By Sing H. Lin, Ph.D., E-Mail: SINGHLIN@GMAIL.COM

Original appeared on January 3, 2007, Latest Revision on July 7, 2014

Abstract

My 21 Year Work: For about 21 years since my tour of The Mystery Spot in Santa Cruz, California in
1993, of Oregon Vortex in Gold Hill, Oregon in 2004 and of the Magnetic Hill in eastern Canada in 2005, I have
been thinking about and investigating on the strange gravity phenomena on hundreds of gravity hills all over the
world and at several known Mystery Spots.

Gravity Hills: Many people have observed and reported a strange gravity phenomenon on strange slopes
of paved roads at hundreds of locations all over the world. People pour water on such strange slope and water
flows uphill. People put plastic water bottle on such strange slope and the plastic water bottle with water rolls
uphill. Vehicles with transmission shifted to neutral gear and brake released simply roll uphill on such strange
slopes.

Mystery Spots: At Oregon Vortex and several other similar Mystery Spots, a well known mystery is the
significant change of relative heights of two persons when they switch their standing positions on a
demonstration platform inside the mystery spot area.

Illusion Theory: Many people simply dismiss such strange gravity phenomena on those gravity hills and in
those Mystery Spots as illusion. Some people have also done some tests and measurements on some of
those gravity hills and claimed that they have proved that it is an illusion. However, my careful examinations of
these tests, measurements and claims indicate that they are NOT valid proofs because of serious defects in
such tests and measurements as explained in this web page.

My 21-year research collected six sets of independent evidences that cast serious doubt on the validity of
illusion theory. These evidences indicate that the strange gravity phenomena on these gravity hills and mystery
spots are real and are not due to illusion.

Mystery in Astronomy: Many astronomers and scientists all over the world have been struggling with the
mysterious dark matters based on astronomical observations. These astronomical observations and analyses  
imply the existence of huge amount of unknown dark matter that is five times more abundant than our familiar
regular matter, but our scientific knowledge still does not understand that "dark side of cosmos" well yet.

My Theory: My 21-year research on this project enables me to develop the dark matter theory for the
gravity hills and mystery spots. This theory and its associated Model indicate that the source for such
abnormal gravity at a gravity hill (or a mystery spot) is a very compact nugget of dark matter with extreme high
mass density that is at least 1,000 times greater than that of average ordinary material on earth surface.

The compact nugget at the location of a gravity hill (or a mystery spot) is not a solid rigid nugget but consists
of many loose sand particles of dark matter with extreme high mass density. This compact nugget is
supported by two streams of loose sand particles of dark matters. One stream is being sucked from the
compact nugget into the center of earth by earth gravity, then over-shoots and keeps going to the conjugate
point on the opposite side of earth surface. The other stream is also being sucked from the conjugate point
into the center of earth by earth gravity, then over-shoots and keeps going back to the original location of the
gravity hill (or the mystery spot).

In other words, these loose sand particles of dark matter are trapped in the gravity well (gravity field) of the
earth and are oscillating between the gravity hill (or the mystery spot) and its conjugate point on the opposite
side of earth surface.

The details of the logic and the supporting information for such dark matter theory and the associated Model
are described in my web page at:

http://
www.shltrip.com/Oregon-Vortex.html

The dark matter's gravity anchor in the earth's gravity well is also described in the web page above.

This Model can explain all the observed strange gravity phenomena and mysteries in the known mystery spots
and hundreds of gravity hills all over the world. Some possible methods to test the validity of this Model are
also described in the web page above.

********************************************
For about 21 years since my tour of The Mystery Spot in Santa Cruz, California, USA in 1993, of Oregon
Vortex in Gold Hill, Oregon, USA in 2004 and of the Magnetic Hill in eastern Canada in 2005, I have been
thinking about and investigating on the issue of whether such strange gravity hill effects and gravity mysteries
are real or illusion and searching for a possible scientific explanation for such strange gravity phenomena and
mysteries. I started presenting this web page on January 3, 2007 soon after my Travelogue website (
WWW.SHLTRIP.COM ) was established in December 2006. I have been revising and updating this web page
from time to time as I gain more insight and relevant information since 2005 in my search for a scientific
explanation for the strange gravity phenomena on hundred of gravity hills and at several known mystery spots.
Most recent update of this web page was on July
23, 2014. As of July 23, 2014, this web page has been
accessed 9,2
88  times by my friends and strangers all over world.

**********************************************
PowerPoint Presentations:

The highlights of this lengthy web page are summarized in the following PowerPoint Presentation (PPP). I have
presented this set of PPP in the Quarterly Meeting of the Distinguished Citizen Society International - Eastern
USA Chapter (DCSIE) on June 8, 2013 and in the Meeting of CACA 40-Plus Club on December 31, 2013, both
in New Jersey, USA.

Click the following link to see the PowerPoint Presentation.






*********************************************
Table of Contents

1. Strange Gravity Phenomenon at Magnetic Hill in Eastern Canada

1.1 First Set of Evidence Against Illusion Theory for Gravity Hills

1.2. Location and Direction:

1.3. Not All Gravity Hills Are Equal

2. Gravity Hills on Coastal Highways:

2.1.  Example One of Coastal Gravity Hills

2.2. More Examples of Known Coastal Gravity Hills

2.3. Second Set of Evidence Against Illusion Theory for Gravity Hills

3. Detection of Abnormal Gravity at Mystery Spot in Michigan by Three Surveyors

3.1. Third Set of Evidence Against Illusion Theory for Gravity Hills

4. More Evidences Against Illusion Theory

4.1. Detection of Abnormal Gravity by Gravitational Time Dilation

4.1.1. Fourth Set of Evidence Against Illusion Theory

4.2. Asymmetric Pendulum as another Evidence against Illusion Theory

4.3. Sixth Evidence Against Illusion Theory

5. Many Other Locations with Similar Strange Gravity Phenomenon

5.1. Strange Slope in Northeastern China

5.2. More Existing Known Gravity Hills

5.3. More Potential Locations

5.4. Cluster of Gravity Hills

6. Is It Magnetic Force or Electric Force?

7. How About Doing Some Tests and Measurements?

7.1. Problems of Using Traditional Land Survey Method on Gravity Hills

7.1.1. Problems of Spirit/Level Bubble and Plumb Line on Gravity Hills

7.2. Contradictory Results from GPS Measurements

7.3. Accuracy of Consumer-Grade Single GPS Receiver for Elevation Measurements

7.4. Topographic Map

7.5. Status of Scientific Proof of Illusion

8. Need for Precision Scientific Measurements on Gravity Hills and Mystery Spots

9. Dark Matter Theory for Gravity Hills and Mystery Spots

10. Technical Background of the Author of This Web Page

Appendix A - Many Reports of Gravity Hills at many locations all over the world at the following
YouTube websites:

Appendix B - Some Chinese websites listed in the following indicate that similar Gravity Hills have also
been observed at several other locations in China.

**************************************************************************

1. Strange Gravity Phenomenon at Magnetic Hill in Eastern Canada

In July 2005 on our way to tour New Brunswick, Nova Scotia and Newfoundland in eastern Canada, we
visited Magnetic Hill near the City of Moncton in the Province of New Brunswick. Please take a look at
the following 8 pictures that I took at the Magnetic Hill.
Picture 1: At this location, visitors can drive their cars to the lowest point (bottom of the hill marked by a
white post on the road side) in the middle of this section of the road as shown in the following second picture.
Picture 2: At the lowest point in the middle of this section of the road, the visitor stops the car, shifts the
transmission of the car to the neutral position and releases the brake. (Some visitors even turn off the engine
entirely at this point.) Then the car will start rolling up the hill (slope of the road) on its own and will keep on
going up the hill as shown in the following two pictures.
It is worthwhile to enjoy such strange experience if you have an opportunity to travel near that area in the
future for sightseeing. There are several tourist attractions in that area near beautiful Bay of Fundy such as
Hopewell Rocks to see world's highest tidal range, Mary's Point and Johnson's Mills to see huge number of
migratory shore birds feeding on mud flats of Bay of Fundy during migration season, beautiful Fundy National
Park, whale watching in Bay of Fundy, Reversing Falls at Saint John, beautiful Cape Brenton Highlands
National Park, etc. as described in details in my Travelogue web page at:

http://
www.shltrip.com/Nova_Scotia_and_New_Brunswick.html

Due to the popularity of this strange phenomenon on this section of the road, the local government was willing
to spent money to construct a parallel new road (Mountain Road) to bypass this section of the road so that
many visitors can try it to experience the sensation of the strange gravity phenomenon on this section of the
road without worrying about collision accident with regular vehicular traffic on the road.

