Showing posts with label personal favorites. Show all posts
Showing posts with label personal favorites. Show all posts

Friday, May 6, 2022

Are Electromagnetic Fields Making Me Ill? How Electricity and Magnetism Affect Our Health

Are Electromagnetic Fields Making Me Ill? by Brad Roth superimposed on Intermediate Physics for Medicine and Biology.
Are Electromagnetic Fields Making Me Ill?
How Electricity and Magnetism Affect Our Health
,
by Brad Roth
Big News! This week Springer published my new book: Are Electromagnetic Fields Making Me Ill? How Electricity and Magnetism Affect Our Health. This book is different from Intermediate Physics for Medicine and Biology: it’s short (122 pages), uses no math, and is aimed at a general audience. Readers of this blog may find parts of the book familiar; over the last couple years I’ve written posts that served as first drafts of some sections. Below is an excerpt from the Introduction.
This book is about electric and magnetic fields, and their effect on your body. We will examine the use of magnets for pain relief, the risk of power line magnetic fields, the safety of cell phones, and the possibility that microwave weapons are responsible for the Havana syndrome. Many medical treatments are based on electromagnetism, including well established ones like heart pacemakers and neural prostheses, and more questionable ones such as bone healing, transcutaneous electrical nerve stimulation, and transcranial direct current stimulation. Innumerable books and articles have been written about each of these topics; my goal in this book is to examine them together, to get the big picture.

This book is not a research monograph. It presents no original discoveries and makes no attempt to be comprehensive. Moreover, it omits numerous details and technicalities that experts often argue about. It does, however, try to offer an overall view of the field that is accurate.

My target readers are nonscientists: journalists, politicians, teachers, students, and anyone who has heard about electric and magnetic fields interacting with biological tissue and wants to learn more. I use no mathematics, avoid jargon, and employ abbreviations only when repeating the same mouthful of words over and over again becomes tedious. I tried my best to make the book understandable to a wide audience….

Sometimes the effect of electric and magnetic fields is controversial. For any debate, I have tried to present both sides. Nevertheless, readers will soon catch on that I’m a skeptic. Each chapter title is a question, of which my answer is usually “probably not” or “no.”
Here is the Table of Contents.
  1. Introduction 
  2. Can Magnets Cure All Your Ills? 
  3. Can a 9-Volt Battery Make You Smarter? 
  4. Do Power Lines Cause Cancer? 
  5. Will Electrical Stimulation Help Your Aching Back? 
  6. Is Your Cell Phone Killing You? 
  7. Did 5G Cell Phone Radiation Cause Covid-19? 
  8. Did Cuba Attack America with Microwaves? 
  9. Is That Airport Security Scanner Dangerous? 
  10. Conclusion

Although Russ Hobbie is not a coauthor on my new book, readers familiar with IPMB will see his influence on each page. In one of our last email exchanges before he passed away, I sent Russ an early draft of the book and he claimed to love it (that may have been Russ being kind, as he always was).

Enjoy!

Listen to me read the final chapter of Are Electromagnetic Fields Making Me Ill?

https://www.youtube.com/watch?v=5jJLkBsU4V0

Friday, July 2, 2021

Alan Magee and the St. Nazaire Railroad Station

Airman Alan Magee, a ball turret gunner for a B-17.
Alan Magee. Reproduced from the
website www.americanairmuseum.com.

On January 3, 1943, airman Alan Magee fell 22,000 feet (6700 meters, or about 4 miles) without a parachute from a damaged B-17 Flying Fortress and survived. How’d he do it?

Let’s examine Magee’s fall using elementary physics. Homework Problem 29 in Chapter 2 of Intermediate Physics for Medicine and Biology explains how someone falling through the air reaches a steady-state, or terminal, speed. A typical terminal speed, v, when skydiving is about 50 m/s. This may be a little slower than average, but v decreases with mass and ball turret gunners like Magee were usually small. Skydivers will reach their terminal speed after about 20 seconds. Magee fell for much longer than that, so starting four miles up didn’t matter. He could have begun forty miles up and his terminal speed would have been the same (presumably he would have suffocated, but that’s another story).

When falling, what kills you is the sudden deceleration when you hit the ground. Suppose you’re traveling at v = 50 m/s and you hit a hard surface like cement. You come to a stop over a distance, h, of a few centimeters (a person isn’t rigid, so there would be some distance that corresponds to the body splatting). Let’s estimate 10 cm, or h = 0.1 m. If the acceleration, a, is uniform, we can use an equation from kinematics to calculate a from v and h: a = v2/(2h) = 502/0.2 = 12,500 m/s2. This is about 1250g, where g is the acceleration of gravity (approximately 10 m/s2).

How much acceleration can a person survive? It’s hard to say. Some roller coasters can accelerate at up to 3g and you feel a thrill. Astronauts in the Mercury space program experienced about 10g during reentry and they survived. Flight surgeon John Stapp withstood 46g on a rocket sled, but that is probably near the maximum. Clearly 1250g is well over the threshold of survivability. You would die.

So, how did Magee survive? He didn’t hit cement. Instead, he crashed through the glass ceiling of the St. Nazaire railroad station. Most sources I’ve read claim that shattering the glass helped break his fall. Maybe, but I have another idea. Some of the articles I’ve examined have German soldiers finding Magee alive on the station floor, but others say he was found tangled in steel girders. Below is a picture of the railroad station as it looked during World War II

The St. Nazaire Railroad Station; the site where Alan Magee landed after falling 22,000 feet. The Glass Ceiling and supporting steel cables and ties are shown.
The Railroad Station in St. Nazaire, France. Modified from a photo posted by @ron_eisele on Twitter.
 

