Natural Science Forum / Physics / General Physics / July 2008

I have conducted an experiment to directly determine the distance/
force centripedal force relationship. However, instead of employing
the usual ball on a string methodology where you swing a ball on a
string and measure the force on the string, I have used a "non-
contact" force of magnetism to counter for centripedal force. This
arrangement is significantly different than ball on a string
measurements and the goal was to determine if there was any difference
in these situations. The non-contact force is much more representative
of the situation present in the orbital mechanics of the Earth and
moon since the moon is not attached to the Earth by a string. It is
held by a non-contact attractive force more closely related to the
kind of force you get with magnetism.

See this unique and clever experiment using only household items/
camcorder and legos to accurately measure the centripedal force by
watching this 7 minute youtube video.

http://www.youtube.com/watch?v=g-RjE1thRrE

The surprising result was that the centripedal force formula appeared
to be wrong for a non-contact force. The force appears to be directly
linear with r as opposed to the expected sqrt(r).  This is an
extremely preliminary result since I have only performed the
experiment a few times and the data really isn't good enough to show a
definitive difference between r and sqrt(r). There is actually very
little difference between the two for small r. So much more work needs
to be done to make any firm conclusions, but I thought I would share
my early results as a unique method of  measuring the centripedal
force and the possibility that the centripedal force relationship
might be different for non-contact forces like gravity. It may be
possible that if the centripedal force formula changes, then the
gravity formula may be forced to changed as well in order to preserve
the known relationship between orbital velocity and radius. Just how
that works ... who knows, but it is a possibility.

A linear relationship would generally mean that everything orbits at
the same velocity no matter how far from the center. We see exactly
this behavior in the rotational curves for the other galaxy where the
velocity appears to flatten out. We currently attribute this to dark
matter, but what if it is due to our lack of understanding of how the
centripedal force relationship works for non-contact forces?

-fhucentripedal