When I was on the waiting line described above in July 2005, an old guy told me that this was his second time
to visit Magnetic Hill. The first time was about 50 years ago when he was a teenager. He said that 50 years
ago, they did not use cars but used bicycles. He sat on the bicycle
, did not pedal the bicycle, but the bicycle
just rolled up the hill on its own.

The brochure entitled “The Story of Moncton’s Mysterious Magnetic Hill” for visitors at Magnetic Hill in
Moncton indicates that the local farmers had observed this recurring strange phenomenon on their horse
wagons in the early 1800’s. When they were going downhill on this section of the road, the horse seemed to
be using substantial effort to pull the wagon to go downhill. But when they were going uphill, the wagon would
run up on the heels of startled horse. There were also stories of barrels and bales of dry goods rolling
mysteriously “uphill”.

Observers also note that water in the roadside drainage ditches also seemingly runs “uphill.” This rules out
magnetic as the force for this strange phenomenon.


1.2. Location of Magnetic Hill and Direction:

The Magnetic Hill is at the junction of Mountain Rd. and Magic Mountain Rd., Moncton, Canada. Phone:+1
506-853-3597. It is
at northwest part of the city of Moncton in the Province of New Brunswick. Moncton is in
eastern Canada, near northeast tip of Bay of Fundy, on Transcanada Highway 2, about 1,036 Km east of
Montreal and 273 Km northwest of Halifax.

Directions: Take exit 450 of the Transcanada Highway (i.e. Highway #2) for Route 126 (i.e., Mountain Road)
and follow the signs of Magnetic Hill. Phone: 506-853-3516.

Map: Click here to see Google Map showing location of Magnetic Hill near Moncton


1.3. Not All Gravity Hills Are Equal

Over the last few years, I have visited 6 gravity hills: one in eastern Canada, three in Pennsylvania, USA and
two in southwest New Jersey, USA. Out of these 6 gravity hills, the Magnetic Hill at Moncton in eastern
Canada is most impressive because the slope of this gravity hill is steepest among these 6 gravity hills that I
have visited.

Some 5-Star famous gravity hills have steeper slopes so that rolling uphill on such steep slope is more
obvious, sensational and impressive. Two examples of such 5-star gravity hills are (a) Magnetic Hill near
Moncton in eastern Canada, and (b) Strange Slope (怪坡) near 瀋陽 in northeast China. These two gravity
hills are so popular, attracting so many visitors that the local governments are willing to invest money to build
a by-pass road for regular traffic to bypass the gravity hill so that many visitors can enjoy the thrill on such
gravity hill without worrying about automobile collision accident with regular road traffic. The local
governments are proud of such gravity hills in their towns, are willing to invest money to promote them as their
tourist attractions with several big road signs to welcome visitors from exit ramp of nearby major highway all
the way to the gravity hill. The visual perceptions of the steep slope by all visitors are very clear and
unambiguous on this particular gravity hill at Moncton. For visitors, it is very exciting and thrilling to sit inside a
vehicle rolling up this steep slope. The starting point and the end point of the gravity hill are well marked. They
charge
$5 entrance fee to Magnetic Hill and practically all visitors are very happy to pay such entrance fee to
experience the thrill.
Some tour guides indicate that Magnetic Hill at Moncton is the third most visited natural
"wonder" in Canada.


But some other gravity hills have very mild and small slope such that the strange gravity hill effect is NOT
clear, not strong, not very sensational and not very impressive. On such mild slope, the visual perception of
the mild slope may be somewhat ambiguous and unclear depending on people. Some people may get an
ambiguity feeling in that they are not sure if it is really an uphill slope. Some people argue that it is an uphill
slope while other people argue that it is a downhill slope. With such ambiguity feeling, many people then easily
get the feeling that it may be just an illusion. Such mild gravity hills are not impressive and are not attracting
many visitors. The local governments do not feel it is worthwhile to invest money to build a bypass road to
bypass the regular road traffic away from such mild gravity hills. The local governments are not willing to
spend money to promote it as a tourist attraction. Worse yet, some local policemen even tell occasional
visitors that there is no gravity hill here, go away, to avoid such visitors causing traffic problems or irritating
the local residents.

Therefore, if you want to see and experience the thrill of a good and powerful gravity hill with a strong feeling,
it is highly recommended that you go to see the Magnetic Hill at Moncton, in the Province of New Brunswick in
eastern Canada.

On the other hand, if you go to see a feeble gravity hill with a mild slope as a first experience, you probably
will be disappointed with an ambiguous feeling. Such ambiguous and feeble feeling may be one of the
contributing factors for so many people to believe that it is just an illusion.

A couple who had experience of visiting both Magnetic Hill in Moncton, Canada and Electric Brae in Scotland
indicated that Magnetic Hill in Moncton is more impressive as described in the following website:

http://
johnmacnab.hubpages.com/hub/Magnetic-Hill

There is a very brief report of a gravity hill with a steep slope of 15 degrees in a desert region in Gansu
province (甘肅省甘南縣祈豐區的戈壁灘上) in northwest China. But I cannot find pictures, or video or other
more detailed information on this very special steep gravity hill. I hope that somebody else can help to get
some good pictures, videos and more detailed information on this steep gravity hill in China.

2. Gravity Hills on Coastal Highways:

Several known gravity hills are on coastal highways where the vast horizontal line of the nearby ocean is
readily visible as the horizontal reference to all visitors of the coastal gravity hills. On such coastal gravity hills,
the human perception of uphill slope should be correct because the reference horizontal line is readily visible in
the nearby ocean.

However, the Illusion Theory still asserts that human perceptions of the top and the bottom of such coastal
gravity hills are still "wrong". The Illusion Theory for such coastal gravity hills is usually supported by their land
survey measurements that indicate that the human perceived bottom is higher than the human perceived top
of such coastal gravity hill.


The evidences in Sections 3 and 4 indicate that significant abnormal gravity has been detected at several
locations on earth surface.
The key defect in existing land survey measurements on gravity hills is that the
liquid
level bubble and the plumb line used in such land survey measurements are affected by the abnormal
gravity on such gravity hills such that the measurement results are wrong as illustrated
and explained on
Figures 1 and 2 in Section 5.

2.1.  Example One of Coastal Gravity Hills

One example of such coastal gravity hills is known as Electric Brae on coastal road A719 in Ayrshire,
Scotland as described in the following Wikipedia website with 2 pictures:

http://
en.wikipedia.org/wiki/Electric_Brae

Two better pictures of this coastal gravity hill showing the visible nearby ocean and its horizontal line can be
seen by clicking the following links:

Picture A: Click here to see a picture of the coastal gravity hill Electric Brae near the ocean

Picture B: Click here to see a picture of the coastal gravity hill, Electric Brae, near the ocean

Several pictures on the following website also provide some nice views of the blue ocean near the coastal
road A719 near the area of the well known gravity hill, Electric Brae:

http://
bikeaboot.lawrab.com/2010/08/linwood-to-electric-brae.html


Three people on bicycles rolling up this coastal gravity hill on the coastal road 719 without peddling can be
seen at the following YouTube website:

http://
www.youtube.com/watch?v=MRuEUSiMalk

Again, this movie shows that the nearby ocean and its horizontal line are readily visible by everybody on this
coastal gravity hill on the coastal road A719.

