Cosmology, Public Lectures, and Wonder.

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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?’


A Mass for Galileo

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Catholic News Service reports that this Sunday a Mass marking Galileo’s birthday was celebrated at the Basilica of St. Mary of the Angels and Martyrs, presided over by Archbishop Gianfranco Ravasi. If I can find a translated copy of the homily online, I’ll link to it.

This year was selected as the International Year of Astronomy because it is the 400th anniversary of the use of a telescope by Galileo. I will be checking throughout this week to see what other celebrations throughout the world commemorated his 445th birthday.

Galileo’s birthday was overshadowed by the 200th birthday of another famous scientist, Charles Darwin whose birthday was February 12. As an astronomy student, I am a bit miffed that Galileo’s birthday has been somewhat forgotten in light of this other day, but I suppose that it’s the result of people liking round numbers. My own university, MSU was involved with celebrations of Darwin’s birthday by joining in an international birthday wish on Youtube. You might notice a Catholic connection in this video as well; it includes Father George Coyne of the Vatican Observatory.

Interestingly, the basilica has functioned as a bit of an observatory itself. It is one of several large churches to have meridian lines which track the movement of the sun throughout the year. The image above of the line at St.Mary of the Angels and Martyrs shows how such a line works (image credit: wikibob). As solar noon (which need not be at 12:00 PM) approaches, the image of the sun approaches the line. Because the sun reaches different heights in the sky at different times of the year, the sun will cross a different portion of the line at different times of the year. In this way, the line functions as a sort of calender, or in this case, a means of testing the accuracy of the calender. Placement of pinholes at locations in the church also allowed the observation of specific stars for the purpose of recording stellar transits. What an appropriate location for a Mass celebrated in memory of Galileo.

Keep your eyes open for more IYA news as I finally get back to blogging.

Image Credit:Wikipedia