“I have a little shadow that goes in and out with me/ and what can be the use of it is more than I can see.” Robert Louis Stephenson
“Glory be to God for dappled things!” G.M. Hopkins
We are born creatures of light and darkness, on many levels. From the darkness of the womb, we are pushed into the startling instancy of light. We sleep and wake according to the pattern of day and night. We spend our lives in the rhythm of sunrise and sunset, the color that lingers as evening fades into darkness, and “rosy-fingered dawn” (Homer), streaks the sky of a new day. Darkness and light become metaphors for ignorance and truth, for evil and redemption, for hate and love, for grief and joy.
Shadow, the product of darkness and light, is a constant for us, and a necessity for establishing the dimensions of what we see. Shadow can function to obscure and deform, to bring drabness and dreariness, and then again, reveal in the shifts—or play– of light and darkness the changing shape of the world around us, ebbing softly into roundness, dividing sharply into angles and planes– a box, a pyramid– or rendering the folds and falls of a tablecloth or a garment. An artist relies on light and shadow to compose a painting, rendering portraits that seem to shine from within like Rembrandt’s, or the dramatic contrast of the chiaroscuro used by Caravaggio.
All over the earth, light and shadow play in an ever-varying drama. Our lives play out that way, too, and so did those of the apostles, in the shadows of fear and hopelessness transformed into light-bearers, as darkness turned to dawn in the garden for Mary of Magdala, as the fearful tightness of the Upper Room yielded to Peace and Joy. There was Thomas, in the shadow of doubt, invited into the wounds of Jesus and believing; there was the Risen Lord tending a charcoal fire, a jolt of shame for Peter the betrayer, now turned into an Easter breakfast of love and mercy in abundance. Peter’s shadow was transformed into healing power for people who sought to lie in his shadow and be cured. There was Stephen, standing in the shadow of certain death, his face glowing like an angel’s. And they are us.
I am musing about the inevitability of shadow. Even as we profess the glory of salvation in Christ Risen, we dwell in spaces of darkness. Set free from bonds of sin and death, we are not spared times of doubt and pain. Shadow seems part of being human. But we are graced—Christed–with this insight: shadows are impermanent. In and around us they dim and flare, flash and fade, stretch and shrink, shaping our own unique play of light and darkness. We know the weight and weariness of the world. But the light that dapples our journey is sure–a promise that will not fail us.
As with Peter and the flame-lit disciples, there is a sort of Divine burnishing going on with us. We develop a certain glow, and to our surprise, flicker as light for others. Christ illumines our common path on the journey of faith and love that the Eastern church calls “divinization.” Standing around the new fire this past Easter Vigil, we heard the Exultet: “Rejoice O earth in shining splendor, radiant in the brightness of your king!” and we saw how the candle flames moved over the faces of those gathered. In truth, we are together aglow, walking in the shining shadow of the Paschal Mystery.
Chemistry describes the connections (a.k.a. bonds) among atoms. At this level, it is the sharing or exchange of only the outermost electrons which facilitates an increase in complexity from smaller atoms to molecules, crystals or metals. In this sharing or exchange of electrons, properties are completely changed. As we will soon see, community at every level is transformative!
BONDING BY SHARING BETWEEN ADJACENT ATOMS (COVALENT BONDING)
To begin, we start with two hydrogen atoms in isolation from one another. Their energy in this state is defined as zero as shown above on the right side of the picture. As the two atoms approach one another they are attracted to one another and so their combined energy is gradually reduced to a lower value until the lowest energy is achieved at the bottom of the curve.
This distance where the two atoms have the most stable energy is called the bonding distance or bond length and signals the formation of the resulting molecule. If the two atoms continue past this point to come closer together, they repel one another increasing the molecule’s overall energy once again. In response to this repulsion, the atoms return to the “sweet spot” where the energy is the lowest.
A single bond distance defines the hydrogen molecule and a specific lowering or release of energy is associated with the formation of that bond, the bondingenergy, for two hydrogen atoms. To break the bond and again separate the atoms requires an input equal to that energy. Hence, the molecule is more “stable” than two atoms existing separately. Coming together is about sacrifice yes, but also synergistic benefit.
A molecule is not the mere juxtaposition of more than one atom with others. It is about a new entity where the outer electrons are shared by the two nuclei making up the molecule. This sharing of electrons is so important, chemists use different terms to name the locations of the electrons. Before the two hydrogen atoms begin sharing the electrons, we say they exist in “atomic” orbitals, emphasizing their isolation from one another.
