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Archive for the ‘Uncategorized’ Category

Hiring a tenure-track astronomer/astrophysicist

Posted by Arjendu on June 29, 2016

Hello everyone. We are looking for a tenure-track astro person. Job posted below, and presumably soon in all the usual places. The online form at jobs.carleton will be active in about a week or so. Please let me know if you have any questions. Teaching at Carleton is a great gig — come join us!

The Carleton College Department of Physics and Astronomy invites applications for a tenure-track position at the Assistant Professor level, to start September 1, 2017. We seek an astronomer or astrophysicist with a strong commitment to teaching undergraduates in a liberal arts environment and the ability to contribute imaginatively to our curriculum and our observational astronomy program. More information about our astronomy facilities is at . The annual teaching load over our three trimesters is expected to be, on average, three courses in astronomy/astrophysics and two in physics. We also look for the capability to maintain an active research program in which undergraduate students can be involved; start-up funds will be provided. Any area of research is welcome, but we are particularly interested in candidates who would expand the breadth of expertise in our department. We seek applicants who will strengthen the departmental commitment to students from underrepresented groups in physics and astronomy, and candidates committed to teaching a diverse student body. Carleton College is a highly selective liberal arts college with about 2000 undergraduates; over the last decade we have graduated 12 – 27 majors annually, of whom one-quarter are women. Our eight-member department strives to provide a challenging yet supportive environment for our enthusiastic and intellectually demanding students. For further information on the department, visit our web site at .

To apply, complete the online application by Friday, October 21, 2016 at . The online application should include a cover letter and a curriculum vitae. In your applications, please include statements on teaching and on research discussing your interest in developing as a teacher and scholar in a highly selective undergraduate liberal arts college that emphasizes close student-faculty interaction. You should also discuss your potential to contribute to a college community that holds as one of its core values a diversity of people and perspectives. In addition, you will be asked to submit contact information for three individuals who can serve as references.

Carleton College does not discriminate on the basis of race, color, creed, ethnicity, religion, sex, national origin, marital status, veteran status, actual or perceived sexual orientation, gender identity and expression, status with regard to public assistance, disability, or age in providing employment or access to its educational facilities and activities. We are committed to developing our faculty to better reflect the diversity of our student body and American society. Women and members of minority groups are strongly encouraged to apply.


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Student essay: Energy and geopolitical alliances

Posted by Arjendu on June 4, 2016

Andrew Bernstein: Geopolitical alliances/US and Saudi Arabia

Saudi Arabia is always referred to as the United States’ unlikely ally in the Middle East. However, examining the history of American-Saudi relations clearly demonstrates that the relationship grew out of economic and energy dependence rather than any alignment of value systems or democratic leadership. Saudi Arabia’s massive oil reserves were discovered in the early 1940s. Almost immediately, in 1943, Franklin D. Roosevelt declared the defense of Saudi Arabia one of the United State’s greatest interests, and sent military missions to train the Saudi army and construct joint military facilities. In 1945, Roosevelt and Abd al Aziz sealed an official alliance between the two powerhouse countries ( Saudi Arabia has the world’s largest oil reserves, and exports the most oil in the world, comprising a fourth of the world’s total. Additionally, Saudi Arabia is the fourth largest exporter of natural gas. Oil (petroleum) and natural gas are the top two sources of American energy consumption, accounting for over half of the total per year. Thus, Saudi Arabia, due to its geopolitical location and the worldwide dependency on fossil fuels, dictates much of the United States’ policy in the Middle East (

