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.
To give travelers a better idea of when to book a specific route, CheapAir took another look, this time analyzing about 3 million itineraries. Researchers found that, depending on the trip, the prime booking window -- when prices hover at their lowest points -- is anywhere from 112 to 21 days before a flight. (Fares go up sharply in the last two weeks before a flight, the site found.) Read next: What You Really Need to Know About When to Buy Flights.