A demonstration of the conservation of the orbital angular momentum of the Earth

PELLIZZA, L.; MAYOCHI, M.; P. B. TISSERAAZZANO, L; PEDROSA, S.

AMERICAN JOURNAL OF PHYSICS

AMER ASSOC PHYSICS TEACHERS AMER INST PHYSICS

Lugar: New York; Año: 2015

0002-9505

We propose a simple but quantitative experiment to demonstrate the conservation of angular momentum. We measure the correlation of the apparent radius and angular velocity of the Sun with respect to the stars, due to the conservation of the angular momentum of the Earth in its orbit. We also determine the direction of its angular momentum vector and show that it is conserved. The experiment can be performed using a small telescope and a digital camera. It is conceptually simple, allowing the students to get a direct physical insight from the data. The observations are performed near the resolution limit imposed by the atmosphere, and in the presence of strong competing eects. This requires a careful experimental setup, and allows the students to improve their skills in experimentation.