From the people that brought you the "Speed of a minibike in Jackass Number Two" study comes "Acceleration due to gravity: Super Mario Brothers," an absurdly detailed scientific study on the evolution of gravity in the Mario series.
Gravity might be a constant in real life, but that's not the case in the Super Mario games, according to a study done by Adam Lefky and Artem Gindin for The Physics Factbook. "[Gravity is] the force that prohibits us from jumping 50 feet in the air," Lefky and Gindin wrote. "However, in Mario's world, gravity does not quite work that way. Mario is able to jump 5 times his height and fall with accelerations that would be deadly to humans."
To measure the nature of gravity in Mario as it has evolved over time, Lefky and Gindin used the formula "s = s0 + v0t + ½ at2," and recorded clips of Mario falling from a ledge in every Mario game from the first NES title to Super Paper Mario on the Wii, counted the frames to see how long he took to fall, and measured pixels to determine the distance of the fall. After figuring out Mario's acceleration due to gravity in each game, they graphed their data according to the bit rates of the consoles.
"We determined that, generally speaking, the gravity in each Mario game, as game hardware has increased, is getting closer to the true value of gravity on Earth of 9.8 m/s squared," they wrote. Still, Mario gravity is far from realistic: the most recent game tested, Super Paper Mario, featured gravity of a whopping 43.05 m/s squared. "With gravity that great, it is a wonder Mario can perform such feats as leaping almost 5 times his own body height!" Lefky and Gindin wrote.
Somehow I think that's the point.