A common myth you hear sometimes is that on a clear day, from some places in West Iceland, you can see parts of Greenland. This is often attributed to the “lensing” effect of cold air in the polar regions, in which cold air masses can act as a lens and carry light further than usual, over the curvature of the earth.
As great a story as this is, it’s unfortunately not true.
The narrative may have very old origins, going back to the Saga of the Greenlanders. In this story, the settler and outcast Erik the Red is said to set out in search of the land seen by one Gunnbjörn when he went west and discovered “Gunnbjarnarsker.” This skerry, an islet or fleck of rock in the ocean, was presumably much closer to Greenland than the west coast of Iceland, so it may well have been possible to see Greenland’s mountains from there.
But not so on Iceland’s mainland. The matter has also been laid to rest authoritatively by Icelandic physicist Þorvaldur Búason. According to Þorvaldur, a 500m tall hill at 500km appears to us as about the size of a ballpoint pen held at arm’s length. Using some geometry, we can tell that Gunnbjarnarfjall, the tallest mountain in East Greenland, would be invisible to the naked eye from the closest point in Iceland’s Westfjords.
It’s also worth noting that given Iceland’s position relative to Greenland, Greenland stretches further North, South, East, and West than Iceland!