If a mouse dropped a 1,000- foot mine shaft, the prominent evolutionary biologist JBS Haldane when proposed, the mouse would increase, shake the dust off itself, and scamper away. Perhaps even right back up to do it once again.
If a rat fell from the same height, nevertheless, it would die.
A human would break, Haldane composes, and a horse would sprinkle.
Haldane does not offer a colorful verb in his 1926 essay On Being the Right Size for what would take place if a 9-ton Tyrannosaurus rex fell under that mine. The huge predator would scream down the shaft at 172 mph, hit the ground with 120 heaps of force and … shatter? Dismember? Detonate? Emerge?
Regardless, the purpose of Haldane’s gruesome thought experiment is to show the drastically various relationship large animals have with gravity compared to smaller sized ones. This relationship, and the differing fates of the mouse and rat, are discussed by the “square-cube” law, which is the easy concept that as a things broadens, its volume cubes while its surface area simply squares. Since an animal’s area supplies the brakes when falling, and its mass identifies the force of its effect, the falls of numerous types can be either thrilling, terrible, or untidy, depending upon seemingly small differences in their size. It may be a basic principle– but since the law includes such rapid development, it’s extremely tough to intuit its periodically dramatic results. That’s particularly true with concerns to the largest land animals to have ever strolled the earth, and particularly essential if you had to outrun them.
For instance, if you took a trip back to the dinosaur age, or it took a trip to you in some kind of clinical catastrophe, you may find yourself ranging from a duplex-sized reptile. However don’t panic. You have the disproportionate impacts of size on your side. The T. rex’s eruptive demise at the bottom of the mine shaft illustrates the most essential factor to consider when facing the huge saurian’s pursuit. In the run for your life, its breathtaking, scary, stupefying size would be, in reality, your biggest benefit.
A full-grown Tyrannosaurus rex was absurdly substantial and absurdly effective. It had rows of teeth it could press through Triceratops bone, could toss human-sized chunks of meat 16 feet into the air with its jaws, was as high as a giraffe, and, at nine heaps, was as heavy as an elephant. And yet if you see one, you should be only mildly worried. Tyrannosaurus rex had proportionally more muscles devoted to its movement than nearly any animal that’s ever lived, Eric Snively, a biologist at Oklahoma State who studies the biomechanics of dinosaurs tells me. And yet you could likely escape it, since a Tyrannosaur couldn’t run.
I asked John R. Hutchinson, lead author of a paper in Nature titled “ Tyrannosaurus Was Not a Fast Runner,” what a Tyrannosaurus’ performance in a race would look like. “A short-distance jog has to do with the best we ‘d expect,” he said. “And not with a quick start, either.”
The incredibly effective, long-legged Tyrannosaurus was sluggish for the very same mathematical reason its death in the mine shaft was so eruptive. Like surface area, bone strength only squares in strength as volume cubes. The result is that as an animal increases in size, it needs proportionally more muscle and leg bone to stand, move, and run. Beyond a particular size, the latter ends up being physically impossible. For all its muscular bulk, the Tyrannosaurus rex‘s leg bones would have shattered under anything more than the tension of a brisk jog. Judging by its mass, muscle, and bones, Snively does not believe an adult Tyrannosaurus rex could have moved faster than 12 or 13 miles per hour. (Though 12 miles per hour approaches the top speed of a typical human, depending on conditioning– it relates to a 20- second 100 meter dash or a 5-minute mile– the T. rex’s sluggish acceleration and motivating teeth would offer the typical runner a reasonable opportunity of outsprinting or outmaneuvering the lumbering predator.) 1
1 Admittedly, there is some concerning speculation that T. rex hunted in packs, which would complicate your escape. Fortunately, the best present proof recommends that, though they may have eliminated in packs like crocodiles, they did not coordinate their pursuits like wolves.
Of course, the Tyran
