I.around [美 əˈraʊnd, 英 əˈraʊnd]副around often appears as the second element of certain verb structures in English (fool around, knock around, move around, etc). For translations, see the relevant verb entry (fool, knock, move, etc).
What they do give you is a very stable surface free of any kind of rocking balanced on 3 points, so any vibration that does couple up doesn't ring around.
Nine sets of doublet microtubules (a specialized structure consisting of two linked microtubules) form a ring around a central pair of single microtubules.