Washington's Gravity Hills: Where Physics Takes a Holiday
Gravity hills — locations where the landscape creates an optical illusion that a slight downhill slope appears to be an uphill slope — exist worldwide. Washington State has several particularly convincing ones, and locals swear they're more than mere illusions.
The most famous is Prosser's Gravity Hill in Benton County, where cars placed in neutral appear to roll uphill. Similar spots exist near Eatonville, near Ellensburg, and on a rural road outside of Centralia.
At each location, the standard explanation is an optical illusion created by the surrounding terrain. And in most cases, careful surveying confirms this. But at the Eatonville location — near the foot of Mount Rainier — surveying equipment has produced inconsistent results. Different survey teams have gotten different readings, and one team's laser level showed a variance they couldn't explain.
The Eatonville gravity hill is also within the zone of intense electromagnetic activity associated with Mount Rainier. Some researchers have proposed that localized gravitational anomalies — while physically improbable — could be connected to the volcanic geology.
"Put your car in neutral at the Eatonville gravity hill on a quiet night," Captain Ron suggests. "Feel it start to move. Then ask yourself: if this is just an optical illusion, why does your inner ear — your body's actual level — agree with what your eyes see? Your vestibular system isn't fooled by horizons."
