by 2008. Supporters of an extraterrestrial origin of carbonados propose that their material source was a
What Is Life During the verses, Gordon moves to a square, Motown-style beat – or "rock-steady Northern soul backbeat" in Leng's words – before returning to the "galloping rhythm" of the more open, "knockout" choruses, and the song is driven equally by Badfinger drummer Mike Gibbins' powerful tambourine work. On "What Is Life", Spector provided what music critic David Fricke terms "echo-drenched theater", in the form of reverb-heavy brass, soaring strings (arranged by John Barham) and "a choir of multitracked Harrisons". The vocals and Barham's contribution, along with a brief slide-guitar commentary from Harrison over the final verse, were overdubbed at Trident Studios,