<html><head /> <body> <META http-equiv="Content-Type" content="text/html; charset=UTF-16"><title>Problems of Predicting Physics</title><meta name="keywords" content="physics,future,21st,abilities,ability,astronomy,brahe,century,creative,definition,education,funding,futurology,history,infrared,longair,malcolm,newton,owl,particle,project,physicist,predict,predicting,prediction,research,science,telescope,twenty-first,tycho,"><table style="font-family:Verdana; font-size:larger; " align="center" border="0" width="50%"><tbody><tr> <td style="background-color:silver; border-color:white; border-left-style:none; border-style:none; " width="730"><span style="font-family:Verdana; font-size:larger; ">Problems of Predicting Physics</span></td> </tr> <tr> </tr> </tbody></table><br><table style="font-family:Verdana; font-size:medium; " align="center" bgcolor="white" border="0" width="50%"><tbody><tr> <td height="131" width="669"><p><span style="font-family:Verdana; font-size:x-small;"><strong>Editors Introduction</strong></span> <span style="font-family:Verdana; font-size:x-small; "> </a> Malcolm Longair is sceptical of our ability to predict the future of physics. In this visual article he uses history to suggest that we might not have always been able to predict the future in the past. Longair argues that we should not try to imagine what physicists will do. Rather, we should look at what physicists actually learn and do in order to understand the types of problems they will tackle tomorrow.</span><br> <br> <span style="font-family:Verdana; font-size:x-small; "> It is a great honour to be asked to give this lecture on the future of physics. As you can imagine, faced with a subject like this, one's immediate reaction is that it is a very dangerous thing to do--it is so easy to get it all wrong.</span><br> <br> <span style="font-family:Verdana; font-size:x-small; ">Let me give some examples of what might have appeared in newspapers at the beginning of recent centuries in the modern era. If there were such a thing as The Hven Messenger in 1600, its headlines might have read:</span></p> <p align="center"><br> <span style="font-family:Verdana; font-size:x-small; "><IMG src="1541_Slide2.jpg" id="2020" type="3" align="center" width="360" height="270" url="1541_Slide2.jpg"></span><br> </p> <p><span style="font-family:Verdana; font-size:x-small; ">Nothing's new, of course. There was no political outcry about the closure of Tycho's great observatory at Hven, just as there was none when the Royal Greenwich Observatory was closed a couple of years ago. Within a few years Kepler had used Tycho's magnificent data to discover the Laws of Planetary Motion. The headlines in 1610 might have read:</span></p> <p align="center"><br> <span style="font-family:Verdana; font-size:x-small; "><IMG src="1541_Slide3.jpg" id="2021" type="3" align="center" width="360" height="270" name="" url="1541_Slide3.jpg"></span><br> </p> <p align="left"><br> <span style="font-family:Verdana; font-size:x-small; ">No one would have predicted in 1600 that the astronomical telescope would have been invented within 10 years or that Galileo would have discovered the satellites of Jupiter, a perfect model for the Copernican picture of the solar system.</span></p> <p align="left"><span style="font-family:Verdana; font-size:x-small; ">In 1700, you might have read the following headlines:</span></p> <p align="center"><br> <span style="font-family:Verdana; font-size:x-small; "><IMG src="1541_Slide4.jpg" id="2022" type="3" align="center" width="360" height="270" name="" url="1541_Slide4.jpg"></span><br> <br> </p> <p align="left"><br> <span style="font-family:Verdana; font-size:x-small; ">Newton seems to have argued with everyone. There's a lovely remark by Rizzetti in 1741 which encapsulates the sort of dilemma which occurs not infrequently in experimental and theoretical physics.</span></p> <p align="center"><br> <span style="font-family:Verdana; font-size:x-small; "><IMG src="1541_Slide5.jpg" id="2023" type="3" align="center" width="360" height="270" name="" url="1541_Slide5.jpg"></span><br> </p> <p align="left"><br> <span style="font-family:Verdana; font-size:x-small; ">I invite you to select your own favourite modern analogy.</span><br> <br> <span style="font-family:Verdana; font-size:x-small; ">In 1800, we might have seen headlines like these:</span></p> <p align="center"><br> <span style="font-family:Verdana; font-size:x-small; "><IMG src="1541_Slide6.jpg" id="2024" type="3" align="center" width="360" height="270" name="" url="1541_Slide6.jpg"></span></p> <p align="left"><span style="font-family:Verdana; font-size:x-small; ">In physics, they might have read:</span></p> <p align="center"><br> <span style="font-family:Verdana; font-size:x-small; "><IMG src="1541_Slide7.jpg" id="2025" type="3" align="center" width="360" height="270" name="" url="1541_Slide7.jpg"></span></p> <p align="left"><br> <span style="font-family:Verdana; font-size:x-small; ">There might have been a bit of concern from the animal-rights movement about what had happened to those poor frogs in Galvani's experiments!