Ancient to Medieval
- Zero – Al Khwarizmi (9th century)
- Acids (Sulphuric, Nitric, HCl) – Jabir Bin Hayan (8th–9th century)
- Binomial Nomenclature – Carl Linnaeus (1735)
- Father of Botany – Theophrastus (4th century BC)
- Father of Zoology – Aristotle (4th century BC)
- Magnetism (Earth as a magnet) – William Gilbert (1600)
- Logarithms – John Napier (1614)
- Circulation of Blood – William Harvey (1628)
17th–18th Century
- Microscope (Simple) – Janssen Brothers (1590s)
- Cell Discovery – Robert Hooke (1665)
- Gravitation – Isaac Newton (1687)
- Electric Charges Law – Coulomb (1785)
- Oxygen – Joseph Priestley (1774)
- Periodic Table – Mendeleev (1869)
19th Century
- Smallpox Vaccine – Edward Jenner (1796)
- Electric Battery – Alessandro Volta (1800)
- Electromagnetic Induction – Michael Faraday (1831)
- Computer (Conceptual) – Charles Babbage (1837)
- Telephone – Graham Bell (1876)
- Light Bulb/Phonograph – Thomas Edison (1877–79)
- Dynamite – Alfred Nobel (1867)
- X-rays – Roentgen (1895)
- Radioactivity – Becquerel (1896)
- Radium – Marie Curie (1898)
20th Century
- Theory of Relativity – Albert Einstein (1905)
- Nucleus – Robert Brown (1831, confirmed later)
- Insulin – Banting & Best (1921)
- Penicillin – Alexander Fleming (1928)
- DNA Structure – Watson & Crick (1953)
- Polio Vaccine – Jonas Salk (1955)
- Laser – Theodore Maiman (1960)
- First Space Orbit – Yuri Gagarin (1961)
- Integrated Circuit – Robert Noyce (1959)
- Cell Phone – Martin Cooper (1973 invention, 1983 launch)
- First Cloned Sheep (Dolly) – Ian Wilmut (1996