The steepest grade on U.S. main-line track is at the small town of Saluda, on a Norfolk Southern route between Spartanburg, South Carolina, and Asheville, North Carolina. The grade goes on for three miles at a slope of 4 or 5 percent. Trains have not been running on the line since 2001, but the tracks are still maintained.
For those who've never experienced a sunrise in the rural Midwest, it's roughly as soft and romantic as someone's abruptly hitting the lights in a dark room. This is because the land is so flat that there is nothing to impede or gradualize the sun's appearance. It's just all of a sudden there.
We might be closer than we think to cures for depression, hypertension, and yes, even obesity.
The answer to scurvy was just one thing, plus a few wrinkles — mostly “not all citrus has the antiscorbutic property” and “most animals can’t get scurvy”. This was only difficult because people weren’t prepared to deal with basic wrinkles, but we can do better by learning from their mistakes.
This means don’t give up easily. It suggests that there is lots of low-hanging fruit, because even simple explanations are easily missed.
Lots of theories have been tried, and lots of them have been given up because of something that looks like contradictory evidence. But the evidence might not actually be a contradiction — the real explanation might just be slightly more complicated than people realized. Go back and revisit scientific near-misses, maybe there’s a wrinkle they didn’t know how to iron out.