Notice the structures below the glass ceiling. I wouldn’t call them girders or struts. To me they look like a web of steel cables or ties. My hypothesis is that this web functioned as a net. Suppose Magee landed on one of the ties and it deflected downward, perhaps dragging part of the ceiling with it, or pulling down other ties, or breaking at one end, or stretching like a bungee cord. All this pulling and breaking and stretching would reduce his deceleration. Let’s guess that he came to rest about three meters below where he first hit a tie. Now his acceleration (assuming it’s uniform) is a = 502/6 = 417 m/s2, or about 42g. That’s a big deceleration, but it may be survivable. You would expect him to be hurt, and he was; he suffered from several broken bones, damage to a lung and kidney, and a nearly severed arm.

If my hypothesis is correct, the shattering of glass had little or nothing to do with breaking Magee’s fall. I’m sure it made a loud noise, and must have given the accident a dramatic flair, but the glass ceiling may have been irrelevant to his survival.

I don’t think we can ever know for sure why Magee didn’t die, short of building a replica of the train station, dropping corpses (or, more hygienically, crash dummies) through the roof, and video recording their fall. Still, it’s fun to speculate.

After the crash, what happened to Magee? He was captured, became a prisoner of war, and was treated for his injuries. In May 1945 the war in Europe ended and he was freed. He returned to the United States and lived another 58 years. He was awarded the Air Medal and a well-earned Purple Heart. Alan Magee's survival represents a fascinating example of physics applied to medicine and biology.

Triumph of Victory. A reenactment of Alan Magees fall.
Don’t expect much dialogue.

Tuesday, May 12, 2020

Beethoven

The first movement of the Moonlight Sonata,   Sonata No. 14 in C♯ minor, Opus 27 No. 2,  by Ludwig van Beethoven, superimposed on Intermediate Physcs for Medicine and Biology.
The first movement of the Moonlight Sonata,
 Sonata No. 14 in C♯ minor, Opus 27 No. 2,
by Ludwig van Beethoven. Jonathan Biss
despises the name “Moonlight Sonata,”
a title not given by Beethoven.
This year we celebrate an important anniversary: 250 years since the birth of Ludwig van Beethoven, one of the world’s greatest composers. Beethoven (1770–1827) was a bridge between the classical era of Haydn and Mozart, and the romantic era of Schubert and Brahms. I know you’ve all heard the opening motif from his Fifth Symphony.

Recently, while stuck at home because of the coronavirus, I enrolled in “Exploring Beethoven’s Piano Sonatas” through Coursera. This class is taught by pianist Jonathan Biss. You can enroll free of charge and, as the old joke goes, it’s worth every penny. No, seriously, the course is outstanding; Biss gives a masterclass on how to appreciate Beethoven’s music and how to teach online (something many of us had to learn quickly when covid-19 shut down in-person classes in March). Biss’s analysis of the Appassionata (Piano Sonata No. 23 in F minor, Opus 57) is particularly memorable.

Beethoven slowly lost his hearing as he grew older, and composed many of his later works (including his masterpiece the Ninth Symphony) when he was deaf. I wonder if he would have benefited from a cochlear implant? Russ Hobbie and I mention such auditory prostheses briefly in Chapter 13 of Intermediate Physics for Medicine and Biology.
The cochlear implant… [is] a way to use functional electrical stimulation to partially restore hearing. A row of electrodes is inserted along the cochlea to stimulate the nerves that are usually excited by the hair cells. Some pitch perception can be restored by performing a Fourier analysis of a sound and stimulating neurons at different places along the cochlea.
The adagio from Sonata Pathetique,  Sonata No. 8 in C minor, Opus 13,  by Ludwig van Beethoven, superimposed on Intermediate Physics for Medicine and Biology.
The adagio from Sonata Pathétique,
Sonata No. 8 in C minor, Opus 13,
by Ludwig van Beethoven.
The date of Feb. 10, 1975 written at the top
was probably when my sister studied it,
as I don't remember playing it in high school.
Whether or not Beethoven would have been helped by such a device depends on why he went deaf. If he lost hair cells in the organ of Conti but had a healthy auditory nerve, then a cochlear implant would have been beneficial. If the auditory nerve itself was the problem, an implant would have been of no use. I don’t know what caused Beethoven’s deafness, and I’m not sure anyone does.

Beethoven’s later years were lonely, and an auditory prosthesis might have let him interact more with people. However—and with all due respect to the heroic scientists and engineers who design and build cochlear implants—he probably would have been disappointed (no, horrified) when listening to music. For a virtuoso like Beethoven, I suspect he would rather hear the music in the privacy of his own thoughts than listen through an imperfect device. If only the cochlear implant had been invented 200 years earlier, Beethoven could have decided for himself.

To learn more about auditory transduction watch this excellent video,
which includes music from Beethoven
’s the Ninth Symphony.

Jonathan Biss discusses playing Beethoven's sonatas.
He
s recording all 32.

What does Jonathan Biss do when quarantined because of the coronavirus?
He gives us a message of hope inspired by Beethoven
s struggles.

Friday, November 8, 2019

A Town Hall About The Health Risks of 5G Cell Phone Technology

A photograph of the 5G Town Hall  Rochester, Michigan  November 7, 2019.
5G Town Hall
Rochester, Michigan
November 7, 2019.
Yesterday I participated in a town hall meeting in Rochester, Michigan to discuss the new 5G cell phone technology. I was invited to attend in part because of my contributions to the book Intermediate Physics for Medicine and Biology, which discusses the health risks of electromagnetic fields.

When preparing for the event, I created a list of frequently asked questions (well, these were the questions I thought people would ask). Not wanting to waste this effort, I reproduce my FAQ below.