More movie clips showing vehicles rolling up this coastal gravity hill near the ocean can be seen at the
following YouTube websites:

http://
www.youtube.com/watch?v=AofTlPpCIxQ

Again, this movie clip and the following four movie clips all show that the nearby ocean and its horizontal line
are readily visible by everybody on this coastal gravity hill on the coastal road A719.

http://
www.youtube.com/watch?v=DBSRLtLBvpA&feature=related

http://www.youtube.com/watch?v=JDhLTozHXlI&feature=related

http://www.youtube.com/watch?v=DsxrAGGcauk&feature=related

http://www.youtube.com/watch?v=5w8dMeysxaY&feature=related

During the Second World War, even General Dwight D Eisenhower, who had a flat nearby at Culzean Castle,
often brought visitors here to see and to experience this strange gravity phenomenon on Electric Brae.

2.2. More Examples of Known Coastal Gravity Hills

The second example of coastal gravity hill is known as Magnetic Hill, located on the coastal road A27
between Ballabeg and the Round Table crossroads, at Ronague near Colby on Isle of Man in the Irish Sea in
Great Britain. On such coastal gravity hill, visitors can see the reference horizontal line on the nearby ocean
as shown in the following YouTube videos:

http://
www.youtube.com/watch?v=UbUmOxytkZo

http://www.youtube.com/watch?v=9tNyPgLIUh4

http://www.youtube.com/watch?v=l_Ewl43YO5k&feature=related

In addition to these two examples of gravity hills on coastal roads where the reference horizontal line on the
nearby ocean is readily visible from these coastal gravity hills, there are more reported gravity hills on coastal
roads such as:

Known as Anti-Gravity Point on a coastal road at a place called Mirbat which is about 40 km east of coastal
City of Salalah in southern part of Oman (on the southeast coast of the Arabian Peninsula), and

A gravity hill in Cascais, on a coastal road N247 on a hill near Malveira da Serra and Guincho Beach, West of
Lisbon, Portugal.

2.3. Second Set of Evidence Against Illusion Theory for Gravity Hills

These movies and pictures on coastal gravity hills show that the vast horizontal line of the nearby ocean is
readily visible as the horizontal reference to all visitors to the Electric Brae and other coastal gravity hills. On
such coastal gravity hills, I believe that human perception of uphill slope is correct because the reference
horizontal line is readily visible in the nearby ocean. This means that the observed strange phenomenon of
vehicles in neutral gear and brake released rolling uphill is real, not an illusion.

Yet the land survey measurements in such area show that human perceived top of the gravity hill is lower than
the human perceived bottom of the gravity hill. Such results of land survey measurements in such gravity hill
areas are wrong because of the influence of the abnormal gravity (on these gravity hills) on the critical level
liquid bubble and the plumb line used in such land survey instruments. The evidences 3 to 6 in Sections 3 and
4 show that significant abnormal gravity has been detected in such gravity hill areas and mystery spots areas.
With the existence of significant abnormal gravity, the level liquid bubble and the plumb line cannot tell the
correct and critical reference horizontal line and the critical reference vertical line for accurate land survey
measurements in such gravity hill areas or mystery spots areas. The wrong reference horizontal line and the
wrong reference vertical line lead to the wrong measurement results by the land survey measurements in such
gravity hill areas or mystery spots areas.  This is explained in more details with Figures 1 and 2 in Section 5.

Several possible scientific methods of precision measurements that may be carried out on gravity hills to
illustrate the serious defects in these existing previous measurements are described in my web page entitled
"Need for Precision Scientific Measurements on Gravity Hills" at:

http://www.shltrip.com/Need_For_Precision_Measurements.html

3. Detection of Abnormal Gravity at Mystery Spot in Michigan by Three Surveyors

In early 1950s’, three surveyors discovered the Mystery Spot at 150 Martin Lake Road, St. Ignace, Michigan,
USA. They stumbled across an area of land where their surveying equipment did not seem to work properly.
No matter how many times they tried to level their tripod, through the use of a plum-bob or bubble level, the
plum-bob would always be drawn far to the east, even as the bubble level was reading level as stated on the
website of this Mystery Spot in Michigan at:

http://
www.mysteryspotstignace.com/

The gravity in that particular area is so abnormal that their land survey instrument could not function properly
to establish the critical reference horizontal line and the critical centering position.

It is highly desirable that suitable experienced land surveyors go to this Mystery Spot in Michigan again to
repeat such experiment to make sure that the strange behavior of land survey instrument at this special
location is repeatable and is a reliable method to detect strong abnormal gravity in such special location.

3.1. Third Set of Evidence Against Illusion Theory for Gravity Hills

The illusion theory asserts that the gravity at those gravity hills is normal and that the strange phenomenon on
gravity hills is due entirely to the illusion in human perception. However, the detection of significant abnormal
gravity by land survey instrument at this Mystery Spot in Michigan indicates that the strange gravity
phenomena in this Mystery Spot are most likely caused by the detected strong abnormal gravity and are not
caused by illusion in human perception.  Since such abnormal gravity has been detected in this Mystery Spot
in Michigan, it is likely that similar abnormal gravity also exists in other similar Mystery Spots and in hundreds
of gravity hills all over the world. Such detected abnormal gravity is the third evidence against illusion theory
for gravity hills.

4. More Evidences Against Illusion Theory

4.1. Detection of Abnormal Gravity by Gravitational Time Dilation

Einstein’s Theory of General Relativity predicts that the closer the clock is to the source of strong gravitation,
the more slowly time passes. In other words, clocks which are far from massive bodies (or at higher
gravitational potentials) run faster, and clocks close to massive bodies (or at lower gravitational potentials) run
slower. This gravitational time dilation has been verified and demonstrated experimentally many times as
described in the following Wikipedia website:

http:/
/en.wikipedia.org/wiki/Gravitational_time_dilation

As an example, this gravitational time dilation effect is significant enough in the design of GPS (Global Position
System). The GPS satellites are orbiting at an altitude of approximately 20,200 km (12,600 mi) where the
earth gravity is weaker than that on earth surface. Calculations using general relativity determined that the
clocks on GPS satellites would be seen by Earth's observers to run 38 microseconds faster per day, and this
effect was corrected for in the design of GPS so that the GPS receiver on earth surface can determine its
position accurately based on the timing information of the GPS signals received from GPS satellites as
described in the following Wikipedia website.

http://
en.wikipedia.org/wiki/Global_Positioning_System

Nick Nelson has been doing research on gravity mysteries of Oregon Vortex for about 30 years. He worked in
Oregon Vortex for two years in 1999 and 2000. He also visited several other mystery spots and has
substantial experience and knowledge on various gravity mysteries in these mystery spots. Based on the
concept of gravitational time dilation from Theory of General Relativity, Nick Nelson, with help from the
management at the Oregon Vortex, performed an important experiment in the 1999 and 2000 involving four
identical digital watches to measure the gravitational time dilation inside and outside of Oregon Vortex. The
results, after 90 days of measurement, indicated that time in the Oregon Vortex run a quarter of a second a
day slower inside than outside as described in Section 6.3 entitled "Time anomalies" and in the Second Part
of the Proposal in the following website of Reference A:

Reference A:
http://www.vectorpub.com/Drasticchange%203-27-05.htm

Those same sections also mentioned that Doug Vogt, Nick Nelson and Dr. Nikolay Barashkov performed
similar important measurements inside and outside the Vortex at Confusion Hill at Piercy in northern California,
Magnetic Hill in Penngrove, California and Mystery Spot in Santa Cruz, California in 1996 to 2002 time frame.
These measurements all found similar and significant gravitational time dilation in such mystery spots.

That same Reference A also mentioned that similar gravitational time dilations have also been observed in
several locations in Russia. Some Russian scientists have been investigating and doing research on such
strange places in Russia with such gravitational time dilation.

