Dudley R. Herschbach earned a B.S and M.S. from Stanford University and his M.A. and Ph.D. from Harvard Univeristy.

Dr. Herschbach on gas production by high pressure chemistry.

Dr. Herschbach, who won the Nobel Prize in 1986, began his talk on high pressure chemistry by providing a brief introduction to the ranges of pressure.  He started with the approximate pressure at the center of the Earth to the pressure of hydrogen gas in outer space, at which point he introduced his main topic, the study of high pressure chemistry.

According to Dr. Herschbach, high pressure chemistry is a field most notably researched by Russel J. Hemley. Dr. Hemley began by extending chemical physics techniques in high-pressure diamond anvil cell experiments and later expanded his research to matter physics, material sciences and planetary sciences.  Much of the works Dr. Herschbach commented on showed that matter, regardless of its makeup, follows the rules of physics. He showed that as energy increases and its volume decreases all matter eventually reaches the same universal pressure incline.  Graphical proof was provided by means of the energy pressure diagram of H₂ and H₂⁺ which displayed their graphs converging towards the same asymptote.

It seems pressure has been a topic of research since Galileo’s time. Dr. Herschbach presented a notable hypothesis, that of Thomas Gold’s, who believed that hydrogen gases where pushing up towards the Earth’s surface near earthquake faults.  He launched a major research drilling operation to prove his hypothesis.  However, after many failed attempts in Scotland his research was met with skepticism as only minor reservoirs of oil where found. Thomas Gold later modified his hypothesis in The Deep Hot Biosphere suggesting that oil came from bacteria and natural gas and its production the result of high pressures.

Dr. Herschbach stated some of the underlying assumptions of deep earth gas theory, they are: 1) hydrocarbons are primordial, 2) hydrocarbons are subsequently not fully oxidized, 3) hydrocarbons are stable at great depths and 4) deep rocks contain pores. His line of interest is in extracting gas from wet rocks and in theory it follows that as pressure increases and depth increases, temperature increases. In squeezing wet rocks, you increase the pressure, increasing the temperature and therefore evaporating the liquids into gas. He presented evidence by providing a Raman spectroscopy of the microscopic view of the diamond anvil cell showing bubbles of CH₄ forming at high pressures.  He also stated that high pressure chemistry has found some organisms still alive in high pressures environments that were once believed to kill everything off.

Dr. Herschbach continued his talk with the pressure workings of a water pump and discussed the development of the barometer.  This included a brief history on Evangelista Torricelli, an Italian physicist and mathematician of the 16^th century.  He later elaborated the rules of physics concerning pressure by explaining the reasons a tanker truck could be crushed by atmospheric pressure alone if the internal pressure fell below atmospheric. His final pressure demonstration was that of placing a whole boiled egg inside a bottle.  This demonstrated the effects of a pressure difference and how in reaching equilibrium the egg was sucked into the lower pressure zone of the bottle.

In conclusion, Dr. Herschbach introduced some of the world’s leading experts in the line of high pressure chemistry, provided theories proving and disproving hypothesis in the development of gas.  To provide a glimpse of the development of pressure research, Dr. Herschbach took his audience through the ages by guiding us through the pressure related works of physicists such as Galileo Galilee and Evangelista Torricelli.

For further reading consider the following:

• Text Book: Holzapfel, W.B.,  Isaacs, N. S., High Pressure Techniques in Chemistry and Physics: A Practical Approach. June 1997.
• Publication: Tatsumi, D.L., Hamilton, R.W., Nesbitt, Chemical characteristics of fluid phase released from a subducted lithosphere and origin of arc magmas: Evidence from high-pressure experiments and natural rocks, Journal of Volcanology and Geothermal Research, Volume 29, Issues 1-4, September 1986, Pages 293-309
• Publication: Wang, K., Duan, D., Wang, R., et al.,  Stability of hydrogen-bonded supramolecular architecture under high pressure conditions: Pressure-induced amorphization in melamine-boric acid adduct, Langmuir, 25, 4787-4791 (2010).