1603 in science

The year 1603 in science and technology involved some significant events.

Astronomy

Johann Bayer publishes the star atlas Uranometria, the first to cover the entire celestial sphere,{{cite book|first=Isaac|last=Asimov|authorlink=Isaac Asimov|title=Asimov's Biographical Encyclopedia of Science and Technology|edition=2nd}} and introducing a new system of star designation which becomes known as the Bayer designation.
Dutch explorer Frederick de Houtman publishes his observations of the southern hemisphere constellations.As a supplement to his grammar and dictionary of the Malay and Malagasy languages, {{cite book|first=Fr.|last=de Houtman|title=Spraeck ende woord-boeck, in de Maleysche ende Madagaskarsche talen, met vele Arabische ende Turcsche woorden. Inhoudende twaelf tsamensprekeninghen inde Maleysche, ende drie in de Madagaskarsche spraken, met alderhande woorden ende namen, ghestela naer dordre vanden A.B.C. alles int Nederduytsch gestellt: noch zijn hier byghevoecht de declinatien van vele vaste Sterren, staende ontrent den Zuyd-pool|location=Amsterdam|publisher=Jan Evertsz. Cloppenburch|year=1603|url=http://objects.library.uu.nl/reader/index.php?obj=1874-205055&lan=en#page//25/21/32/25213223606406628589176308896733666129.jpg/mode/1up|accessdate=2012-01-02}}

Pietro Cataldi finds the sixth and seventh perfect numbers.{{cite book|first=Tony|last=Crilly|title=50 Mathematical Ideas you really need to know|location=London|publisher=Quercus|year=2007|isbn=978-1-84724-008-8|page=41}}

Girolamo Fabrici studies leg veins and notices that they have valves which only allow blood to flow toward the heart.

August 17 – Accademia dei Lincei, the oldest scientific academy in the world, is founded in Rome by Federico Cesi.