After the association of the two hydrogen atoms we say they now exist in “molecular” orbitals emphasizing instead their new identity as a hydrogen molecule instead of two hydrogen atoms. It is in this sharing of electrons that the two atoms are transformed into a single molecule. We call the sharing of the electrons, “covalent”, a co-operative sharing of the outer shell, or valenceelectrons from each of the atoms.
The combination of two atoms to form a hydrogen molecule is transformative for the atoms. The new hydrogen molecules have different physical and chemical properties than the originally separate hydrogen atoms. New possibilities for reactions now exist for the molecule that were not available before and other possibilities have been given up. The molecule is a trade-off with greater complexity.
Covalent bonds not only exist between atoms of the same type, but also between atoms of different types. These almost always share their bonding electrons somewhat unevenly, because the original atoms each have a different attraction for the electrons. Examples include water, H-O-H, better known as H2O, and carbon dioxide, CO2, or O=C=O. In both these bonds, the oxygen atom is known to attract the electrons more strongly than either the hydrogen or carbon atoms, resulting in uneven or polar bonds.
What is perhaps more amazing is that because water is a bent molecule it will interact with electric and magnetic fields, but carbon dioxide will not because it is linear. The details are not important here, except to say even the three-dimensional shape produced by the coming together of atoms makes the difference in the properties of the molecule.
Sharing of these outer shell electrons between atoms and the formation of a
3-dimensional molecule from atoms leads to an abundance of possibilities not open to just atoms alone. In fact, in the world of practical chemistry, it is the rearrangement of these very bonds that leads to the transformation of one compound to another, what we call chemical reactions.
Covalent compounds exist as molecules, literally “little lumps” of matter, very small communities where electrons are shared as needed among the member atoms. The elements called nonmetals such as oxygen (O), hydrogen (H), and carbon (C) (see above), participate in this type of sharing. They are known to hold onto these outer electrons quite tightly (have high ionization energies) and so although they are not likely to give them away, sharing is possible.
Metal atoms by contrast hold onto their electrons more loosely than nonmetals (have low ionization energies), so we will see a completely different type of bonding as atoms of metals and non-metals combine as discussed in the second section and as atoms of metals come together themselves (the third section)
In the periodic table notice the existence of “metalloids” which are intermediate in their properties between metals and nonmetals. These elements sometimes behave like metals and at other times like nonmetals, depending on what other elements are around them. (Sounds like some people whose behavior is dependent on their environment, eh?)
BONDING BY COMPLETE EXCHANGE (IONIC BONDING)
Another possibility for the combination of atoms involves the transfer of electrons rather than their equal or unequal sharing. A beautiful example of this is common table salt: NaCl, sodium chloride. Sodium (Na) is a highly reactive metal; indeed, it will violently react with water and form a solution of lye [drain cleaner], NaOH, in the process. Chlorine (Cl2), a yellow-green gas is poisonous, and was used in World War I as a chemical weapon before its ban by the Geneva Convention.
Yet, when sodium and chlorine are existent together as sodium chloride (NaCl), we obtain again an entirely new set of properties. Some of its most common uses include, but are not limited to: flavoring our food, melting snow and ice on our roads and sidewalks, softening our well water, and making paper and rubber.
How is it that this transfer of electrons comes about? Sodium metal, Na, begins with 11 electrons, in what we call “shells” of 2, 8, and 1. Each non-metal chlorine atom, Cl, begins with 17 electrons, with 2, 8, and 7 electrons in its shells. Shells listed first are nearest the nucleus and not likely to be exchanged, but those listed last, the valence, or outer-shell electrons, are furthest from the nucleus and are more loosely held.
As shown in the diagram, by the simple transfer of the one valence electron in the last shell from sodium to the last shell of 7 electrons in chlorine we are left with the sodium ion, Na+, with 10 electrons in shells of 2 and 8 and the chloride ion, Cl–, with 18 electrons in shells of 2, 8, and 8.
For reasons we won’t explore here these octets, or sets of 8 electrons, in the last shell are much more stable than the electron arrangement in the neutral atoms, not containing these octets in the last shells. The resulting Na+ and Cl– ions, being opposite in charge, are strongly attracted to one another.
In fact, we call sodium chloride, NaCl, for simplicity’s sake. This one-to-one ratio is simply the lowest ratio (1:1) of atoms in sodium chloride. The actual number of pairs is overwhelmingly great at room temperature. Atoms come together in such great numbers that we can see a single crystal of sodium chloride at room temperature. Think of that the next time you hold a crystal of salt in your hand!
Ionic compounds are almost always composed of a metallic element with a nonmetallic clement. The loosely held electrons are donated from the metal to the nonmetals, which hold on tightly to them. Examples include
calcium chloride, CaCl2 (used to melt snow from our sidewalks in winter)
sodium nitrate, NaNO3 (used to preserve some lunch meats and bacon), and
aluminum sulfate, Al2(SO4)3 (used in the purification of drinking water).
