| PLANCK | Max -; theoretical physicist who founded quantum theory (6) |
| HUYGENS | Dutch mathematician, astronomer, and physicist, who founded the wave theory of light, discovered the true shape of the rings of Saturn. He discovered Saturn's moon Titan with a telescope in 1655. |
| PHOTON | Quantum theory unit |
| DIRAC | English theoretical physicist who applied relativity theory to quantum mechanics and predicted the e |
| EINSTEIN | Gennan-born theoretical physicist who developed the theory of relativity, Albert _ (8) |
| HAWKING | Stephen -; theoretical physicist who wrote A Brief History of Time (7) |
| WHEELER | Theoretical physicist who worked with Niels Bohr on explaining nuclear fission and coined the terms |
| KAKU | Dr. Michio ___ (Theoretical Physicist who has written bestsellers and has appeared on science TV sho |
| STEPHENHAWKING | Theoretical physicist who received the Copley Medal from the Royal Society in 2006 (7,7) |
| FEYNMAN | Richard ___, American theoretical physicist who received the Nobel Prize in Physics in 1965 |
| MAXPLANCK | German physicist who first formulated quantum theory, winner of the 1918 Nobel Prize in Physics (3,6) |
| BROGLIE | Louis de -; French physicist who contributed towards the formulation of quantum theory (7) |
| BOHR | Given to debates over quantum theory with fellow physicist Einstein, a Danish Nobel laureate who was a mentor and idol of Oppenheimer (4) |
| NIELSBOHR | Danish quantum theory physicist |
| LIGHT | It's both a particle and a wave, in quantum theory |
| ATOMS | Quantum theory particles |
| ALBERT | (and 23 across) German-born theoretical physicist (6) |
| ALBERTEINSTEIN | German-born theoretical physicist (6,8) |
| GELLNANN | Murray -; theoretical physicist noted for his work on the theory of elementary particles (4-4) |
| SHELDON | Character in The Big Bang Theory TV series, a theoretical physicist at Caltech (7) |
