Friday, December 28, 2007

Top Ten Biological Physics Books

Each year at this time, we are bombarded by top ten lists, such as "Top Ten News Stories of 2007" or "Top Ten Movies of the Year". Russ Hobbie and I cite many excellent books in the 4th Edition of Intermediate Physics for Medicine and Biology. Below I list ten of my favorites. Other good books are cited in the Nov 23 entry of my blog.

Random Walks in Biology Howard Berg, 1983, Princeton University Press. This book is simply the best introduction to the role that diffusion plays in biology.

Air and Water Mark Denny, 1993, Princeton University Press. A wonderful book that covers some of the same topics we discuss in our first 10 chapters. It approaches the material from the point of view of a physiologist with some knowledge of physics, compared to our approach as physicists with some knowledge of physiology.

Machines in Our Hearts: The Cardiac Pacemaker, the Implantable Defibrillator, and American Health Care Kirk Jeffrey, 2001, Johns Hopkins University Press. More of a history book than an engineering book, it tells the fascinating story of how pacemakers and defibrillators were developed.

Electric Fields of the Brain: The Neurophysics of EEG Paul Nunez and Ramesh Srinivasan, 2005, Oxford University Press. The electroencephalogram from a physicists point of view.

Electricity and Magnetism, Vol. II Edward Purcell, 1985, Berkeley Physics Course, Vol. 2, McGraw Hill. Other E&M books may be more comprehensive (for example Griffiths or Jackson), but when I'm looking for insight I go to Purcell.

Statistical Physics Frederick Reif, 1964, Berkeley Physics Course, Vol. 5, McGraw Hill. I admire Reif's statistical approach to thermodynamics. Much of Chapter 3 in our book follows the same path as Reif. It is a great choice for those looking for an introduction to statistical mechanics.

Div, Grad, Curl, and All That: An Informal Text on Vector Calculus, Fourth Edition H. M. Schey, 2005, Norton. A gentle introduction to vector calculus. Much more intuitive than other math books I know of.

Scaling: Why is Animal Size so Important? Knut Schmidt-Nielsen, 1984, Cambridge University Press. A delightful discussion of how physics and physiology conspire to constrain how large animals can become. See also his book How Animals Work.

Life in Moving Fluids Steven Vogel, 1992, Oxford University Press. One of the best introductions to biological fluid dynamics that I know. Vogel has many other fascinating books, including Vital Circuits about the circulatory system.

When Time Breaks Down Arthur Winfree, 1987, Princeton University Press. A book that had a huge influence on my own research on the electrical behavior of the heart. See also his book The Geometry of Biological Time, especially the second edition that contains updated information on cardiac electrophysiology.

Friday, December 21, 2007

Should the Premed Requirements in Physics be Changed?

Nearly 30 years ago, Abraham Liboff and Michael Chopp--both faculty members at Oakland University--published an article in the American Journal of Physics titled "Should the Premed Requirements in Physics be Changed?" (Am. J. Phys., 47:331-336, 1979). Their conclusions are still relevant today, and eloquently confirm the purpose of Intermediate Physics for Medicine and Biology. Abe and Mike concluded:

"The reasons usually given for including the physics component in the premedical curriculum include its importance in a liberal arts education, and the use of physics grades as a screening yardstick for admissions committees. However, educators have ignored the wide range of applications of physics to medicine in diverse areas such as physiology, problem solving, quantitation, diagnostic techniques, etc.

Most premeds take physics too late in their undergraduate program to accommodate physics electives. In medical school there is no tradition of specialized physics, as occurs in chemistry and biology. The net result is that medical students are disadvantaged in physics, unable to cope with advances in technology requiring a stronger base than the usual ten hours of undergraduate physics.

The new MCAT examination perhaps signals a change in thinking by the medical community, in that the test goes for towards recognizing the essential role that physics plays in modern medicine. Not only is knowledge of each of the sciences required, but, equally important, problem-solving and quantitative skills are tested, reflecting the sort of techniques emphasized in physics.

To directly address the question of the poor undergraduate physics preparation of future physicians and other health care professionals, we suggest that at least one, and probably, two, semesters of additional physics be added to all premedical programs. This added work should be specialized material in the physics of medicine and should require both a year of calculus and a year of introductory physics as prerequisites."

Friday, December 14, 2007

Technetium Shortage

The shutdown of a nuclear reactor at Chalk River, Ontario has caused a shortage of an isotope of technetium (Tc-99m) used for medical imaging (see the New York Times article for details). What is technetium, and how is it produced? The following is a quote from the 4th edition of Intermediate Physics for Medicine and Biology (page 497):

"The most widely used isotope [for medical imaging] is Tc-99m. As its name suggests, it does not occur naturally on earth, since it has no stable isotopes. We consider it in some detail to show how an isotope is actually used....The isotope is produced in the hospital from the decay of its parent, Mo-99 [molybdenum], which is a fission product of U-235 and can be separated from about 75 other fission products. The Mo-99 decays to Tc-99m.