With oil revenue accounting for over 75% of its GDP, Saudi Arabia has consistently been one of the 10 richest countries over the last century, both overall and per capita ( The United States has allied with Saudi Arabia against Iran and Iraq, and when Iraq invaded Kuwait, the US sent 400,000 troops to protect Saudi Arabia ( Despite our military’s defense of Saudi Arabia, the alliance has become increasingly strained as their way of life is no different than the other Middle Eastern countries whose treatment of women and stringency of law justifies our military action. “Saudi Arabia is an authoritarian regime that discriminates against women, doesn’t permit religious freedom, and prevents freedom of the press. It has been exporting a fundamentalist Wahhabist ideology for years that demonizes Shia, Jews, Christians, and the West” ( The relationship consists entirely of our accessibility to Saudi Arabia’s oil resources in return for military assistance and anything else they might want from us. That relationship is dangerous, and scary, because it places us largely at their mercy. Without their oil, our economy would be severely damaged. Negative consequences from this partnership have already been seen. We have sold 10 billion dollars of arms to Saudi Arabia for their war in Yemen, which has led to a massive Al-Qaeda resurgence in the region, a direct threat to American safety. When a Senator called our compliance with the Saudi Arabians “feckless” (Sen. Chris Murphy, D-CT), Saudi Arabians threatened economic consequences and Congress immediately backed off (

09/11 represented a major event in American-Saudi relations, as the terrorists used Saudi Arabian passports and the majority were of Saudi descent. However, our government has largely refused to attach any blame to Saudi Arabia as they proclaimed their innocence. However, we have strategically attempted to move away from our oil dependency from Saudi Arabia in the last 15 years. By 2013, Saudi Arabia was the source of 17% of our oil, down 25% from 2003, while Canada became our greatest oil source, up 70% from their exports to the US in 2003 ( By 2015, Saudi Arabia provided 11% of our oil, down another 33% in just two years ( In the past few weeks, a bill unanimously passed in Senate allowing families of 09/11 victims to sue Saudi Arabia, again because most of the perpetrators were Saudis ( Quickly, Saudi Arabia promised to sell off all their American assets and stop importing oil, cutting off the alliance and destabilizing the United States economy. Despite the widespread support of the Democratic Party, President Obama condemned and vetoed the bill immediately.

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Student essay: Energy and ‘Freedom’

Posted by Arjendu on June 4, 2016

Hami Abdi: Oil’s Impact on Freedom

The Middle East is located where the southern shores of the Tethys Sea occupied a 100 million years ago. Over the years, the organic remnants from aquatic life buried under miles of sediments at the bottom of the sea got transformed into crude oil through a long series of chemical reactions involving the heat from the hot zones deeper into the earth. The creation of oil is a remarkable process. Unfortunately, this does not change the fact that oil contributes to the lack of freedom in Middle Eastern countries.

Countries with oil can find it hard to establish democracy, a concept closely tied with freedom. The Rentier-State theorem implies that countries that generate enough revenue from their natural resources to obtain financial freedom from their citizens tend away from democracy. These countries are named rentier states. The intuition is that since rentier states can manage without the need to tax their citizens, the citizens become less demanding. The situation is exacerbated when the government provides allocations to its citizens, even though this allocation makes up a small percentage of its total expenditure. Thus, as a result, rentier states have a small group of people in the government that possess the large oil-related revenues controlling the entire nation.

For instance, observe United Arab Emirates’ Dubai. As per many Middle Eastern cities, Dubai has no taxes. Moreover, the city is generating lots of revenue as is evident by its luxurious hotels, vehicles, and other facilities. However, hidden in between the dashing city lights and the magnificent skyline are all the poorly-treated construction workers that are making all of this happen. These workers are underpaid and made to work under life-threatening conditions (e.g. installing beams on the 76th floor amidst a sandstorm). Unfortunately, for reasons mentioned in the previous paragraph, these workers are essentially unable to invoke a change. There are undoubtedly other instances of violation of human rights and freedom in Dubai and other Middle Eastern countries that cannot be corrected given the rentier-state structure.