The event was....interesting. I was impressed by the passion of these concerned citizens, who packed a large room on a cold Thursday evening and for over two hours asked questions and voiced their opinions (mostly voiced their opinions). I’ve taught plenty of apathetic 20-something-year-olds who don’t engage with the lecture or challenge what I say, so I found this feisty crowd refreshing. Unfortunately, I was not convinced by their claims of dire health effects from 5G technology, and they were not convinced by me. The most disturbing moment was when I said something along the lines of “if you want to know more about the risks of cancer, consult the National Cancer Institute” and the response was a chorus of “No, No, No!” Goodness, if we can’t trust the National Cancer Institute to understand cancer, who can we trust? But no one threw a tomato at me, so I’ll call the evening a success. The FAQ below summarizes my view on this matter.

FAQ: 5G Cell Phone Health Effects

What is 5G?

5G is the fifth generation of technology for cell phones. It uses higher frequencies of electromagnetic radiation than 4G technology (up to 300 GHz, with a wave length of 1 mm).


What does IPMB say about the health risks from cell phones?

Section 9.10.5 of Intermediate Physics for Medicine and Biology addresses possible health risks from microwaves, mobile phones, and wi-fi. Russ Hobbie and I cite a 2005 review by John Moulder, Ken Foster, and their colleagues, which concludes that “Overall, a weight-of-evidence evaluation shows that the current evidence for a causal association between cancer and exposure to RF [radiofrequency] energy is weak and unconvincing.” We also cite “an exhaustive (390 page) report…by the International Committee on Non-Ionizing Radiation Protection (Vecchia et al. 2009)” that reaches a similar conclusion. Next we write that “Sheppard et al. (2008) evaluated all the proposed mechanisms for radio-frequency interactions with biological molecules and processes…[and conclude that] the principal mechanism for biological effects, and the only well-established mechanism, is the heating of tissues.” Finally, “Foster and Moulder (2013) reviewed the current state of research [on the health effects of wi-fi, and conclude that the evidence provides] ‘no basis to anticipate any biological effects.’”

The 2013 review by Foster and Moulder summarizes my opinion on this topic.
“Impossibility” arguments are difficult to sustain in biology; but the lack of a generally-accepted mechanism by which low-level (below ICNIRP and IEEE limits) RF fields in the GHz frequency range could produce biological effects, after many years of sustained efforts to uncover such mechanisms, makes it increasingly unlikely that any mechanism will be found.

What have Foster and Moulder said lately about health risks from wi-fi?

Ken Foster and John Moulder are experts on the interaction of electromagnetic radiation with the body. They are skeptical about many claims of health risks caused by power-line, cell-phone, and wi-fi radiation. Both are now emeritus professors; Foster at the University of Pennsylvania and Moulder at the University of Wisconsin. Intermediate Physics for Medicine and Biology cites Foster and Moulder several times, but the 5th edition of IPMB was published in 2015. What have they said lately?

Foster published a post two months ago in a Scientific American blog looking specifically at 5G technology and health risks. His conclusion: “So far, at least, there’s little evidence of danger.”

The most interesting development is a critique of Foster and Moulder’s 2013 review by Martin Pall, an emeritus professor at Washington State University. He concludes that “there are seven repeatedly found Wi-Fi effects which have also been shown to be caused by other similar EMF [electromagnetic field] exposures. Each of the seven should be considered, therefore, as established effects of Wi-Fi.” Pall’s central hypothesis is that cell phone radiation affects calcium ion channels, which if true could trigger a cascade of biological effects. In a rebuttal, Foster and Moulder (2018) write
Pall (2018) criticizes our 5-year-old review of studies related to Wi-Fi and health (Foster and Moulder 2013). We respond to his critique, and also note weaknesses in his selection and interpretation of studies on biological and health effects of Wi-Fi type signals...

Having examined the additional papers that Pall cites, we reaffirm our earlier conclusion: a number of studies have reported bioeffects of Wi-Fi exposures, but technical limitations make many of them difficult to interpret and artifacts cannot be excluded. We are not aware of any health-agency warnings about health risks of Wi-Fi technology. Despite some level of public controversy and an ongoing stream of reports of highly variable quality of biological effects of RF energy (e.g. articles in a recent special issue of the Journal of Chemical Neuroanatomy, Volume 75, 2016) health agencies consistently conclude that there are no proven hazards from exposure to RF fields within current exposure limits (even as they consistently call for more research).
My advice is to read the review, the critique, and the rebuttal, and then draw your own conclusion. You may find many of the technical details difficult to understand (I do), but you will better appreciate the complexity if these issues, and the difficulty in drawing definite conclusions from imperfect data. I don’t agree with Pall’s claims.

What does Bob Park have to say about the health risks from cell phones?