</span><br> <br> <span style="font-family:Verdana; font-size:x-small; ">As a final example, in 1900 we might have read:</span></p> <p align="center"><br> <span style="font-family:Verdana; font-size:x-small; "><IMG src="1541_Slide8.jpg" id="2026" type="3" align="center" width="360" height="270" name="" url="1541_Slide8.jpg"></span></p> <p><span style="font-family:Verdana; font-size:x-small; ">Within the first three decades of the twentieth century, relativity and quantum mechanics were discovered and these completely changed our understanding of the foundations of physics.</span><br> <br> <span style="font-family:Verdana; font-size:x-small; ">The message I want to get across is that there are great perils in predicting what will happen scientifically in the twenty-first century. On the other hand, what all these examples show is that, when we discover new ways of doing physics--increasing the angular and spectral resolution of our experiments and their sensitivity, opening up new regions of parameter space, increasing the size of the data sets, finding new applications of concepts in physics--we always discover new things which are built into the infrastructure of what we call physics. The other thing to note is the importance of being aware of advances in cognate sciences and capitalising upon them.</span><br> <br> <span style="font-family:Verdana; font-size:x-small; ">Let me give you my two credos about physics. When students come up to Cambridge to read physics, the first thing I give them is my definition of physics: "Physics is what physicists do." In my view, this is the only really satisfactory definition of what physics is about.</span></p> <p> <a href="1541_introbig.html" target="_browser"><a href="1541_introbig.html" target="_browser"><img src="1541_intro2.gif" align="right" border="0" vspace="0"> </a><span style="font-family:Verdana; font-size:x-small; ">The corollary of that is credo number two: "Physics is extensive." In other words, it keeps expanding its boundaries, bringing other disciplines and insights within its remit. For example, Watson and Crick discovered the double helix structure of the DNA molecule when they were members of the X-ray Crystallography Group in the Cavendish Laboratory. This great discovery led immediately to the new discipline of molecular biology, which was spun off as a completely separate discipline. I still think of what they do at the MRC Laboratory for Molecular Biology as splendid physics.</span><br> <br> <span style="font-family:Verdana; font-size:x-small; ">Let me describe the traditional school and university view of what physics is about. Here are the subjects which are taught in our core physics course at Cambridge. We are lucky in being able to concentrate solidly upon this core in the first three years. It is not so different from the split of subjects which were reviewed this month by the International Review Panel for Physics, charged with reviewing the health and standing of UK physics on an international basis:</span></p> <p align="center"><br> <span style="font-family:Verdana; font-size:x-small; "><IMG src="1541_Slide13.jpg" id="2017" type="3" align="center" width="360" height="270" name="" url="1541_Slide13.jpg"></span><br> <br> <br> </p> <p align="left"><span style="font-family:Verdana; font-size:x-small; ">In their first three years, we hope the students will be able to assimilate all the topics in this list:</span></p> <p align="center"><br> <span style="font-family:Verdana; font-size:x-small; "><IMG src="1541_Slide14.jpg" id="2019" type="3" align="center" width="360" height="270" name="" url="1541_Slide14.jpg"></span><br> <br> <br> </p> <p align="left"><span style="font-family:Verdana; font-size:x-small; ">It all looks pretty conventional. If you look at what we're actually doing as research scientists, however, it all looks very different. The research programmes are very different from what we teach in our undergraduate physics courses, but the important point is that you cannot actually do any of the advanced research topics unless you are on top of a very large amount of this crucial core material.</span><br> <br> <span style="font-family:Verdana; font-size:x-small; ">I feel very passionately about this. We have got to concentrate upon teaching the core syllabus in physics, because it provides us with the essential tools with which to do extensively all the wonderful things that physicists can and will do.</span><br> <br> <span style="font-family:Verdana; font-size:x-small; font-style:italic; ">This story is taken from a lecture on the future of physics given by Malcolm Longair at the London School of Economic and Political Science on May 15, 2000. Copyright The London School of Economics and Political Science.</span></p> </td> </tr> </tbody></table> </body></html>