The glowing paths show how, from our point of view, our closest star’s travels across the sky change with the seasons. Variations in cloud cover cause the gaps in the silvery trails that form each day.
After three months, Quinnell removed the photographic paper the can contained, which now held a negative latent image of the apparent movements of the sun, which are caused by the Earth spinning on its axis. “The image forms with time, like a suntan,” he explains.
The paper was then scanned into a computer and the image inverted using software to create the positive version shown here. This type of photography is known as solargraphy.
The highest path represents the sun’s “peak”, when it appears highest in the sky, which takes place on 21 June in the northern hemisphere. After this day the trails grow shorter and climb lower in the sky, revealing the approach of winter.
Together, the 23.5-degree tilt in the Earth’s axis and its revolution around the sun are what give us our seasons. This striking image illustrates these changes and reveals the passage of time.
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