The Property of Molecules Brownian Motion

1. The Property of Molecules Brownian Motion Jade Bowerman Caleb McNutt Ed Perez Miguel Obiang

2. History • 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

3. Original Theory • More in depth analysis by Robert Brown • Incidentally discovered while studying pollen grains of clarkia pulchelladuring 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] http://www.antique-microscopes.com/photos/Spencer_Trunnion_microscope-1.jpg

4. Discrepancies 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

5. The Studies Between • 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] http://gallery.mailchimp.com/8f8d44f1fc10bd074f648a4de/images/stock_market_up.jpg [2]

6. Einstein’s Discussions • 1905 AnnusMirabillispapers • 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] http://www.sciencemag.org/content/307/5711/F1.medium.gif

7. Expansions on the Theory • 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

8. Importance in the Current 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

9. Works Cited • R. Brown, “A Brief Account of Microscopial Observations,” Edinburgh New Philosophical Journal. 358-371 (1828). • A. Einstein, “Investigations on the Theory of the Brownian Movement,” Dover Publications, Inc. 1-19 (1956). • B. Ford, “Brownian Movement in Clarkia Pollen: A Reprise of the First Observations,” The Microscope,40 (4): 235-241, 1992. • 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 Physique18, 1-114 (1909).