Robert Park is an emeritus professor of physics at the University of Maryland, and was the director of public information at the Washington office of the American Physical Society. He is the author of Voodoo Science, and wrote a weekly column titled “What’s New” debunking pseudoscience. His health has not allowed him to contribute to the recent discussion about the risks of cell phones and 5G technology (and, oh, how we miss him). Here’s what he wrote in “What’s New” on Sunday, May 6, 2012.
1. ALBERT WHO? DEAD PHYSICIST DISPELS MOBILE-PHONE MYTH. According to news reports last week: "There is still no evidence of harm to health from mobile-phone technologies," or other wireless devices such as Wi-Fi. A study for the UK's Health Protection Agency (HPA) is said to be the most complete review yet and new evidence is still being examined, according to Professor Anthony Swerdlow of the Institute of Cancer Research, who chaired the study. I once had a rubber stamp made that said: “More research is needed,” since its found at the end of every science paper. The unanswered question is why anyone thought microwave radiation might be a cancer agent in the first place? Cancer is linked to the formation of mutant strands of DNA. More than 100 years ago in his 1905 paper on the photoelectric effect, Albert Einstein predicted an abrupt threshold for photoemission at about 5 eV, just above the lovely blue limit of the visible spectrum, demonstrating wave-particle duality. He was awarded the 1923 Physics Nobel Prize [actually, Einstein received the Nobel Prize in 1921, and Robert Millikan received it in 1923, in part for his experimental work on the photoelectric effect]. Its also the threshold for the emission of invisible ultraviolet radiation that causes hideous skin cancers. The cancer threshold, is therefore, 1 million times higher than the microwaves band. The same enormous mistake was made in the 1980s when epidemiologists falsely warned that exposure to power line emission can cause cancer. Power lines abruptly stopped causing cancer in 1997 after the U.S. National Cancer Institute conducted a better study. Its painful to witness this sad history being replayed with mobile-phone radiation. Aside: My apologies to regular readers who have heard this 20 times before, but it has not gotten through to everyone.
Park’s argument remains as true now as eight years ago, except that a 300 GHz photon has an energy of one-thousandth of an electron volt, which is “only” a few thousand times less than the threshold for photoemission or UV skin cancer (and is about 25 times smaller than thermal energy, 0.025 eV). The possibility of DNA damage—the underlying cause of cancer—remains extraordinarily remote, but not as ridiculously remote as it was for cell phone technology ten years ago.


Electromagnetic radiation is considered a possible carcinogen. What’s that mean?

Something that is “possibly carcinogenic to humans” doesn’t probably cause cancer. It probably doesn’t cause cancer, but we can’t say for certain. RF radiation was not placed into two more threatening categories: “probably carcinogenic to humans” and “carcinogenic to humans.”

The website Science-Based Medicine states that
Despite the negative evidence to date, in 2011, the International Agency for Research on Cancer classified EMF [low-frequency electromagnetic fields] as a “possible” carcinogen. They have a low threshold for this category, which is rather long. It requires limited evidence of carcinogenic potential in humans and inadequate evidence in animals. This is the, “Probably should do more research just to be sure, but basically don’t worry about it,” category.

Who was Eleanor Adair, and what did she think about microwaves?


I have written about Eleanor Adair before in this blog. She was a leading expert on the interaction of microwaves with biological tissue, and was skeptical of any health hazards claims. A New York Times interview included this exchange:
Q. If I were to say to people, “Hey there’s this really cool idea: Why heat your whole house when you could use microwaves to heat yourself?” they would say: “You’ve got to be kidding. Don’t you know that microwaves are dangerous? They can even cause cancer.” What do you say to people who respond like that?

 A. I try to educate them in exactly what these fields are. That they are part of the full electromagnetic spectrum that goes all the way from the radio frequency and microwave bands, through infrared, ultraviolet, the gamma rays and all that.

And the difference between the ionizing X-ray, gamma ray region and the microwave frequency is in the quantum energy. The lower you get in frequency the lower you get in quantum energy and the less it can do to the cells in your body.

If you have a really high quantum energy such as your X-rays and ionizing-radiation region of the spectrum, this energy is high enough that it can bump electrons out of the orbit in your cells and it can create serious changes in the cells of your body such that they can turn into cancers and various other things that are not good for you.

But down where we are working, in the microwave band, you are millions of times lower in frequency and there the quantum energy is so low that they can’t do any damage to the cells whatsoever. And most people don’t realize this.

Somehow, something is missing in their basic science education, which is something I keep trying to push. Learn the spectrum. Learn that you’re in far worse shape if you lie out on the beach in the middle of summer and you soak up that ultraviolet radiation than you are if you use your cell phone.

Any new data about health effects of electromagnetic fields in the last few years?


A recent article examining the “Occupational Exposure to High-Frequency Electromagnetic Fields and Brain Tumor Risk in the INTEROCC Study: An Individualized Assessment Approach,” (Vila et al., 2018) provides the following highlights
• Evidence on health effects of long-term occupational exposure to high-frequency EMF remains weak
• Individualized cumulative occupational RF [radiofrequency, 10 MHz–300 GHz] and IF [intermediate frequency, 3 kHz–10 MHz] exposure indices were assigned to study subjects
• No clear associations with RF or IF EMF and glioma or meningioma risk were observed
• The possible role of RF magnetic fields on brain tumor promotion/progression should be further investigated.
As Bob Park said, everyone supports doing additional research (as do I). But I don’t see a lot to be worried about here.


Bill Curry concluded that 5G technology “is likely to be a serious health hazard.” Well?


I’ve written about physicist Bill Curry and his claims previously in this blog. That post begins
A recent article by William Broad in the New York Times—titled “The 5G Health Hazard That Isn’t”—tells the sad story of how unfounded fears of radiofrequency radiation were stoked by one mistaken scientist.

What is electromagnetic hypersensitivity?


Some people claim they’re extremely sensitive to weak electromagnetic fields. The SkepDoc Harriet Hall wrote a blog post titled “Myths About Electromagnetic Hypersensitivity and Multiple Chemical Sensitivity.” She begins
As if we didn’t have enough things to worry about already, now we are being told to fear our toasters. A typical headline trumpets “The Effects of Invisible Waves.” We are increasingly exposed to electromagnetic radiation from cell phones, cell phone towers, wireless Internet routers, cordless phones, and power lines. Other sources ... are our household appliances: TVs, hairdryers, light bulbs, and yes, your trusty toaster. These invisible villains are said to lead to a variety of symptoms, including poor sleep, fatigue, heart palpitations, headache, nausea, dizziness, memory impairment, prickling and burning sensations, along with skin rashes. They’ve even been blamed for depression, anxiety, colds, digestive disorders, and chronic pain. It’s called electromagnetic hypersensitivity or EHS.
Hall concludes
The symptoms described by “electromagnetic hypersensitivity” sufferers can be severe and are sometimes disabling. However, it has proved difficult to show under blind conditions that exposure to EMF can trigger these symptoms. This suggests that “electromagnetic hypersensitivity” is unrelated to the presence of EMF.
I recommend you read the entire article.


