The binasuan is a
Filipino
Filipino may refer to:
* Something from or related to the Philippines
** Filipino language, standardized variety of 'Tagalog', the national language and one of the official languages of the Philippines.
** Filipinos, people who are citizens of th ...
folk dance in which the performer holds full
wine glasses in each hand while performing balancing tricks. Wine may be used to fill the glasses, but other liquids may be substituted. The arms are rotated over and under the shoulder in order to keep the palms facing up so as not to spill the liquid while nevertheless allowing the
radius
In classical geometry, a radius ( : radii) of a circle or sphere is any of the line segments from its center to its perimeter, and in more modern usage, it is also their length. The name comes from the latin ''radius'', meaning ray but also the ...
to cross over the
ulna
The ulna (''pl''. ulnae or ulnas) is a long bone found in the forearm that stretches from the elbow to the smallest finger, and when in anatomical position, is found on the medial side of the forearm. That is, the ulna is on the same side of t ...
via
pronation
Motion, the process of movement, is described using specific anatomical terms. Motion includes movement of organs, joints, limbs, and specific sections of the body. The terminology used describes this motion according to its direction relative ...
. Binasuan originated in
Pangasinan
Pangasinan, officially the Province of Pangasinan ( pag, Luyag/Probinsia na Pangasinan, ; ilo, Probinsia ti Pangasinan; tl, Lalawigan ng Pangasinan), is a coastal province in the Philippines located in the Ilocos Region of Luzon. Its capit ...
and is popular at festive events such as weddings.
Since the binasuan inverts the arm through rotation, it is sometimes given as a macroscopic, physical demonstration of the rotation properties of a
spin-½ spinor. As the liquid never spills, the rotation can all occur within the same plane. Upon a rotation of 2π
radian
The radian, denoted by the symbol rad, is the unit of angle in the International System of Units (SI) and is the standard unit of angular measure used in many areas of mathematics. The unit was formerly an SI supplementary unit (before that c ...
s, the elbow changes between pointing up and down. Upon a rotation of 4π
radian
The radian, denoted by the symbol rad, is the unit of angle in the International System of Units (SI) and is the standard unit of angular measure used in many areas of mathematics. The unit was formerly an SI supplementary unit (before that c ...
s, the palm "
doubly covers" the shoulder, and the elbow points in its original direction.
{{Philippines-stub
Dances of the Philippines
Culture of Pangasinan