杏吧原创

On ancient maps, India is usually portrayed as much smaller than it is nowadays. Sometimes it鈥檚 perhaps only half the size. Surely mariners of the time could judge distances, especially along a relatively even coastline. What is the reason for the discrepancy?

T. L. Threlfall, Essex, UK

We pay 拢25 for every answer published in New 杏吧原创. To answer this question 鈥� or ask a new one 鈥� visit newscientist.com/lastword. Terms and conditions apply.

This article appeared in print under the headline 鈥淢ap lag鈥