IPMB cited a point-counterpoint article that suggests cell phones are dangerous. True?


Point-counterpoint articles appear every month in the journal Medical Physics. They are a wonderful teaching tool, allowing students to consider and discuss questions at the cutting edge of medical physics. The one cited in Chapter 9 of IPMB is by Khurana, Moulder, and Orton (2008), titled “There is Currently Enough Evidence and Technology Available to Warrant Taking Immediate Steps to Reduce Exposure of Consumers to Cell-Phone-Related Electromagnetic Radiation.” Every point-counterpoint article pits one researcher against another, arguing opposing sides of the claim made in the article title. In this case, Vini Khurana supports the proposition, and John Moulder opposes it; Colin Orton is the moderator. I encourage you to read the article for yourself. I agree with Moulder’s conclusion that
weak epidemiological evidence of an association of mobile phone use with brain cancer incidence, when combined with the biophysical implausibility of a causal link and the strongly unsupportive animal studies, does not support the case that regulation of mobile phone use is urgently needed.

Last year I saw an article that says 5G cell phone radiation is unsafe! What’s up?


The Nation published an article titled “How Big Wireless Made Us Think That Cell Phones Are Safe: A Special Investigation. The Disinformation Campaign—and Massive Radiation Increase—Behind the 5G Rollout,” by Mark Hertsgaard and Mark Dowie. David Gorski published a critique of this article for the website Science-Based Medicine. He writes
The Nation indulges in fear mongering about cell phones and cancer An article published last week in The Nation likens wireless telephone companies to tobacco and fossil fuel episodes in their tactics of spreading fear, misinformation, and doubt regarding the science of cell phone radiation and health. To produce this narrative, the investigation’s authors rely on unreliable sources and cherry pick scientific studies, ignoring the scientific consensus that cell phone radiation almost certainly doesn’t cause cancer, all the while disingenuously claiming that they aren’t taking a position on the health effects of radio waves.
Read The Nation article and the critique and decide for yourself. At the least, you’ll learn how physics can be applied to medicine and biology.


What’s the bottom line regarding the risk of cancer from 5G cell phones?


Electromagnetic radiation consists of packets of energy called photons. The energy of a photon increases with the frequency of the radiation. Cancer is caused when DNA is damaged by very-high-frequency photons, such as x-rays (ionizing radiation). If the frequency is in the range of 300 GHz, the energy of a photon is far too small to disrupt bonds in DNA. It is, in fact, smaller than the energies associated with thermal motion of molecules. So, photons associated with 300 GHz radiation cannot cause cancer by damaging DNA. Of course, you could have a whole lot of 300 GHz photons, and they might pool their effort and together have enough energy to break bonds. We have a word for that: heat. 300 GHz radiation can heat tissue, but such heating is well understood and easily measured; Cell phone radiation is too weak to cause a significant temperature increase. So, we are left with no plausible mechanism for health risks from cell phone radiation. Perhaps some secondary effect could make your body less able to fight off cancer once it is induced by other mechanisms, but no one really knows how that might occur. Moreover, the epidemiological evidence suggests there is little risk. Cell phone use has increased dramatically since the turn of the century, but the incidence of brain cancer hasn’t increased. The National Cancer Institute says “The only consistently recognized biological effect of radiofrequency radiation in humans is heating... There are no other clearly established effects on the human body from radiofrequency radiation.” I wouldn’t say it’s impossible that cell phones put you at risk for cancer, but it’s unlikely. In my opinion, it’s exceedingly unlikely. We have many other things to worry about instead.


References


Foster KR, Moulder JE (2013) “Wi-Fi and Health: Review of Current Status of Research,” Health Physics, Volume 105, Pages 561-575.

Foster KR, Moulder JE (2018) “Response to Pall, ‘Wi-Fi is an Important Threat to Human Health’,Environmental Research, Volume 445-447, Pages 445-447.

Khurana VG, Moulder JE, Orton CG (2008) “There is Currently Enough Evidence and Technology Available to Warrant Taking Immediate Steps to Reduce Exposure of Consumers to Cell-Phone-Related Electromagnetic Radiation,” Medical Physics, Volume 35, Pages 5203-5206.

Moulder JE, Foster KR, Erdreich LS, McNamee JP (2005) “Mobile Phones, Mobile Phone Base Stations and Cancer: A Review,” International Journal of Radiation Biology, Volume 81, Pages 189-203.

Pall ML (2018) “Wi-fi is an Important Threat to Human Health,” Environmental Research, Volume 164, Pages 405-416.

Sheppard AR, Swicord ML, Balzano Q (2008) “Quantitative evaluation of mechanisms of radiofrequency interactions with biological molecules and processes,” Health Physics, Volume 95, Pages 365-396.

Vecchia P, Matthes R, Ziegelberger G, Lin J, Saunders R, Swerdlow A (2009) “Exposure to High Frequency Electromagnetic Fields, Biological Effects and Health Consequences (100 kHz – 300 GHz),” Munich: International Commission on Non-ionizing Radiation Protection.

Vila, J, Turner MC, Gracia-Lavedan E, Figuerola J, Bowman JD, Kincl L, Richardson L, Benke G, Hours M, Krewski D, McLean D, Parent M-E, Sadetzki S, Schlaefer K, Schlehofer B, Schuz J, Siemiatycki J, Tongeren M, Cardis, E (2018) Occupational exposure to high-frequency electromagnetic fields and brain tumor risk in the INTEROCC study: An individualized assessment approach. Environment International, Volume 119, Pages 353-365.

