After being savaged on social media, actor Amitabh Bachchan on Monday deleted a tweet and Instagram post on the alleged bacteria-destroying powers of noise. The posts shared by the 77-year-old actor on his social media handles – Big B is among the most followed Indian celebrities online – repeated a snippet of superstition that has been doing the rounds ever since Prime Minister Narendra Modi asked citizens to clap and bang plates on Sunday evening. PM Modi’s stated intent was to show appreciation for health workers, essential service providers and others who are putting themselves out there so that the rest of us may home quarantine; a WhatsApp forward, however, has been circulating the theory that rising decibel levels kill bacteria at the time of the new moon or “Amavasya.”