Boiling Water at High Altitudes: A Representation of American Scientific Literacy

A recent survey by the Pew Research Center found that Americans are more likely to answer correctly questions related to basic science concepts than to scientific understanding [1]. Among the bank of questions, ones such as which layer of the earth is hottest and whether uranium is used in nuclear energy were answered correctly more often than ones such as whether the amplitude of sound waves causes its loudness. The question answered incorrectly most often was whether water at higher altitudes boils at lower temperatures with only 34% of respondents knowing that, indeed, it does.

Fig. 1: Results of Pew Research Center survey (Pew Research Center, same as reference 1)

Public scientific literacy is an important goal to work towards for developed countries. As Cary Funk and Sara Kehaulani Goo of the Pew Research Center posit, the ability to understand scientific concepts is crucial to people being well enough informed about current issues such as GMOs and the energy crisis to make educated decisions in the polls. Scientific literacy also makes daily life easier by finding more efficient solutions to everyday problems.

As a small step towards improving scientific understanding, let us discuss why it is easier to boil water at higher altitudes.

Liquid water and water vapor exist in a sort of equilibrium. There are a number of factors that can shift this equilibrium, but one we interact with daily is temperature. Say you spill a glass of water. Of course, a large spill would require immediate attention, but if only a thimbleful of water was spilt, some would be inclined to let it evaporate. Evaporation involves two main processes at play. First, the water is receiving kinetic energy from its surroundings in the form of heat energy. Second, the water is in higher concentration in the spill than in the spill’s surroundings and therefore a concentration gradient is formed at the water’s surface.

So what has this all got to do with boiling water? Well, water boils when transforming into a gas. Therefore, boiling water is a phase transition described by the equilibrium between liquid water and water vapor. Besides temperature, pressure also affect liquid-gas equilibrium as described by the ideal gas equation,

                  1.       PV=nRT (P is pressure, V is volume, n is number of molecules in moles, R is the gas
                   constant, T is temperature)

LeChatelier’s principle states that a system in equilibrium will move away from an induced change. In the case of an increase in pressure, we can see that if n and T remain the same then the ideal gas law describes a shift to decrease V, volume. On the other hand, a decrease in pressure should cause a shift towards a higher V. This means that at lower pressures, water prefers to exist in a gaseous state and the equilibrium shift will cause the water to boil. This is the foundational concept of rotary evaporators, which use the concept of reduced-pressure boiling to remove solvents.

Fig. 2: Deriving atmospheric pressure in atm's (Pearson)

Now all that is left is to link pressure to altitude, which isn’t too hard. By definition, atmospheric pressure is defined as the weight of the atmosphere over an area at sea level [2]. For example, one inch of land at sea level partitions a pillar of atmosphere weighing 14.7 lbs, so atmospheric pressure in PSI is 14.7 lbs/in². A logical extension of this concept would tell us that at any altitude greater than sea level, the pillar of air would be shorter and would consequently weigh less. This is the missing link we were searching for between pressure and altitude. Putting all of the above information together, we see that a decrease in pressure causes liquid water to favor boiling and that an increase in altitude causes atmospheric pressure to decrease. Therefore, water boils easier at higher altitudes.

Scaling the results of the survey to education levels, the Pew Research Center also found a correlation between higher education and scientific knowledge. But this is not a given. Even as college students, we must all work towards insuring that we are among the scientifically literate ready to contribute educated opinions to today's social debates.

Approaching Herbalism from a Scientifically Literate Perspective

Is there really a founding for believing in herbal medicine? This seems to be a question many Americans are asking in a time when the concept of “human is better” is waning in favor of a return to an attitude that acknowledges we have a lot to learn from nature. Much of herbal medicine may seem like hocus-pocus, but scientists are not as against herbalism as some would think.

A first thought when someone mentions herbal medicine might be something along the lines of dried seahorse and mummified gecko. This is especially true for Americans where there is a high Chinese cultural medicine presence and where such practices are often caricaturized by the media. However, not all herbal medicine is so strange. Some common examples of herbal medicine practice could be honey-ginger tea for a sore throat and aloe (Aloe vera) for sunburns, both of which can be commonly bought in major store chains. As it turns out, much of the world uses some form of herbalism [1]. This shouldn’t come as a surprise. It is against human nature to accept illness as it comes, so wherever there are people there is likely to be medicine as well. But living in the time we do, both traditional herbal medicines and contemporary scientifically produced medicines are readily available. So which should we choose?

Fig. 1: Herbal medicine utilization by country (ClubNatu, same as source 1)

Herbal medicine is steeped in traditional medicine practices that developed before the scientific method and its instruments were available. Yet even so, many herbal remedies have come about through a rather logical process. Take even a fictitious, highly religious pre-scientific society where medicines are attributed to gods. If a medicine doesn’t heal its patient, then the instinct is to throw it out primarily because it’s useless and perhaps also because it makes the gods look bad. Our ancestors were smart enough to develop a working knowledge of herbs through thousands of years of trial and error, a highly valued logical test still used today in medicine development.