In southwestern China in the mountainous area of Yunnan and Tibet, there is a very special valley known as
Shangri La (
香格里拉) as described in the 1933 novel "Lost Horizon" written by British author James Hilton.
That book was also turned into a movie, also called Lost Horizon, in 1937 by director Frank Capra. According
to this novel, a key feature of Shangri La is that people living in Shangri La age much slower than people living
outside of Shangri La. (However, the novel and the movie might have dramatized and exaggerated the effects
of gravitational time dilation.) The ancient Tibetan scriptures indicate the existence of seven such special
places according to the following Wikipedia website:

http://
en.wikipedia.org/wiki/Shangri-La

May be it is also worthwhile for Chinese scientists to seek out such special location(s) including the well
known Strange Slope (
怪坡) near ShenYang (沈阳) plus many other similar Strange Slopes and to do the
clock speed measurements to see if gravitational time dilation indeed exists in such special locations in China.  

4.1.1. Fourth Set of Evidence Against Illusion Theory

Such measured results of significant time dilation in Oregon Vortex in Oregon, Confusion Hill in northern
California, Magnetic Hill in Penngrove, California and Mystery Spot in Santa Cruz, California are strong proof
that the gravity in these mystery spots is significantly abnormal based on Einstein’s Theory of General
Relativity. This is an important evidence against Illusion Theory because Illusion Theory asserts that the
gravity in all those gravity hills and mystery spots is normal and all the observed strange gravity phenomena
are due entirely to illusion in human perception.

4.2. Asymmetric Pendulum as another Evidence against Illusion Theory

Another set of evidence against Illusion Theory is asymmetric behavior of pendulum in Oregon Vortex. The
idea is quite simple in that if the gravity in these gravity hills or Mystery Areas is abnormal with a significant
horizontal component of gravity, then the simple regular pendulum will show asymmetric behavior because of
the horizontal component of gravity.

Reference A:
http://www.vectorpub.com/Drasticchange%203-27-05.htm

Reference A indicates that some researchers had already done such experiments at Oregon Vortex in
Oregon, USA. Researchers push the weight at the bottom of the pendulum away from its equilibrium position,
and found that it is harder to push in one direction vs. opposite direction. Their measurements in Oregon
Vortex indicate that the difference in required forces to push the weight in the two opposite directions is about
20%.

This is again a good evidence for the existence of abnormal gravity in such special areas and a good evidence
against the Illusion Theory.

4.3. Sixth Evidence Against Illusion Theory

N. Nelson and I. Shnaper had conducted an experiment in the Mystery House in Oregon Vortex to measure
the strength of gravity. Their measured results indicate that the strength of gravity in Mystery House in
Oregon Vortex is 10 % less than that of normal gravity outside of Oregon Vortex. Such measured significant
abnormal gravity is another evidence against Illusion Theory because Illusion Theory asserts that the gravity in
all these spacial locations is normal and all the observed gravity mysteries are due to illusion in human
perception.

With such detected strong abnormal gravity in these mystery areas described in Sections 3 and 4, I believe  
that the strange gravity phenomena and mysteries in these Mystery Spots areas and gravity hills are caused
by such abnormal gravity and are not due to illusion in human perception.

Therefore, I do not believe in the illusion theory for gravity hills and for mystery areas because of these six    
independent sets of evidences described in Sections 1.1, 2.1, 3.1, 4.1, 4.2. and 4.3.


5. Many Other Locations with Similar Strange Gravity Phenomenon

5.1. Strange Slope in Northeastern China

Another location with similar strange phenomenon is known as the Strange Slope (怪坡), which is near
Qingshuitaizhen (
清水台镇) about 35 km northeast from the downtown of ShenYang (沈阳), the capital of
Liaoning Province in northeast China. (
位於遼寧省瀋陽市新城子區清水台鎮周家村東北方的寒坡嶺.)

Map: Click here to see Google Map showing location of this Strange Slope in northeast China

More information and photos on this Strange Slope are available at the following websites:

http://
english.cri.cn/4406/2008/01/08/1122@311974.htm

http://www.cjfoy.com/english/u4/syb04.asp

http://www.huaxia.com/lnsy/liaon_gdfq33.htm  

There are four lanes on this strange slope. Two lanes are for vehicles to go up and down the strange slope.
The other two lanes are for people to ride bicycles to go up and down the strange slope. A friend of mine,
Peter Lu,  who visited this strange slope said that when he was going down the strange slope on a bicycle, he
had to peddle pretty hard. But when he was going up the strange slope, he did not have to peddle at all. The
bicycle just rolled up the strange slope. Peter Lu said that this gravity hill has a very steep uphill slope that is
very obvious to all visitors. The slope on this gravity hill is much steeper than that of mild slope on a mild
gravity hill on Pleasant Valley Road near Titusville in New Jersey, USA.

5.2. More Existing Known Gravity Hills

There are hundreds of other places in the world that also have such strange gravity phenomenon. There are
names like gravity hill, antigravity hill, Confusion Hill, magnetic hill, magic hill, Mystery Hill, Magnetic Spot,
Electric Brae, spook hill, strange slope, etc. being used for such strange places. Please see the descriptions
and the long list at the following websites:

http://www.newscientist.com/backpage.ns?id=lw118

http://en.wikipedia.org/wiki/Gravity_hill

http://www.research.umbc.edu/~frizzell/gravhills.html

www.newscientist.com/backpage.ns?id=lw118

In addition to shifting the transmission to neutral position, some people even turn off the engine of the car
entirely, but the car with brake released still rolls up such strange slopes on its own.

There are also many movie-clip reports of such strange slopes at many places all over the world as shown at
many YouTube websites listed in Appendix A.

Some Chinese websites listed in Appendix B indicate that similar strange slopes have also been observed at
several other locations in China.

5.3. More Potential Locations

The hundreds of known locations of strange slopes in Sections 1, 2, and 5.2. are all on the existing paved
roads where cars (with brake released) roll up the hills on their own and startled the drivers. But very large
areas of the earth surface are still wilderness, heavy forests, farm fields, desert or golf courses where there
are no paved roads. If there are strange slopes with abnormal gravity in such areas, we probably still do not
know about them because there are no paved roads for the cars to roll up the hill.

Furthermore, if the directions of the roadway and their slopes are not aligned with the direction of the  
abnormal horizontal gravity force, such abnormal horizontal gravity force is not strong enough to pull vehicles
to move sideway. Then nobody will notice the possible existence of abnormal horizontal gravity force in such
locations.

Some of my friends are experienced golf players. These friends told me that sometime golf players cannot
rely on their visual perception of the slope of a golf course to predict accurately which way the golf ball will
roll. Sometime the golf balls just roll in a very strange and unexpected way. It may be possible that the gravity
hill effect may exist on some parts of some golf courses, but people do not recognize it as gravity hill effect
because there is no paved road there for vehicles in neutral gear to roll uphill.

In many developing countries, as more new highways are constructed and paved, more gravity hills are being
discovered on such paved new roads. Therefore, the total number of locations on the earth surface with such
horizontal gravity force from unknown source may be much more than those known hundreds of locations
described in Section 5.2.

5.4. Cluster of Gravity Hills

There are two nearby gravity hills on the same road (Gravity Hill Road) near New Paris in Pennsylvania, USA.
These two gravity hills on the same road are separated by only 0.3 miles. There are also two nearby gravity
hills on the same road (Pleasant Valley Road) between Titusville and Hopewell in New Jersey, USA. These
two gravity hills on the same road are separated by only about 2 miles.

As of August 2011, I have visited only four different locations of gravity hills and two out of the four locations
have such cluster of  multiple nearby gravity hills. If I visit more locations in the future, I may find more clusters
of gravity hills. This means that gravity hill is often not alone, but may have one or more small areas with
gravity hill effect not too far from the known gravity hill. In other words, there may be often a cluster of nearby
gravity hills, but we may not know the existence of these additional nearby gravity hills  because (1) there is
no paved road on those additional nearby gravity hills  or (2) the direction of the road is not aligned with the
direction of the gravity force of the additional gravity hills, such that vehicles cannot roll uphill on such
additional gravity hills. These additional gravity hills that we do not know about may not be on the same road
as the known gravity hill in that area of cluster of gravity hills.

Some researchers indicated that Cosmos Mystery Area in South Dakota, USA has a cluster of three areas
with abnormal gravity. Only one of the three areas in the cluster is open to the tourists.

