Author: Else Starkenburg
Graduation Year: 2008
Department: Theoretical Philosophy
How Dark is the Universe? An evaluation of two competing astrophysical theories. (2008)
s there a better theory among two rivalling scientific theories? Hypothetico-deductive (HD) testing, originally designed by Hempel and Popper, has been explicated by Kuipers (2000) in its straightforward comparative form to answer exactly these sorts of questions. This master thesis provides a (first?) practical and contemporary example of such a comparison, from the field of astronomy.
Both rivalling theories considered here attempt to explain the same discrepancies in observations: the unexpected high speeds of objects in the outer parts of galaxies, or galaxy systems. It seems that there is not enough mass inside these systems to keep these objects in their orbits. The (Cold) Dark Matter (CDM) solution to this problem, supported by most astronomers, assumes there is more matter inside a galaxy than we can see or measure: part of it is “dark”. Modified Newtonian Dynamics (MOND), on the other hand, argues that not the postulated matter content of the Universe, but our laws of gravity should be changed.
Is the majority of the astronomical community right in regarding CDM as the better theory?
I show in this thesis that from a purely empirical point of view the theories are in a state of divided success. However, from aesthetic arguments, as classified by McAllister (1996), CDM theory seems more appealing, which might explain its higher popularity. Furthermore, I discuss a future outlook and whether it will be possible to combine these two very different, but (partly) successful, theories into one.
|Last modified:||01 November 2013 2.50 p.m.|