Technetium is made available to hospitals through a 'generator' that was developed at Brookhaven National Laboratories in 1957 and is easily shipped. Isotope Mo-99, which has a half-life of 67 h, is adsorbed on an alumina substrate....As the Mo-99 decays, it becomes pertechnetate (TcO4-). Sterile isotonic eluting solution is introduced under pressure above the alumina and passes through after filtration into an evacuated eluate container. After removal of the technetium, the continued decay of Mo-99 causes the Tc-99m concentration to build up again. A generator lasts about a week."

Friday, December 7, 2007

Is Computed Tomography Safe?

Drs. David Brenner and Eric Hall recently warned that the increased popularity of CT scans, particularly in children, can lead to an increased incidence of cancer ("Computed Tomography – An Increasing Source of Radiation Exposure," New England Journal of Medicine, 357:2277-2284, 2007). Widespread awareness of this research may lead to the avoidance of unnecessary CT examinations. (This conclusion remains controversial, see statements by the American Association of Physicists in Medicine and the Radiological Society of North America.) Brenner and Hall's earlier work on this issue is discussed in the 4th edition of Intermediate Physics for Medicine and Biology (page 472).

Friday, November 30, 2007

What Should Every Biological Physicist Know?

Is there a common core of knowledge that every Medical or Biological physicist should know? Oakland University has a Medical Physics PhD program, and we define our knowledge core through our PhD qualifying exam. Students take three exams in Theoretical Physics, Mathematical Methods, and Biophysical Sciences (or, more succinctly, Physics, Math, and Biology). If you would like to see what sort of questions we ask on this exam, go to, where you can download copies of all exams for at least the last decade. If you look closely, you will find questions from Intermediate Physics for Medicine and Biology every year.

Friday, November 23, 2007

A "Citation Index" for Intermediate Physics for Medicine and Biology

Who does Intermediate Physics for Medicine and Biology cite most? I went through the index of our book and tallied the number of entries for various scientists. (Disclaimer: this is the number of pages listed in the index, which is not necessarily the same as the number of times cited.) Most are authors of leading textbooks. Here is a list of scientists who Russ Hobbie and I cite a dozen times or more:

16 Robert Plonsey: Emeritus Professor of Biomedical Engineering at Duke University and author of several textbooks including the classic "Bioelectric Phenomena"

16 William Press: first author of my favorite book on numerical methods, "Numerical Recipes". His unfortunate coauthors didn't make the list because we usually cited the book as "Press et al."

16 Robert Resnick: Prolific textbook coauthor, including the excellent "Quantum Physics of Atoms, Molecules, Solids, Nuclei, and Particles"

15 Mark Denny: Author of the delightful book "Air and Water".

14 Leon Glass: Leading researcher at McGill University studying nonlinear dynamics as applied to biology and medicine. Coauthor of the influential book "From Clocks to Chaos".

13 Jose Jalife: Leading researcher in cardiac electrophysiology at the Upstate University of New York, and co-editor of the often-cited book "Cardiac Electrophysiology: From Cell to Bedside".

13 Brad Roth: Humble, I'm not.

13 John Wikswo: Physics Professor at Vanderbilt University known for his research in biomagnetism and electrophysiology.

12 Frank Attix: Author of the textbook "Introduction to Radiological Physics and Radiation Dosimetry", a standard for medical physics.

12 Arthur Guyton (1919-2003): Author of the much-cited book "Textbook of Medical Physiology" (with coauthor Hall in recent editions).

Friday, November 16, 2007

Weight Control

How do we add material to each edition without making Intermediate Physics for Medicine and Biology a lot larger? Answer: The web. We no longer need the tables that occupied many pages in the Appendices of earlier editions. You can now find all that data online, for instance at ab2.html. Also, we deleted sections of previous editions that we did not feel were essential. Deleted text -- some dating back to the first edition -- is available on the book web site

For the curious, the 1st (1978) edition had 557 pages and the 2nd (1988) edition had 623 pages. After the 2nd edition the page size became larger making comparisons difficult. The 3rd (1997) edition had 575 pages and the 4th (2007) edition has 616 pages. Like many Americans our weight is creeping up, but we fight a constant battle to keep the book from becoming super-sized.

