1 Ã Van de Graaff generator 1 Ã electrically-insulating stool Some confetti, or aluminium foil, or foil cake trays. The demonstration. This demonstration involves high voltages, and so it should never be done by anyone with a pacemaker or other internal electrical device, or who thinks they might be pregnant.
Minimum Advance Purchase. Airlines increase prices dramatically 14 days and 7 days before departure, respectively, according to figures analyzed by FareCompare. To avoid these sharp spikes, you should aim to purchase your ticket a minimum of 15 days prior to departure. Air travel experts at FareCompare say that the window for purchasing tickets at the best price is between three months and 14 days in advance.
Their findings seek to answer every traveler's No. 1 question regarding airfares: How far in advance should I book to get the cheapest fare? And they do. Sort of. The short answer: Seven weeks before takeoff. On average, fares bottomed out 49 days before the flight, then increased slightly, but remained steady until about a month out.