Mirjam Guesgen

Freelance Science Writer

I am a freelance science writer currently based in Toronto, Canada, with a particular interest in animal welfare.

I love communicating complex, scientific ideas in an engaging, balanced, thought-out and informative way.

Night light

On my recent travels to the UK, I was fortunate enough to fly on one of the new A380 planes. These planes have a variety of features, including drinking fountains, a huge selection of movies and even a bar (for those fortunate enough to travel first class). What stood out the most to me, however, was that the lighting appeared to change over the course of the flight. Starting with the usual yellow-ish glow, this soon transformed into a pale pink, then purple and eventually a deep blue, dotted with ‘stars’. 

After doing a bit of research I found out that, as well as the aesthetic quality, this form of lighting was meant to help reduce jetlag. Anyone who has traveled internationally will tell you, you can’t have a great trip overseas without having to endure the burdens of fatigue, decreased alertness and sometimes stomach problems associated with jetlag. 

Jetlag is caused by a mis-match between your internal body clock and the external clock at your new destination. Your body clock does much more than just tell you when you should be awake and when you should be asleep. It also regulates melatonin and cortisol levels as well as core body temperature. The strange (but actually adaptive) thing about your body clock, is that it’s not 24 hours long as you may expect, it’s actually closer to 25 hours. This means that we need environmental cues, particularly light, to sync it to ‘real time’.

By cleverly timing when you’re exposed to light, you can shift your clock either forwards or backwards. Bright morning light can advance your clock (making your body think it’s later than it actually is), whereas bright evening light can delay your clock (making it think it’s earlier than it actually is).

You can probably see by now the intention of the “mood lighting” on the A380. By mimicking the lighting conditions of the arrival destination, airlines aim to reduce jetlag by syncing your body clock to the destination clock. Now this is all well and good, but it actually takes quite bright light to shift your clock (circa 2500 lux or 5 times the intensity of normal room lighting). Also, to have any real effect, light has to be administered like a drug at particular times (see above). If you really want to kick jetlag in the butt, administering melatonin in the morning (to delay clocks) or in the evening (to advance them) can help.

So, it seems the pretty lighting is much like the bar onboard: a good idea but something that I can never really take advantage of.