Is it possible to cry a river?

Musicians Arthur Hamilton, Justin Timberlake and unsympathetic people across the world have encouraged others to ‘cry me a river’, a put-down phrase to make light of people’s problems.

In a paper for the Journal of Interdisciplinary Science Topics, Natural Sciences students Leah Ashley and Robbie Roe have examined the plausibility of people around the world crying enough tears to create a river, based on the flow rate of the world’s shortest river – the Roe River in Montana, United States, which is 61m in length and discharges between 156-193 million gallons per day.

Taking the lower volume limit as the most achievable target this equates to 709,190,040 litres per day – and with the average volume of a human tear being around 6.2 micro litres, this would be far more than the world’s population could cry, even if everyone on Earth was feeling particularly crestfallen.

However, while copious blubbering may not be able to create a river, it could fill an Olympic size swimming pool, the students suggest. Taking into consideration that a pool of 50m x 25m x2m would be equivalent to 2,500,000L, and using the population of the Earth and multiplying this by the volume of a tear, the students found that an Olympic swimming pool could be filled if everyone cried 55 tears – an amount possibly produced by Justin Timberlake on a daily basis when reflecting on his origins as a member of NSYNC.