Our next stop for California Friday is Gravity Hill in Sylmar. For those of you that grew up in the San Fernando Valley, you probably remember going to Gravity Hill to experience your car rolling “uphill” without any power. To make it extra creepy, it was best to experience this phenomena in the dark of night because Gravity Hill was next to a cemetery. Then add in a legend about a school bus crash that happened there and the children that died will push your car to keep you from the same fate … that makes it even more creepy!
Gravity Hill in Sylmar is on Kagel Canyon Rd, next to the cemetery at Glen Haven Memorial Park.
For a great demonstration showing a ball and car and water roll “uphill”, check out this video made in 2009. The comments with stories are great to read too!
I place quotes around “uphill” because nothing is rolling uphill. Looking at the LARIAC elevation data, you can see the road slopes downhill from north to south.
Note that the contour lines crossing the road are closer together in the northern portion vs. the southern portion. At this particular place the layout of the surrounding land produces an optical illusion making a slight downhill slope (the southern portion) appear to be an uphill slope. Thus, things will appear to be rolling uphill against gravity.
The most important factor contributing to the illusion is a completely or mostly obstructed horizon, because without a horizon, judging the slope of a surface is difficult as a reliable reference is missing. This is true for almost all gravity hills around the world.
Even an investigative team went to Gravity Hill in 2006 to document what was going on at this location. Check it out.
If you have not visited Gravity Hill, go check it out. And if you have kids, tell them a few stories first so they freak out when the car rolls “uphill” … at night would be even better!