Last evening I attended a lecture at the Cleveland Museum of Natural History by Prof. Carlos Frenk of Durham University. His talk, ‘The Great Cosmic Gamble: Making Galaxies from Nothing,’ was the most crowded lecture of the Frontiers of Astronomy series the museum has been hosting. Why?
Astronomy does well in the public sphere. It’s easy to get people excited about stars and planets and comets and pretty things like nebulae. It is a science in which people can get involved. Bring a telescope to a public spot, point it at Saturn and they too can have the chance to observe its rings. There are numerous reasons for the suitability of astronomy to science outreach, enough for several posts. Cosmology more than any other field in astronomy, perhaps in science, captures our interest. Why shouldn’t it?
Cosmology is the study of the universe as a whole and its origins. It is the science of the ‘Big Picture,’ a field which overlaps with philosophy and theology. The questions cosmology addresses are some of those which strike at the core of wonder-the desire for knowledge: ‘What is the universe like?’ ‘How big is the universe?’ ‘How old is the universe?’ ‘What might its future hold?’.
Prof. Frenk is a proponent of Cold Dark Matter, one of several theories which seeks to explain the 21% of the universe which has mass, but for whatever reason does not interact with light, hence the moniker dark matter. There are several competing theories, as one audience member’s question about Modified-Netwonian Dynamics pointed out, but theories such as those which Frenk works with are the most accepted in the scientific community. Of course because this matter does not interact with light, it is quite difficult to figure out what it is, even if its gravitational effect tells researchers where it is. One hope researcher’s have for large particle colliers such as the Large Hadron Collider is they they may be able to produce particles which fit dark matter models.
Interestingly, dark matter and ‘everyday matter’ account for less than 30% of the ‘stuff’ in the universe. Leading cosmological theories call the remaining component of the universe, dark energy. Unlike matter, dark energy does not exert gravitational force. Indeed it seems as if dark energy is the cause of the accelerating expansion of the universe. One question I’ve always harbored is whether dark energy might be explained as a fifth fundamental force, joining the ranks of electromagnetism, gravity, weak nuclear, and strong nuclear. If not then why? I’m just a lowly undergraduate vying to go into observational astronomy, so I don’t know the answers to this.
Recently the Society of Physics student’s asked members a question close to my heart, ‘What makes you wonder?’ I think that I will make this a regular feature, maybe weekly so that I can kick myself into writing more regularly here. So this is the first installment of a hereto unnamed feature about things which make us wonder. This week I wonder, ‘Can dark energy be explained by adding a fifth fundamental force to physics?’