Why Blue Sky?
The physics of why we see a blue sky is an interesting topic in its own right, but the blue sky can also be likened to our physical connection to one another as well as being a metaphor for the spiritual unity we experience through that connection.
First, let's briefly look at the physics of the blue sky:
Without the atmosphere that surrounds our planet, the sky would appear to us as (just as astronauts see it in space) all black with the tiny white dots of the stars and, during the daylight hours, the light from the sun just a larger white spot in the blackness. Instead, the interaction between the light from the sun and molecules in our atmosphere gives us the big, beautiful canopy of blue sky beneath which we live our daily lives.
To see how this happens, we need to back up a bit… the universe is made up of particles, many of which have a type of energy associated with them that we call electric charge.
Any time a charged particle vibrates in space, it gives off electromagnetic radiation. If it vibrates faster, the radiation has a shorter wavelength and a higher energy. If it vibrates slower, the radiation has a longer wavelength and a lower energy. Visible light is simply electromagnetic radiation (within a specific range of energy and wavelength) that we can detect with our eyes.
Now here is something very cool about electromagnetic phenomena: not only does a vibrating charged particle emit electromagnetic radiation, the converse is also true—electromagnetic radiation will cause a charged particle to vibrate!
The molecules in the earth's atmosphere (like all molecules) consist of groupings of charged particles. When the light from the sun meets the air molecules, some of the energy of the light is absorbed by the molecule which causes the charged particles within it to begin to vibrate. And then those vibrating charged particles emit their own electromagnetic radiation, which in this case, is more light!
So, we have the molecules of the atmosphere absorbing energy from the light that is coming from the sun, and then the charged particles within the molecules emitting electromagnetic radiation in the form of more light. There are some more complex aspects of this interaction of absorption and emission that result in a preference for the shorter wavelengths, the color blue of the emitted light. But to put it most simply; the absorption and emission of light-energy by the atmosphere creates our Blue Sky.
Our bodies are part of this "ocean of electromagnetic energy"…
Like the multiplicity of individual molecules that make up the atmosphere, we are all continually receiving and sending (absorbing and emitting) information (energy) in the form of our communication with one another using the miraculous mechanism—the brain and nervous system. We are all physically connected within this field of electromagnetic energy.
And we can cultivate our awareness and our sensitivity to this connection through meditation, so that we can actually feel the electromagnetic "ocean" of pulsating energy that is this physical universe.
Indeed, we are continually creating this living universe with the energy of our thoughts and our bodies. My teacher Shri Brahmananda Sarasvati asks us to feel it. Actually feel the energy flowing through your body, feel it connecting with the pulsation of the entire universe, there is no need to imagine it, because this is real—your body is interacting with the light from the stars! In this sense, physically, we are all One!
Now for the metaphor:
Just like the multitude of molecules—continually absorbing and radiating energy—create the one, abiding Blue Sky above the earth…
Just like the bodies of all beings—also absorbing and radiating energy—take part in the creation of this pulsating, electromagnetic ocean of vibration that is the one physical UNIverse…
By absorbing and radiating the soul energy of LOVE, the multitude becomes the ONE... the eternal, omnipresent I AM.
We are like the Blue Sky!