Starmus Festival Session 2

Day two of the Starmus festival got underway with a talk by Dr Brian May on the history of stereoscopy in astronomy.
He started by outlining the start of stereoscopy in the middle of the 19th century and pointed particularly to Charles Smythe, a future Scottish Astronomer Royal, who was the First person to use stereoscopy for astronomical purposes during an expedition to Tenerife in the middle of the 19th century.
From about 1860 to the turn of the century stereoscope fell out of favour but at the turn of the 20th century stereo comparators were invented which provided an easy way of identifying anything that had moved when looking at two photos taken at different times. These comparators were very useful for identifying fast moving objects like comets and asteroids and remained in use up until the 1970’s. He went on to show how stereoscopy was a useful, even spectacular, way of looking at planetary and lunar features such as craters and mountains.
At greater range combining photos from Hubble gave some spectacular views of the universe.
He also pointed to how stereoscopy was being used by the Bessel project to develop a 3D map of our own Galaxy.
Finally he showed some spectacular 3D images of volcanoes erupting as seen from the International Space Station.
It is impossible to convey the force of this talk without seeing the images on show but he certainly made the case for wider use of stereoscopy in astronomy for the future.
The second talk of the day was given by John Mather, NASA project manager for the JWST on the subject of the James Webb space telescope.
John started by explaining why infrared astronomy is necessary, primarily because the light from the most distant galaxies has been redshifted into the infrared by their great distance. He also pointed out that infrared astronomy necessarily needs to be conducted from above the Earth’s atmosphere which is opaque to infrared radiation.
He explained that with these capabilities the JWST will take move beyond the range of Hubble and into the early Universe. In due course the telescope will, it is hoped, be able to see exoplanets with oceans.
All this, of course depends on it launching properly unfolding and achieving proper focus. Because, if there are problems, fixing them will be very difficult if not impossible.
The third talk of the day was given by Stephen Hawking on the quantum origins of the Universe.
After some entertaining knock about regarding his role in Star Trek playing poker with Newton and Einstein he turned his attention to the question of the origin of the Universe and the role quantum mechanics played in it.
The essence of his argument is that the origins of the universe and therefore the origins of mass and time itself are essentially quantum in character.
Whilst much of this has been predicted theoretically, not least by Hawking himself, recent hard data from the WMAP and Planck satellite have given experimental underlining to the whole Big Bang theory.
He went on to explain the basis of the theory of gravitational wave and pointed to the results published by the BICEP 2 group whilst pointing out the problems with that data and the likelihood that the wider data due to be published by Planck in the near future may modify those results.
All of this, he argues, means that there is no relevance to asking the question of what came before the Big Bang because the question itself is meaningless.
The final talk was given by Mark Boslough on the subject of asteroid impacts. He is involved in the Space defence project aimed at finding these objects and preventing them from hitting Earth.
Mark looked at the Chelyabinsk asteroid impact which was well filmed by a series of dashboard cameras. He has been able to show that the destructive force of these air burst impacts is much higher than an equivalent nuclear blast because of the way the air burst takes place and the shock wave it creates as the asteroid continues towards the ground at very high speed.
As a result of his work he believes there are two distinctly different types of air burst which have distinctly different effects.
The first sort produce effects like the Tungunska impact which flattened vast areas of forest in Russia. The other type is typified by an impact over the Libyan desert which produced silicate glass from the sands of the desert. It seems likely that there should be many more of these types of silicate glass than has so far been found.
The only defence against these sort of impacts is to find them early – years or decades before they are due to hit and then deflect them. If you don’t find them early enough there is nothing you can do about them.
Mark pointed out that recent research is pointing to these events happening more often than has previously been thought. In his view the next object of substance to hit Earth is likely to be a sub 50 metre asteroid. We need to start looking more intensely for these objects.
This is clearly an ongoing area of work.

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