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-
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-
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-
How can a third-
The science behind rocket science is not all that complicated. 95% of the materials and technology required to launch a two stage-
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-
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-
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-
Professor Block's book, Shrouds of the Night, co-
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!