LETTERS TO THE EDITOR:
Of Atoms and Nucleons
I enjoyed the recent issue dedicated to a day in the life of Pomona College. There were many tasteful photos, including one from my research laboratory. However, I must say that I was shocked upon reading the caption associated with this particular photo:
"Assistant Professor of Physics David Tanenbaum and students Torrin Hultgren '00 and Anastasia Clower '00 with the nuclear force microscope in his lab..."
Why is this shocking? There is currently no such thing as a "nuclear force microscope." The caption should have referred to an "atomic force microscope (AFM)." This may seem a subtle difference, but any student who completes our General Physics course will know that an atom is about 100,000 times larger than a nucleon! Thus while an atomic force microscope has a resolution comparable to the sizes of atoms which are 0.1 nanometers (or 10 -10 meters), a "nuclear force microscope" would have a resolution on the size scale of a nucleon, which is about 1 femtometer (or 10 -15 meters). For comparison the smallest objects you can see with a good traditional optical microscope are about 0.1 micrometers (or 10 -7 meters).
There is a large ongoing research effort to develop a new microscope that combines the ability of the atomic force microscope to image individual atoms with magnetic resonance imagings capacity to tell one atom from another. This might be the closest thing to a "nuclear force microscope" at this time. Among the leaders in this field is a team at the IBM Almaden Research Center, headed by Dan Rugar '75. The magnetic resonance force microscope (MRFM) uses the magnetic tip of a cantilever one thousand times thinner than a human hair to measure minuscule forces associated with spin magnetic dipole moments of individual particles. Last year we were fortunate to have Dan visit us and give a physics colloquium on this exciting topic.
--David Tanenbaum
assistant professor of physics
From a Former Falstaff
I just finished reading the article on a day in the life of a certain English professor [in PCM Spring 2000] and it prompted me to send this note.
I was a student of Martha Andresen in the 1986-87 school year (Falstaff in Act IV of Henry IV in the fall and Claudius in Act IV in the spring). Reading the article brought back many fond memories of her class. I recall the excitement and the camaraderie of preparing the productions and whole-heartedly agree that it allowed me to enjoy and understand the works in far greater depth. I was very glad to see the same process thriving today.
While I graduated as a government major, when I think back on classes and instructors whose insights and teachings seem to have stayed with me the most, I routinely think of Martha Andresen and Brian Stonehill (I suspect I am not alone in these choices). Between Shakespeare and Joyce there is a lifetime of ideas to be contemplated, discussed, analyzed and applied to one's own life. I consider myself quite fortunate to have had professors who were able to demonstrate this to me.
--Charles Kallgren '87
Berkeley, California
Travel Endorsement
I've just returned from Pomona's alumni pilgrimage on the Mississippi River on the American Queen. In the 1970s, I was the travel agent who worked with the Alumni Office and various faculty leaders to set up Pomona's alumni travel programs.
I left the travel business in 1980 but have read with interest all of the alumni tour brochures I've received over the years. Many proved interesting, but this was the first time I had the time, money and inclination to join one. When I received the program for this trip, I signed on and looked forward to the tour throughout the fall and winter. It was everything I'd imagined it would be.
I've always felt a bit proprietary about the Pomona tours and now want to say "Cheers" to the Alumni Office for continuing such an important program and also to Horst Engel of V.I.P. Travel. To all other alumni travelers I recommend both the Pomona tours and their travel agent for any kind of trip you might have in mind.
--Connie Barnett '57
San Francisco, California
Environmental Kudos
Just a quick note to let you know I appreciated the Fall 1999 issue of PCM. As someone who has been talking and teaching about "limits to growth" for more than a quarter of a century, I sometimes despair of ever getting the attention of the over-consuming public. Your choice of articles and your editorial putting them in context were truthful without being depressing. I particularly loved your comparison of the millennium to waiting for the odometer to turn over. (Do kids still do that, I wonder.)
