Snow begins as ice crystals that form and grow in cold clouds. Their shapes depend on the conditions they encounter, including temperature and the availability of water vapour. Crystals can join together as they fall, producing flakes of different sizes. What reaches the ground may be light and powdery, dense and wet, or somewhere between […]
Calendars and the organisation of days
Calendars organise days into named and numbered patterns that help people record events and coordinate activities. They connect everyday schedules with longer cycles such as months and years. A calendar is both a system of rules and a practical tool. The arrangement printed on a wall or displayed on a screen is one visible expression […]