Kiss the Sky

This image represents (to scale) the earth with its atmosphere out to the Karman line at 100 km above the earth’s surface (about 62 miles), where it is generally agreed that ‘space’ begins, where aeronauts become astronauts.  The blue line shows how thin is the spherical envelope of atmospheric gases hugging the earth’s surface, captured and held in place by gravity.  (More about the Karman line  here)

To look up at the sky is to look up into the atmosphere from its most dense layer at the earth’s surface.  And although the atmosphere is transparent (think of  looking  up into the night sky), the scattering of intense sunlight during the day---particularly the short wave-lengths we perceive as blue---creates a dome of diffuse blue light encompassing what seems to be the whole world.   The blue sky seems to be the final backdrop for everything: it seems to envelope reality itself.

The star-filled night sky shows a different truth, but that view is easy to forget on a bright sunny day with the blue sky above.  Excuse me while I kiss the sky, sings Jimi Hendrix.  But what is behind that gorgeous blue, what’s on the other side?   What would it be like to see through the blue dome of sky? 

There’s an interesting contrariness here, for ordinarily we think of light as showing the truth of things; we throw light on a subject to see it more clearly.  But here there’s too much light.  The medium, as usual, is the message, and it’s a deceptive one.  The sky is a limit of sorts, as it seems to be, but it’s also a visual barrier  between ourselves and the thousands of stars visible at night with our naked eyes.  And even that star-filled vision is deceptive, for it gives no indication that what we are looking at is only the merest beginning of all the rest of everything that exists.

Here’s an ancient and different take on the ever present sky, the Egyptian sky-goddess Nῡt, who is said to swallow the sun every evening and give birth to it again the following dawn.

                                                                   

Update: Fred Hoyle, the British astronomer who coined the term "Big Bang," says, "Space isn't remote at all.  It's only an hour's drive away if your car could go straight upwards."