The Big Dipper represents the Celestial Mechanism and symbolizes the internal process through which the Original Spirit comes into being.

As above so below and as within so without.
-- Hermes Trismegistus (legendary Egyptian mystic)
The shallow may take the I Ching to be a book of divination, but the profound consider it the secret of
the celestial mechanism.
-- Lu Dongbin (The Taoist I Ching)
But this celestial mechanism of practicing reversal in the midst of accord has a secret, which is communicated verbally and instructs the heart; one must seek the guidance of the true teacher, for it cannot be known through arbitrary guesswork. Although it is called reverse action, in fact it is action in accord with principle. It is called reversal because it goes contrary to the course of action of ordinary people. -- Liu Yiming (18th c. Taoist master) Inner teachings of Taoism

The big dipper rotating around the North Star during the four seasons, creating a Swastika

The Big Dipper rotating around the North Star symbolizes turning around the light internally, which can also be translated as circulating the light. The North star, unmoving and unwavering in space, symbolizes the center on which one focuses.

But the heavenly heart in the head, does it ever move, even slightly? You ask, can't the heavenly heart move? I answer: How can the true intent in the square inch move! If it really moves, that is not good.
-- The Secret of the Golden Flower, chapter 2 #3

The Big Dipper consists of seven stars. Seen from the Earth, stars are little sparks. In ancient times, the stars were the main means of navigation at sea during the night (the state of psychological darkness, in which the Golden Flower is not shining) and guided one to one`s destination. Internally, stars symbolize reminders to turn around the light and guide one to the Original Spirit.

Make the divine presence your destination.
-- Al-Ghazali (11th c. Persian mystic and writer)
The stars are engaged in divine remembrance.
-- Sultan Bahu (17th c. Sufi)
The stars are God’s holy commandments.
-- The Philokalia, Symeon Metaphrastis