What is it about?

Antigravity hills, also known as spook hills or magnetic hills, are natural places where cars put into neutral are seen to move uphill on a slightly sloping road, apparently defying the law of gravity. We show that these effects, popularly attributed to gravitational anomalies, are in fact visual illusions. We re-created all the known types of antigravity spots in our laboratory using tabletop models; the number of visible stretches of road, their slant, and the height of the visible horizon were systematically varied in four experiments. We conclude that antigravity-hill effects follow from a misperception of the eye level relative to gravity, caused by the presence of either contextual inclines or a false horizon line.

Featured Image

Why is it important?

The over 20 natural cases of antigravity hills reported so far are all variations on a single theme. Our study shows that the phenomenon can be recreated artificially, with no intervention whatsoever of magnetic, antigravitational, or otherwise mysterious forces. The spooky effects experienced at these sites are produced by a visual illusion.


Using miniature or even life-size reproductions of our tabletop models, it should be easy to recreate the fascination of this challenge to gravity in amusement parks and, for twice the benefit, science museums anywhere.

Dr Paola Bressan
Universita degli Studi di Padova

Read the Original

This page is a summary of: Antigravity Hills are Visual Illusions, Psychological Science, September 2003, SAGE Publications, DOI: 10.1111/1467-9280.02451.
You can read the full text:




The following have contributed to this page