Have a look at this photo and see if you can tell whether it is a sunrise or sunset?
Yes, it’s tricky.
Sunrises and sunsets can appear identical as there is no difference in the light coming from the sun itself at those times and it passes through the same distance of atmosphere.
Arguably there are more aerosols and pollutant particles in the air at the end of the day than the start. This can lead to a redder colour in the sunset, but this is hard to detect. Especially since we never see sunrise and sunset side by side in nature.
Some scientists and psychologists might also argue that our perception is different at the start and the end of the day for both physical and subjective reasons. We have spent a day in daylight at sunset, affecting both our minds and our eyes. But that is another minor influence – and no help in gauging photos.
The only way to crack this photo is not actually to look at the sun, but at the landscape.
The puddle is bigger and deeper-looking on the left side and this indicates south. (See the video on this page for more on the logic of puddles and navigation.)
Also the tree to the right of the sun has been swept from the left to right, suggesting that southwest is to the left. (More on how to read the wind’s effects.)
We are therefore looking closer to west than east. It’s a sunset.
(By the way… If you see any motion, then it is easy and not just because setting suns sink and get darker and rising suns rise! The angles are different too. In the northern hemisphere the sun moves left to right as it both sinks and rises. Played in reverse it will move the wrong way! TV and film editors regularly get tripped up by this. A sunrise played in reverse never looks the same as a sunset – unless you happen to be on the equator, where it rises and sets vertically.)
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How to Find Your Way Using the Sun