1) A small hole such as a space especially in a rock, soil, etc.
→ porous dust grain,
From L. porus "a pore," from Gk. poros "a pore," literally "passage, way," from PIE root *per- "to lead, pass over."
Lik, from Gilaki lik "hole," variants luk, luke, liuk, luxa, Tabari luk, li, Sangesari, Semnâni lu, Aftari lo.
A reproductive body in flowerless plants corresponding to the seeds of flowering ones.
From Modern L. spora, from Gk. spora "a seed, a sowing, seed-time," related to speirein "to sow, scatter."
Hâg, variant of xâg, → egg.
Fr.: minimum de Spörer
A period of low → solar activity that lasted from about A.D. 1420 to 1570. It occurred before → sunspots had been studied, and was discovered by analysis of the proportion of carbon-14 in tree rings, which is strongly correlated with solar activity.
Named for the German astronomer Gustav Spörer (1822-1895); → minimum.
Fr.: loi de Spörer
The empirical law that predicts the variation of → sunspot latitudes during a → solar cycle. At the start of a sunspot cycle, sunspots tend to appear around 30° to 45° latitude on the Sun's surface. As the cycle progresses, they appear at lower and lower latitudes, until 5° to 10°, at the end of the cycle. This tendency is revealed on a → butterfly diagram. Although named after Gustav Spörer, the "law" was first discovered by Richard Carrington.