On Thursday night, President Donald Trump delivered a speech from the White House press briefing room in which he baselessly claimed that the election was being stolen from him. Cable news networks swiftly denounced the president’s lies, with MSNBC, NBC, ABC, and CBS all cutting away from the press conference while it was still in progress. Even Fox News, which continued to carry the briefing, said there was no evidence of fraud. CNN’s anchors were harsher, with Jake Tapper calling the president “pathetic” and Dana Bash calling him “dangerous” and “nonsensical.” It was Anderson Cooper’s retort, though, that became the sound bite of the night. “That is the president of the United States,” Cooper said. “That is the most powerful person in the world. We see him like an obese turtle on his back flailing in the hot sun, realizing his time is over.”
This colorful (if a bit fat-shaming) burn on the president of the United States raises the question: Can an obese turtle turn itself over?
It depends. Obesity is a common problem for aquatic turtles in captivity, especially those in small tanks that don’t leave much room to swim. Excessive amounts of starch-heavy food are a recipe for turtle obesity. Obese turtles can often have difficulty retreating into their shells because of the fat that has accumulated around their necks. Fat may also bulge around their arms and legs. The extra weight can make it such that these turtles become beached on land and suffer from limited mobility in water. While there isn’t a universal set of scientific standards for turtle obesity, researchers have found that adapting the obesity benchmarks for dogs and cats—30 percent higher than the ideal body weight—is adequate for studying these reptiles.
A turtle’s or tortoise’s ability to flip itself over from a supine position has a lot to do with the shape of its shell. Tall, domed shells are optimal, as they allow turtles to take advantage of gravity to help right themselves. A small wiggle of the leg is typically enough. Turtles with flatter shells have to use their necks as a pivot while thrashing their arms and feet.
There are a number of reasons why obesity would make it harder for a turtle to flip. Obesity can cause a turtle’s shell to flatten. In addition, when turtles turn over, they have to raise their centers of mass and overcome the gravity imposed on them based on their position. Obese turtles will have to contend with a higher gravity barrier due to their weight. If they can’t use their legs, which may be thicker and have reduced ability to push against the ground, to overcome this higher barrier, they won’t be able to flip over again.
Explainer thanks veterinarian and Slate contributor Matthew Miller and Johns Hopkins University mechanical engineering professor Chen Li.