Gravity Hill: How does it work?

[beagledave]

Near Shullsburg, Wisconsin is a stretch of County U road referred to as Gravity Hill (http://wicip.uwplatt.edu/lafayette/ci/shullsburg/gravity.html).

I've never been there myself, but it's close enough to my area that you hear about it occasionally. Essentially, if you drive your car to this section of the road, slip it into neutral..the car will move uphill while in neutral..."or so it seems"

The locals claim it is unique...there may be other similar (http://page.infinit.net/odipierr/autreslieux.htm) spots as well.

Has anyone been to this place..or another similar spot?

Anyone have an explanation behind the appearance of unassisted uphill movement?

[bup]

It's an optical illusion. The horizon isn't flat, but your mind takes the horizon as being perpendicular to gravity.

You're going downhill.

[x-ray vision]

You own link answers your question.

[jack@ss]

There's a Gravity Hill in Salt Lake City. I have been there once in the late 80s, and don't remember exactly where it is, but it's up the road from Memory grove, around City Creek.

[cmkeller]

Has anyone been to this place..or another similar spot?

Anyone have an explanation behind the appearance of unassisted uphill movement?

I've been to Magnetic Hill in Moncton, New Brunswick, Canada, as well as the Confusion Hill Gravity House in Piercy, California (which is missing from the list in your link).

It's all an optical illusion. The mountain slope you're on is so steep that the road you're on, which is on a relatively lesser slope but is still uphill, appears to be downhill. So it seems to you that your car (or the rolling ball, or whatever) is traveling against gravity...but it isn't.

[Bongmaster]

There is a similar hill in Bucks County PA, about 1/2 an hour from my home. It all has to do with the lay of the land, it makes it appear to be a hill going up but in reality you are going down.

[Baron]

And I thought our Gravity Hill in northern NJ was the only one...(off Rt. 208 in Wyckoff)

[Squink]

Near Shullsberg ? The excess gravitational attraction may be due to the consumption of large quantities of tasty 5 year old cheddar from the local cheesery (http://www.explorewisconsin.com/shullsburgcheesestore/). ;)

[yabob]

One common form of the illusion is that you have a very gentle slope, with some reference like trees or telephone poles that happen to lean a little bit more than the slope, in the same direction. The slope isn't steep enough to be visually apparent, and you tend to orient on the tree or telephone pole as vertical, leading you to think the slope is in the opposite direction from what it actually is because you are judging it by the angle it makes with the pole. Consequently, objects can roll "upill".

[Hail Ants]

I remember seeing a 'gravity hill' about 20+ years ago on one of those god awful 80s shows, That's Incredible I think.

[mipiace]

There must be "Gravity Hills" all over the place. The one in lake Wales Florida is called Spook hill and supposedly when you park at the "bottom" of the hill you are on an Indian burial ground. The ghosts pull you back up the hill to move you from their sacred spot.....it's the same principal though, it's actually down hill.

[Strainger]

I can't believe that Booger Mountain in Cumming, GA wasn't mentioned in beagledave's link. :mad:

[notquitekarpov]

BTW there are also numerous rivers and creeks that appear to flow uphill due to the same optical illusion...

[japatlgt]

Yeah, there's one in Nashville. Same deal. It's an illusion.