Oil also restricts external countries from interfering and preventing internal violations of human rights and freedoms. Throughout the world, there is a large demand for fossil fuel, given our daily routines. In particular, 40% of our total consumption of energy (104,426 TWh) comes from oil – that is equivalent to 3592 mega-tonne of oil equivalent! Interfering with internal affairs of Middle Eastern countries would mean perhaps jeopardizing about 27% of the world’s energy sources, given that the Middle East is responsible for producing 66% of the world’s oil supply. Furthermore, these countries provide perfect shields for extremists and radicals that eventually lead to the rise of extremist groups, such as Al-Qaeda. Hence, in a way, the world’s dependence on oil contributes to terrorism and loss of human freedom in the Middle East.

Lastly, the reliance on oil prevents economic growth, and thereby, essentially imposes economic restraints on the citizens of Middle East. As discussed previously, rentier states obtain essentially their entire revenue from external sources. It has been shown that this leads to an unproductive domestic economy because its governments are not compelled to apply free market principles to create an environment conducive to economic growth. Thus, many Middle Eastern countries have relatively low standards of living, and their market lacks the necessary infrastructure to nourish maximum economic freedom.

References However, if we want to include only the oil that is exported from the Middle East, the 27% should be closer to 22.6%, as per this article:
More on Rentier State:
Formation of oil in Middle East:

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Student essay: Energy and New England history

Posted by Arjendu on June 4, 2016

Sally Donovan

Soil, Ecology, and History: 19th Century Energy Production in New England

Charcoal production played an important role in shaping settlement and industry in 19th century New England. As new fertile land was discovered out west, the agricultural industry migrated out of New England, leaving many agricultural settlements desperate for new industry. During this time, wood charcoal production replaced agriculture as the new industry of New England. The driving force behind this industry was iron. Wood charcoal was used in coal blast furnaces to produce iron, an important resource in the Civil War as well as westward expansion and industrialization. From a historical perspective, one can see how the demand for energy played an important role in shaping the post-agricultural development of 19th century New England. Furthermore, remnants of this industry are still prevalent today. In 2015 LiDAR analysis located 20,500 relic charcoal hearths in Litchfield County (Johnson et al., 2015). Litchfield Country, a region in the Northwest corner of Connecticut, measures196 km2. Considering this, it is likely there are thousands of undocumented relic hearths scattering the landscape of New England. Given the abundance of hearths, researchers are beginning to look into the environmental impacts of these hearths. While production sites were abandoned over 100 years ago, new studies are finding charcoal hearths continue to impact the region’s soil geochemistry and forest ecology today.

To produce charcoal, local timber was harvested and gathered in hearth sites. These hearths, which measured approximately 150 m2 in size, were filled with 25 to 50 cords (90-180 m3) of wood, covered in soil, and fired at temperatures reaching 450 degrees Celsius (Young et al. 1996). Then, over the course of 14 days, the wood was slowly carbonized to charcoal. During carbonization, the wood was dried and heated until it began to spontaneously break down. This produced charcoal and water vapor, methanol, acetic acid, and other complex chemicals, which are released as gas in the form of hydrogen, carbon monoxide, and carbon dioxide. These outputs, in combination with prolonged periods of heat, created a cycle of repetitive disturbances that damaged the local soil environment. Of these disturbances, previous studies (Hart et al. 2008; Gomez-Luna et al. 2009; Tryon 1948) found high amounts of charcoal inputs had an especially significant impact on the local soil environment, resulting in considerable long-term alterations to soil chemistry and morphology. For example, in a study analyzing relic charcoal hearths in the Pennsylvania, Young et al. (2006) reported significant differences in soil calcium concentrations, pH, and percent carbon between hearth and adjacent soils. Furthermore, in a study assessing hearths in southwestern Ethiopia, Nigussie and Kissi (2011) found charcoal residues left on hearth sites increased cation exchange capacity and exchangeable bases as well as elevated levels of total nitrogen and available phosphorus. In Ghana, Oguntunde and Fosu (2004) reported organic carbon and total nitrogen decreased on hearth soils.

