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.
How and when to book a cheap flight. New research shows that the best time to book a summer flight is as late as five weeks before your holiday, contrary to travel industry experts who advise travellers book as early as possible. See also: How to get best holiday deals. Isabel Choat. theguardian.com, Wednesday 22 January 2014 06.00 GMT.