Some transformative impacts of computer science on astronomy

Roger F Malina

Observatoire Astronomique de Marseille Provence (OAMP)

President Leonardo/OLATS: Observatoire Leonardo des Arts et Technosciences

Three areas• Virtual Observatories

– Data paid for by tax payers is public– Few astronomers now take their own data

• Scientific Simulation– The Simulation is the Theory

• Scientific Visualisation– Most data is mediated by computerised instruments– How to make data ‘intimate”

The Hubble Deep Field

Virtual Observatories

• 75% of Hubble Telescope publications come from scientists ‘mining’ the archive

• Most astronomers no longer “observe”

• New “fields: “Multi-wavelength astronomy”

• New professions: Data Analysts– Cf the 19th century “calculators”

• Dan Boorstin: Epistemological Inversion– Data Poor to Data Rich with respect to Theory

Virtual Observatories

• Rebirth of amateur astronomy– NASA public data release policies ( 6 months)

• “Crowd sourcing” projects:– Berkeley Open Infrastructure Consortium

• SETI@home, Stardust, Martian Craters……

• Petabyte revolution: “end of theory” – Statistical analysis of very large data sets– database science – Correlations, trend analysis,

The “Millenium Simulation”

Scientific Simulation

• Many problems not amenable to “compact predictive descriptions” cf E=MC2, F=MA

• Complex systems, chaotic systems, many body problems,

• Stellar evolution, planetary formation, structure formation in universe

• The Simulation is the Hypothesis

Scientific Simulation• C Hayles: retrodiction versus prediction

– S Kauffman : Phenomena “beyond prediction”

– Galilean Fallacy: causality

• Search for “critical comparisons”

• Comparison of Computer Codes

• Problem of non unique solutions – Cf “inversion’ problem.

• Same phenomena may have multiple explanatory simulations

Visualisation, Sonification:\ Making data intimate

Scientific Visualisation

• All astronomical data is now digital– Kodak has stopped making photographic

plates for astronomers

• The majority of astronomical data comes from light/energy “invisible” to humans

• Ontological challenge:– We have no sensory experience with the

phenomena we study– How to do ‘ground truth”

Some Impacts of Computer Science on Astronomy

• The scientific method is changing– scientific simulation as the explanation

• The content of astronomy is changing– New problems can be attacked– Coupling to government/industry funding

• The profession of astronomer is changing– Social organisation of astronomy..internet..– New opportunities for art-science

collaboration