Today I saw a picture floating around social media that claimed that going camping for a week would reset your biological clock to be in tune with the sun. Is this true or is it woo?
Let’s examine the science behind this claim.
Higher wavelength visible light (electronics screen “blue” glow especially!) impacting your retinas reduces melatonin production. That means if you’re staring at electronics, you’ll get sleepy much slower than if you’re in darkness. This is a proven scientific fact, check.
During sunset, more shorter wavelength light is absorbed in the atmosphere due to the angle of incidence between the sun and the atmosphere. This causes more Rayleigh scattering reactions since the apparent thickness of the atmsophere is greater. As a result, the sky appears red. Random Trivia: This is also why the sky is blue during the day and the sun appears yellow rather than white.
This is also a known phenomena that we pretty much figured out in the 1870s. Thanks, Lord Rayleigh.
As you can guess, the sun setting causes your melatonin production rate to increase since there is less blue visible light bouncing around. You start to feel sleepy at a faster rate. That makes sense.
The camping part of this image is pretty irrelevant (other than ensuring you can’t do too much after sunset beyond the range of your camp) but cutting out electronics and artificial light would definitely reset your circadian rhythm to more closely follow the rising and falling of the sun. One thumbrule I’ve heard is that it takes about a week to completely shift your circadian rhythm by one hour. That seems pretty reasonable.
Overall, I’d say this picture checks out in that it doesn’t claim anything that can’t be supported by science. In fact, I’ve been trying out switching out my lightbulbs for colored LED bulbs in order to shift the lighting in my place to red in order to try to better regulate my sleep cycle. I’m sure all of the screens glowing isn’t helping but I’d like to think every little bit helps. Woo? Eh.