I found myself deeply depressed on New Year's Day by the widespread delight that "everyone" around the world was sharing in the celebration--except, of course, those billions living on less than a dollar a day. I had just finished a book by Niles Eldredge called Dominion which puts the issue of global survival in a different context. After reviewing the evolution of humans into the only species capable of living outside local ecosystems, he comments that we are the only species that thinks only of its own kind. Squirrels think of owls, foxes, oak trees, etc. But humans think only of humans. Which means that even if we fix things for all humans--which we don't seem to be doing--we still haven't taken account of the needs of the other species that must survive as well if those local ecosystems are to keep the big one alive.
And on that happy note, let me simply say thanks for making a little noise about it all.
--Joan Dye Gussow '50
Piermont, New York
Environmental Rebuke
In "Icebergs of the Third Millennium" in the Fall 1999 PCM, Professor Hazlett says "human activity accounts for a whopping 40 percent of all the energy fixed by photosynthesis worldwide. If population forecasts that project a doubling of human numbers by the middle of the next century come true, our use of available photosynthetic energy might climb to 80 percent."
Essentially every fact in this quote is incorrect.
First, human activity, even according to the paper that made this claim, only "co-opts" about 19% of photosynthetic energy. And this includes amounts that not even the authors of the study would consider "destruction." For example the study considers replanted forests as "co-opted."
The second fact is the projection that population will double in 50 years. This is not the opinion of the U.N., which expects population to increase by less than 50 percent.
Professor Hazlett's conclusion that "our astonishing economic growth, exploitation, material amusements and resource consumption can't last much longer" is thus without foundation and gets the cause and effect reversed. As capitalist societies grow wealthier, they use less land and less plant growth per capita. For example, Europe is more forested now than 50 years ago. Any forecast of plant energy use will have to take increasing wealth and efficiency into account.
Elsewhere, Professor Hazlett states: "Each of us in the U.S. requires a mean of 0.6 hectares of land--an area about 200 feet square--to produce the food we need... Worldwide, there are about 1.5 billion hectares of arable land. With the global population at 6 billion, this averages out to only 0.25 hectares per person, less than half the American requirement."
A U.S. resident does not require 0.6 hectares to be fed. Professor Hazlett apparently neglected exports. About 40% of U.S. farmland grows crops for the rest of the world. More puzzling is his exclusion of permanent pastures from his calculation. Add permanent pastures and exclude U.S. exports, and world agricultural land per capita increases from less than half the U.S. number to about 75%.
Professor Hazlett's conclusion that "the planet cannot produce the food it takes for everyone to eat like an average citizen in the United States" is false. According to World Bank data, crop yields have increased in countries of every level of development over the past 15 years. We can feed everyone in the world a "U.S. diet" either by increasing yields per acre (the more likely answer in the long run) or increasing the amount of land used for agriculture.
Since Professor Hazlett is a geologist, I expected his conclusions regarding oil to be built on stronger foundations. Alas, this is not the case. Professor Hazlett says the projected date for cheap oil to run out is 2025 and that this estimate has remained constant since around 1980. But the USGS has increased its calculation of identified reserves by 52% and its estimate of total oil resources by 32% since 1981. The world's proven-reserves-to-annual-production ratio has increased from about 29 years in 1980 to over 40 years in 1998.
More importantly, any "exhaustion date" is pure fiction since it assumes a constant state of technology. Increasing oil recovery rates by 1% will increase known reserves by 60 to 80 billion barrels, and better technology to recover oil from shale will increase recoverable reserves by 10 times.
Professor Hazlett's conclusion that the jetliner may go the way of the passenger pigeon overestimates the cost of fuel and again ignores improving technology. Major airlines spend less than 10% of their revenues on fuel. This percentage is likely to decline. In 1960 U.S. airlines only got 27 seat-miles per gallon of fuel used; by 1996 this number had risen to 48. Fuel efficiency will increase further as newer jets replace less efficient ones. A Boeing 777 provides about 64 seat-miles per gallon even when only 70% full.