Friday, August 16, 2019

This View of Life

What’s the biggest idea in science that’s not mentioned in Intermediate Physics for Medicine and Biology? Most of the grand principles of physics appear: quantum mechanics, special relativity, the second law of thermodynamics. The foundations of chemistry are included, such as atomic theory and radioactive decay. Many basic concepts from mathematics are discussed, like calculus and chaos theory. Fundamentals of biology are also present, like the structure of DNA.

In my opinion, the biggest scientific idea never mentioned in Intermediate Physics for Medicine and Biology, not even once, is evolution. As Theodosius Dobzhansky said, “nothing in biology makes sense except in the light of evolution.” So why is evolution absent from IPMB?

A simple, if not altogether satisfactory, answer is that no single book can cover everything. As Russ Hobbie and I write in the preface to IPMB, “This book has become long enough.”

At a deeper level, however, physicists focus on principles that are common to all organisms; which unify our view of life. Evolutionary biologists, on the other hand, delight in explaining how diverse organisms come about through the quirks and accidents of history. Russ and I come from physics, and emphasize unity over diversity.

Ever Since Darwin, by Stephen Jay Gould, superimposed on Intermediate Physics for Medicine and Biology.
Ever Since Darwin,
by Stephen Jay Gould.
Suppose you want to learn more about evolution; how would you do it? I suggest reading books by Stephen Jay Gould (1941-2002), and in particular his collections of essays. I read these years ago and loved them, both for the insights into evolution and for the beauty of the writing. In the prologue of Gould’s first collection—Ever Since Darwin—he says
These essays, written from 1974-1977, originally appeared in my monthly column for Natural History Magazine, entitled “This View of Life.” They range broadly from planetary and geological to social and political history, but they are united (in my mind at least) by the common thread of evolutionary theory—Darwin’s version. I am a tradesman, not a polymath; what I know of planets and politics lies at their intersection with biological evolution.
Is evolution truly missing from Intermediate Physics for Medicine and Biology? Although it’s not discussed explicitly, ideas about how physics constrains evolution are implicit. For instance, one homework problem in Chapter 4 instructs the student to “estimate how large a cell …can be before it is limited by oxygen transport.” Doesn’t this problem really analyze how diffusion impacts natural selection? Another problem in Chapter 3 asks “could a fish be warm blooded and still breathe water [through gills]?” Isn’t this really asking why mammals such as dolphins and whales, which have evolved to live in the water, must nevertheless come to the surface to breathe air? Indeed, many ideas analyzed in IPMB are relevant to evolution.

In Ever Since Darwin, Gould dedicates an essay (Chapter 21, “Size and Shape”) to scaling. Russ and I discuss scaling in Chapter 1 of IPMB. Gould explains that
Animals are physical objects. They are shaped to their advantage by natural selection. Consequently, they must assume forms best adapted to their size. The relative strength of many fundamental forces (gravity, for example) varies with size in a regular way, and animals respond by systematically altering their shapes.
The Panda's Thumb, by Stephen Jay Gould, superimposed on Intermediate Physics for Medicine and Biology.
The Panda's Thumb,
by Stephen Jay Gould.
Gould returns to the topic of scaling in an essay on “Our Allotted Lifetimes,” Chapter 29 in his collection titled The Panda’s Thumb. This chapter contains mathematical expressions (rare in Gould’s essays but common in IPMB) analyzing how breathing rate, heart rate and lifetime scale with size. In his next essay (Chapter 30, “Natural Attraction: Bacteria, the Birds and the Bees”), Gould addresses another topic covered in IPMB: magnetotactic bacteria. He writes
In the standard examples of nature’s beauty—the cheetah running, the gazelle escaping, the eagle soaring, the tuna coursing, and even the snake slithering or the inchworm inching—what we perceive as graceful form also represents an excellent solution to a problem in physics. When we wish to illustrate the concept of adaptation in evolutionary biology, we often try to show that organisms “know” physics—that they have evolved remarkably efficient machines for eating and moving.
Gould knew one of my heroes, Isaac Asimov. In his essay on magnetotactic bacteria, Gould describes how he and Asimov discussed topics similar to those in Edward Purcell’s article “Life at Low Reynolds Number” cited in IPMB.
The world of a bacterium is so unlike our own that we must abandon all our certainties about the way things are and start from scratch. Next time you see Fantastic Voyage... ponder how the miniaturized adventurers would really fare as microscopic objects within a human body... As Isaac Asimov pointed out to me, their ship could not run on its propeller, since blood is too viscous at such a scale. It should have, he said, a flagellum—like a bacterium.
I’m fond of essays, which often provide more insight than journal articles and textbooks. Gould’s 300 essays appeared in every issue of Natural History between 1974 and 2001; he never missed a month. Asimov also had a monthly essay in The Magazine of Fantasy and Science Fiction, and his streak lasted over thirty years, from 1959 to 1992. My twelve-year streak in this blog seems puny compared to these ironmen. Had Gould and Asimov been born a half century later, I wonder if they’d be bloggers?

Gould ends his prologue to The Panda’s Thumb by quoting The Origin of Species, written by his hero Charles Darwin. There in the final paragraph of this landmark book we find a juxtaposition of physics and biology.
Charles Darwin chose to close his great book with a striking comparison that expresses this richness. He contrasted the simpler system of planetary motion, and its result of endless, static cycling, with the complexity of life and its wondrous and unpredictable change through the ages:
There is a grandeur in this view of life, with its several powers, having been originally breathed into a few forms or into one; and that, whilst this planet has gone cycling on according to the fixed law of gravity, from so simple a beginning endless forms most beautiful and most wonderful have been, and are being, evolved.

