What Is Life in the UK as perhaps the strongest of all of Harrison's singles. Writing in 1981, "NME" critic Bob Woffinden grouped "What Is LIfe" with "My Sweet Lord", "Isn't It a Pity" and "Awaiting on You All" as "all excellent songs". Reviewing the 2001 reissue of "All Things Must Pass", for "Rolling Stone", James Hunter wrote of how the album's music "exults in breezy rhythms", among which "the colorful revolutions of 'What Is Life' ... [move] like a Ferris wheel". The following year, in Rolling Stone Press's "Harrison" tribute book, David Fricke included "What Is Life" among his selection of "essential
Petrography origin of the rock. Electron microprobe analysis of individual grains as well as whole rock chemical analysis by atomic absorption, X-ray fluorescence, and laser-induced breakdown spectroscopy are used in a modern petrographic lab. Individual mineral grains from a rock sample may also be analyzed by X-ray diffraction when optical means are insufficient. Analysis of microscopic fluid inclusions within mineral grains with a heating stage on a petrographic microscope provides clues to the temperature and pressure conditions existent during the mineral formation. Petrography as a science began in 1828 when Scottish physicist William Nicol invented the technique for producing polarized light