Apparently
this sort of hill is fairly common around the world. Many years ago I went to
Straws Lane near Macedon and a plastic bottle full of water convinced me it was rolling uphill.
Here's an "experiment" with a sense of humour
Here's an "experiment" with a sense of humour
Wikipedia says this uphill stuff is an illusion.
[I
understand the third point of reference /triangulation bizzo, but a hill is a
hill is a hill. ]
The slope of gravity
hills is an optical illusion, although sites are often accompanied by claims
that magnetic
or even supernatural
forces are at work.
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. Objects one would normally assume to be more-or-less perpendicular
to the ground (such as trees) may actually be leaning, offsetting the visual
reference.
The Wikipedia
article then goes on about some kind of physics experiment and an Ames Room –
way over my head.
There is
also a reference in Wikipedia to what cyclists call a “false flat”.
A low-gradient
climb, usually occurring partway up a steeper climb. So-called because while it
may look deceptively flat and easy (especially after the steep climb preceding
it), it is still a climb.
This sort
of made sense to me til I tried to plot it like a simple graph line. Now I get
it even less.
It all
makes me feel as stupid as Why is it so?’s professor Julius Sumner Miller.
