| 1998 | 
			 | 
			Stanford University, Department of Art, California, USA  | 
		
		
			| 1999 | 
			 | 
			Senate Paris, "intersculpt '99", Symposium on digital sculpture, France  | 
		
		
			| 2000 | 
			 | 
			University of Hawai'i at Manoa, Honolulu, USA | 
		
		
			| 2002 | 
			 | 
			Gulbenkian Foundation, "The Nothing... Nada Symposium", Lisbon, Portugal | 
		
		
			| 2003 | 
			 | 
			Cheltenham Science Festival, "scientists are from Mars, artists are from | 
		
		
			 | 
			 | 
			Venus", England | 
		
		
			| 2005 | 
			 | 
			Kunstmuseum Bonn, Symposium, "Bilder, Formen, Bewusstsein", Germany | 
		
		
			| 2005 | 
			 | 
			Café des Sciences, "Science et art; trafic d'influence", Geneva, Switzerland | 
		
		
			| 2007 | 
			 | 
			Alanus Hochschule für Kunst und Gesellschaft, Alfter/ Bonn: Symposium: | 
		
		
			 | 
			 | 
			"X-Over - Die bewegende Kraft der Kunst": Title of talk: "Zeichnung:  | 
		
		
			 | 
			 | 
			: Aesthetik, Symbol und Wirklichkeit" | 
		
		
			| 2007 | 
			 | 
			The Globe, CERN, Geneva: "Parallel tracks in art and science." | 
		
		
			| 2008 | 
			 | 
			L'Atelier, Genève: "Le dessin: esthétique, symbolique et réalité" |