The third Sunday of October begins the daylight saving time, where the clocks are advanced by one hour until the third Sunday of February. We already know that the main objective of this schedule is applied is energy saving because we can enjoy the natural light until later. But have you ever stopped to think about how this can best be understood through physics? Look that:

Why is daylight saving time used?

In Brazil, summer time is applied during the summer solstice, that is, in the second half of the year. At this time, the slope of the Earth makes the day longer. What happens is that the Sun crosses the horizon at a much smaller angle, so it takes about 2 hours to fully dawn, just as it takes longer until it is totally dark. In this way, the day ends up gaining about 4 hours. With daylight saving time, the idea is that this extra length of light is used, especially at the end of the day.

Why do not some regions use daylight saving time?

Nearly 30 countries adopt daylight saving time at least in some part of their territory, generally it is applied in the most distant regions of the equator, since equatorial zones do not show much variation in the length of days and nights throughout the year. This is what happens in Brazil, for example, where the North and Northeast regions do not use daylight saving time.

Did you see how daylight saving time also has to do with physics? How about reading a little more about the relation of physics to the seasons?