Other Question #8798

Hamza, a 30 year old male from Calgary asks on August 21, 2012,

There is a place in Saudi Arabia near Medina known as Wadi Jinn or Wadi Baiza, so there the car run automatically without even pressing the gas pedal. Even the water fill plastic waterbottle on uphill both car and bottle. Even the water on the road travel up the hill....so plz research and reply.

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The answer

Barry Shell answered on August 22, 2012

Such places are typically optical illusions caused by the local terrain. If you were to make proper measurements with good land surveying instruments, you would find that the cars and the water are simply moving downhill, but IT LOOKS LIKE things are moving uphill due to the surroundings. Quoting from the Wikipedia entry on Gravity Hills: "The most important factor contributing to the illusion is a completely or mostly obstructed horizon; without a horizon, judging the slope of a surface is difficult as a reliable reference is missing."There's an example here in Canada called Magnetic Hill in New Brunswick and there are many other examples of such gravity hills around the world.

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