Two Summer Vacations in a Year ?

Situation:

We might have saw this image in our 3rd or 4th grade science book and with this image a line is mentioned "earth revolve in an elliptical orbit around the sun and sun is at the center of that ellipse." with that you also read "the summer and winter on earth is depend on the distance between the earth and sun"

But if you see the image and the line that written on the book are completely contradictory. As the image says that at two times in a year earth closest and farthest from the sun. That simply means, we experience two times every season in a same year. Which is obviously wrong!

So, if all the things in our book is write then why we have only one summer vacation in a year?

Reality:

In reality, the sun is not at the center of the ellipse. The sun is at the focus of the ellipse and a ellipse has two focus point and a center point. which you see in the image.

So the image on our book is also not correct. The original orbit of earth is like:-

This is one thing about the season change. Along with that earth is tilted on its axis at an angle of about 23.5 degrees, which means that different parts of the planet receive different amounts of sunlight throughout the year. When the Northern Hemisphere is tilted towards the sun, it is summer in the Northern Hemisphere and winter in the Southern Hemisphere. Similarly, when the Southern Hemisphere is tilted towards the sun, it is summer in the Southern Hemisphere and winter in the Northern Hemisphere.

Therefore, because of the way the Earth is tilted and orbit path around the sun, it is not possible for there to be two summer vacations in a year.

If you want to know more about mathematics click here