Gravity hill: Difference between revisions
No edit summary Tag: Reverted |
No edit summary Tags: Mobile edit Mobile web edit |
||
(28 intermediate revisions by 25 users not shown) | |||
Line 1: | Line 1: | ||
{{Short description| |
{{Short description|Illusion in which objects appear to roll uphill}} |
||
{{Redirect2|Magnetic hill|Mystery hill|| |
{{Redirect2|Magnetic hill|Mystery hill||Magnetic Hill (disambiguation)|and|Mystery Hill (disambiguation)}} |
||
[[File:Magnetic Hill, New Brunswick.JPG|thumb|Water appearing to run uphill at [[Magnetic Hill (Moncton)|Magnetic Hill]] in [[New Brunswick]]]] |
[[File:Magnetic Hill, New Brunswick.JPG|thumb|Water appearing to run uphill at [[Magnetic Hill (Moncton)|Magnetic Hill]] in [[New Brunswick]]]] |
||
[[File:Magnetic Hill-Moncton-New Brunswick-20170620.jpg|thumb|Magnetic Hill in [[Moncton]], [[Canada]]]] |
|||
A '''gravity hill''', also known as a '''magnetic hill''', '''mystery hill''', '''mystery spot''', '''gravity road''', or '''anti-gravity hill''', is a place where the layout of the surrounding land produces an [[ |
A '''gravity hill''', also known as a '''magnetic hill''', '''mystery hill''', '''mystery spot''', '''gravity road''', or '''anti-gravity hill''', is a place where the layout of the surrounding land produces an [[illusion]], making a slight downhill slope appear to be an uphill slope. Thus, a car left out of gear will appear to be rolling uphill against [[gravity]].<ref>{{Cite web|url=https://math.ucr.edu/home/baez/physics/General/roll-uphill.html|title=Can Things Roll Uphill?|website=Math.ucr.edu|access-date=8 April 2022}}</ref> |
||
Although the slope of gravity hills is an illusion,<ref>{{Cite journal|last1=Bressan|first1=Paola|last2=Garlaschelli|first2=Luigi|last3=Barracano|first3=Monica|date=2003|title=Antigravity Hills are Visual Illusions|journal=Psychological Science|language=en|volume=14|issue=5|pages=441–449|doi=10.1111/1467-9280.02451|pmid=12930474|s2cid=10405595|url=https://zenodo.org/record/1006741}} [https://zenodo.org/record/1006741#.Wdx33hhh1YI Free full text]</ref> sites are often accompanied by claims that [[magnetism|magnetic]] or [[supernatural]] forces are at work. The most important factor contributing to the illusion is a completely or mostly obstructed [[horizon]]. Without a horizon, it becomes difficult for a person to judge the slope of a surface, as a reliable reference point is missing, and misleading visual cues can adversely affect the [[sense of balance]]. Objects which one would normally assume to be more or less [[perpendicular]] to the ground, such as trees, may be leaning, offsetting the visual reference.<ref>{{Cite web|url=http://www.sciencedaily.com/videos/2006/0609-the_mysterious_gravity_hill.htm |publisher=Science Daily |website=ScienceDaily.com |title=The Mysterious Gravity Hill:Physicists Show "Antigravity" Mystery Spots Are Optical Illusions |url-status=bot: unknown |archive-url=https://web.archive.org/web/20080217004146/http://www.sciencedaily.com/videos/2006/0609-the_mysterious_gravity_hill.htm |archive-date=2008-02-17 }}</ref> |
|||
A 2003 study looked into how the absence of a horizon can skew the perspective on gravity hills, by recreating a number of antigravity places in the lab to see how volunteers would react. As a conclusion, researchers from the Universities of [[University of Padua|Padua]] and [[University of Pavia|Pavia]] in Italy found that without a true horizon in sight, the human brain could be tricked by common landmarks such as trees and signs.<ref>{{Cite web|url=https://www.sciencealert.com/gravity-hills-physics-defying-optical-illusion-car-drifts-uphill|title=These Gravity-Defying Hills Are One of The Strangest Natural Phenomena We've Seen|website=ScienceAlert.com|date=6 March 2017 |access-date=8 April 2022}}</ref> |
|||
The illusion is similar to the [[Ames room]], in which objects can also appear to roll against gravity. |
The illusion is similar to the [[Ames room]], in which objects can also appear to roll against gravity. |
||
Line 13: | Line 16: | ||
==See also== |
==See also== |
||
* [[List of gravity hills]] |
* [[List of gravity hills]] |
||
* [[The Crooked House]] – a |
* [[The Crooked House]] – a pub (now demolished) with an internal gravity hill illusion. |
||
==References== |
==References== |
Latest revision as of 13:16, 9 December 2024
A gravity hill, also known as a magnetic hill, mystery hill, mystery spot, gravity road, or anti-gravity hill, is a place where the layout of the surrounding land produces an illusion, making a slight downhill slope appear to be an uphill slope. Thus, a car left out of gear will appear to be rolling uphill against gravity.[1]
Although the slope of gravity hills is an illusion,[2] sites are often accompanied by claims that magnetic or supernatural forces are at work. The most important factor contributing to the illusion is a completely or mostly obstructed horizon. Without a horizon, it becomes difficult for a person to judge the slope of a surface, as a reliable reference point is missing, and misleading visual cues can adversely affect the sense of balance. Objects which one would normally assume to be more or less perpendicular to the ground, such as trees, may be leaning, offsetting the visual reference.[3]
A 2003 study looked into how the absence of a horizon can skew the perspective on gravity hills, by recreating a number of antigravity places in the lab to see how volunteers would react. As a conclusion, researchers from the Universities of Padua and Pavia in Italy found that without a true horizon in sight, the human brain could be tricked by common landmarks such as trees and signs.[4]
The illusion is similar to the Ames room, in which objects can also appear to roll against gravity.
The opposite phenomenon—an uphill road that appears flat—is known in bicycle racing as a "false flat".[5]
See also
[edit]- List of gravity hills
- The Crooked House – a pub (now demolished) with an internal gravity hill illusion.
References
[edit]- ^ "Can Things Roll Uphill?". Math.ucr.edu. Retrieved 8 April 2022.
- ^ Bressan, Paola; Garlaschelli, Luigi; Barracano, Monica (2003). "Antigravity Hills are Visual Illusions". Psychological Science. 14 (5): 441–449. doi:10.1111/1467-9280.02451. PMID 12930474. S2CID 10405595. Free full text
- ^ "The Mysterious Gravity Hill:Physicists Show "Antigravity" Mystery Spots Are Optical Illusions". ScienceDaily.com. Science Daily. Archived from the original on 2008-02-17.
{{cite web}}
: CS1 maint: bot: original URL status unknown (link) - ^ "These Gravity-Defying Hills Are One of The Strangest Natural Phenomena We've Seen". ScienceAlert.com. 6 March 2017. Retrieved 8 April 2022.
- ^ Schweikher, Erich; Diamond, Paul, eds. (2007), Cycling's Greatest Misadventures, Casagrande Press LLC, p. 114, ISBN 978-0-9769516-2-9, retrieved July 20, 2013
External links
[edit]- Dunning, Brian (January 11, 2011). "Skeptoid #240: Mystery Spots". Skeptoid.