So, what difference does a transfer of electrons cause compared to sharing? Check out the contrasting properties of covalent and ionic compounds:
ions in crystals
types of elements
nonmetals with nonmetals
metals with nonmetals
physical state (250C)
usually gases, also liquid & solid
solubility in water
usually lower, except for acids
electrical conducitivity of solid
does not conduct electricity
does not conduct electricity
electrical conductivity of solution with water
does not conduct electricity, except for acids
does conduct electricity
BONDING BY OPEN AND WIDESPREAD SHARING (METALLIC BONDING)
Metals have a third way of coming together. Individual atoms of metals have loosely held electrons in their outermost shells as we know from their easy donation of electrons to nonmetals in ionic bonding. Yet when metals come together with other metals the sharing is remarkably different: they now share the electrons over a vast community. The outermost electrons are free to move in a matrix of nuclei with only their inner shells of electrons. We call these freely wandering valence electrons, the “sea” of electrons.
This property is what makes metals such wonderful conductors of electricity. The electrons are free to move throughout the metal from one place to another, when moved by an electric field. This sea of electrons is also the reason that metals are malleable and can be pounded in sheets, like aluminum or gold foil. Metals are also ductile and can be drawn in wires for the same reason. We use copper, for instance, to wire our homes and businesses.
widespread connection among metal atoms
types of elements
metal with metal
usually very high
physical state (250C)
solid, except for mercury (Hg)
solubility in water
does not dissolve in water
electrical conductivity of solid
conducts electricity easily
electrical conductivity of solution with water
no electrical conductivity due to dissolution
The way electrons are either shared or exchanged among atoms and how that leads to the creation of molecules, metals, or crystals, can remind us of the benefit for us as human beings to freely exchange or share our resources. For us too, the possibility of greater complexity and new possibilities awaits.
I don’t know about you, but I’m good at donating that to which I’m not particularly attached to someone in need. And, I have become better at receiving what seems to be “extra” from other people, especially if I really need it. I do the transfer of resources to and from myself (an ionic process) fairly well.
And, I suppose I’m even OK at sharing what little I have with others if they put in a similar share and none of us is particularly attached to what we’re sharing. My instinct to follow the wisdom of the metallic atoms seems intact too.
But, when I look at what I’m attached to, especially when I think a resource is scarce, I have grown accustomed to keeping “extra” for myself. My first inclination is the opposite of sharing, hoarding. So it makes me wonder: what new possibilities I’ve been missing because I haven’t participated in as much sharing (a covalent process) as the atoms do naturally? It’s a good question!
There’s a lot to learn from atoms, besides academic chemistry!
Bless the Lord, all you molecules that share electrons,
All you atoms that transfer electrons, bless the Lord.
All you metals with your seas of electrons, bless the Lord,
The Gospel today tells the story of Jesus on the road to Emmaus. I have heard it forever, but each time, I reflect on how much I have or have not come to know Jesus in any way over these years. Each time I hear it, I can ask what makes me even think I know Jesus?
Who did I meet on this road? Was it only the Jesus who overthrew the moneychangers; was it only the Jesus who cursed the hypocrites who called themselves the church leaders; was it only the Jesus who fought against the same old traditions that were holding the people back from knowing more about God? Did I meet that Jesus so that I could feel justified in my angry feelings about so much that is happening in my world today?
Have I really met the Jesus who is peace, compassion, mercy and forgiveness? Am I ready to meet that Jesus? Somedays it is so much easier to be angry and disappointed, just like Jesus seemed to be sometimes. But what about turning the other cheek or loving my neighbors, that was Jesus too, right? Why do I have to give in all the time? Well, maybe because I have come to know Jesus and it is not “giving in” that Jesus wants or “giving up” either. Jesus wants our hearts, our minds, our very beings to be His forever and ever and to show His compassion to everyone. Am I really ready to meet that Jesus!
I have written about life in our backyard from time to time, and Holy Week offers another chance to notice the connection between the way we look at the world and the way God sees it.
Actually, full disclosure up front, I’m not a fan of Lent. If it were up to me, we would have one 24-hour period of repentance (not 40 days) at the beginning of Holy Week. Something like the day of Atonement in Jewish tradition. Forty days seems like too much emphasis on repentance, and not enough on the other half of that coin – Easter Resurrection. I think it comes from my Philadelphia Catholic upbringing that focused on the “Jesus died for your sins” approach. As a young girl, I could not understand the logic of that approach: when I was not even born yet, Jesus died for my sins, so why was it my fault? I think this is the heart of Catholic guilt. You are to blame even if you weren’t there. And sometimes it takes a lifetime to see it differently.
