Last week, thousands of people around the globe celebrated the summer solstice, which marks the start of summer and the longest day of the year in the Northern Hemisphere.
The number of hours of sun is determined by the angle of the earth's north-south axis to the sun. The greater the tilt towards the sun, the more sunshine the northern half of the earth gets. There is also a winter solstice, when the hemisphere undergoes the shortest day of the year.
The summer solstice is celebrated in many cultures around the world and has played a very important role in history. For example, the Egyptians built their pyramids so that when the sunset on summer solstice is viewed from the Sphinx, it is located right between two of the pyramids.
In South America, the Incas held summer solstice ceremonies with food and animal sacrifices in honour of the earth. They all worshipped our planet.
Summer solstice celebrations at Stonehenge, in Britain, still take place today, continuing a 5,000-year-old tradition.
All of these traditions focused on the fact that it was a new growing season and important time for the crops. Ancient cultures were in tune with their environment and they paid close attention to the changes around them.
