{"id":1415,"date":"2015-11-03T22:17:34","date_gmt":"2015-11-03T22:17:34","guid":{"rendered":"http:\/\/blog.wabash.edu\/magazine\/?p=1415"},"modified":"2023-05-24T17:56:48","modified_gmt":"2023-05-24T17:56:48","slug":"grappling-with-the-quantum","status":"publish","type":"post","link":"https:\/\/blog.wabash.edu\/magazine\/2015\/11\/03\/grappling-with-the-quantum\/","title":{"rendered":"Grappling with the Quantum"},"content":{"rendered":"

<\/strong>
\nTrying to Understand the Fundamental Rules Governing Our World<\/strong><\/p>\n

The 36th LaFollette Lecture
\nOctober 30, 2015<\/p>\n

by Dennis E. Krause<\/strong><\/p>\n

I\u2019m deeply honored to be speaking this afternoon.\u00a0 I was surprised and excited when Dwight Watson came to my office at the beginning of the year with the invitation.\u00a0 Naturally there was trepidation\u2014what was I going to talk about?\u00a0 However, I was excited because it would give me a chance to talk about the things that have been perplexing me over the years and which have been driving much of my research and teaching.\u00a0 It would also give me the opportunity to talk more about what I do and how I do it.\u00a0 Finally, I felt that by looking at my work from a humanities perspective, I would learn something new, and that is exactly what happened.<\/p>\n

While I\u2019m honored to be first physicist to give the LaFollette Lecture, I actually believe I\u2019m the second physical scientist to speak, following Paul McKinney who gave the thirteenth LaFollette Lecture in 1992.\u00a0 It shouldn\u2019t be surprising to note that I\u2019ll be speaking on some of the same things he discussed over 20 years ago since the problems of the quantum remain as fascinating now as then.<\/p>\n

The charge of this talk is to address how my research touches the humanities broadly speaking, which sent me searching for a definition of the \u201chumanities.\u201d\u00a0 One that I found seems to describe well how the term is used in academia:<\/p>\n

The humanities can be described as the study of how people process and document the human experience.<\/i> [1]<\/a><\/i><\/p>\n

But I\u2019m a theoretical physicist.\u00a0 I\u2019m trying to find and understand the rules that underlie the operation of the physical universe, not the people within it (however interesting that may be).\u00a0 Then I found another definition that seemed to work better for me:<\/p>\n

Since the nineteenth century the humanities have generally been defined<\/i> as the disciplines that investigate the expressions of the human mind<\/span>.<\/i> [2]<\/a><\/i><\/p>\n

While the painter, photographer, and poet are each trying to capture some aspect of the physical world on canvas, digital media, or paper, I\u2019m trying to capture some element of the universe with mathematical equations.\u00a0 These are all the result of human minds trying to express thoughts and feelings about our world.<\/p>\n

There is, however, a big difference between what I do and what these artists do.\u00a0 As a professional physicist, I am not free to do whatever I want. \u00a0Richard Feynman referred to it as \u201cimagination in a terrible strait-jacket.\u201d[3]<\/a> Since I\u2019m trying to capture some essence of the real universe, the results of my efforts must be consistent with what is already known about the universe.\u00a0 I\u2019m not free to invent new spatial dimensions unless I can devise a way to show they really may exist.\u00a0 One of my hobbies is writing fiction (although I don\u2019t have nearly the time I wish to devote to it).\u00a0 There I\u2019m free to imagine a small town in northern Minnesota where the townspeople must drape the body of a freshly killed victim over an ancient oak tree to ward off an unspeakable horror.\u00a0 But as a physicist, I can\u2019t tell any story I want.\u00a0 I can\u2019t invent some new law of physics unless I can also show that it is consistent with everything we know now and how it can be tested by experiment.\u00a0 If it cannot be readily tested, it is just speculation and is of no interest to me.\u00a0 And if my theory is tested and disagrees with the results of experiment, it is wrong.\u00a0 It doesn\u2019t matter how beautiful and elegant the equations may be, if they fail to describe the world, they must be discarded.\u00a0 In physics, theories must work.<\/p>\n