The existence of such cluster of multiple nearby gravity hills has important implication on selection of suitable
multiple sites for the proper procedure for precision measurements of the elevations of the top and the bottom
of a gravity hill because moving a theodolite off the road of a known gravity hill being measured does not
guarantee that the theodolite will not be subject to the unexpected influence of other unknown nearby gravity
hills in the cluster as described in my web page on precision scientific measurements on gravity hills at:

http://
www.shltrip.com/Need_For_Precision_Measurements.html

6. Is It Magnetic Force or Electric Force?

The following observations and tests on several gravity hills at several different places indicate that the
strange phenomenon on gravity hills is not due to magnetic force and not due to electric force.

(i) People poured water on several strange slopes and the water flew uphill on such strange slopes. Some
other people put plastic water bottle with water on such strange slopes and the plastic water bottle rolled
uphill on such strange slopes. They are shown on the movie clips in the following YouTube websites:

http://
www.youtube.com/watch?v=e2hAiM2yjso&NR=1

http://www.youtube.com/watch?v=XFqsdpCB-O8&feature=related

http://www.youtube.com/watch?v=jd0A4bnp-YU&feature=related

http://www.youtube.com/watch?v=0Qscv5ei29Q&NR=1

(ii) People have also observed rivers flowing uphill on some strange slopes as shown in the following YouTube
websites:

http://
www.youtube.com/watch?v=9A028qv_A_0&feature=related

http://www.youtube.com/watch?v=i3PUxcSBn64&feature=related

http://www.youtube.com/watch?v=RlQSiJWkQ4I

The Water in the ditches also seems to flow uphill on both sides of the strange slope at the Magnetic Hill near
Moncton, and at
other strange slopes in Ireland, China and other places,

(iii) Two plumb lines, with an iron ball on one line and a plastic ball on another line, are parallel to each other
on
a strange slope in China, and

(iv) Tests by using a compass on
a strange slope in China showed no unusual magnetic force. Some other
measurements of magnetic field on some mystery spots in California, USA indicate that the strength of
magnetic field inside the mystery spots in higher by several percents relative to normal magnetic field outside
of the mystery spots. However, abnormal magnetic field a few percent higher than the normal earth magnetic
field is not strong enough to pull a vehicle in neutral gear and brake released to roll uphill.  

7. How About Doing Some Tests and Measurements?

One of the important questions on the strange phenomenon on all these gravity hills all over the world is
whether the observed strange gravity phenomenon is due to illusion or not.

In the literature, there are various claims of proof of illusion for such strange gravity phenomenon. There were
several news articles and websites indicating that some investigators have used precision land surveyor
instruments to do careful measurements of the relative heights (i.e., elevations) at suitable intervals (e.g., 5
meters) along the gravity hill. Their measurements indicate that the visually perceived lowest point of the
Strange Slope is higher than the visually perceived highest point on the slope. Being shocked and stunned by
such measurement results, they conclude that the strange phenomenon on the Strange Slope is all due to the
illusion of the visual perception.

However, when these measurements, tests and proofs are examined more carefully, I found that these
existing proofs are invalid with serious defects as explained in details in the following.

7.1. Problems of Carpenter's Level and Traditional Land Survey Measurements on Gravity Hills

The key problem in using a carpenter's level or a typical land survey instruments for measurements on these
strange slopes of gravity hills is that they depend critically on the plumb line and Spirit/Level liquid Bubble to
establish their critical reference horizontal plane/line and critical reference vertical line for their measurements.
None of these measurements took any precaution step to check if the gravity at such gravity hill location is
normal or not. This problem and serious defect are explained in more details in the following:

7.1.1. Problems of Spirit/Level Bubble and Plumb Line on Gravity Hills

Precision measurements of angles in land survey method require the use of precision angle measurement
instrument known as theodolite. For precision measurements, the theodolite
must be (A) placed precisely and
vertically over a reference point to be measured. This is known as centering, and (B) its vertical axis aligned
with local gravity, known as leveling. The former is done using a plumb line or plumb bob, the latter using a
spirit bubble” or  “level liquid bubble”. The plumb line or the spirit/level bubble or a long water hose depend
on the local gravity force to establish the local vertical direction and local horizontal plane as the key basic
references for various precision measurements. The required careful and elaborate procedure to achieve the
critical centering and leveling are demonstrated by an instructional video on the following YouTube website:

http://
www.youtube.com/watch?v=c9U0xlmCzGI&feature=related

With such careful centering and leveling, the measured results from such theodolite are usually very accurate
at most "regular" locations with no abnormal gravity and no strange gravity phenomenon.

However, at the very special locations of a gravity hills or mystery spots, significant abnormal gravity with
significant horizontal component of gravity have been detected as described in Sections 3 and 4.

Many people over hundreds of years have noticed consistently the very strange gravity phenomena of water
flowing uphill, water bottles rolling uphill, vehicles in neutral gear rolling uphill, barrels and bales of dry goods
rolling mysteriously “uphill”, Chang of Height demonstrations in several Mystery Spots, etc. Many kinds of
strange names such as Gravity hill, Anti-gravity Hill, Confusion Hill, Magnetic Hill, Electric Brae, Magic Hill,
Mystery Hill, Spook Hill, Strange Slope, Oregon Vortex, Mystery Spot, etc. have been used to describe such
“strange place”. Such long history provides a strong indication that something is very strange on such gravity
hills and mystery spots. The local gravity fields in such special areas are abnormal with a strong horizontal
component as described in Sections 3 and 4.

These evidences indicate that the plumb line and the level liquid bubble under the influence of abnormal gravity
Cannot provide correct critical reference horizontal plane/line and critical reference vertical line for accurate
land survey measurements at a gravity hill or a mystery spot as illustrated in the following Figures 1 and 2.
About Author                                 Contact Author
21-Year Investigation of Gravity Hills and Mystery Spots
Leading into Dark Matters Trapped and Anchored in Earth's
Gravity Well as the Source of Abnormal Gravity
Picture 5: The blue minivan on the left lane is rolling up the strange slope backward while three other vehicles
(2 white color and 1 red color) on the right lane are going down to the bottom of the strange slope to try the
experience of rolling up the strange slope.

Some people stop at the bottom of the strange slope in the middle of this section of the road and roll up the
slope backward like the blue minivan does in this picture. But some other people do not stop at the bottom,
but go further to the far end which is higher than the bottom, then turn their vehicles around, then come down
to the bottom in the middle of this section of road and stop there, so that they can roll up the hill forward (like
that in Pictures 2, 3 and 4) instead of backward.
Picture 6: Several vehicles and a motor cycle are waiting on the line for their turns to go down the slope to try
the
thrill and sensation on this strange slope. Notice that the road surface for the waiting line of vehicles is
reasonably level (i.e., not on a steep slope) and that the area for waiting line of vehicles is substantial in size.

There were quite a few visitors with their cars, vans, trucks, recreational vehicles, motorcycles, etc. waiting
on line to try this strange phenomenon at Magnetic Hill when I was there in July 2005.
Picture 7: Three more vehicles waiting on line for their turns to try the strange slope. At the top of the slope,
there are two orange colored posts and two or more instructors telling visitors on what to do when they drive
down to the bottom of the slope to experience the strange phenomenon of Magnetic Hill.
Picture 8:  More vehicles waiting on line for their turns.


1.1 First Set of Evidence Against Illusion Theory for Gravity Hills

Notice that in Pictures 7 and 8, we cannot see the bottom of the strange slope from the area of vehicle waiting
line at the top of the strange slope. We can see the far end of this section of road but cannot see the bottom
in the middle of this section of road. I was standing upright on the top of the strange slope in taking all these
Pictures 1 to 8 so that my camera had at least 5 feet of clearance from the ground surface. Even with such 5
feet of clearance at the area of waiting line of vehicles, my camera still cannot see the bottom of the strange
slope, but can see the far end of the road. This is a strong evidence that the bottom of the strange slope in
the middle of this section of road is indeed lower than the top of the strange slope and lower than the far end
such that we cannot see the bottom from this waiting line of vehicles on the top of the strange slope. This is
one of the reasons that I do not believe that the strange gravity phenomenon on such strange slopes is due to
"Illusion" as claimed by many people and by many articles on Internet.