Listen to Stephen Jay Gould talk about evolution.
https://www.youtube.com/embed/049WuppYa20

 National Public Radio remembers Stephen Jay Gould (May 22, 2002).
https://www.youtube.com/embed/7mTirfwTMsU

Friday, July 26, 2019

The Oxford English Dictionary

The Meaning of Everything: The Story of the Oxford English Dictionary, by Simon Winchester, superimposed on Intermediate Physics for Medicine and Biology.
The Meaning of Everything,
by Simon Winchester.
I’m a fan of Simon Winchester, and I recently finished his book The Meaning of Everything: The Story of the Oxford English Dictionary. I enjoyed it immensely, and it motivated me to spend a morning browsing through the OED in the Oakland University library, which owns the 1989 twenty-volume second edition.

Rather than describe a typical OED entry, I’ll show ten examples using words drawn from Intermediate Physics for Medicine and Biology.

bremsstrahlung

The entry for bremsstrahlung in the Oxford English Dictionary.

In OED entries, the information right after the word in parentheses is the pronunciation based on the International Phonetic Alphabet, and the text within brackets is the etymology. Bremsstrahlung is German (G.; the OED uses lots of abbreviations). It has its own OED entry, so I guess it’s considered part of the English language too. The entry spans two columns, so I had to cut and paste photos of it. To my ear, bremsstrahlung is the oddest sounding word in IPMB.

candela

The entry for candela in the Oxford English Dictionary.

The origin of candela is from Latin (L.). IPMB and Wikipedia define the candela as lumen per steradian. I don’t see the solid angle connection listed in the OED.

chronaxie

The entry for chronaxie in the Oxford English Dictionary.

Russ Hobbie and I spell chronaxie ending in -ie, which is the most common spelling, although some end it in -y. Chronaxie is from a French (F.) term that appeared in an 1909 article by Louis Lapicque, cited in IPMB.

cyclotron

The entry for cyclotron in the Oxford English Dictionary.

My favorite part of an OED entry are the quotations illustrating usage. Several quotes are provided for cyclotron. The first is from a 1935 Physical Review article by Ernest Lawrence, the cyclotron’s inventor. XLVIII is the volume number in Roman numerals, and 495/2 means the quote can be found on page 495, column 2.

defibrillation

The entry for defibrillation in the Oxford English Dictionary.

Two definitions of defibrillation exist. IPMB uses the word in the second sense: the stopping of fibrillation of the heart. Other forms of this medical (Med.) term are listed, with defibrillating being the participial adjective (ppl. a.) and defibrillator the noun. Carl Wiggers is a giant in cardiac electrophysiology, and the Lancet is one of the world’s leading medical journals.

electrotonus 

The OED’s definition of electrotonus is different from mine.

The entry for electrotonus in the Oxford English Dictionary.

In IPMB, Russ and I write
The simplest membrane model is one that obeys Ohm’s law. This approximation is valid if the voltage changes are small enough so the membrane conductance does not change, or if something is done to inactivate the normal changes of membrane conductance with voltage. It is also useful for myelinated nerves between the nodes of Ranvier. This is called electrotonus or passive spread.
IPMB says nothing about a constant current stimulus, and the OED says nothing about passive spread. I wonder if I’ve been using the word correctly? Wikipedia agrees with me.

The two vertical lines in the top left corner on the entry indicate an alien word (used in English, but from another language). I would have thought bremsstrahlung more deserving of this designation than electrotonus.

fluoroscope

The entry for fluoroscope in the Oxford English Dictionary.

Wilhelm Röntgen discovered x-rays in late 1895, so I’m surprised to see the term fluoroscope used only one year later. X-rays caught on fast. Nature is one of the best-known scientific journals.

leibniz

My PhD advisor John Wikswo and I are engaged in a quixotic attempt to introduce a new unit, the leibniz.

The entry for leibniz in the Oxford English Dictionary.

If I were going to append a new definition, it would look something like this:
2. A unit corresponding to a mole of differential equations. 2006 HUANG et al. Rev. Physiol. Biochem. Pharmacol. CLVII. 98 Avogadro’s number of differential equations may be defined as one Leibnitz. 2006 WIKSWO et al. IEE P-Nanobiotechnol. CLIII. 84 It is conceivable that the ultimate models for systems biology might require a mole of differential equations (called a Leibnitz). 2015 HOBBIE and ROTH Intermediate Physics for Medicine and Biology 53 In computational biology, a mole of differential equations is sometimes called a leibniz.

quatrefoil

The entry for quatrefoil in the Oxford English Dictionary.

Wikswo coined the term quatrefoil for four-fold symmetric reentry in cardiac tissue. Quatrefoil appears in the OED, but its definition is focused on foliage rather than heart arrhythmias. I guess Wikswo didn’t invent the word but he did propose a new meaning. I can’t complain that this sense of the word is missing from the OED, because quatrefoil reentry wasn’t discovered until after the second edition went to press. My proposed addition is:
3. A four-fold symmetric cardiac arrhythmia. 1999 LIN et al. J. Cardiovasc. Electrophysiol. X. 574 A novel quatrefoil-shaped reentry pattern consisting of two pairs of opposing rotors was created by delivering long stimuli during the vulnerable phase.

 tomography 

The entry for tomography in the Oxford English Dictionary.

Godfrey Hounsfield built the first computed tomography machine in 1971. I didn’t realize that tomography had such a rich history before then. I don’t like the OED’s definition of tomography. I prefer something closer to IPMB’s: “reconstructing, for fixed z, a map of some function f(x,y) from a set of projections F(θ,x').”