Similarly, Professor Hazlett's concern about the effect of oil price increases on the cost of food is misplaced. Transportation, fuel, oil, electricity, pesticides, fertilizers and lime account for less than 10 cents of every dollar spent at the supermarket.
Of course we will not always use oil for energy, but our transition from oil to the next form of energy will be as painless as our transition away from firewood or animal muscle.
Professor Hazlett predicts real food costs will increase and "never again, perhaps, will so many people be able to move so easily, so cheaply or so swiftly." I am willing to bet $1,000 that real food costs will be lower in the future and $1,000 that people will travel more cheaply or swiftly. I am also willing to bet $10,000 that economic growth will continue.
--Peter G. Morrissey '90
New York City
Reply from Richard Hazlett,
associate professor of geology
Mr. Morrissey's letter illustrates one of the main points of my article--that we are all struggling with a welter of data that is easily misunderstood and/or used out of context to reinforce our own belief systems. Unfortunately, I do not have enough space here to detail all the errors in his data and his argument, but here are a few of the most important ones.
With respect to the "40% of photosynthetic energy" reference, I'm surprised that Mr. Morrissey questions this figure since we are both citing the same 1986 article from the journal Bioscience, titled "Human appropriation of the products of photosynthesis: nearly 40% of potential terrestrial net primary productivity is used directly, co-opted, or foregone because of human activities."
Regarding agriculture, I believe Mr. Morrissey is simply misreading the data. Much new farmland can no longer be cheaply acquired, while per-capita global grain production has been in seesaw decline since the early '80s, due largely to losses of cheap water, topsoil and soil fertility. Increases in average grain yields have fallen below or barely kept pace with the rate of population growth since 1990, despite new agrotechnologies (Worldwatch Institute). The 0.6 hectare value comes from the USDA and refers to crops only. Permanent pasturage is hardly relevant. Adjusting for food exports (but not the considerable amount of food the U.S. imports), the area of cropland used per American falls to 0.5 hectare, still double the amount available per person worldwide. Esteemed scientists E.O. Wilson, the Pimentels, Rees and Wackernagel have pointed out that our level of consumption is globally unsupportable. In particular, I refer Mr. Morrissey to the Pimentels' 1996 text Food, Energy and Society.
While it is true that per capita demand for some raw materials begins to slacken after societies achieve high levels of prosperity, that demand remains high enough to be a concern in a world with growing, upwardly mobile populations and finite limits. The average American, who consumes over 500 times the resources of a typical Ethiopian, simply does not have less impact on global resources and the environment than a peasant farmer on the outskirts of Addis Ababa.
As for petroleum, it is now well demonstrated that neither oil shales nor tar sands can easily be exploited in quantities sufficient to meet global demand. And the latest forecast for onset of a permanent production crisis, from Minniear, puts the "day of reckoning" around the year 2008 (March issue, Journal of Geoscience Education). This is a far gloomier forecast than 2025. Mr. Morrissey needs to study the principles of the Hubbert curve and production peak and to appreciate that it takes 5-12 days for the current world economy to consume a billion barrels of oil. Inflating even the most optimistic USGS estimates to 2.5 trillion barrels left, that does not give us many years to go. Even if we discover new technologies to keep oil cheap, this would only have the unfortunate consequence of stimulating more demand in growing markets. It is fast becoming time for big changes.
I thank Mr. Morrissey for pointing out a few errors, but on balance, I think he is off the mark due to incomplete reading. With so much conflicting information available, it is easy to find and interpret data in ways that bolster our own beliefs. What is hard is to read widely enough and with enough discernment to find where the limits to our knowledge and the likelihood of truth really lie. I continue to work at it almost every day. So good luck to you, Mr. Morrissey, and read on.
We welcome letters to the editor pertaining to the College or the magazine. All letters are subject to editing for style, clarity and length. When a letter questions or challenges a previously published PCM article, the author of the article may be invited to respond.
