Hello and welcome to the spring equinox. Now some people think the spring equinox is just the day that’s been designated to mark the beginning of spring somewhat randomly chosen. Maybe when the weather is getting warmer but in fact, that’s not the case the spring equinox comes from astronomical motions. In fact it’s related to the motion of the earth around the Sun and to demonstrate that to you today I have made myself a little Sun and a little earth and so you can imagine right the earth is rotating once every day and it goes around the Sun once a year okay so 365 rotations as we go around the Sun.
Now you can imagine that if the earth has no tilt the length of every single day is the same as we travel around the Sun that’s not the earth we live on though. The earth we live on has a 23 and 1/2 degree tilt to its orbit ok to its rotation axis I should say and so it rotates like shown in image as it goes around the Sun and so you can imagine depending on where you are on the earth the northern or southern hemisphere and where the earth is relative to the Sun the length of the day will change. Now we’re talking about the spring equinox that happens to be the point in the Earth’s orbit where the rotation axis is perpendicular to the Sun and so every point on the earth experiences a day where the day is equally as long as the night.