The argument some give in favor of a return to herbal medicine is that it’s more “natural” than modern synthetic drugs. This is not a well-based argument from a scientific perspective. Instead, we should consider factors such as effectiveness, side-effects, general safety of the herbs and the ecological impacts of its widespread prescription, each of which must be individually assessed per herb. The effectiveness of herbal remedies is a subject of increasing research attention as many have proven to possess clinical efficacy. Aspirin, for example, emerged from a more mild treatment of salicylic acid, a chemical found to exist in the bark of the white willow (Salix alba) tree used in traditional medicine. It has recently become a growing practice to scientifically test a wide number of natural products and traditional remedies as a high-throughput system for scouting out potential new treatments. Some herbal remedies have also been found to offer their effects with less side effects than modern medicine [2]. This could be due to a plethora of possible reasons including active dosage or the presence of other compounds to neutralize negative effects.

Fig. 2: Most popular natural products (including herbs) in the United States (NCCIH)

So where do herbal medicines fall short? All medicines have their associated risks, but a lack of herbal toxicity knowledge and of prescription guideline enforcement brings into question the safety of some herbal medicines [3]. The ecological effects of manufacturing herbal medicines must be considered as well. Paclitaxel, a drug with anti-tumor properties listed on the World Health Organization’s List of Essential Medicines, is a natural product from the bark of the Pacific Yew (Taxus brevifolia) tree [4]. However, wild-crafting this compound would devastate the tree population. Thus there is an inherent economic limitation on herbal paclitaxel, and so the synthetic generation of this natural compound is now the main route of production.

Herbal medicine is a topic that has been making a comeback under the realization that we have much more to discover about our medical pasts through a scientific approach. Personally, I am inclined to believe this is a step in the right direction since it is never bad to know more about plants that could potentially save our health. After all, it takes just one paclitaxel to make the search worth it. Social opinions on herbalism as a form of alternative medicine are shifting towards the positive, and as scientifically educated individuals we should keep ourselves updated on this movement.  

On The Definition of Sustainable Energy

Let’s finally cover what I meant by truly sustainable energy production.

Listing electrical energy generation methods portrayed as sustainable, many would consider solutions such as solar power, wind turbines, hydroelectric dams, geothermal plants, sun farms, wave generators, nuclear power and nuclear fusion to fit the image of futuristic green power. But while all of the above may be green, not all of them are sustainable. To me at least, it seems that green energy is measured from the present as a bench point: anything that produces less greenhouse emissions or causes less ecological destruction than methods currently employed is considered "green." However, sustainable energy production is a more definite construct that can be described through thermodynamics.

From thermodynamics we know that every work-energy conversion in our universe is irreversible, meaning that energy is lost as heat every time something is done. Taking the planet earth as a giant engine, which is accurate in the sense that most life processes convert available energy into work and expend heat, we can conclude that the earth needs constant energy input in order to continue running. Aside from ambient space radiation produced by other sources, the sun is the only source of energy earth knows consistently from day to day. This is something many of us should experientially understand, contrasting the death of winter when days are short to the blossoming of spring when long sunlight returns.

Fig. 1: Boston sun angle during the seasons, affecting solar energy influx (Science Blogs)

Therefore, in order to be sustainable within the lifetime of our sun, an extremely high life expectancy for planet earth, our energy generation tactics should be geared towards the sun’s life-giving energy. Does this mean that solar is the only way to go? No, absolutely not. The sun’s energy hitting the earth enacts a grand cascade of events that grow wind, help generate tides and keep the water cycle flowing. This extends the definition of sustainable energy generation to include wind power, wave power, and hydroelectric generation.

Another side category of what I would consider sustainable energy sources includes those whose failure would correspond with the end of life on earth. One example is geothermal energy. Sure, eventually the earth’s core may cool down, but there would be bigger problems associated with this scenario than humans running out of electricity, such as the dissipation of the earth’s magnetic field letting a bombardment of solar radiation char the planet. Wind power may also be considered part of this category, as wind is in part generated by the Coriolis Effect that depends on the earth continuing to spin. If the earth stopped spinning, bad things would ensue.

