BESC 320 – Water and Bioenvironmental Science

(Lecture 1; 17, 19 January 2018)

Course web page: http://people.tamu.edu/~tdewitt/besc320/index.html

Philosophy and Learning Goals Nearly every fact you learn is boring. Synthesis is sublime Memorizing information is not learning in a meaningful sense Learning concepts (integration and organization of information) is

meaningful Learning to reflect, to twist facts and concepts into new

syntheses that solve stubborn problems… that is the goal This requires building a framework to accommodate interrelated

information—the larger the framework the more complete and useful it will be

Concept rotation / lateral thinking (you write a definition):

Goals for this course:Learn disciplinary information from multiple relevant fields Learn to think conceptuallyLearn to think integratively (build conceptual framework with information

from different domains)Learn to think creatively (come up with ideas no one else has thought)Learn to think thoroughly (carry through logical scenarios to distant yet

probable ends)Learn to think about connectedness of disciplines and entities (e.g.

interactions of physics, ecology, infrastructure, stakeholder values)Learn to think globally/internationallyLearn to think quantitatively (e.g. understand research and modeling)Practice group communication (practice preparing and giving oral

presentations; practice group work).

Read scientific literature (gain information & facility extracting information)Practice participation in scholarly oral discourseSpark and feed your sense of wonder about the worldNOT LEAST: Apply understanding and synthetic skills to solve problems in water use and sustainability.

Source: Inside Higher Ed

Structure of course—tour of syllabus

Invention example: Desalination of irrigated croplands. Pickleweed sequesters salt in specialized cells. Stem sections with too much salt die, and the plant grows new shoots. Why not grow this plant, bred to crazy extremes, in salinized cropland, harvest and remove the plants (and salt)?

For Friday: Locate, read and reflect on a water-related news story— We will discuss some of these.

“The primary goal is to reduce suffering, and to do that one must understand the world.” —The Buddha

Mankind has done a fair job of discerning the nature, workings, and history of the physical world. Here’s what we have been able to piece together:

14 bya the universe was formed 4.5 bya our planet was formed contained key ingredients for emergence and maintenance of life

On the latter point, water, carbon dioxide, nitrous oxides, and mineral ions in liquid water and an energy source started life (Miller/Fox experiments). Water is the lynchpin. For in water, the chemistry of life, no matter what form it was to take, was possible.Obviously it took the form of what you see today… cellular, nucleic-acid based, self-replicating organisms. Organisms, for purposes of this class, are self-contained water vacuoles, conducting chemistry that powers self replication. Traits that make us spiritually human in this view are epiphenomena—greed, love, passion, etc.—and these traits also impact our interaction with water outside our self-contained vacuolar selves.

Water Physical Sciences I (chemistry)

OverviewWater is dihydrogen monoxide, H2O. It has extremely unique properties that make it vital for probably all life processes. The structure of water is as follows. Note that oxygen has two electrons to share and hydrogen in its ionic state (a proton, when dissolved in water) has a single electron deficit—thus two H bond to one O:

The electron surplus for the O creates a negative charge on its side of the molecule, with positive charge on the 2H side. Because of this shift in charge across the molecule we call water a polar molecule.

Water’s polarity allows it to interact with so many other molecules it is called the “universal solvent”.

Water even interacts with itself:

Hydrogen bonds hold liquid water together.

Normal orientations

Polarity also allows water to interact with an electric field.

Disrupted orientationsThis is how the composition of water was discovered by Lavoisier.

Antoine Laurent Lavoisier (1743-1794) is considered to be the father of modern chemistry. He discovered the composition of water by running electric current through liquid water. The electric field breaks up liquid

water’s tight conformation (contrast last two figures) and liberates the component gases. This process is known as hydrolysis (hydro: water; lysis: to cut). Lavoisier quickly found there were two component gases , one lighter than air, and one fundamentally like air. One of the gasses he found could be breathed by animals to sustain life. He named that gas oxygen (oxy: acrid; gen: to make) under the (flawed) idea that it is a component of acids. The other (lighter) gas was flammable—but only in the presence of oxygen. He found when the second gas was burned it makes water, so he called it hydrogen (hydro: water: gen: to make).So… electricity takes water apart, and fire puts water together.

Water can dissolve (bring into solution as ions) most compounds or elements you can think of…

solids like iron and rock gases like oxygen and carbon dioxide and other liquids like sulfuric acid and sodium hydroxide

Here is what water does to table salt: (consider stage performance)

Water therefore serves as a storage compartment , transfer medium , and chemical mediator for a huge fraction of chemistry on our planet.

Think of all the nutrient cycles from BESC 201:

Carbon cycle

Know this equation forward (photosynthesis) and backward (respiration)

Phosphorus cycle

Nitrogen cycle

Water participates in all the terrestrial and organismal components of the cycles above. Why is water so important and ubiquitous in planetary functions?

Universal SolvencyAny time you see a charge indicated on a molecule, it is an ion, and is likely dissolved in water. For example, phosphates (PO4

-) are created by disolution of minerals and from decay of organics. Any time you see an “ate” in a chemical name—indicating it is a salt—you know it dissolves in water.

We could do the same line of arguments for other cycles, like sulfur. Which should remind you about acid rain:

2H2O + SO2 + SO4-- 2H2S04

(try this with carbon dioxide)

Other Unique Properties of Water Clouds are white (increase albedo of planet) As for most substances, water becomes more dense as

temperatures drop. Except as temperature drops below 4 °C water grows less dense and solidifies at 0 °C.

Water has high specific heat capacity allowing it to adsorb and emit relatively large amounts of heat without a change in temperature

Water has large latent heats of evaporation and freezing as a result of hydrogen bonds, with the result that phase changes of water are an important heat-transport vehicle

Strong cohesion (surface tension) & adhesion (wetting), the balance of which makes for capillarity

water (dyed) mercury

What are some important consequences you can think of regarding water’s high cohesion and adhesion?

More fun with the properties of water: cohesion, adhesion, capillary action and surface tension:

http://science.jrank.org/pages/1182/Capillary-Action.html (Note the video at the bottom begins slow but gets good)

Reflect & consider:

Why does rain fall in drops? Why not cubes?Why do water droplets run together?How do the former answer relate, abstractly, to this:

How do sweating, panting and swamp coolers work to cool?

How do trees hoist water to their limbs hundreds of

feet above ground?

What are some important consequences you can think of regarding water’s high cohesion and adhesion?

(H2O)3 — chemical formula for ice cubes —Dr. DeWitt

Your education really is the job of a lifetime and it commences now.— David Foster Wallace

How do we study without a text?

Lecture notes point to concepts. Rely on your notes to know what detail to learn— outsource learning

material (e.g. Wiki’s etc.). Pay attention to my cues (“you need to know this”; “understand this in

concept”) Even my tangents if they have information content (not just stories about

Lynn Margulis). External content is important—that is why I provide links in the notes to any

external content I use—so you can review the material outside of class. Example questions:

What is “planetary physiology”?a. dynamics of vulcanism on Earthb. atmospheric exchanges with spacec. connected cycles acting on a planetary scaled. use of satellites to monitor planetary conditionse. telepathy

What percentage of Earth’s water is fresh?a. 97 %b. 30 %c. 5 %d. 3 %e. 0.03

What holds water together, making it dense and viscous? (see Wiki on hydrogen bonds )