The story of charcoal production in New England is one that is not usually told from the perspective of energy. However, the demand for energy was the driving force behind a long line of other developments. As a result of charcoal production, the region’s economy and industry flourished, the population increased, and the end product, iron, played a crucial role in the Civil War and westward expansion. Furthermore, the demand for energy played an important role in shaping New England’s forest ecology, an additional topic not traditionally linked to energy. Similar to many energy extraction methods today, charcoal production supplied a temporary boost the region’s economic and industrial development, however this process has left a lasting legacy effect on the production site environment.

Gomez-Luna, B. E., Rivera-Mosqueda, M. C., Dendooven, L., Vazquez-Marrufo, G., and Olade-Portugal, V., 2009, Charcoal production at kiln sites affects C and N dynamics and associated soil microorganisms in Quercus spp. temperate forests of central Mexico: Applied Soil Ecology, v. 41, no. 1, p. 50-58.
Hart, J. L., Van De Gevel, S. L., Mann, D. F., and Clatterbuck, W. K., 2008, Legacy of charcoaling in a Western Highland Rim forest in Tennessee: American Midland Naturalist, v. 159, no. 1, p. 238-250.
Johnson, K., Ouimet, W. and Raslan, Z., 2015, Geospatial and Lidar­based analysis of 18th to early 20th century timber harvesting and charcoal production in Southern New England. Geological Society of America Northeastern Section Meeting. Breton Woods, NH.
Nigussie, A., and Kissi, E., 2011. Effect of charcoal production on soil properties in southwestern Ethiopia: Middle-East Journal of Scientific Research, v. 9, no. 6, p. 807-813.
Oguntunde, P. G., Fosu, M., Ajayi, A. E., and van de Giesen, N., 2004, Effects of charcoal production on maize yield, chemical properties and texture of soil: Biology and Fertility of Soils, v. 39, no. 4, p. 295-299.
Tryon, E. H., 1948, Effect of charcoal on certain physical, chemical, and biological properties of forest soils: Ecological Monographs, v. 18, no. 1, p. 81-115.
Young, M. J., Johnson, J. E., and Abrams, M. D., 1996, Vegetative and edaphic characteristics on relic charcoal hearths in the Appalachian mountains: Vegetatio, v. 125, no. 1, p. 43-50.

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Student essay: Energy and health

Posted by Arjendu on June 4, 2016

Julia Krumholz: Energy Poverty and its Effect on Health

It is unsurprising that access to energy can improve quality of life, measured in parameters such as wealth, literacy, and health. However, the extent to which energy can shape the health of a person is more surprising. Energy poverty, or lack of access to electricity and heat (or the fuel needed to produce electricity and heat) leave more than one billion people in developing countries with insufficient access to healthcare. Lack of electricity especially leads to health crises, where the ability for health facilities to treat people is dependent on access to electricity (Provost 2013).

The correlation between energy poverty and average life span is strong, with energy use directly proportional to life expectancy (Figure 1). The most at risk are people who live in rural areas of developing countries. Lack of infrastructure in rural areas means a lack of power lines, transformers, and generators required to deliver energy both to homes or health facilities. An estimated $40 billion would be required to extend energy grids to the 1.5 billion people living without electricity (The Economist 2010). A major challenge to cost-efficient grid extension is finding materials for conductors. Metals such as copper and aluminum have relatively low resistance, making them good conductors, but also provide large cost barriers when required in high quantities. Reducing the size of conductors saves money, but also increases to voltage drop across the line, providing less power to households (ESMAP 2000).

Due to the lack of power availability in rural areas of developing countries, health facilities in these regions face a number of challenges. For example, without electricity, many clinical services cannot be performed after sunset. If facilities have access to biomass, burning biomass can provide light, although the light is lower quality, can release harmful particles into the air, and can present a fire hazard (Knoth 2014). This deficiency in high quality light also affects the quality of operations that can be performed, with invasive surgeries highly dependent on the ability of the doctor to see. Without electricity, health emergencies in the nighttime become nearly untreatable, resulting in deaths that would be preventable with electricity.

