Isotopes
Magic Keys to Understanding Life and the Cosmos

Mark H. Thiemens

2349th Meeting Abstract
Friday, September 11, 8:00 PM

About the Lecture:

Life is intrinsically interwoven with its environment

New understanding of nature is always attained when closer inspection of nature is facilitated.  Clues to almost any physical, chemical, and biological process in the universe across time are available from very precise measurements of stable isotopic compositions, particularly isotope ratios.  Such measurements can be made on physical samples here on Earth or remotely using telescopes and satellites.  Interpreting these clues requires detailed understanding of the fundamental physics and chemistry of processes that alter these ratios.  Based on new, fundamental discoveries about the quantum laws that alter these ratios, an extraordinary range of problems can be investigated and better understood, ranging in scale from the atomic to the astronomical and in time from the present to billions of years ago.  Precise measurements of isotope ratios recently have allowed us to interrogate and better understand the interactions of planetary atmospheres and surfaces, including biosphere interactions here on Earth.  These studies have been particularly important in developing our understanding of the history of both the Earth and Mars.  This talk will discuss how processes that occur on planetary scales of size and time can be studied - particularly using isotope ratios - and how these studies can be used to understand the origins and evolution not only of astronomical phenomena but also of life.

About the Speaker:

Matt Mountain

Mark H. Thiemens has spent his career studying and analyzing isotopes and isotopic compositions, particular in meteorites, chunks of space rock that have survived the fiery plunge from space through the Earth’s atmosphere. His research has addressed an unusually wide variety of problems—from ozone chemistry to global warming to questions about the prospect of life on Mars. His most recent work is on understanding climate dynamics from chemical clues embedded in South Pole ice.

Mark is Dean of Physical Sciences, Distinguished Professor and Chancellor's Associates Chair in the Department of Chemistry and Biochemistry at the University of California, San Diego. Prior to joining UCSD he was at the Enrico Fermi Institute and at the Brookhaven National Laboratory. He earned a BS at the University of Miami, and an MS and a PhD in Oceanography at Old Dominion University and Florida State University, respectively.

He is perhaps best known for discovering and exploring isotope anomalies in oxygen and sulfur not predicted by classical theory, and developing a quantum mechanical understanding of them. His work has stimulated new approaches to the theories of isotopic reaction mechanisms that have led to a deeper understanding of the Earth's atmospheric composition, the Earth's evolution, and atmosphere-surface interactions on Earth and Mars.

Mark is a member of the National Academy of Sciences and a Fellow of the American Academy of Arts and Sciences, the American Geophysical Union, the Geochemical Society, the European Association for Geochemistry, and the American Association for the Advancement of Science. Among many awards, he was named an Albert Einstein Professor by the Chinese Academy of Sciences and has been awarded the Alexander Von Humboldt Award (twice), Ernest O. Lawrence Award of the Department of Energy, and the Goldschmidt Medal of the Geochemical Society. Perhaps most emblematic of his many contributions to Earth, planetary, and cosmological sciences, an asteroid has been named for him: Asteroid 7004Markthiemens.


←Previous Abstract | Next Abstract →
Lecture Series Index - Home