An interview with the Israeli scientist, Prof. Avi Leib, a member of the scientific committee for planning the advanced space telescope that the USA is building to explore the depths of the sky
By: Alex Doron
The success of the "Hubble" space telescope, which provided a very impressive series of discoveries about what is happening in the vastness of the sky, "woke up a great, new appetite" in the scientific community. It is now preparing for the promotion of a more ambitious operation, in which a huge telescope will be launched into space whose mission is to try and discover the first stars formed in the universe.
An Israeli scientist also takes part in the important project: Prof. Avi Leib, an astrophysicist at Harvard University in Cambridge, Massachusetts, USA.
According to the plan, the new space telescope, the NGST (Next Generation Space Telescope) as it is called, by its temporary name, will be launched in 2008 or 2009. The project is managed by NASA, in cooperation with the European Space Agency. Its high sensitivity to weak light sources - resulting from its large dimensions (planned diameter: 8 meters) - will allow you to see through it to distances that were not achievable until now.
Prof. Leib - one of the world's leading scientists in the theoretical research of the first light sources created in the universe - is a member of the scientific committee that plans the state-of-the-art telescope.
In an interview with Maariv, Prof. Leib stated that the intention is to place the sophisticated facility (2700 kg, equipped with cameras and very sensitive spectrographic systems), in an orbit 1.5 million km away from the Earth, in the opposite direction from the Sun. It will be hidden from her with a special sun visor - to allow it to cool down to a temperature of 35 degrees above absolute zero. These conditions will give the telescope, which is supposed to "live" in space for 10-5 years, the sensitivity required for its activity in the infrared field.
Prof. Leib: "We are asking, using the next generation telescope, to find out when the first light sources in the universe were created, how did they appear after the 'big bang', from what was outlined in the primordial universe? The Book of Genesis, known to every child in Israel, provides the religious answer to this. The scientists are looking for scientific answers. In the last decade, considerable research effort has been dedicated to this matter and it requires images of what is happening in the depths of the sky."
The first stars to form in the universe were born very close to the big bang. Therefore, the light progressed from them on its way to us, for a long time, identical to the age of the universe (estimated at about 14 billion years).
Prof. Leib: "The long time it takes for light to progress also determines that the first stars are very, very far away from us, and therefore their characters are weak. A particularly sensitive telescope is required to discover them."
Another problem: the radiation from these stars is diverted into the red range (in the light spectrum), due to the expansion of the universe. The next generation telescope therefore focuses on the infrared range and not on the visible light range.
Prof. Leib: "The prevailing theory today regarding the way in which the universe was created, holds that it began from a situation where matter and radiation were almost uniformly distributed. Tiny inhomogeneities in the material's distribution grew over time. Areas of the universe that were dense on average - became denser, because of their gravity. Finally they collapsed - and created the bodies we see around us today (the stars). Evidence of the initial conditions in the universe was discovered in studies of the cosmic background radiation - the main remnant from the Big Bang. The discoveries were confirmed in the experiments of two American research groups that in the astronomical community call them: the Maxima group and the Boomerang group.
"But the process of creating the primordial bodies in the universe has not yet been observed and this is the purpose of the state-of-the-art space telescope. It will make it possible to see the first star clusters formed immediately after the big bang. It should provide images from the period that bridges the beginning conditions in the primordial universe, and the complex conditions seen around us today."
The state-of-the-art telescope will use the most advanced technologies that have not yet been tried - and this is the reason why such a long planning and construction project is required (over 8 years