Another problem posed by lack of electricity in health facilities manifests in the inability to properly store medicines or blood. Many medicines and vaccines require refrigeration. Work is required to move heat from areas of cold temperature to areas of hot temperature, as mandated by the second law of thermodynamics, and electricity is needed to provide the energy for thatinput of work. This problem further targets areas that receive power but suffer from frequent power outages, as the one-time heating of some medicines or vaccines ruins the whole batch from further use (Knoth 2014).

Additionally, the probability of an infant neonatal mortality rate (probability of a child to dying in its first 28 days of life) also increases with energy poverty. Access to incubators, which is dependent on access to electricity, greatly improves the chances of infant survivorship. For example, one study in Kenya found that neonatal mortality rate dropped from 40% to 28% in health facilities when facilities were given access to incubators (World Health Statistics 2012). Access to electricity therefore boosts life expectancy by increasing survivorship of infants.

Lastly, access to electricity decreases the use of open fires and kerosene lamps for cooking, methods that can lead to toxic household pollution. In 2012, nearly 1.5 million people died from exposure to smoke biomass, and that number is expected to grow as a bigger contributor to deaths than malaria and HIV/AIDS combined by 2030 (Figure 2) (International Energy Agency 2011). This pollution disproportionately affects women and girls, who have the highest exposure to open household fires for cooking.

Overall, while lack of electricity manifests into a number of problems, healthcare access greatly drops with increased energy poverty. Although it may seem costly to extend power grids to rural areas, the money saved in unsuccessful operations, wasted medicine, and decreased trips to the hospital may offset this cost. The upfront cost of extending power grids results in a major barrier to providing electricity to rural areas of developing countries, but could save money in the long run due to savings in healthcare and human lives.

Figure 1. Comparison of life expectancy and per capital energy use, as of 2013. Life expectancy increases as access to energy increases.

Figure 2. Premature deaths associated with air pollution and other diseases, given as data from 2008 as well as expected scenarios for 2030. Provided by International Energy Agency from 2011.
Works Cited
Energy Sector Management Assistance Programme. 2000. Reducing the Cost of Grid Extension for Rural Electrication. ESM227.
International Energy Agency. 2011. Energy for all: Financing access for the poor. OECD/IEA.
International Energy Agency. 2016. Modern energy for all. OECD/IEA.
Knoth, Gretchen. 2014. 6 ways energy poverty threatens health care for the poorest. One.
Pielke, R. 2013. Graph of the Day: Life Expectancy vs. Energy Use. Science, Innovation, and Politics.
Provost, C. 2013. Energy poverty deprives 1 billion of adequate healthcare, says report. The Guardian.
The Economist. 2010. Power to the people. Technology Quarterly, The Economist Newspaper.
World Health Organization. 2012. World health statistics 2012. WHO Library Cataloguing-inPublication Data.

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Student essay: Energy and refugees

Posted by Arjendu on June 4, 2016

As part of my intro course on physics of energy I asked students to look at something in the ‘real world’ through the lens of energy — I’d just gotten through an extended discussion on the correlation between GDP and energy consumption, etc, etc, and wanted them to practice seeing the hidden role of energy in so many things we think are actually about something else. I’m planning to post some of the better ones (as I get permission for them). Here’s one, unedited:

Energy at the Heart of the Refugee Crisis
Rebecca Fairchild

With the prevalence of media and news sources, it feels nearly impossible to remain ignorant to the severity of the global refugee crisis. When considering the situation, factors such as political systems, systematic violence, racist immigration policies and health care concerns immediately come to mind. For this assignment, I chose to investigate one factor that is frequently overlooked that plays an extremely prominent role in the plight of refugees- energy and energy access. According to one study conducted by Stanford University, there are approximately 60 million refugees and 80% of these people are without easy or reliable access to electricity. As a result of the scarcity of electrical power, people rely on sources of fuel such as coal, diesel and wood that are dangerous, unsustainable and pose significant risks to their health and safety.
The Daabad refugee camp in Kenya (home to many people fleeing from southern Sudan) is a very illuminating example of the economic implications of relying on unclean forms of energy. At this camp, families spend $17.20 per month on diesel fuel which is equivalent to 25% of their monthly income. In comparison, families in many European countries spend about 4% of their income on energy. In total, the cost of supplying diesel fuel to this one camp is 2.3 million dollars each year. These numbers can be extrapolated to a global scale with staggering results. In total, refugee camps spend 2.1 billion dollars supplying fuel to refugees and consume the equivalent of 3.9 million tons of oil in doing so. Much of the energy that is used in these camps goes to cooking food and fueling lanterns. In fact, the consumption of oil in these two activities has lead to a yearly output of 6.85 million tons of carbon dioxide by refugee camps.

The use of diesel oil as a power source is supplemented by wood, which poses equally significant environmental implications. Combined the amount of wood that is harvested for fuel by people in refugee camps has lead to the loss of 64,700 acres of forest loss per year. It is important to note that the majority of refugee camps are located in countries that already are facing enormous environmental crises with regards to deforestation and pollution. The compounded practices of refugees and citizens in these countries have lead to the contamination and loss of streams and water sources (water access is also a significant problem in many of these countries) and the severe loss of habitat and subsequent endangerment of many species.

On top of the environmental implications, the current sources of energy used by refugee camps pose enormous risks to refugees health and safety, specifically for women and children. The lack of electricity available in the refugee camps makes for streets that are poorly lit at night. As a result, children and women are placed at a high risk of rape or abduction when they must leave their house (to go to the bathroom etc) at night. Similarly, due to traditional gender roles within many of these camps, women and children are expected to collect the wood for fuel in the woods. In doing so, many fall victim to sexual predators. In one refugee camp, a counseling service reported that 500 women and children were raped collecting firewood within a five month span. The number was likely much much higher though, because collecting wood is illegal, and women were afraid to report cases for fear of legal retribution. Furthermore, the process of collecting the wood is a lengthy undertaking and makes it hard for children to find time to study and participate in education, thus furthering the cycle of poverty and lack of education in camps. Even when fuel is gathered safely, utilizing these forms of fuel is often highly dangerous. Annually, 20,000 deaths per year are reported due to fires from cooking, dangerous fumes and ingestion of diesel (diesel is often kept in water bottles which is confusing to young children). I found these reports entirely appalling and am questioning why there is not more of a push from medical organizations to restructure energy access as a means of dealing with some of these medical and safety concerns.

One proposal to helping deal with the energy crisis in these refugee camps is implementing clean energy sources in the camps. In particular, it has been proposed to instal solar grids to supply electricity to the camps. One factor that has barred many camps from doing this is the large capital required to implement such systems. It has been calculated that the cost of implementing such a system would be a 335 million dollar one time investment. In the long run, it is suggested that the installation of such systems would save $223 million. Humanitarian aid organizations are run on rolling donations, which makes access to this degree of economic capital nearly impossible. Furthermore, many countries are resistant to installing such systems because, in doing so, they are forced to acknowledge that the refugee settlement will be fairly permanent. Nonetheless, The Azraq refugee camp is planning to implement a solar power system. It is projected to cost 10 million dollars to instal, but, since the camp pays $800,000 monthly in energy costs, it is projected to pay for itself in anywhere from two to four years. This signals towards the economic viability of green energy within refugee camps.
Personally, I am very compelled by the argument to move towards green energy within the refugee camps. From the evidence gathered, it is clear that the current system is vastly insufficient and green energy, from what I can tell, will provide a consistent form of energy that will make great strides in many of the adverse conditions that refugees face. Beyond this, I believe that the movement to instal such systems will lay a precedent globally and provide concrete examples to support the feasibility of relying on green sources of power.

