T HE P ROPERTY OF M OLECULES B ROWNIAN M OTION Jade Bowerman Caleb McNutt Ed Perez Miguel Obiang

H ISTORY Referenced as early as 60BC by Roman poet Lucretius Studied by Jan Ingenhousz using coal powder and alcohol in 1785 Revisited in a separate study by Robert Brown in 1827 Noticed during study of pollen atop water Confirmed for both organic and inorganic matter

O RIGINAL T HEORY More in depth analysis by Robert Brown Incidentally discovered while studying pollen grains of clarkia pulchella during 1826 Found erratic movement by small pollen bits Reanalyzed in 1827 A Brief Account of Microscopical Observations A Brief Account of Microscopical Observations Tested first with live pollen then dead pollen Common belief placed the motion as a factor of life Finished observations using inorganic matter Organic and Inorganic matter responded the same under observation [1] [1]

D ISCREPANCIES IN 1991 Brown’s microscope capabilities briefly brought into question Believed his microscope could not accurately observe the particle motion Refuted quickly after by Brian J. Ford, professional microscopist Rebuilt Brown’s microscope from A Brief Account of Mircroscopical Observations Provided video evidence of the microscope’s capabilities

T HE S TUDIES B ETWEEN Thorvuld N. Theile (1880) Mathematically interpreted as a method of least squares Louis Bachelier (1900) Related to stock markets and economic theories Neither captured the physics behind the motion Both failed to present the unpredictable nature of the particle movement [2] [2]

E INSTEIN ’ S D ISCUSSIONS 1905 Annus Mirabillis papers Used physics principles to sufficiently explain Brownian Motion Proved the Second Law of Thermodynamics Entropy never decreases in a system First proposed by Carnot in 1824 Provided mathematics for Avogadro's Number Still a theoretical constant for gas since 1811 A step towards molecular and atomic theories [3] [3]

E XPANSIONS ON THE T HEORY Jean Perrin (1908) Molecules recognized to intervene in heat transfer Carnot Cycle refuted as an ideal Tested that water poured into a tub does not become still, but more chaotic Entire body appears calm, but molecules continue moving Argued for the existence of atoms Continued Einstein’s assertion of relation between Brownian Motion and Avogadro's Number

I MPORTANCE IN THE C URRENT AGE Brownian Motion Explain molecules and atoms Helped pushed science into the Atomic Age Provided sufficient backing for the Second Law of Thermodynamics Continued the Conservation of Energy

W ORKS C ITED R. Brown, “A Brief Account of Microscopial Observations,” Edinburgh New Philosophical Journal (1828). A. Einstein, “Investigations on the Theory of the Brownian Movement,” Dover Publications, Inc (1956). B. Ford, “Brownian Movement in Clarkia Pollen: A Reprise of the First Observations,” The Microscope, 40 (4): , Lucretius, “On the Nature of Things,” Internet Classics Archive. Book II, Atomic Motions (60 BC). P. Morters, Y. Perez, “Brownian Motion,” Cambridge University Press. (2010) J. Perrin, “Brownian Motion and Molecular Reality,” Annales de Chimie et de Physique 18, (1909).