The Illusion Theory asserts that: (1) the gravity at such gravity hill is normal (e.g., not unusual), (2) the bottom
of such strange slope is higher than the top of the slope, (3) those vehicles are rolling downhill and (4) all
those vehicles that look like rolling "uphill" on such slope as shown on Pictures 2, 3, 4 and 5 are due to illusion
in human perception.

If the bottom of the slope were higher than the top of the slope as asserted by the "Illusion Theory", then we,
at my standing upright position on the top of the strange slope with at least 5 feet of clearance above ground
level, would be able to see the "higher" bottom from the area of waiting line of vehicles in Pictures 7 and 8.


However, the fact that on the waiting line in Pictures 7 and 8, we do see the far end but do not see the bottom
of the slope in the middle of this section of road is a strong evidence that (A) the bottom of the slope in the
middle is indeed lower than the top of the slope and lower than the far end as shown in Pictures 2, 3, 4 and 5
and (B) this strange gravity phenomenon is real and is NOT due to illusion.  More i
ndependent evidences
against "Illusion Theory" including the problems in i
ts supporting measurements are described in Sections 2, 3,
4 and 7 on this web page.

A picture taken by other people from the bottom of the slope looking toward the top of the slope can be seen
at the following website:

http://
www.forensicgenealogy.info/images/mag_hill_macton_reverse.jpg

The story associated with this picture is on the following website:

http://
www.forensicgenealogy.info/contest_362_results.html

This picture shows that this camera at the bottom of the slope cannot see the large area for the waiting line of
vehicles at the top of the slope beyond the instructor and the orange color post. If the bottom of the slope
were higher than the top of the slope, as claimed by the Illusion Theory, this camera at the "higher" bottom
would be able to see the large area of waiting line of vehicles beyond the position of the instructors and the
orange post. The fact that this camera at the bottom cannot see the large area of waiting line of vehicles on
the top of slope is another evidence that the bottom of the slope is indeed lower than the top of the slope.  

Similarly, many other people have also taken movie clips when their cars in neutral gear were rolling up this
Magnetic Hill in Moncton  as shown on the following YouTube websites:

http://
www.youtube.com/watch?v=Ml6E45x825M&feature=related

http://www.youtube.com/watch?v=JLgdZGbOclk

http://www.youtube.com/watch?v=zhr0owdDLqo&feature=related

In these three movie clips, notice that when their cameras in their cars are pointing to the top of the slope
(where the instructors and the area for the waiting line of vehicles are located), the videos show that these
cameras cannot see the large area for the waiting line of vehicles on the top of the slope. If the bottom of the
slope were higher than the top of the slope, as claimed by the Illusion Theory, these cameras in the cars
would be able to see the large area of waiting line of vehicles beyond the position of the instructors. The fact
that these cameras cannot see the large area of waiting line of vehicles on the top of the slope is another
evidence that the bottom of the slope is indeed lower than the top of the slope.  

Therefore, both the views in Pictures 7 and 8 from the area of the waiting line of vehicles on the top of the
slope and the views from the bottom of the slope consistently indicate that the bottom of the slope is indeed
lower than the top of the slope.
Picture 3: The vehicle started to roll up hill from the bottom.
Picture 4: The vehicle continued rolling up hill.
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讀萬卷書    行萬里路

Home                                                              About Author                                               Contact Author
10. Technical Background of the Author of This Web Page

Dr. Sing H. Lin is a retired Telecommunication engineer and manager with technical expertise in the area of
radio/wireless communication technologies and systems. He received his Ph.D. Degree in Electrical
Engineering from the University of California at Berkeley, California, USA in 1969 and BSEE degree from
National Taiwan University in 1963. He joined Bell Laboratories in New Jersey, USA in 1969. He has 68
technical publications and presentations in various technical journals and conferences, 3 patents, and a
Chinese certificate of a copyright on a mapping table for Chinese Spelling Code.

He had been a member of the US Delegation to International Telecommunication Union (ITU) for many years
in developing the global standards and recommendations for radio/wireless communications systems
including the Third Generation (3G) mobile wireless communications systems and beyond. In 1998, this
international team of wireless technology experts, including Dr. Sing Lin, completed the development of ITU
standard for 3G mobile wireless communication system. This 3G wireless mobile system standard provides
the platform that spawned the rapidly growing smart phone industry with many useful applications attracting
huge number of users all over the world. The total global annual sales of smart phones is about 500 million
units in 2011 and is growing very fast. The smart phone industry is now moving forward into the international
4G system standard which is also known as LTE (Long Term Evolution).

Dr. Sing H. Lin and his colleagues in the old Bell Laboratories had conducted many years of experiments on
effects of multipath radio propagation and rain attenuation on the performance of terrestrial and
earth-satellite microwave communication radio links. Such experiments and huge amount of data were
collected from numerous microwave radio links in USA and in some foreign countries such as Saudi Arabia.
Results from such  experimental data, analyses and developed theories are important for engineering
microwave communication radio links to meet performance objectives. Some of these results were published
in the following technical papers:

S. H. Lin, H. J. Bergman and M. V. Pursley, "Rain Attenuation on Earth-Satellite Paths - Summary of 10-year
Experiments and Studies," The Bell System Technical Journal, Vol. 59, No. 2, February 1980, pp 183 to 228.

S. H. Lin, "Statistical Behavior of a Fading Signal," The Bell System Technical Journal, Vol. 50, No. 10,
December 1971, pp. 3211 - 3270.

S. H. Lin, "Statistical Behavior of Deep Fades of Diversity Signals," IEEE Transaction on Communications,
Vol. COM-20, No. 6, December 1972, pp. 1100 - 1107.

By using Statistical Theory of Extremes, Dr. Sing H. Lin has also developed a theory and a method to obtain
nationwide long term (25 to 50 years) distributions of rain rate at more than 200 locations in USA. Such
theory and method are published in the following technical papers:

S. H. Lin, "Statistical Behavior of Rain Attenuation", The Bell System Technical Journal, Vol. 52, No. 4, April
1973, pp. 557 - 581.

S. H. Lin, "Rain Rate Distributions and Extreme Value Statistics," The Bell System Technical Journal, Vol. 55,
No. 8, October 1976, pp. 1111 - 1124.

S. H. Lin, "More on Rain Rate Distributions and Extreme Value Statistics," The Bell System Technical
Journal, Vol. 57, No. 5, May-June 1978, pp. 1545 - 1568.

Note: The technical papers in Bell System Technical Journal (BSTJ) from 1922 to 1983 are available online in
the following BSTJ website:

http://
www3.alcatel-lucent.com/bstj/

A complete list of his 68 technical publications and presentations in various technical journals and
conferences and of his patents is in his web page at:

http://www.shltrip.com/Patent_and_Publication.html

When he was a Ph.D. student in the University of California at Berkeley, he did take and enjoyed the
graduate course on Radio Astronomy. As a radio engineer in Bell Laboratories, in New Jersey, USA, he
participated in a team project on radiometer measurements and experiments as related to satellite
communication technologies. He learned the Dickie radiometer technologies from a team of radio
astronomers, including Robert W. Wilson, in Bell laboratories at Crawford Hill in Holmdel, New Jersey.

His interest in astronomy continues from his student life through his professional engineering life and into his
retiree life. In his retiree sightseeing trips, he enjoyed touring the Very Large Array (VLA) site operated by
the National Radio Astronomy Observatory near Socorro, New Mexico and the National Solar Observatory
and Apache Point Observatory on Sacramento Peak in New Mexico, USA in February 2006. More
information on and a picture of Dr. Sing H. Lin are available at the following web page:

http://www.shltrip.com/aboutus.html

His e-mail address is: SINGHLIN@GMAIL.COM

He has retired from his professional Telecom engineer job and is living in New Jersey, USA.