Works Cited
Leach, Anna. “Clean Energy in Refugee Camps Could save Millions of Dollars.” The Guardian. Guardian News and Media, 17 Nov. 2015. Web. 22 May 2016.
Okoo, Sarah. “Why Kenya Can’t Ignore Energy Crisis in Refugee Camps.” Business Daily. N.p., 12 Jan. 2016. Web.
Pyper, Julia. “Solar Power to Light Up Syrian Refugee Camps in Jordan.” Green Technology. Grid Edge World Forum, 14 Dec. 2015. Web. 22 May 2016.
Sorrel, Charlie. “How Using Clean Energy In Refugee Camps Could Prevent Rape and Save Children.” Co.Exist. N.p., 3 Dec. 2015. Web. 22 May 2016.

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Energy links on Twitter

Posted by Arjendu on April 7, 2016

As some of you have probably already deduced, this blog is mostly moribund. I think that’s because when I want to have a ‘discussion’ about something physics-related, or share a quick thought, Facebook seems to work just fine. And if I want to share some interesting idea, Twitter seems to work better. Anyway, just for completeness, here’s my twitter account, with several energy-related posts a week:

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Women in Science Links

Posted by Arjendu on March 11, 2016

On my facebook page, I’m going through an exercise (for no real reason, just because I felt like it) of linking every day to female scientists/thinkers/tinkerers that I think people might find interesting. There’s no reason why I can’t inflict that project on blog readers as well, so here goes. I’ll start with a single post summarizing links to date. Enjoy.

Rachel Carson, one of my daughter’s (s)heroes.

Shirley Jackson: American physicist (Ph.D. in nuclear engineering from MIT) and currently president of the Rensselaer Polytechnic Institute (not without controversy, the stories associated with the latter).

Someone whose invention is a regular and constant feature of my life, and is responsible for a great deal of math and physics around the world (‘a mathematician (physicist) is a device for turning caffeine into theorems (results)’ ): Melitta Benz Melitta Benz and

Profiles of 18 women working on sustainable energy issues in MN…/women-in-energy?

Émilie du Châtelet: Among her many contributions: The principle of conservation of energy. (including Valentina Tereshkova, of course). And I’d like in particular to recall Kalpana Chawla and Laurel B Clark, who were on the ill-fated space shuttle Columbia. It was a Saturday and I was home, holding my month-old daughter in the usual new parent zone of exhaustion and exhilaration, when I heard the news. Of course I was utterly overwhelmed with feelings.

Hedy Lamarr: Actress, inventor of a frequency-hopping spread-spectrum technology that underlies today’s CDMA/Wi-Fi/bluetooth, …

Madam Wu: who did the very first experiment showing parity violation.
According to Clauser and Shimony, Rep. Prog. Phys., Vol. 41, 1978 she also did a very early — 1950 — experiment which “confirm[ed] the existence of states of two-particle systems which are ‘non-separable’, even though the particles are spatially remote from each other”. That is, a Bell Test, pre-Bell. (I heard about this test a few weeks ago at ‪#‎SQuInT2016‬)

Hypatia To quote my friend Howard Wiseman: “In this month of March, in this season of Lent, 1600(*) years ago, Hypatia of Alexandria, the last great philosopher-mathematician of the ancient world, the highest intellect of her age, was dragged before the church of Caesarion, stripped naked, and brutally murdered by an angry mob. The Patriarch of Alexandria, Cyril, who had whipped up the mob (with the primary aim of dispossessing and expelling the Jews from the city) was later made, and still remains, a Saint of the Catholic church. Spare a minute to weep in her memory.” And for all we say that the pen is mightier than the sword, remember the power of demagoguery. There’s a movie about her called ‘Agora’ that you might want to watch.

