Yoga literature speaks often of opposing pairs. In an asana practice you always consider equal and opposing forces. I suppose it's the Newtonian way of looking at Yoga in the U.S. Every action has an equal and opposite re-action. Push your right (back) heel down in Trikonasana and extend your right hand into the air.
Living in India and working for a U.S. company is about as close to balancing opposing pairs as I can imagine. I'm literally half way around the world. I work nights (U.S. Daytime hours) and sleep during the day. They speak english here but it sounds like another language. They drive on the opposite side of the road. Pedestrians do NOT have the right of way. It's a different world.
I read an editorial in the Times of India yesterday about the challenge of balancing the Spiritual with the Material in today's India. Now there's an editorial you won't see very often in U.S. papers. Talk about living in two worlds. Do I live the Spiritual life or the pursuit of Material possessions? The article stated how "Ishvara Pranidhana" (dedicating all efforts to God) is deeply imbued in the Indian psyche. Yet, today's YUCIs (Young Up and Coming Indians) are more interested in the latest cell phones, ipods, automobiles, motorcycles and clothes.
The practice of yoga removes duality in the mind (which, is where all opposites reside). When duality dissolves Reality is perceived. There is only one Reality - not two. We are in the world, but not of it. We are a part of the one globe - no matter what our longitude or latitude.
The practice of meditation (dharana, dhyana, samadhi)is the means by which the real world is perceived - the one place where we all live - within our mind.