The ancients revered the spiral as a symbol of life everlasting; the natural world is full of representations of the spiral, usually formed according to the Fibonacci series, a mathematical mystery known to the Pythagoreans. Some modern folks were astonished when the DNA molecule, the microscopic code of all life on earth, was revealed to be a helical spiral. But the mystics just nodded their heads.
One of the most well-known symbols of the spiral is the Caduceus of Hermes, a sort of staff carried by the god Hermes (also known as Mercury). The symbol has no superficial explanation, but suffice it to say it represents the coincidence of opposites, the Tao of opposing Yang and Yin in balance, represented by the two opposite entwining serpents. The knob at the top of the staff represent the supreme monad of these two forces in the universe. The wings just beneath are the primal energies that emanate the universe below.
The symbol is shown in prehistoric Britain as a double spiral, one feeding into the other, continuously. (This is also depicted as a triple spiral, which would be the equivalent of the staff of the caduceus as the middle way, combined with the two snakes in a triple form). These symbols are usually seen carved in stone at burial sites, and represent life feeding death which then feeds rebirth, just eddies in one eternal river. Likewise, the caduceus is said with one touch to cause the living to die, and the dead to return to life.
Or as the band Genesis put it so well: You gotta get in to get out.
I came across this video recently, and realized, just as Hermes stated on the Emerald Tablet: That which is above is like unto that which is below. Or, the form of the microscopic DNA and the macroscopic movements of the stars and planets are all really the same principle.