Jerry Dobson is a Kansas University professor of geography.

Add this to the list of areas where human perception falls short of reality: our ability to judge geographical flatness.

Take Kansas, for example, long considered the height of flatness. A recent poll led in part by Jerry Dobson, a Kansas University professor of geography, showed that 33 percent of respondents thought Kansas was the flattest state in the union.

For those passing through Kansas on their way to the ski slopes of the Rockies, it can be easy to forget about the Flint Hills or Smoky Hills when facing down 300 miles of western Kansas. “I knew Kansas had a reputation for being flat,” Dobson said. “But the more I looked, the less flat I saw.”

Dobson set out to get to the bottom of the flatness issue. While many have surveyed topography before, studies typically focus on slope and features — the hills, the mountains, the mesas and so forth. Dobson took flatness as his central variable and set out to rank the states to see which was the flattest of them all.

Dobson assumed that humans can see about 3 miles in any direction. He also reasoned that a land feature higher than a tree on the horizon would be not-flat. He built these assumptions into an algorithm and applied it to elevation data gathered from a space shuttle. Breaking the U.S. states into grids of 90 meter cells, he used the algorithm to scan the states for flatness as a human would see it.

Dobson guessed all along that Kansas would not even be among the top five flattest states, and he was right. It came in at number seven. The distinction of flattest belongs to Florida, which has a maximum elevation 345 feet above sea level.

Dobson himself spent much of his life in one of the country’s least-flat states, Tennessee, which ranks 43rd. After moving to Kansas, people asked him if he missed the mountains. He had to admit that he did, but the big skies in Kansas all but made up for it. Now he’s a full convert. “I love Kansas, and I love flat lands,” he said.