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Quantum video games in class

Posted by Arjendu on February 6, 2016

I am teaching our junior quantum mechanics out of Townsend’s book, which starts with Dirac notation and spin states, and when it lands in the position representation the students still haven’t made the full connection to the material they learned in their ‘modern physics’ course.

Here they are re-introduced to things like bound states (particle in a box so far mainly) and we read but did not discuss in detail a derivation of the tunneling coefficients. Yesterday was my designated ‘wrap-up the reintroduction/transition from Dirac notation to position space’ day. I chose to spend the class meeting time 1/2 on doing in-class simulations and 1/2 getting started or finishing the quantitative problems I had assigned. I found myself spending a big part of the afternoon discussing one particular problem with the students, which would perhaps have gone differently if I hadn’t (a) assigned it as a ‘mini-test’ (which meant that they couldn’t consult with anyone but me about it) or (b) gone over some material in class instead of the simulation. I am still a little puzzled about the number of visits I had, since things have gone differently with this section of the course with previous classes, but difference from previous years is a given, so I am just noting this and moving on. About the only thing I intend to change if I assign it in the same way in the future is to remember to ask everyone to look at the problems and make sure they knew how to start every one of them before they came to class.

I have assigned some version of the simulations as take-home assignment before, but we never got to discuss things together as a class, and I wasn’t available to guide their explorations. This time, by the end of the class I saw and heard some sense of understanding for some or many of my students about the qualitative and conceptual sense of time-dependent quantum mechanics at this level: How wave packets spread, in what sense they are superpositions of states and how you might move back and forth between the position and momentum representation, and how uncertainty connected with that, some sense of how different choices of superpositions of states affects the dynamics, how properties of time-evolving states are such that some expectation values are ‘stationary’ while others not, how even things like tunneling were built into the initial condition. We also discussed — very quickly, but more than once — other interesting notions like how symmetry affects things like energy eigenfunctions and eigenvalues, how tunneling splitting between states for a 2-well problem works, and how when generalized leads to band structure. It was possibly ambitious and maybe none of this landed or will stay or be useful but we shall see. I certainly walked away reminded of the importance of the transition — from introduction to the math to ‘understanding’ -in my grasp of most of these ideas. I do know that the difficulty of the transition was because the math was new and it took some time to translate into intuition. I learned all this in the world before computer simulations/movies/visualizations existed, and I am *sure* it would have gone better and faster for me by far if I had had access to such tools. Perhaps all of us teach the course we wish we had had.

Below is an adapted version of what I said in my pre-class note for my quantum mechanics class.

Tomorrow in class I’d like us to start with numerical experiments (quantum video games) on the position-representation quantum mechanics that we’ve just revisited. We will work on HW for the second 1/2 of the class.

We will play with some jnlp apps to improve our intuition.

If you spend 20 minutes or so tonight (or before class tomorrow) looking at the apps (links below), it would save an enormous amount of start-up time in class tomorrow. Just try to get a sense of what the various knobs and buttons on the apps do, and play around a bit with the settings. These apps should work with lab computers, and/or with your laptops. I just installed it on my office laptop.

Here are the basic ideas to explore

(a) Tunneling: This jnlp app allows you to ask all sorts of questions about tunneling:

(b) Bound states:; make sure you click over to the two-well and multi-well bound states; both to to get a sense of more complicated problems and also how band structure arises in quantum mechanics.

When they walked in to class, they found 10 questions that I thought they could explore and were free to choose what they wanted and how many they wanted as long as they kept working at the questions. We spent 20-25 minutes exploring these questions (I had checked that we had enough laptops in the class and they landed up being in pairs or threes), and then we talked for 10 minutes together as a class. We finished with them working on the problems assigned.

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Two visiting positions (possibly 2 years each)

Posted by Arjendu on December 26, 2015

Here’s the link with more information:

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