Sunday, January 13, 2013

Taming the mind - Part V

The human eye can discern only a very small portion of the electromagnetic spectrum. This small slice of the electromagnetic spectrum that we can see is also known as visible light. Light is an intriguing phenomenon. It has no mass. The basic unit of light is called a photon, which is a tiny particle of light. Sunlight that reaches earth starts its journey deep inside the sun. There is a continuous stream of light is liberated from the surface of the sun. This light takes about 8 minutes to traverse the approximately 93 million mile journey to earth. The world we see around us in daylight is a result of a continuous stream of light particles striking the photosensitive part of the eye called the retina. When a particle of light lands on our retina after a 93 million mile journey from the sun, its energy is absorbed and this particle of light ends its existence at the back of the human eye.  

The energy generated by the impact of light on the retina sets off a cascade of reactions and the resulting electrical impulses are carried from the photosensitive cells of the retina to the visual cortex at the back of the brain. Here an image is constructed based on the light input that falls on the eye. Although all the image processing occurs at the back of the head in the visual center of the brain, it is projected in front of us giving us the illusion that this image is created in “in front of our eyes.” When our eyes are open to the world around us, the mind can be thought of as a dark auditorium where thoughts are like shadows lurking in the background. These thoughts continuously interpret and catalogue the stream of images that the brain processes every waking moment. When we close our eyes, this dark auditorium like mind changes. The shadowy thoughts that appear to have entered through the back door of the mind, now pierce the realm of our consciousness through the dark space in front of us.