R. A. Millikan
Discovery : Cosmic Rays

Ramanathan
Discovery : Molecular Scattering Of Light In Fluid

Ramanujam
Discovery : In Number Theory

Ramsay Travers
Discovery : Neon Gas

Richard Feynman
Discovery : Quantum Electrodynamics

Richard Trevithick
Discovery : Locomotive

Robert Koch
Discovery : Bacteriology

Robert Peary
Discovery : North Pole

Robert Recorde
Discovery : Equal Sign (=)

Robert Wilhelm Von Bunsen
Discovery : Laboratory Gas Burner

Roberts Mallet
Discovery : Seismograph

Roentgen
Discovery : X - Rays

Rogei Bacon
Discovery : Gun Powder

Rohm Korff
Discovery : Induction Coil

Ronald Ross
Discovery : Malarial Parasite

Rudolf Diesel
Discovery : Diesel Engine

Rudolf Virchow
Discovery : Cell Doctrine

Rutherford
Discovery : Breaking Up The Nucleus Of An Atom

Raazor (safety) : K.G. Gillete
Rabies Vaccine : Louis Pasteur
Radar : Dr. A.H. Taylor and L.C. Young
Radio : G. Marconi
Radio transmitter : Alexanderson
Radioactive Dating : Willard Libby
Radioactivity : Marie Curie
Radio-activity of Uranium : Henry Becquerel
Radium : Madame Curie
Railway Engine : Stephenson
Raincoat : Charles Macintosh
Raman effect : C.V.Raman
Rare Gas : Cavandish
Rayon American : Viscose Co.
Razor (electric) : Col. J. Schick
Refrigerator : James Harrison, Alexander Catlin
Replacing human heart : Christian Barnard
Revolution in Chemistry : Antoine Laurent Lavoisier
Revolver : Samuel Colt
Rise of German Science : Hermann von Helmholtz
Rubber (vulcanized) : Charles Goodyear
Rubber (waterproof) : Charles Macintosh