Friday, November 9, 2007

A Bridge Between Biologists and Physicists

Peter Kahn reviewed the third edition of Intermediate Physics for Medicine and Biology in the American Journal of Physics (vol. 67, pp. 457-458, 1999). Kahn wrote

"Hobbie's book presents a wealth of material. Clearly the target audience is physics students interested in biological processes, although biology students with strong backgrounds in physics and mathematics will benefit greatly from reading the book. It will prove useful as a text for those wishing to help advanced physics undergraduates and graduate students appreciate the important role that physics plays in understanding biology. It will be of value to biologists, physiologists, and neurobiologists as a reference. And, maybe, it will be a bridge over which biologists and physicists can initiate and maintain a dialogue."

Friday, November 2, 2007

Page Proofs

This week is a major anniversary for the fourth edition of Intermediate Physics for Medicine and Biology. One year ago this Tuesday, the page proofs arrived. Russ Hobbie and I painstakingly checked 632 pages of text, figures, tables, and equations, equations, equations (I estimate about 2000 of them). The job took over our lives for two weeks, but we finished before Thanksgiving, bringing to an end the process of preparing the 4th edition that had begun five years earlier.

Friday, October 26, 2007

I Heartily Recommend This Book

In the Jan/Feb 1999 issue of the IEEE Engineering in Medicine and Biology Magazine, Cynthia Paschal reviewed the third edition of Intermediate Physics for Medicine and Biology. She wrote "This third edition of Hobbie’s fine text incorporates the best of the previous editions with some new topics and examples. As before, every chapter includes numerous figures, graphs, tables, and logically developed equations....I heartily recommend this book as the sole text for a year-long intermediate undergraduate course in biophysics. The text is also useful for an introductory biophysics graduate course."

Friday, October 19, 2007

The Nobel Prize

Last week the 2007 Nobel Prize winners were announced. Congratulations to these distinguished scientists. In the 4th edition of Intermediate Physics for Medicine and Biology, Russ Hobbie and I discuss many Nobel Laureates and their research:

1) Felix Bloch and Edward Purcell shared the 1952 Nobel Prize in Physics for their discovery of nuclear magnetic resonance (p. 519).

2) Alan Hodgkin and Andrew Huxley won the Nobel Prize in Physiology or Medicine in 1963 for their research on nerve action potentials (p. 154).

3) The Nobel Prize in Physiology or Medicine was shared in 1979 by a physicist, Allan Cormack, and an engineer, Godfrey Hounsfield, for the development of computed tomography (p. 455).

4) Erwin Neher and Bert Sakmann received the Nobel Prize in Physiology or Medicine in 1991 for the invention of the patch clamp technique for studying ion channels (p. 238).

5) For his work elucidating the structure of potassium channels (p. 240), Roderick MacKinnon shared the 2003 Nobel Prize in Chemistry with Peter Agre.

6) Paul Lauterbur shared with Sir Peter Mansfield the 2003 Nobel Prize in Physiology or Medicine for the development of magnetic resonance imaging (p. 527).

Medical and biological physics is truly interdisciplinary: it involves Nobel Prize-winning work in physics, chemistry, and physiology and medicine.

Friday, October 12, 2007

Distances and Sizes

One of the things Russ Hobbie and I added to the 4th edition of Intermediate Physics for Medicine and Biology is an introductory section about distances and sizes in Chapter 1 (pp. 1-3). Our goal is to introduce the relative sizes of different biological objects (cells, bacteria, viruses, etc.). We try to provide something similar to what you would find in Morrison's book "Powers of Ten" or in Goodsell's book "The Machinery of Life". The section also serves as a nice way to introduce many of the topics developed in more detail later in the book, and allows students to practice the valuable skill of making back-of-the-envelope estimates, such as estimating the number of hemoglobin molecules in one red blood cell. We hope you like it.

Friday, October 5, 2007

Medical Physics: The Perfect Intermediate Level Physics Class

In 2001, Nelson Christensen of Carleton College published an article in the European Journal of Physics (vol. 22, pp. 421-427) titled "Medical Physics: the Perfect Intermediate Level Physics Class." The primary textbook for his class was the 3rd Edition of Intermediate Physics for Medicine and Biology. Below is the conclusion to his paper:

"A medical physics course should be looked upon as a beneficial addition to the undergraduate physics curriculum. The course should be considered as an ideal addition to the intermediate level physics curriculum, as it covers almost all of the major subjects that physics undergraduates should see. Students are often bored by lack of direct applications or good examples when covering physics subjects. In our class we talked about physics within the context of medical applications. For every physical topic there was a medical application; students loved it.

The interdisciplinary nature of a course like medical physics offers other advantages. A course like this provides an opportunity for keen pre-medical students to return to physics. A number of the pre-meds are genuinely interested in physics, but lack a good opportunity or reason to take an upper-level physics course. The differing backgrounds of the physics and pre- medical students presented an additional benefit in that a fantastic environment for stimulating discussions was created. The students would share with one-another their expertise.

