By Morgan Nguyen
November 28, 2017
Cell Phones and Sunrises: Cities are perpetually ablaze with activity, suggesting that humans are less influenced by Earth's light-dark cycle than we used to be. However, a new study from Aalto University in Finland that analyzes the cellphone call records of over one million people claims otherwise; researchers found cell phone activity grew longer and shorter over the course of the year, waxing and waning with the amount of daylight. Shifts in call records correlated closely with seasonal shifts in light. Over the course of 3-4 months, the latest call times crept later while the earliest call times grew earlier. The peak calling periods changed in the same pattern as well: the morning peak moved earlier, the evening peak later. Does the timing of the sunrise and sunset affect our circadian rhythms in a way that is visible in cell phone records? The study could provide further evidence that the chemicals that govern our bodies' internal clocks are linked to Earth's orbit and the sun's daily ascent and descent.