Bodes Law, the Asteroids and Pseudo-Science

Lets look at the sun-planet separations.

In 1766 the German astronomers Titius and Bode discovered an interesting numerological pattern that "predicted" the position of the planets.

Most intriguing is the gap that appear in our table. If the pattern is filled in the prediction is that a planet should be found at 2.8 AU. By 1800 astronomers were eagerly seeking this "missing planet". In 1801 the discovery appeared to be made by the Italian astronomer Piazzi with the detection of a star-like object moving against the background of fixed stars. This "new" planet was called Ceres. But ...

In 1802 another "new" planet called Pallas was found then in 1807 2 more and then ... Get the idea? There was an embarrasment of riches here. In fact, what was discovered was the asteroid belt - a topic will consider in turn as we begin to explore the solar system in more detail. Is the Titius-Bode Law Really a Law?

• What does it mean for a statement to be a law in science?

• Is the T-B relationship similar to or on "par" with Kepler's 3rd Law - both deal with similar topics?

To answer the second question we need only consider that Kepler's 3rd Law although coming before Newton's Law of Gravitation can be shown to be a logical consequence of using Newton's laws. As well it is not restricted in application to the solar system. It also appears to be completely applicable - there are no embarassing exceptions. To answer the first question is a bit more difficult but it seems that in order to be a law a statement must point towards a deeper connection with reality. This might not be obvious at the time and it would certainly be reasonable, in 1766, to have felt that T-B was more than "mere coincidence". But we have never been able to furnish a more fundamental reason for T-B and for that reason it is now considered a "fluke".

Assignment #2 (Astro 201 | Astro 211)

Seeds: Chp19