ScopeX 2008 Auditorium Report – by Robert Groess
(Note by Lerika Cross: the first talk in the Auditorium was given by Johan Smit titled: "How a Telescope Sees". This was aimed at the learners that were bussed in and formed the item in their structured programme. Robert did not have to introduce Johan and did not attend Johan's talk.)
The calibre of this year's speakers at ScopeX was nothing short of phenomenal. All sessions were very well attended and thanks to a generous time schedule, kept people attracted longer than the allotted time. If you were lucky enough to attend, you'll know what I mean. If you missed out, here's a little teaser on what you missed out on:
Case Rijsdijk – Fingerprinting the Universe
One of the key messengers that we have relied upon to tell us much of what we know about our universe, have been the faithful photons bridging the gap between the light-years from distant objects. Understanding the electromagnetic spectrum leads to a powerful way of fingerprinting the universe. Everything gives off some form of electromagnetic (EM) radiation of some kind. Even we give off radiation – mainly in the form of heat in the infrared part of the spectrum. Light is just another form of EM radiation. If you ever wanted to know how light is generated inside atoms, Case told us about it.
And then the ever famous Bohr Model of the atom. We know it to be not entirely accurate – but it still provides a very useful representation of how atoms function. Case used some very illuminating interactive animations to illustrate many of these concepts. Absorption and emission spectra made for a fascinating discussion about how the rainbow is used to tell what stars and other objects in the universe are made of, without us actually having to go there. And not only what they are made of but what they are doing. Spectroscopic binaries are just one such example. By using Doppler techniques, these objects can be understood and it is this same principal which is used by traffic officials with laser speed trapping devices.
Case wrapped up his presentation by bringing us up-to-date with recent headline research at SAAO about eclipsing binary stars and even a supernova (SN2008D) in the galaxy NGC2770, some 90 million light-years away. Case showed us a computer simulation on what is thought to go on inside a supernova which took a supercomputer 3 days to complete, and would take approximately 1000 years on your current PC to do the same. Case warned not to try this at home.
The EM window has taught us much about what we know about astronomical objects, but there are detectors being built which are on the hunt for elusive gravitational waves. These waves are predicted to exist from Einstein's theory of relativity, but so elusive are they, that they have yet to be experimentally detected.
Mark Comninos – The CHEETAH-1 Commercial Satellite Launch Vehicle
How can a third-world country like South Africa ever enter the space race? What good could ever possibly come from it? Well, Mark Comninos, MD of MARCOM Aeronautics & Space (Pty) Ltd., inspired by Space Shuttle Columbia's maiden voyage, showed us how easily this can be done. And also the lucrative US$ 2 billion per annum market which South Africa is well suited to tapping into.
The science behind rocket science is not all that complicated. 95% of the materials and technology required to launch a two stage-to-orbit vehicle can be sourced directly from South Africa. The vision which MARCOM is pushing forward is to have a two-stage liquid fuel rocket to be flight ready within 3 years. The launch site will be Denel's Overberg Test Range Facility in the Western Cape which, in the world of spaceflight, is a geographic gem. Orbital inclinations from 34 to 117 degrees can be directly serviced from this site!
Of the three classes of launch vehicle, the light payload (~1,000kg), medium payload (~5,000kg) and heavy payload (~20,000kg), MARCOM is set to carve out a niche in the light payload category with an estimated 1 – 4 launches planned per year. In terms of the flight dynamics of such a launch vehicle, Mark has written a very comprehensive and realistic flight control simulator, which demonstrates the capability South Africa has to be fully competent in spaceflight.
Mark ended off by saying each of the 5 onboard computers on Columbia's maiden flight was nothing more than a Commodore 64. Your cell phone today has more computing power than these pioneering spaceflights ever had.
Dr. Pierre Cilliers – Polar Space Weather and International Polar Year
Why would anyone go to Antarctica to study space weather and the Sun? Wouldn't the tropics be much better suited to something like that? Well the Earth's magnetic field lines are perpendicular to the Earth's surface at the poles. And what that means is the electrically charged particles which are channelled along the Earth's magnetic field lines are directed towards the ground in the Arctic and Antarctic regions. In effect, it allows us to study some aspects of the space environment without actually going into space. All of this and much more is studied from the South African base, SANAE-IV.
Space weather research has become an increasingly important activity, since, as Dr. Cilliers puts it, when the Sun sneezes the Earth catches a cold. The solar wind comprises electrically charged particles which travel at speeds of between 600 – 1000 km/s. When a solar flare is ejected in our direction, we have anything from 1 to 3 days' warning before the flux of particles interacts with our Earth's magnetic field. The effects can be quite expensive to electrical power lines and switchgear which act as conduits of currents set up by this solar weather and leads to transformer burnouts and general power disruptions. While ESKOM cannot blame space weather for the recent load shedding campaign, there are documented cases of transformers overheating and the most likely cause was induced low frequency currents from solar particles.
Dr. Cilliers also discussed the extremely rapid decline of the Earth's magnetic field strength as measured from the Hermanus Magnetic Observatory. Here the magnetic field has decreased by an astonishing 20% in the last 60 years. The South Atlantic Anomaly, a region east of Brazil in South America, boasts the weakest magnetic field strength of any place on Earth. Here the field has been in decline by an incredible 10% in the last 20 years. There is evidence which leads to the suggestion that the Earth may be in the process of a Magnetic Field reversal. Geological records show that such field reversals happen on timescales which are miniscule by geological standards – of the order of 1000 years or so. Dr. Cilliers ended off by telling us what life is like at SANAE-IV and also showed a positively gripping DVD about Antarctica and South Africa's presence there.
Keynote Speaker: Professor David L. Block – Shrouds of the Night
The Universe is replete with masks. Masks of galaxies. Masks of space. Masks of time. The enigma of time continues to defy simple definition. All attempts at grabbing a handle on time have so far either resorted to mathematical manipulations or have met with an undeniable sense of je-ne-sais-quoi. Professor Block looks to the Garoka Mudmen of the Papua New Guinean highlands to understand their concept of space and time and how differences in their thinking with that of western culture, could lead to nuggets of insight which may be seminal in tackling this riddle. The Papuan's base their priorities more in spatial terms than temporal ones. When we make an appointment with someone, it is the time and date which is of greater importance to us than where we meet. However, for the Papuans, they choose where to meet and time flows by until all parties have arrived. Another interesting analogy would be by looking at images of erupting volcanoes, such as Popocatepetl in Mexico. Snapshots of the eruption lead to a very definitive sense of causality. First the volcano reveals but a puff of smoke. Next a stronger plume is evident. Then a bellowing cloud of ash. And so on until the full extent of the eruption is visible. It is blatantly clear to anyone with causal intuition in which order the snapshots should be placed. Even pre-school children are up to the task. And so the mask of time requires further interrogation in order to reveal the subtle nature of that dimension we know so little about.
Professor Block's book, Shrouds of the Night, co-authored by Professor Ken Freeman of Mount Stromlo Observatories, will be on sale from around September 2008. Written with the lay-person in mind, Shrouds of the Night promises to be the much awaited sequel to Professor Block's book, Starwatch, which is now out of print.
The final auditorium event of ScopeX 2008 was the screening of the DVD about Antarctica and South Africa's involvement there – which retained a capacity crowd until the end, after a really delightful interaction with Dr. Cilliers about life in Antarctica. A very special word of thanks to all our guest speakers and to all the ScopeX supporters, for making the day what it was!