Something I've thought about from time to time is the importance of rhythm. It is ingrained into our very being; from our conception, we're geared towards rhythm. From a heartbeat, to the tiniest detail inside our DNA(the nanoscopic 'machines' that work in a rhythm), to our everyday steps, our thought processes, our motions; all of these derive from rhythm. It transcends the physical and intertwines our thoughts and our emotions.
It connects us on a spiritual level so much so that we listen for a rhythm when we're upset, happy, sad, angry, jealous, etc; we listen to music, which is based solely on rhythm. When we don't listen to music, we close ours eyes and listen to our hearts and/or our breathing--the rhythmic thump or inhale/exhale.
It is the foundation of nature. All life on this planet has a rhythm, and is inclined towards rhythm. Some animals are even known to dance to the rhythm of music.
The cells that make up plant life even carry on a rhythm.
The ocean's waves are one of the most relaxing rhythms known to man.
The moon has a rhythm in its orbit around the Earth, and likewise the Earth around the sun, and the solar system around the galaxy, and the galaxy around--we know not what, but I can assure you, whatever the Milky Way is circling, it also has an orbit around something.
From the atomic scale to the intergalactic scale, to the universe itself, there is rhythm.
I just thought this was an interesting topic.