But I digress.
Every living things knows the dying/rising cycle. I see it in our back yard all the time. Trees know it. Finches who were once grey and brown, come back to their brilliant golds and yellows. Snow drops and daffodils come back, because they know dying and rising. The grasses, the bees, the hummingbirds, the rose bushes. All know. They do not focus only on dying or only on rebirth. Winter does not say, “I am more important.” Spring does not say, “I am number one.” Nature is in balance. There is a season for each, a time for each. One leads to the other in an exquisite rhythm.
There is a balance and a beauty in the Holy Week drama when taken as a whole, when we see the complete story, the epic story from beginning to end (which is actually another beginning). So this year, I encourage you to be sure to take it all in as one beautiful, even theatrical, performance of Love.
In Act 1, Jesus prepares his followers for the long journey ahead without his physical presence by giving them the Bread of Life on Holy Thursday, teaching them servant leadership and forgiveness of sin. On Good Friday, Act 2, Jesus gives himself over to misguided and fearful men, in a time of moral and ethical corruption and social chaos. A self-sacrifice without assurances of a happy ending or a last minute rescue. In Act 3, the fallow waiting of Holy Saturday mimics the dormancy of the winter earth and the quiet time of expectation, of the hidden and mysterious working of God. The bursting forth of the Risen Christ in Act 4, reflects the explosive power of Spring, when all of nature awakens. All of life is changed and God unites our story of salvation with the story of creation.
So when you watch the back yard come back to life, remember that every blade of grass, every bumble bee and songbird is God calling out to you: Alive!
Scientists study various parts of creation, but since our knowledge of creation by this 21st century is so vast, at least compared to what it once was, it has become convenient to split our study of it into disciplines. As convenient as these divisions are in taming the enormous amount of knowledge, scientia, we have about the universe, the splitting of creation into bits makes its beautiful integrity less obvious. In this writing, I hope to reclaim a sense of this most wondrous fabric of the universe by examining how the various parts relate to one another and in that relationship how creation reflects its Trinitarian Creator we call God.
Each specialty in science studies a slice of creation, and in each one, we see how the whole made from its parts is more than their simple sum, because of the relationship that exists among them! What is less obvious is that this pattern occurs in every other science and just like a nested Russian doll, one layer can fit inside the other. Unlike the nested Russian doll, however, the synergy of coming together produces something new: what is made from the union of the parts has different and more complex properties as well as a potential for providing the building blocks for the next level. Some people call the coming together of the parts holons, to emphasize that the whole is not equal to, but greater than the sum of its parts.
In the coming months, I would like to take you on a “guided tour” through various levels of our universe. Some of these will be familiar to you, depending on where you have spent your life looking at creation; others will be unfamiliar, even at first perhaps uncomfortable. Don’t stress…be curious about the unity and the relationships. Don’t get distracted by the plurality of dialects within the various subdisciplines used to describe this integrative process. It is all the same process of community reflecting the Trinity as it produces more than a simple addition of the original parts.
What are these various levels? How many are there? Today’s blog begins with a simple catalogue, not necessarily complete, of various types of scientists and what they study:
Particle physicists study particles of the smallest types, like quarks, and how they combine to form the nuclei of atoms.
Chemists study atoms and how they form smaller molecules by their interactions.
Biochemists study larger biomolecules and chemical cycles that occur in organelles and cells.
Histologists study how whole cells operate and how they come together to make tissues.
Anatomists and physiologists study how tissues make up the organs which make up the systems in the body, and how they operate.
Microbiologists study how the smallest living creatures live, move and are alive.
Zoologists and botanists study not only organisms in their entirety, but collectives of organisms, like herds, as well.
Ecologists study relationships within local ecosystems and regional biomes.
Meteorologists study short-term weather patterns; oceanographers, the composition, life in and currents of the oceans; geologists, how rock emerges from the mantle, is transformed by weather and pressure, and then subtends back into the mantle. Each studies the Earth as a whole.
Climate scientists study the rhythms of long-term weather patterns on Earth, and how these rhythms are affected by the rhythms of the solar system.
Astronomers study the solar system itself and galaxies, even clusters of galaxies.
Cosmologists study the universe: its beginning and how it has evolved and is evolving.
In the coming monthly installments of the blog, I propose a guided tour of what synergies and interactions a scientist might see within his/her specific discipline, but not necessarily in the above order. My hope is that we will all begin to see more clearly just how close God is to us, at every level of the universe, no matter where we are! We may even understand more deeply how where we are informs us about Whose we are, and how what we do in our own communities reflects God’s own Self too. All aboard!