Public engagement and the Arrow of Time

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26 January 2015

“We can turn eggs into omelets but not omelets into eggs; ice cubes melt in warm water, but glasses of water don't spontaneously give rise to ice cubes.” So began the lecture given by Sean Carroll, Caltech physics professor and science communicator, speaking to a packed house at the Reuben H. Fleet Science Center in San Diego on January 5, 2015.

Sean Carroll receiving his 2014 Gemant AwardScience took center stage in Carroll’s exploration of concept of the “The Origin of the Universe and the Arrow of Time” for a largely public audience. The occasion was the AIP Gemant Award lecture, and Carroll, the 2014 award recipient, easily garnered enough interest to fill the 250 seat IMAX theatre to capacity. The lecture was unique in that it marked the first time that the Gemant Lecture was given to a primarily public audience. The date was chosen to coincide with the AAPT annual winter meeting in San Diego, and was publicized by AAPT as a plenary lecture. The Fleet Center also publicized the talk widely to its own members and to the general public in San Diego. The local PBS radio and TV station ran an interview with Carroll on the day of the event causing the phones at Fleet to ring steadily and creating a waiting list of science fans.

When Bo Hammer, Associate VP for Physics Resources and organizer of event logistics, and I arrived at the Fleet Center, a crowd was waiting outside. Those with reservations were seated first and then the walk-ins filled all available seats. The use of the IMAX theater provided an enormous screen to project images and simulations, as well as an intimate experience for the speaker and audience members. Steven Snyder, Executive Director of the Fleet Center, welcomed the crowd on behalf of the Fleet Science Center, noting that in addition to all the exhibits at Fleet, there are 19 museums collocated in Balboa Park. Snyder, a physicist himself, noted the presence of a large number of physics teachers from around the county in the audience, and asked the crowd to give these educators a round of applause in gratitude for the important work they do for our nation. I introduced Carroll and presented the Gemant Award, including a $5,000 cash award and the certificate with his award citation:

“for extraordinary public outreach on particle physics and cosmology, as an educator, author, public lecturer, and consultant for TV and radio programs, and for his pioneering work communicating with a variety of international audiences using social networking.”  

Another part of the award is a $3,000 grant to further the public communication of physics given to an institution designated by the winner. For this, Carroll has chosen The Story Collider, a New York based nonprofit devoted to publicizing stories about science. 

Carroll is a leader in understanding the nature of the cosmos, including the origin of the universe and the interactions between gravity and ordinary and exotic forms of matter.

Carroll treated the audience to an animated explanation of the ideas about time that appear in his book: From Eternity to Here: The Quest for the Ultimate Theory of Time. He talked about how the past and future are consistent in the observable universe. This is an irreversible process explained by the Second Law of Thermodynamics—that the entropy of a closed system will never decrease with time. He defines the arrow of time as simply that distinction, pointing from past to future.

But Carroll notes that this irreversibility is not found in the laws of physics: we can clean up a room and freeze an ice cube, but these are considered reversible processes in open systems. The macroscopic increase in entropy is a consequence of the configuration of the universe. The arrow can be explained by assuming that the very early universe was extremely orderly, and disorder has been increasing ever since.

But why did the universe start out so orderly? He described how what happened before the Big Bang may be responsible for the arrow of time we observe today, and proposed other possible models of the universe. As Carroll explained during a lively discussion with the audience after his talk, the quest to understand these big questions in cosmology will keep him and other scientists working for years to come.

Carroll’s mastery of conveying these and other esoteric concepts to broad audiences makes him a deserving recipient of the 2014 Andrew Gemant Award.

Nominations for 2015 Gemant Award are due by January 31.