It's when you're sitting in an office chair in the center of an interactive museum exhibit, swiveling around at a dizzying pace because you are flapping an arm-length wing, that it really hits you:
Biomechanics, the subject of a lavishly detailed new temporary exhibition at the Field Museum, can sit right in that part of the Venn diagram where scientific knowledge intersects with practicality and amusement.
Also: Maybe you should stop soon rather than suffer an embarrassing post-spin stumble or, worse, stomach lurch.
And this: Time for a more engaging chair to enliven home office?
"The Machine Inside: Biomechanics," crafted at the Field and there through Jan. 4, 2015, is a show for every person who's ever wondered how blood gets up to a giraffe's head, how squishy earthworms manage to dig in hard ground or how much less strong the human bite is than the hyena's.
It is not for people who see nature as a nuisance or whose curiosity about egg strength ends with whether they arrive home from the grocery store unbroken.
"The Machine Inside" teaches that eggs, with their domed shape distributing forces efficiently, "can withstand up to 90 pounds of downward pressure before breaking." That shape, visitors learn, also gives strength to the trilobite, the Atlantic horseshoe crab and the skull of homo sapiens.
The show takes a high concept — that all biological creatures comprise interconnected mechanical systems — and repeatedly over its 7,500 square feet explains how and why this is so.
It is testament to the patterns and variability in the natural world that the exhibition never feels as if it is belaboring the point.
Some of the most fascinating points are where nature, literally, inspired the development of machines. Velcro came about because Swiss engineer George de Mestral closely examined the burrs that clung to his dog after their hike in the Alps. A better chain-saw blade came about because logger Joseph Buford Cox spent hours watching longhorn beetle larvae alternating their two C-shaped jaws to chew efficiently through wood.
A show about biomechanics has been on the museum's to-do list since Mark Westneat arrived at the Field in 1992, said the biomechanics researcher and the exhibition's lead content adviser.
Planning began in earnest in the last five years, he said, with the Denver Museum of Nature & Science as a development partner. And now, although Westneat moved recently to a full-time academic position at the University of Chicago, the show is ready for public consumption and, after it leaves Chicago, travel. A second edition, at two-thirds the size, has been made to rent out internationally.
What makes "Biomechanics" work, beyond the imagination of its makers, is its clear organization combined with an apparent aim to get visitors involved. The individual sections are arranged by types of related systems: "Fins and Wings," "Pumps and Pipes," "Insulation and Radiators," "Legs and Springs" and so on.
In the section on eating ("Jaws and Claws"), we learn that humans are less than one-fifth the biters hyenas are, but that hyenas are nothing compared to the piranha, 25 times more powerful with its jaws.
Heat regulation shows us the range in size of white-tailed deer is dependent on habitat. Adults are about 400 pounds in Ontario, Canada, 250 pounds in Missouri and 75 pounds in the Florida Keys. The same species needs more weight to retain heat in the north, much less to dissipate it in the south.
Visitors who feel like doing the pumping work of a giraffe's powerful heart can squeeze a sort of ball and watch "blood" slowly climb a full-sized giraffe neck. It's like a science geek's version of a carnival strongman test, and it truly is a test.
"It's not stuck. You have to pump really hard," Chicago fourth-grader Anita Ye told a classmate during an exhibition preview Tuesday.
Asked about the exhibition as a whole, Ye sounded like someone who was in on the planning meetings. "There are, like, games that relate to the science of things," she said. "And also what's interesting is you can compare which animals are stronger and which ones are weaker."
The emphasis throughout is on using real specimens rather than models. A fennec fox specimen demonstrates what big ears it has, the better to regulate body heat.
The video — including high-speed footage that visitors control with a dial of a tiny fly, a shrimp that punches and a snake that soars — feels like it's there to make a point rather than merely to satisfy the contemporary exhibition requirement of a video component.