There is a rumor that surfaces twice a year at the time of the spring and
fall equinoxes. Many people believe that since the equinox is a time of
balance where the daylight hours and nighttime hours are equal, that -- by some
mystical force -- one can balance eggs on their end on these days. Some believe
that one can only balance an egg within a few hours before or after the exact
time of the equinox. 1
Philip Plait (a.k.a. the Bad Astronomer) writes: "Usually you cannot stand
a raw egg because the inside of an egg is a very viscous (thick) liquid, and the
yolk sits in this liquid. The yolk is usually a bit off-center and rides high in
the egg, making it very difficult to balance. The egg falls over. However, with
patience, you can usually make an egg stand up. It may take a lot of patience!"
He has a photo on his web site that shows himself and three eggs standing on
their end. 2
Being able to stand an egg on its end is clearly determined by the internal
structure of the egg, gravity, condition of the surface of the egg at its end,
the condition of the surface that the egg is being balanced on, how level the
surface is, etc. None of these factors have anything to do with the passage of
the seasons. So, a person probably has as much luck standing an egg on its end
on the equinox as on any other day of the year.
Plait reports that only a small percentage of eggs can be balanced. He
believes that the successfully balanced eggs have small irregularities that act
as miniature legs and prop up the egg.
The Textbook League suggests that this belief originated in China where it is
believed that an egg is easy on Li Chun -- the first day of spring. This happens
in February, about six weeks before the vernal equinox. Apparently some New
Yorkers took this belief, attached it to the spring equinox. 3,4
Needless to say, balancing an egg on it stubby end is a lot easier than on
its pointed end.
Scientists speculate about "self-moving objects" on the equinox:
Isaac Newton's second law states that force on an object produces
acceleration according to the equation F = MA, where F is force, M is the mass
of the object, and A is the accelleration. The first year physics in university
is often described as studying two laws: F = MA and "you cannot push on a rope."
Newton's Laws imply that if there is no force, there is no acceleration, and the
object remains stationary.
A minority of scientists are speculating that Newton's laws may have to be
modified under certain conditions. They propose a revised theory called modified
Newtonian dynamics" or MOND which only applies at extremely low accelerations.
Alex Ignatiev of the Theoretical Physics Research Institute in
Melbourne, Australia, suggests that in places where there is nearly zero
acceleration with respect to the center of our galaxy, MOND may be detectable.
He calculated that there are two locations on the surface of the Earth where the
earth's spin, rotation and orbital velocity cancel out twice a year -- on the
equinoxes. These spots are briefly near zero acceleration with respect to our
galaxy center. On 2008-SEP-22, one location would be in northern Greenland at 79º50'
N and about 56" W. He calculated that an object might brifly shift by one fifth
of a trillionth of a millimeter before returning to its original location a
fraction of a second later. He believes that gravitational wave detectors could
detect such a movement. 5
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