Q&A with Paul Halpern

 

 

 

Paul Halpern is the author of the new book The Allure of the Multiverse: Extra Dimensions, Other Worlds, and Parallel Universes. His many other books include Flashes of Creation. He is a professor of physics at Saint Joseph's University, and he lives near Philadelphia.

 

Q: What inspired you to write The Allure of the Multiverse?

 

A: I have a longstanding interest in science fiction and alternative histories since childhood.

 

Some of my favorite stories and novels imagine changes to reality, such as the time traveling dinosaur hunters in Ray Bradbury’s classic, “A Sound of Thunder,” who return to find they are in another branch of time.

 

My scientific interests similarly reflect alternatives; in that case, unusual solutions of Einstein’s general theory of relativity.

 

Given all the discussions of multiverse ideas in films and all the debates about the concept in science, I thought it would be a good topic for me to write about. 

 

Q: How would you define the multiverse, and what do you see as its allure?

 

A: According to some definitions of the universe, it represents everything. In that case one might wonder how there could be anything beyond it. Yet as modern physics shows us, there are many fields that envision the tangible, observable part of the universe as being influenced by other realms.

 

For example, quantum physics operates in an abstract stage called Hilbert space. Inflationary cosmology describes the space around us as once being a small region of a greater cosmos.

 

For these theories, the allure of the multiverse is trying to envision domains that are not directly measurable to make sense of the observable universe—and pin down why it has particular properties.

 

Q: How did you research the book, and did you learn anything that especially surprised you?

 

A: I researched the book by conducting numerous interviews of prominent physicists, reading the transcripts of oral histories of others, looking at trailblazing articles about multiverse ideas, and so forth.

 

One thing that surprised me is that some of the scientists who I expected to be very realistic and opposed to anything that is not directly testable actually thought that multiverse ideas should be taken seriously, while some of the others who were known for speculative ideas, dismissed even considering multiverse schemes.

 

Q: The writer Dan Falk said of the book, “The multiverse is a staple in today's science fiction, but as Halpern shows us, the idea of a multitude of universes has a rich history, with scientists and philosophers debating its merits for centuries.” What do you think of that description?

 

A: I agree with Dan Falk, that the multiverse has antecedents in longstanding debates about the nature of other worlds, cycles of time, higher dimensions, and other departures from linear models of the universe.

 

Q: What are you working on now?

 

A: I am completing an article about the best movies with multiverse themes, and starting to prepare for new classes in the spring.

Q: Anything else we should know?

 

A: I hope readers consider my book a serious and balanced look at a topic that conjures up a wide range of reactions, from an absolute embrace of multiverse ideas to a complete disdain for them.

 

I hope to aim for the middle, which is the notion that it is best to have absolute testability in science, but when that isn’t possible, sometimes more abstract schemes provide a context for what is observed.

 

--Interview with Deborah Kalb. Here's a previous Q&A with Paul Halpern.