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Bom Jesus Magic Road Gravity Magnetic Hills Explained


Integza

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This video is about Gravity Hills and tries to explain how they work, if you never heard about the subject, a Gravity Hill is an illusion created by nature in which a road appearing to go up actually has a downhill slope. I also approach other illusions like the Ames Room and the impossible motion ramp.

If is not clear in the video, I'm Portuguese and Braga is my home city, this road is quite a tourist attraction and almost every day you can spot people with their cars in neutral trying it out, to see in which direction the car goes.

If after the video you still have any doubt about the subject just ask in the comment section and if you like videos about science, do visit my channel:

 

 




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  • 2 weeks later...

sometimes it IS a gravetic anomaly though.

No it's not my friend.

Even if that diagram is correct and we consider the maximum amount on it, it would mean that in some places on earth you would be pulled more or less 400 mGal, what is about 4 mm/s2. Doing the simple math you would be accelerated at 9.8 -0.004 = 9.796m/s2 or 9.8 +0.004 =9.804 m/s2, as you can see this variations are really tiny, but the most important part here is the fact that in the end, you're still being accelerated downward, so these fluctuations can not explain why a ball would roll uphill.

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Even if that diagram is correct and we consider the maximum amount on it, it would mean that in some places on earth you would be pulled more or less 400 mGal, what is about 4 mm/s2. Doing the simple math you would be accelerated at 9.8 -0.004 = 9.796m/s2 or 9.8 +0.004 =9.804 m/s2, as you can see this variations are really tiny, but the most important part here is the fact that in the end, you're still being accelerated downward, so these fluctuations can not explain why a ball would roll uphill.

This is good and correct explanation, as maps like the one GAHD posted are of vertical acceleration toward the center of the Earth.

 

However, variations in the shape and density of the Earth can result in gravitational acceleration with a horizontal component.

 

I recently read Thomas Pynchon’s 1997 novel Mason & Dixon. Among its more fanciful flights of ideas, it mentions a bit of real science: that 18th century astronomers, who leveled their telescope platforms using plum lines, found errors in the measurements of the direction of stars and planets due to “vertical deflection”, caused by horizontal gravitational forces, mostly by nearby mountains, which can be as great as 60 arcseconds (0.017 deg). Astronomers of that time would compensate by making observations from opposite slopes of a mountain and averaging the angular measurements.

 

A bit of simple math ( 9.8 m/s/s * tan(0.017 deg) =~ 0.0029 m/s/s = 290 mGal) shows that the horizontal component of vertical deflection have values similar to the anomalies shown in the diagram.

 

As best I can tell using data like that at EngineeringToolbox’s “rolling resistance” page, the greatest vertical deflection is about 10 time too small to cause the most efficient ordinary wheel (such as a railcar wheel on a track) to roll on a geographically level surface.

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This is good and correct explanation, as maps like the one GAHD posted are of vertical acceleration toward the center of the Earth.

 

However, variations in the shape and density of the Earth can result in gravitational acceleration with a horizontal component.

 

I recently read Thomas Pynchon’s 1997 novel Mason & Dixon. Among its more fanciful flights of ideas, it mentions a bit of real science: that 18th century astronomers, who leveled their telescope platforms using plum lines, found errors in the measurements of the direction of stars and planets due to “vertical deflection”, caused by horizontal gravitational forces, mostly by nearby mountains, which can be as great as 60 arcseconds (0.017 deg). Astronomers of that time would compensate by making observations from opposite slopes of a mountain and averaging the angular measurements.

 

A bit of simple math ( 9.8 m/s/s * tan(0.017 deg) =~ 0.0029 m/s/s = 290 mGal) shows that the horizontal component of vertical deflection have values similar to the anomalies shown in the diagram.

 

As best I can tell using data like that at EngineeringToolbox’s “rolling resistance” page, the greatest vertical deflection is about 10 time too small to cause the most efficient ordinary wheel (such as a railcar wheel on a track) to roll on a geographically level surface.

Exactly my point. Since "level" via plumb-bob or bubble-level in of itself is caused by gravitational acceleration, it's an anomaly you can't test with the carpenters tools that video showcases. It still exists, your inner ear and most everyday occurrences will never notice it, but it's a thing. 

giphy-facebook_s.jpg

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