Life In The Darkness
Circadian Light : Key to Survival In Darkness

Imagine you are trapped in a dark, dangerous, and damp place with no means of escape. What would you do? Initially, you might find this darkness soothing but after a while, the feeling of being trapped will overpower you.

The world is currently abuzz with the news of 12 boys and their football coach trapped inside a flooded cave somewhere in northern Thailand. Fortunately, they were rescued on Monday.

Currently, the boys are alive and kicking. The military officials have predicted heavy rainfall in the coming days and said that it will take up to 4 months for the flood waters to recede making it possible for them to escape the caves.

Besides the psychological trauma, living in darkness for such extended period can change boys’ perception and internal sense of time. Thus, they are subjected to the risk of insomnia, depression, and result in friction within the group.

Let us know what scientists think about their body and mind’s reaction to this prolonged exposure to the darkness- and if there any measures that can help them.

However, this isn’t the first instance where people are trapped in a cave for days. French geologist, Michel Siffre holed himself up for two months, near Nice in an underground glacier. After two months when his friends called him up to inform him that two months have passed, he did not believe it. According to him, only one month had passed. His perception of time was distorted as he had no connection with the clocks, calendars, and daylights.

According to the scientists, people’s timing of their sleep changes day by day i.e. their body clock begins to ‘free-run’.

For example, people who are completely visionless have varying internal clock timings. Some people’s biological clock runs closer to 25 hours, whereas the other’s might have their body clock running slightly under 24 hours. Therefore, their sleep timing changes day by day, as they are no longer able to keep up with the outer world’s timings.

If you were about to drill a hole approximately 0.8 inches deep between your eyebrows, you would probably hit suprachiasmatic nucleus (SCN) i.e. a tiny patch of brain tissue. These internal rhythms are generated by SCN. The intrinsically photosensitive retinal ganglion cells located at the back of the retina acts as SCN’s window on the world. Every morning when sunlight hits the eye, it acts as a retuning button for SCN, irrespective of the speed of the biological clock.

In case you are trapped somewhere below the ground, or due to some injury your eyesight is lost and your brain cannot register the light- your body will begin free-run as the light connection is lost. This is exactly what those trapped boys in Thailand must be experiencing now.

Since it is highly unlikely that they all share the same biological timing, the timings when they will feel sleep and wide-awake will also change. This, in turn, would create friction among the team as some of them might want to sleep in this confined space whereas at the same time some may feel wide-awake.

Owing to the advancement in science and technology, antidotes are available for this too. In 2010, when 33 miners in Chile were trapped in a copper mine for about 69 days, a special ‘circadian lighting’ was provided to replicate the natural dark/light cycle outside.

A similar strategy can be used for the ongoing rescue mission in Thailand. SCN can be reset using the artificial light provided that the light used during the day is bright enough. It will enable SCN to synchronize with the outside world and preventing the body from going on free-run.