Missing Words

Some words from IPMB are not in the OED; for example chemostat, electroporation, and magnetosome. Kerma is absent, but it’s an acronym and they aren’t included. Brachytherapy is absent, even from the long entry for the prefix brachy-. Sphygmomanometer doesn’t have its own entry, although it’s listed among the surprisingly large number of words starting with the prefix sphygmo-. Magnetocardiogram is included under the prefix magneto-, but the more important magnetoencephalogram is not. I was hoping to find the definition of bidomain, but alas it’s not there. Here’s my version.
bidomain (ˌbaɪdəʊ'meɪn). Phys. [f. BI- + -DOMAIN.] A mathematical description of the electrical behavior of syncytial tissue such as cardiac muscle. 1978 TUNG A Bi-domain Model for Describing Ischemic Myocardial D-C Potentials (Dissertation) 2 Bi-domain, volume-conductive structures differ from classical volume conductors (mono-domain structures) in that a distinction is made between current flow in the extracellular space and current flow in the intracellular space. 1983 GESELOWITZ and MILLER Ann. Biomed. Eng. XI. 200  The equations of the bidomain model are a three-dimensional version of the cable equations.

The OED took decades to complete, mostly during the Victorian era. The effort was led by James Murray, the hero of Winchester’s book. He supervised a small group of assistants, plus a motley crew of contributors whose job was to search English literature for examples of word use. Winchester’s stories about this collection of oddballs and misfits is engrossing; they volunteered countless hours with little recognition, some contributing tens of thousands of quotations, each submitted on a slip of paper during those years before computers. I can think of only one modern parallel: those unsung heroes who labor over Wikipedia.

The Professor and the Madman: A Tale of Murder, Insanity, and the Making of the Oxford English Dictionary, by Simon Winchester, superimposed on Intermediate Physics for Medicine and Biology.
The Professor and the Madman,
by Simon Winchester.
If you like The Meaning of Everything, you’ll love Winchester’s The Professor and the Madman, also about the Oxford English Dictionary. In addition, Winchester has written several fine books about geology; my favorites are Krakatoa and The Map That Changed the World.

To close, I’ll quote the final paragraph of a speech that Prime Minister Stanley Baldwin gave in 1928 at a dinner celebrating the completion of the OED, which appears at the end of Winchester's Prologue to The Meaning of Everything.
It is in that grand spirit of devotion to our language as the great and noble instrument of our national life and literature that the editors and the staff of the Oxford Dictionary have laboured. They have laboured so well that, so far from lowering the standard with which the work began, they have sought to raise it as the work advanced. They have given us of their best. There can be no worldly recompense—expect that every man and woman in this country whose gratitude and respect is worth having, will rise up and call you blessed for this great work. The Oxford English Dictionary is the greatest enterprise of its kind in history.
Intermediate Physics for Medicine and Biology nestled among volumes of the Oxford English Dictionary.
Intermediate Physics for Medicine and Biology
nestled among volumes of the Oxford English Dictionary.

Friday, April 19, 2019

Me, Me, Me

Most of my blog posts are about the textbook Intermediate Physics for Medicine and Biology. This post, however, is all about me. IPMB makes a few appearances, but its mainly me, me, me.

OUTV Interview

I was recently featured in a Focus on Faculty interview filmed by the Oakland University TV station (OUTV). I uploaded a copy to Youtube, and you can view it here. I apologize for the hair; I was supposed to get a haircut before filming began, but I got busy. Watch for a cameo by IPMB.

OUTV interviews Brad Roth at Oakland University.
https://www.youtube.com/watch?v=IKjab7_unRA

Daughters Kathy and Stephanie with me, and with Auggie, Smokie, and Harvest.
(l-r) Daughters Kathy and Stephanie with me,
and with Auggie, Smokie, and Harvest.

Harvest

Long-time readers of this blog will remember Suki, my beloved Cocker Spaniel-Westie mix who helped explain concepts in IPMB. After her death about a year ago, my wife and I decided to get another dog. Let me introduce you to Harvest, our 65-pound Treeing Walker Coonhound. She is as lovable as Suki (though not quite as smart). We adopted her from the Making Miracles Animal Rescue. On the right is a picture of me with my daughters Kathy and Stephanie, along with Harvest and my two granddogs Auggie (the foxhound) and Smokie (the greyhound), about to start a 5k walk. We like to take them to a dog park, and as we enter yell "Release the Hounds!"

The photo of Harvest and me published in the October 2018 issue of Physics Today
The photo of Harvest and me published
in the October 2018 issue of Physics Today.
Harvest is already famous. She was featured in the October 2018 issue of Physics Today. The magazine had a selfie contest that Harvest and I entered. Unfortunately, in the magazine our location is listed incorrectly; we are actually in our home in Rochester Hills, Michigan. To the left is the selfie that appeared in Physics Today.

Harvest with the IPMB Ideal Bookshelf.

Live Action IPMB Ideal Bookshelf

The logo for the Intermediate Physics for Medicine and Biology Facebook page is a drawing of the IPMB Ideal Bookshelf. You know how Disney often makes live-action movies out of previous animated shows? (Dumbo is the most recent example.) I’ve done the same thing. Below is a photograph of the “live-action” version of IPMB's My Ideal Bookshelf. Harvest helped me with the filming, so on the right I include a photo of her on the set.

The IPMB Ideal Bookshelf, consisting of books cited in Intermediate Physics for Medicine and Biology.

How to Get Published

Below is a video (divided into two parts) of Michael Sevilla (Distinguished Professor of Chemistry at Oakland University) and me talking to a group of graduate students about how to publish their research. Enjoy!

Part 1 of a discussion about Academic Publishing: How to Get Published in a Peer Review Journal, held Nov. 15, 2013 at Oakland University and hosted by the graduate student group Grad Connection. The host is then-graduate student George Corser, and the guests are Brad Roth and Michael Sevilla.

Part 2.