Om has a vibratory effect that can be felt all over the cosmos, even if one person chants it. But we’ll come back to that.
bhur bhuvah svah
Now bhur is a short form for bhu loka–this world that we see with our eyes, which again is the waking state. Bhuvah loka means the world that is above the ordinary world, equivalent to the dream state. And, then svah is the short form of swarga loka–the plane above the bhuvah loka.
Bhu loka, bhuvah loka, and swarga loka. These are all different planes and, in the human being, waking state, dream and deep sleep represents them. Deep sleep or shushupti for most human beings is ‘swarga‘ or heaven where everything is forgotten. One doesn’t even remember who one is. There is no world and therefore, there are no troubles of this world. So, in a way psychologically, deep sleep is also swarga. Cosmologically, it means a state where one is in peace and happiness–swarga!
So, om bhur bhuvah svah means: This mantra being chanted with the power of Om or the energy-giving pranava behind it, affects me in all my three states of waking, dream and deep sleep and all the three planes of existence, linked with states of mind, which is the bhu loka, bhuvah loka and swarga loka.
“While the prayer is directed to the visible Sun, it is also directed internally to the Absolute Reality, of whom we are all sparks.”