Universiteit Leiden

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This Week's Discoveries | 4 June 2019

dinsdag 4 juni 2019
Niels Bohrweg 2
2333 CA Leiden
De Sitterzaal

First lecture

The Birth of modern Astronomy

Harm Habing (Leiden Observatory)
For many Harm Habing is "the face" for the Dutch infrared astronomy, and particularly the space research involving the cool universe. For years he was involved in the preparations of the second Dutch satellite: IRAS, the first infrared satellite that made a complete map of the infrared sky. His new book ‘The Birth of modern Astronomy’  was published by Springer Verlag in 2019.

This book is an eyewitness report of the incredible evolution of astronomical research after 1945. This  growth in width, depth and accuracy was made possible by observing the sky by radio-, infrared and X-ray telescopes,  by the  building of optical telecopes much larger than  before and located on high and dry mountain tops and by replacing photographic plates by plates with millions of CCD-pixels. Observations from space proved to be essential. IT-technology became widely used to deal with large data bases and for simulations. The number of researchers increased at least by factors of ten. Funding of the huge costs of personnel and of instruments was obtained from civilian, i.e. non-military, sources.

Major discoveries: 

  • The detection of exoplanets, now expected to exist in larger numbers than the stars in our Milky Way galaxy
  • The discovery of neutron stars and of two kinds of black holes: those comparable in mass to that of the Sun, and ‘supermassive black holes’ with a mass that is a billion times larger.
  • An explanation of the remarkable atomic composition of matter: of all atoms 90% are of hydrogen, 9% are of helium and all others together are at most 1%.
  • The discovery of locations where stars and their planets are formed and where a complex carbon-dominated chemistry is at work.
  • The detection of ‘dark matter’ and ‘dark energy’, both of a nature unknown to physics. ‘Dark energy’ is the cause of the accelerated exopansion of the Universe
  • The discovery of a ‘radio photo’ of the Universe some 300 000 years after the Big Bang; a very accurate measurement of this radio photo led to a determination of the age of the Universe (13.6 Gyr), with an uncertainty margin of a few percent.
  • The emergence of a consistent description of the formation of the Universe beginning at an infinitesimal part of a second after the BigBang.
  • The BigBang itself remains a mystery

Second lecture, Lorentz Center highlight

AI and Cybersecurity: Challenges and Opportunities.

Prof. Subrahmanian (Dartmouth College)
Prof. Subrahmanian is The Dartmouth College Distinguished Professor in Cybersecurity, Technology, and Society. He is one of the world leaders in logical reasoning with uncertainty, probabilistic logics, temporal probabilistic logics, and managing huge, heterogeneous databases with incomplete and inconsistent information, and multimedia databases. He is one of the organizers of the workshop: Artificial Intelligence in Cybersecurity that is being held in the Lorentz Center from 3 June 2019 through 7 June 2019.

Read more about the lecture series This Week's Discoveries

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