Finally, there can be no denying that medical physics and biomedical engineering are evolving at a breakneck pace. There are opportunities available in abundance in these fields. Students are interested in medical physics for a number of reasons. There are equally good reasons for the faculty to provide a course in medical physics. This is exciting physics and exciting science!"

Friday, September 28, 2007

Teaching from Intemediate Physics for Medicine and Biology

How can you structure a class using the 4th edition of Intermediate Physics for Medicine and Biology? At Oakland University, we offer two classes--"Biological Physics" and "Medical Physics"--as part of our undergraduate medical physics major. Biological Physics covers the first 10 chapters of the book, and Medical Physics covers the last 8 chapters. Below is the information about these classes in our undergraduate catalog (Note: PHY 102 and 152 are the second semesters of the non-calculus and calculus based introductory physics classes, and MTH 155 is the second semester of introductory calculus):

PHY 325 Biological Physics (4 credits)
Applications of physics to biology, including biomechanics, fluid dynamics, statistical mechanics, diffusion, bioelectricity, biomagnetism, feedback and control.
Prerequisite: PHY 102 or 152, and MTH 155

PHY 326 Medical Physics (4 credits)
Applications of physics to medicine, including signal analysis, imaging, x-rays, nuclear medicine and magnetic resonance imaging.
Prerequisite: PHY 102 or 152, and MTH 155

Friday, September 21, 2007

"The Making of the Book" Story

Nowadays, when a movie comes out on DVD it often includes extras such as "the making of the movie" story. If you want to see "the making of the book" story, go to the American Physical Society, Division of Biological Physics Newsletter website and download the December 2006 Newsletter. It contains an extended interview with Russ Hobbie, in which he describes how he came to write Intermediate Physics for Medicine and Biology.

Friday, September 14, 2007

The Errata

We found an error in the 4th edition of Intermediate Physics for Medicine and Biology this week. Actually, it was Hugo Vrenken of the VU University Medical Center in Amsterdam who found a typo on page 539 in Problem 19 of Chapter 18: an equation has an extra factor of 4 in the denominator. Russ and I tried to ferret out all the mistakes in the book before publication, but inevitably we missed a few. If you are reading the book, you can find the not-yet-too-long list of known errors (the errata) at the book's website: . Although we really hate to find mistakes in our book, Russ and I are committed to letting our readers know about any that do exist. Please help us by contacting me if you find any mistakes. Thanks!

Friday, September 7, 2007

If you think about it, there are few books that cover this subject

Peter Kahn reviewed the third edition of Intermediate Physics for Medicine and Biology in the American Journal of Physics (vol. 67, pp. 457-458, 1999). Kahn wrote "If you think about it, there are few books that cover this subject. This reflects on the one hand the rigidity of the Physics curriculum, and on the other hand the fact [that] biologists are inadequately prepared to apply physics to the problems they encounter."

Friday, August 31, 2007


From the Preface to the Third Edition of Intermediate Physics for Medicine and Biology, Russell Hobbie wrote:

"Between 1971 and 1973 I audited all the courses medical students take in their first two years at the University of Minnesota. I was amazed at the amount of physics I found in these courses and how little of it is discussed in the general physics course. I found a great discrepancy between the physics in some of the papers in the biological research literature and what I knew to be the level of understanding of most biology majors or premed students who have taken a year of physics. It was clear that an intermediate-level physics course would help these students. It would provide the physics they need and would relate it directly to the biological problems where it is useful. This book is the result..."

Thursday, August 23, 2007

A Good Way to Become a Medical Physicist

John Wikswo wrote a review in Physics Today of the 2nd Edition of Intermediate Physics for Medicine and Biology (Physics Today, vol. 42, 75-76, Jan 1989). He concluded with "A good way to become a medical physicist or biophysicist is to master everything in Hobbie's Intermediate Physics for Medicine and Biology."

Tuesday, August 21, 2007

Intermediate Physics for Medicine and Biology

In 1978, Russell Hobbie wrote the first edition of "Intermediate Physics for Medicine and Biology". It became a classic in the field, and I used it as a textbook when I was a graduate student. A few years ago, Russ was getting ready to prepare the 4th edition of his book, and he asked me to be a co-author. What an honor. We had a great time working on the book, and I think you will like the results. We added a new chapter on ultrasound, and increased the number of homework problems significantly.

You can find the website for the book at

In the preface of our book, we write "We would appreciate receiving any corrections or suggestions for improving the book". Let me reiterate this. If you find any mistakes, please let us know.

Thanks for your interest in our book. Contact Russ or me if you have any questions.