So what is not covered under the definition of sustainable electricity generation that is commonly perceived as such? The top two that really get to me are nuclear energy and fusion energy. The selling point of nuclear energy is that it is clean in terms of greenhouse gas generation. However, clean does not directly translate into sustainable. The input into nuclear reactors is uranium, and lots of it. Uranium is not an uncommon element on earth, but a large 1000MWe nuclear power plant requires about 200 tons of refined uranium to operate for one year [1]. Refining uranium is itself a wasteful process, and mining large amounts of ore has an ecological impact as well. Nuclear fusion is often sold as the sustainable energy solution of the future, but in actuality nuclear fusion requires the same input as the sun does: hydrogen. With so much hydrogen on earth, why would this be a problem? Call me paranoid, but any time someone wants to convert something necessary for life into a luxury item (yes, electricity is a luxury item) and some useless helium, then I begin to worry. And relative to the sun’s supply of hydrogen, earth’s hydrogen bank is chump change. The hydrogen fusion reaction that generates the most energy is that of deuterium (₁H²) with tritium (₁H³) as described by this equation [2]:

                                                        1.  ₁H² + ₁H³ = ₂He⁴ + neutron

If we calculate the mass difference

       2.  m(₂He⁴) + m(neutron) – m(₁H²) – m(₁H³) = 4.002602 + 1.008665 – 2.01412 – 3.016050  =                   5.011267 – 5.030152= -0.018885 amu

then insert this mass difference into Einstein’s mass-energy equation

                  3.  ΔE=Δmc²

                  4.  Δm=0.018885 amu(1.66053892 x 10^-27 kg/amu)

                  5.  E=(3.135928 x 10^-29 kg)(3 x 10⁸ m/s)² = 2.82 x 10^-12 J/He nucleus formed

and convert the result into a meaningful number

       6.  2.82 x 10^-12 J/He(2.778 x 10^-7 kWh/J)(1 He nucleus formed/2H nuclei consumed)=
            3.92 x 10^-19 kWh/H nucleus consumed(6.022 x 10²³ H nuclei/mol H)(1 mol H/((2.014102 +                   3.0160492)/2) g) = 9.39 x 10⁴ kWh/g H

we get that 9.39 x 10⁴ kWh of power can be generated from one gram of hydrogen gas (assumption made that hydrogen composition is half deuterium, half tritium). Considering that the average American consumes 10,908 kWh annually [3] and that the population of America is about 321 million [4], approximately 37,300 kg of hydrogen gas would be consumed annually to support America alone by fusion energy. This is not zero input.

All in all, what I am trying to say is that science has laid out a very specific definition of what sustainable energy truly is, so it is the job of every person to evaluate whether what is being portrayed as sustainable energy generation is truly backed by the facts.

Does your definition of sustainable energy sourcing differ? Let me know your thoughts in the comments below!

Iggy Azalea and the Scientific World View

Possibly my favorite Iggy Azalea music video is of her song "Fancy." My interest in the video has nothing to do with whether or not I am, indeed, fancy, but has to do instead with that in portraying an extravagant high school she unknowingly created a snapshot of the scientific wealth of our society. To show you what I mean, I am posting below a walkthrough of the many scientific fields and concepts related to major symbols in just the first minute of her music video:

• Shiny night gown – polymer chemistry (spun polyester, dyed synthetics), petroleum engineering (plastic input extraction)
• Tablet – materials science (circuit components), computer science (HTML, CSS, OS), electrical engineering, math (image processing)
• Sunglasses – materials science (polymer optical properties), physics (light wave polarization, optical refraction)
• White board – polymer chemistry (plastic surface), organic chemistry (marker ink)
• Paper air planes – ecology (responsible (assumedly) forestry), paper chemistry (lignin removal, cellulose bleaching), aerodynamics (gliding flight, airfoil), psychology (motives to throw airplanes in class)
• Plaid shirt – textile chemistry (cellulose extraction and bleaching, softening, dyeing, cotton anti-static/anti-wrinkling), mechanical engineering (industrial looms), computer science (pattern programming)
• Fuzzy hats – polymer chemistry, mechanical engineering (machined faux-fur weaving)
• Lunch table – materials science (metallic corrosion), polymer chemistry (blue anti-rust coating)
• Lunch – organic chemistry (food coloring, gelatin protein matrix, pesticides/insecticides, Maillard reaction), agricultural chemistry (fertilizer), polymer chemistry (plastic trays, PETE bottles, HDPE bottle caps, PS utensils, jello cups), materials science (plastic-metal laminate jello lids)
• Cheerleaders – biochemistry (ATP/ADP, insulin signaling, neuronal action potential, calcium ion muscle contractions), human physiology (muscular/cardiovascular systems), physics (inertia, statics)
• Stadium complex – materials science (metallurgy for light posts, optical materials for lamps, concrete), structural engineering (stadium structure)
• Pink designer shirt – economics (brand-name price factor), sociology (brand choice)

If my bizarre method of enjoying this Iggy Azalea music video speaks to anything beyond my personality, recognizing that each scene contains a collection of scientific triumphs demonstrates that science is not just a complex skill set that takes forever to build, it is a way of thinking as any other profession is. And even if the average person does not possess the full scientific skill set, which is a fair expectation, the scientific way of thinking, namely recognizing the everyday role of scientific principles and applying the scientific method and philosophy when confronted with problems, is a learnable world-view for the average person.