Category Archives: LECTURE

Magnitud Aparente En esta lección hablaremos sobre la Magnitud Aparente de los objetos celestes. Hiparco clasificó las magnitudes de las estrellas en seis categorías, desde la más brillante, asignándoles la magnitud 1, hasta las más tenues al ojo humano, asignándole la magnitud 6. Veremos cómo se miden estas magnitudes de acuerdo con la definición moderna,Continue reading “Lecture 17”

Radio de Hill Objects in the solar disc grow by accretion increasing their gravitational influence over the surrounding material. The Hill radios will define the distance around which the planet, in growing or full grown, will capture any object that is inside this distance. In the video I develop the notes for this distance. TheContinue reading “Lesson 16”

Las Fuerzas de Marea Las Fuerzas de Marea son fuerzas que se ejercen sobre cuerpos (lunas, por ejemplo, o planetas) que son responsables de la deformación física de estos, debido a la acción de la gravedad. El achatamiento de los planetas es una consecuencia de las fuerzas de marea, como lo es también la fuerzaContinue reading “Lecture 15”

Centripetal and Centrifugal Forces Spanish version at the end available As indicated by the expression “centri”, while the ‘centripetal’ is directed towards the center, the ‘centrifugal is directed outwards, in the opposite direction of the center. Already with this definition there is something that does not sound complete. First, this suggests that this is theContinue reading “Lecture 13”

Calculating “g” In this lecture we will explore the nature of “g”, the acceleration of gravity, from the characteristics of the centrifugal force that a body experiences on a rotating system. Besides of the fact that the attraction of bodies is described and governed by the Universal Gravitational Law, and the weight of a bodyContinue reading “Lecture 14”

Harmonic Motion Bodies in a circular path around a center undergo harmonic motion, whit a good approximation applied to the planets around the Sun and moons around planets. In this video we are going to determine the differential equation and give a solution to calculate the resonance gaps in the Asteroid Belt. The lecture isContinue reading “Lecture 12”

Total Orbital Energy The total orbital energy in a gravitational bound system is a constant. It will be the same calculated at aphelio as well as perihelium. The total energy will be equal to 1/2 <U> the time-average potential energy of the system. The symbol < > is an indication for the average over oneContinue reading “Lesson 11”

Starting with the fact of the Second Law of Kepler, and using the result of the Orbital Angular Momentum as a constant value in terms so the reduced mass and the eccentricity of the ellipse, the Third Law of Kepler can be shown. The square of the period of a planet is directly proportional toContinue reading “Lesson 10”

Velocities at perihelium and aphelion Using the deduced equation for the position vector in terms of the orbital angular momentum, we may develop equations to calculate the velocities in the perihelium and in the aphelion. errata: a correction must be made in the word “aphelium” and substitute it for the proper expression aphelion. Watch theContinue reading “Lesson 9”

Kepler’s Second Law In this 13 minutes video, you will be introduced to the Second of the three laws of Johannes Kepler. This mathematical treatment of the law, makes clear about the changes in velocities at different places in the elliptical trajectory, and explains why the planets are faster at perihelium. Watch the video, byContinue reading “Lesson 8”