A Defiance of Natural Law
At the base of Lutes Mountain, on the outskirts of Moncton, a peculiar stretch of road seems to defy gravity. When a vehicle is stopped at the bottom of the slope, shifted into neutral, and the brakes are released, it begins to roll backward, seemingly uphill. Water poured onto the pavement also appears to flow against the grade. This phenomenon, known locally since at least the 1800s, became a major tourist attraction after it was reported on by journalists in August 1933. By the 1950s, Magnetic Hill was one of Canada’s most visited natural attractions, alongside Niagara Falls and Banff National Park.
The experience is a sensory contradiction. Your eyes perceive a clear uphill incline, yet the motion of your vehicle tells a different story. The name "Magnetic Hill" is a misnomer; the force at work is not magnetism; it is a compelling trick of the mind. Even a plastic ball, which is not magnetic, will appear to roll uphill here. The effect is a type of optical illusion known as a gravity hill, and dozens of similar spots exist around the world.
The Science of the Illusion
The "uphill" roll is a result of perceptual psychology. The illusion is primarily caused by the complete or partial obstruction of the horizon. The human brain uses the horizon as its main visual reference point for determining what is level. Without it, the brain is forced to find other cues in the landscape. At Magnetic Hill, the surrounding terrain slopes in such a way that it creates a false horizon.
This skewed frame of reference makes a slight downhill slope—the actual topography of the road appear to be an uphill slope. Trees and other landscape features, which one might assume are perpendicular to the ground, may actually be leaning slightly, further confusing the brain's ability to judge the true angle of the road. Studies by researchers at the Universities of Padua and Pavia in Italy confirmed that without a true horizon, the brain can be easily tricked by these misleading landmarks. The illusion is so effective that it overrides the body's other balance systems, like the mechanism in our inner ears. Surveyor's levels and GPS measurements confirm that the road your car "climbs" actually descends over its entire length.