Skip to content

{ Category Archives } Science

Stability

[This is the fourth in a series of articles giving the background to Ed Belbruno's work on the Interplanetary Transport Network. The earlier articles were Halfway to anywhere, Lagrange points (1), and Three is a crowd. This article looks at the stability of the Lagrange points.] What does it mean to ask if something is [...]

Three is a crowd

[This is the third in a series of articles giving the background to Ed Belbruno's work on the Interplanetary Transport Network. The first earlier articles were Halfway to anywhere, and Lagrange points (1). This article derives the final two Lagrange points, L4 and L5.] One of the reasons Stephen Hawkins and others are so silly [...]

Lagrange points (1)

The sun’s mass M is about 333,000 times the earth’s mass m, so at the same distance an object is pulled 333,000 times harder by the sun. [For convenience, we will often use k = M/m]. Sitting on the surface of the earth, this is completely outweighed by the fact that the centre of the [...]

Halfway to anywhere

[Ed Belbruno promoting his second - more popular book "Fly Me to the Moon" (a short - pp176 - autobiographical account of his ideas). His more technical book was Capture Dynamics and Chaotic Motions in Celestial Mechanics, pp224, 2004] I am hoping to write a few articles on orbital mechanics, leading up to the idea [...]

Natural units

It is clear that for engineering everyone needs to use the same system of units (for example, the great Hubble space telescope debacle illustrates the perils of mixing different sets of units when trying to make something – Hubble was launched in April 1990, but it was soon realized that its main mirror had been [...]