Appendix A - Many Reports of Gravity Hills at many locations all over the world at the following
YouTube websites:

http://
www.youtube.com/watch?v=1-kLZZLQEg8

http://www.youtube.com/watch?v=2LawmLgSSRY

http://www.youtube.com/watch?v=UUSDMPmo56U&feature=related

http://www.youtube.com/watch?v=M_o7JW1f7NQ

http://www.youtube.com/watch?v=U9_Q33sGB4U&feature=related

http://www.youtube.com/watch?v=c23ayRI6cz4&feature=related

http://www.youtube.com/watch?v=D7cV32S3s_0&feature=related

http://www.youtube.com/watch?v=7ByJ24XMvZk&feature=related

http://www.youtube.com/watch?v=5SR2X6zr2HE&NR=1

http://www.youtube.com/watch?v=wF_fTnleS00&feature=related

http://www.youtube.com/watch?v=QR_GPXunr1s&NR=1

http://www.youtube.com/watch?v=eY8KC8ZHa70&NR=1

http://www.youtube.com/watch?v=PV-xFVf0QHw&NR=1

http://www.youtube.com/watch?v=IeyEZ9RZi7c&feature=related

http://www.youtube.com/watch?v=y-Ex2K5KUJ8&NR=1

http://www.youtube.com/watch?v=C7xP09iuZh0&NR=1

http://www.youtube.com/watch?v=qQ5GC_i23ls&NR=1

http://www.youtube.com/watch?v=GwnbLrwc734&feature=related

http://www.youtube.com/watch?v=t-NXwaElIIM&NR=1

http://www.youtube.com/watch?v=TrkG4IFG04U&feature=related

http://www.youtube.com/watch?v=k76ik_y0PJ4&NR=1

http://www.youtube.com/watch?v=mxTOiylFLB8&feature=related

http://www.youtube.com/watch?v=-oNqEiIkZb8&feature=related

http://www.youtube.com/watch?v=QCbqV2bXS5Q&feature=related

http://www.youtube.com/watch?v=ZHPmdO_f-wI&feature=related

http://www.youtube.com/watch?v=XqJsGXbJruU&feature=related

http://www.youtube.com/watch?v=x4xKPCGtn_w&feature=related

http://www.youtube.com/watch?v=fta_7O-Myms&NR=1

http://www.youtube.com/watch?v=pQRw7o-WBgg&NR=1

http://www.youtube.com/watch?v=0vNV0zCJ_MM&NR=1

http://www.youtube.com/watch?v=Lkl5qhFaD3k&feature=related

http://www.youtube.com/watch?v=XqJsGXbJruU&NR=1

http://www.youtube.com/watch?v=lIwRSpbisG8&feature=related

Appendix B - Some Chinese websites listed in the following indicate that similar Gravity Hills have
also been observed at several other locations in China.

http://www.qzwb.com/gb/content/2000-08/27/content_5895.htm

http://www.qzwb.com/gb/content/2002-02/22/content_414707.htm

http://www.china.org.cn/features/photos/liaoning/liaoningview/75.htm

http://www.epochtimes.com/b5/3/12/17/n431204.htm   

http://www.epochtimes.com/b5/2/2/22/n172201.htm

http://news.china.com/zh_cn/social/1007/20030915/11540459.html
The plumb line and the spirit/level bubble used in the land survey instruments on a gravity hill are affected and
tilted by such strong horizontal component of gravity force as illustrated on Figure 1 and Figure 2 above. Since
the horizontal component of gravity force is strong enough to pull vehicles in neutral gear to roll uphill, it is also
strong enough to pull the plumb line and the level liquid bubble such that the local reference horizontal plane
established by the theodolite is  tilted and is not correct shown as the red dashed line in Figure 2. On Figure 2,
as viewed from the Bottom of the gravity hill, the Top of the gravity hill becomes below the tilted horizontal
plane represented by the red dashed line.

In other words, with the tiled red dashed plane taken as the (wrong) reference horizontal plane, the uphill slope
becomes a downhill slope on Figure 2.

Therefore, such land survey measurements indicate erroneously that the human perceived top is lower than the
bottom of the gravity hill based on its tilted horizontal plane. Such wrong measurement results are often used
as the support for the illusion theory for gravity hills.

Although there are many reports on Internet of the results of such land survey measurements on gravity hills,   
I have not seen any reports of land survey measurements indicating that the surveyor(s) took any special care
to check to see if the gravity on the gravity hill is normal or not before they performed the traditional land
survey measurements.

Some possible methods to check to see if the gravity on gravity hill or a mystery spot is normal or not are
described in Sections 3 and 4 and  on the following web page:

http://
www.shltrip.com/Need_For_Precision_Measurements.html

Since those surveyor(s) did not check to see if the gravity at the gravity hill is normal or not and blindly
assumed that the tilted Red Dashed Plane in Figure 2 established by the plumb line and the level bubble as the
reference horizontal plane in all those land survey measurements, we cannot trust the results from such blind
measurements on gravity hills.

This potential deficiency of spirit/level bubble at such strange slopes has also been noted by other researchers
 as shown in the following paragraph:

"It would be impossible to prove or disprove the antigravity phenomenon using a spirit level as described. If the
antigravity effect can act on a motor car, it can probably also act on a few millilitres of fluid containing a
bubble, causing the bubble to float downhill instead of uphill. I'm surprised the Skeptical Inquirer fell for that
one." quoted from the following website:

http://www.newscientist.com/backpage.ns?id=lw118

Many people miss the serious defects in such results from blind land survey measurements, and therefore, fall
into this trap of erroneously accepting such wrong results as valid proof of illusion theory for the strange gravity
phenomenon on these gravity hills. Consequently, we see the word "illusion" all over the place in many articles
on Internet when they refer to this strange gravity phenomenon on many gravity hills.

The bottom line is that one cannot trust the results from such blind measurements on gravity hills or mystery
spots unless special independent measurements have been done to check to see if the gravity on such gravity
hills or mystery spots is normal or not.


7.2. Contradictory Results from GPS Measurements

In view of the problem of measurements based on plumb line or spirit/level bubble or water hose on gravity
hills described in Section 7.1, some people looked for other methods to measure the elevations of the top and
the bottom on a gravity hill. One of the possible candidate methods is the use of  GPS (Global Positioning
System) receiver which will not be influenced by the potential local abnormal gravity. It may be a better method
for measurements of the elevations of the top and the bottom of a gravity hill.

Two investigators had done two such sets of independent measurements by using GPS receiver on a gravity
hill known as the Gravity Hill near New Paris in Bedford County in Pennsylvania, USA.

Results of investigator (a) is in the following website (a):

http://www.research.umbc.edu/~frizzell/pabedcogravhill.html

Results of investigator (b) is in the following two websites (b):

http://
www.groupsrv.com/science/about7161.html

http://www.groupsrv.com/science/post-31649.html

However, the results from these two independent measurements using GPS on the same gravity hill are totally
opposite and contradictory.

Results of Investigator (a) indicate that the lowest point by visual perception on this section of road at Gravity
Hill is higher than the highest point by visual perception and conclude that the strange phenomenon at this
Gravity Hill is due to illusion.

But the independent second set of measurements by GPS from investigator (b) indicates that the lowest point
and the highest point by visual perceptions on this strange slope at Gravity Hill are indeed correct as confirmed
by his GPS measurements. The conclusion from investigator (b) is that this strange phenomenon at the Gravity
Hill is NOT an illusion.

The key reason for such contradictory results from GPS measurements is due to the large and time varying
error in elevation measurements by using a single consumer-grade inexpensive GPS receiver as described in
the next Section.


7.3. Accuracy of Consumer-Grade Single GPS Receiver for Elevation Measurements

According to the website of a major supplier, Garmin, of GPS receivers at:

http://www.garmin.com/aboutGPS/

The accuracy of the basic, older version of single consumer-grade GPS receiver is about 15 meters (50 feet)
on average which is not good enough for our purpose of measurements on these strange slopes because the
difference between the high point and the low point may be only 10 to 15 feet on these strange slopes.