This may make it seem that science is antithetical to the humanities.\u00a0 Don\u2019t we have our cold, impersonal \u201cscientific method\u201d?\u00a0 In my long experience in science, the only time I hear mention of the \u201cscientific method\u201d is possibly in an introductory physics class or in an oral comprehensive exam when I\u2019m quizzing a humanities major.\u00a0 Like apprentices in any skilled craft, we learn the method through practice.\u00a0 As for being \u201ccold, impersonal,\u201d nothing can be further from the truth.\u00a0 Some recent quotes by Nobel laureate physicist Steven Weinberg accurately describe what we actually do:<\/p>\n

Descartes and Bacon are only two of the philosophers who over the centuries have tried to prescribe rules for scientific research.\u00a0 It never works.\u00a0 We learn how to do science, not by making rules about how to do science, but from the experience of doing science, driven by desire for the pleasure we get when our methods succeed in explaining something.<\/i> [4]<\/a><\/i><\/p>\n

So the world acts on us like a teaching machine, reinforcing our good ideas with moments of satisfaction. After centuries we learn what kinds of understanding are possible, and how to find them.\u00a0 We learn not to worry about purpose, because such worries never lead to the sort of delight we seek.\u00a0 We learn to abandon the search for certainty, because the explanations that make us happy never are certain.\u00a0 We learn to do experiments, not worrying about the artificiality of our arrangements.\u00a0 We develop an aesthetic sense that gives us clues to what theories will work, and that adds to our pleasure when they do work.\u00a0 Our understandings accumulate.\u00a0 It is all unplanned and unpredictable, but it leads to reliable knowledge, and gives us joy along the way.<\/i> [5]<\/a><\/i><\/p>\n

I hope you noticed words that aren\u2019t usually used to describe what scientists do: \u201cpleasure,\u201d \u201csatisfaction,\u201d \u201cdelight,\u201d \u201chappy,\u201d \u201caesthetic,\u201d and \u201cjoy.\u201d\u00a0 I do what I do not just because it (hopefully) provides insight about the world\u2014I also do it because it is fun<\/i>!<\/p>\n

So I\u2019m a theoretical physicist, but what do I actually do?\u00a0 Most folks in academia specialize and so can readily answer the question: What do you do?\u00a0 It is a little harder for me, because I don\u2019t see myself as a particle physicist or a nuclear physicist or a\u2026\u00a0 Rather, I view myself as a general theoretical physicist who is on the lookout for very simple problems that can reveal something new and interesting about our world.\u00a0 Most theorists investigate problems that are vastly more complicated than the ones I study.\u00a0 Fortunately I\u2019ve been lucky to find simple problems that turn out to be very interesting, and I will share one of these with you later.\u00a0 However, before I get to it, we need to take a very brief tour of physics.<\/p>\n

When people learn that I\u2019m a physicist, the usual response is \u201cOh, that\u2019s hard,\u201d or \u201cOh, I failed that class in college,\u201d or simply: \u201cOh\u2026\u201d However, we\u2019re all physicists to some extent since we all need to have some sense of the rules obeyed by our universe.\u00a0 When someone tosses a ball to you, you can probably catch it without difficulty because you\u2019re familiar with how gravity and air resistance affect the motion of objects flying through the air.\u00a0 You know that larger objects are harder to accelerate than smaller ones. You\u2019re familiar with the affects of acceleration as you go around a bend, and know that freeways have wider turns than slower roads since these effects depend on speed.\u00a0 You know that the rate at which time passes is the same for everyone even though at times it may not seem like it.<\/p>\n

The rules governing the objects of our everyday world are called \u201cclassical\u201d and were developed by Galileo, Newton, and others through the 19th<\/sup> century.\u00a0 The classical world has certain features that most of us would consider \u201ccommonsensical\u201d (although they need to be learned by newborn infants).\u00a0 These include:[6]<\/a><\/p>\n