Optical Illusion

By Sri Ekawati

Mystery of Magnetic Hill in Kelud Volcano, East java
Desa Sugihwaras, Kecamatan Ngancar, Kediri


Some people think hill in Kelud Volcano has a mystery. When car even truck is placed in neutral, it will begin to roll backwards, apparently uphill. Sharp observers will also note that water also seemingly runs uphill. Non-high education people think this mystery is related with mystic or metaphysic. The others think there is magnetic field anomaly or gravitation anomaly in that location.
This phenomenon motivates a scientist or researcher to investigate the hypothesis that there is an anomaly of magnetic field or gravitation in that location. They start to measure the magnetic field and the gravitation there. Unfortunately, the entire hypothesis is broken. Mr. Seno and Mr. Amin (Lecturer from ITS), states there is no magnetic anomaly or gravity anomaly in that location. Even they states the hill is 5% slope downward. Mr. Amin states that Mystery of Kelud hill is only an optical illusion. The location of this phenomenon is not only in East Java, Kelud Volcano, Indonesia but also in all over the World. Many have no specific name and are instead often simply referred to as 'Gravity Hill' or 'Magnetic Hill'. Magnetic hill or gravity hill is an optical illusion where a downwards slope appears upwards.


Optical illusion

Before I discuss an optical illusion of magnetic hill or gravity hill, I want you to see some example of optical illusion from http://www.eyetricks.com/illusions.htm.




Illusion of Magnetic Hill in Kelud Volcano, East Java


We say the streets that upwards, downwards and straight depend on the reference point. In another word, something upward or downward is relative to something as reference. We use the three as reference point of vertical direction. As we know the direction of the three is always vertical perpendicular with the sun in the afternoon.

A phenomenon in the magnetic hill is the three is not vertical as common. The street actually downward but our eyes tell our mind upward. This is some optical illusion that created naturally. The directions of the threes are slant. This happens because of soil creep. Soil creep is the slow, down slope movement of soil under the influence of gravity. Frost heave, thermal expansion and contraction of the surface, alternate wetting and drying of the soil can cause soil creep.

Source :

http://www.eyetricks.com/illusions.htm
http://rovicky.wordpress.com/2007/07/20/misteri-jalan-bermagnet/
http://en.wikipedia.org/wiki/List_of_magnetic_hills