The use of newer Differential GPS (DGPS) single receiver that includes correction signal from land-based
broadcasting stations may achieve an accuracy of 3 to 5 meters (10 to 16 feet).

Furthermore, the newer GPS single receiver that includes the correction signal from the WAAS (Wide Area
Augmentation System) coming from geostationary satellite broadcast, may improve the accuracy to better
than 3 meters (10 feet) on average. A long list of sources of errors in GPS measurements is given at the end
of the web page above.

However, these accuracy numbers are referring to the navigation position on the horizontal plane. It says that
at least three GPS satellites must be visible to the GPS receiver in order to determine the horizontal position,
but at least four GPS satellites must be visible to the GPS receiver in order to determine the elevation. This
implies that the elevation measurements are more vulnerable to errors. Information on some other websites on
GPS  indicate that the accuracy in elevation measurements may be worse than those on horizontal plane by
about a factor of 3. This makes the accuracy of elevation measurements by single consumer-grade GPS
receiver on such gravity hill highly questionable.

These GPS accuracy numbers are usually given as "on average" which means that the measurement error is
time varying depending on several factors listed near the bottom of the Garmin website given above. For
example, one of such factors is called Geometrical Dilution of Precision that can degrade the precision in
certain cases. This happens when several of the orbiting GPS satellites seen from the GPS receiver are in a
similar (angular) position relative to the receiver. It makes the precision much worse than if the seen satellites
have equal angular spacing over the sky.

The 24 GPS satellites are moving rapidly on their orbits and their relative positions, as seen from a GPS
receiver, vary rapidly because these satellites are not on high orbits of synchronous satellites. Such rapid
variations in their relative positions viewed from a GPS receiver result in rapidly time varying measurement
errors. I did a test personally by holding an old GPS receiver at a fixed location and just watch the measured
elevation displayed on the GPS receiver screen. The displayed elevation is not constant but is time varying
every few seconds and may vary by as much as 100 feet even though the GPS receiver is not moving at all.
All such variations are due entirely to the time varying measurement error.

Furthermore, I put two consumer-grade GPS receivers, of identical model from the same manufacturers, side
by side with no space between the touching sides of the two receivers, the measured elevations displayed on
the two identical GPS receivers are different!

The bottom line is that the accuracy of using a single consumer-grade GPS receiver is not good enough for
accurate determination on which end of the slope of a gravity hill is higher.

A more accurate comparator measurement method using surveyor-grade multiple GPS receivers with radio
links and a computer is described in Section 4.1. in my web page at:

http://
www.shltrip.com/Need_For_Precision_Measurements.html


7.4. Topographic Map

Some people have suggested looking at the local topographic map near the area of a gravity hill to determine
which ends of the strange slope is really higher. It seems to me that there are several possible methods used
to generate those topographic maps such as (1) old fashion land survey instruments that depend on a
spirit/level bubble to establish local reference horizontal plane for measurements, (2) airborne laser or radar
ranging technique, (3) satellite based laser or radar ranging technique.

If the local topographic map near a gravity hill was generated by method (1) using a spirit/level bubble, then
such map cannot be trusted to resolve the illusion issue because of the problem of spirit/level bubble described
in Section 7.1.

8. Need for Future Precision Scientific Measurements on Gravity Hills and Mystery Spots

In view of the various serious problems in measurements on gravity hills, it is clear that there is a strong need
for conducting more precision scientific measurements on gravity hills and mystery Spots. In last few years, I
have collected a set of scientific methods for precision measurements that can be done on gravity hills and
mystery spots as described in my web page at:

http://
www.shltrip.com/Need_For_Precision_Measurements.html

The ideas for these scientific methods originate from my interactions and e-mail correspondence with several
scientists and engineers in last few years.

I believe that the results of such future scientific precision measurements will show more clearly that the
strange gravity phenomena and gravity mysteries on those known gravity hills and known mystery spots are
real, are caused by abnormal gravity in those special locations and are NOT an illusion in human perception.

9. Dark Matter Theory for Gravity Hills and Mystery Spots

9.1. 21-Year Research on this Project

Due to my scientific curiosity, I often enjoy taking a side tour from my sightseeing trips to visit various Mystery
Spots and Gravity Hills at many places. I toured Mystery Spot in Santa Cruz, California 21 years ago in 1993
as described on my web page at:

http://www.shltrip.com/Oregon-Vortex.html

The strange experience of gravity mysteries in that Mystery Spot planted the seed in my mind to start thinking
and doing research on such gravity mysteries since 1993. Then I toured Oregon Vortex in Oregon in 2004, and
the Magnetic Hill in eastern Canada in 2005. I have also toured a cluster of two nearby gravity hills along
Gravity Hill Road near New Paris in south central Pennsylvania, USA, a cluster of two nearby gravity hills along
Pleasant Valley Road near the junction of Pleasant Valley Road and Bear Tavern Road in Hopewell Township
in south west New Jersey, USA. I visited the Mystery Hill in North Carolina in January 2014.

I have also been reading many reports of many other gravity hills at many other locations all over the world
and several of several other known mystery spots. With such background and information, I have been thinking
and doing research for 21 years for a possible scientific explanation for the strange gravity phenomena on
those hundreds of known gravity hills and mystery spots on earth surface.

My 21-year research as described in Sections 1 to 8 above convinced me that the observed strange gravity
phenomena and gravity mysteries on those gravity hills and mystery spots are real and are not due to illusion in
human perception. This is a good foundation naturally leads into the next key and touch question on what is the
source for the abnormal gravity causing all those observed strange gravity phenomena and gravity mysteries
observed in those gravity hills and mystery spots?

9.2. Important Question Leads into Important New Theory and Model

The important question in Section 9.1. and the good foundation from Sections 1 to 9.1. lead me to develop the
dark matter theory for the gravity hills and the mystery spots. This theory and its associated Model indicate
that the source for such abnormal gravity is a very compact nugget of dark matter with extreme high mass
density that is at least 1,000 times greater than that of average ordinary material on earth surface.

However, a well known characteristic of dark matter is that dark matter does not interact with our familiar
ordinary matter in any force except gravity. This characteristic seems to indicate that the compact nugget of
dark matter cannot stay at the location of a gravity hill (or a mystery spot) steadily for many years as the
source of the strange gravity phenomena observed at the location of the gravity hill (or the mystery spot)
because the earth gravity will suck such compact nugget of dark matter into the center of the earth. This
problem stimulated my thinking into the following more sophisticated model of dark matters trapped and
anchored in earth's gravity well.

The compact nugget at the location of a gravity hill (or a mystery spot) is not a solid rigid nugget but consists
of many loose sand particles of dark matter with extreme high mass density. This compact nugget is
supported by two streams of loose sand particles of dark matters. One stream is being sucked from the
compact nugget into the center of earth by earth gravity, then over-shoots and keeps going to the conjugate
point on the opposite side of earth surface. The other stream is also being sucked from the conjugate point
into the center of earth by earth gravity, then over-shoots and keeps going back to the original location of the
gravity hill (or the mystery spot).

In other words, these loose sand particles of dark matter are trapped in the gravity well (gravity field) of the
earth and are oscillating between the gravity hill (or the mystery spot) and its conjugate point on the opposite
side of earth surface.

The details of the logic and the supporting information for such dark matter theory and the associated Model  
are described in my web page at:

http://
www.shltrip.com/Oregon-Vortex.html

The dark matter's gravity anchor in the earth's gravity well is also described in the web page above.

This Model of compact nugget of loose sand particles of dark matter supported by the stream of oscillating
dark matter with extreme high mass density can explain all the observed strange gravity phenomena and
mysteries in the known mystery spots and hundreds of gravity hills all over the world. Some possible methods
to test the validity of this Model are also described in the web page above.
Figure 1 for the Top and the Bottom of an uphill slope.
Figure 2 - On a gravity hill, the plumb line and the level liquid bubble yield (wrong) tilted horizontal plane due
to the influence of abnormal gravity.