Wednesday, January 11, 2012

Space

I am continually amazed as I think about the nature of our world. We live in constant interaction with the molecules of the universe. We perceive things around us as solid objects: the keyboard on which I pound out these words, the desk on which my computer sits, and the dense mass of the mountains I can see out my window. We also perceive things in between the solid objects as empty space.

Yet, the space between the mountains and me, and my desk and me for that matter, is far from empty. That "space" is filled with molecules of nitrogen, oxygen, argon, and carbon-dioxide. The "emptiness" also contains water vapour, trace amounts of household chemicals, vapours given off by plastics and electronics, particles of my own body as dead skin cells flake off and float on the air or bio-chemicals from my lungs are expelled into the atmosphere. (It is all of this stuff that our bodies are continually giving off that allows a good tracking dog to detect us and follow our trail through the woods.) The space between me and the mountains is also filled with dust and industrial particles from a major city, electrons sent out from the sun in a continuous solar wind, and photons of light. Physicists are still unclear on the best way to describe the elementary particle/wave that is a photon but we can see that they are there.

The things that seem solid are less solid than our perception would lead us to believe. The molecules which make up these solid items have a significant amount of space between them and the individual protons, in the nucleus of these atoms, associate with electrons that are far away from the proton itself. To get an idea of these subatomic distances, let us consider a thought experiment in which we scale up these protons and electrons to the size of things which we are used to handling.

Here, I must give a few disclaimers about how this thought experiment will work. It will not be strictly accurate. Whenever we try to describe such molecular and atomic interactions, words will fail us. Mathematics is a language better suited to describing such things and yet most of us do not have sufficient mathematical fluency to converse about these subjects. A mathematical physicist would look at my crude description of protons and electrons and find many flaws within it. So think of it as a metaphor that might poetically, not scientifically, explain some of the sizes and spaces between things.

Allow me to take your imagination on a journey down into atomic spaces. The size of a proton is approximately 0.8418 femtometres (fm) or 0.8418 X 10^-15 metres. A very simple atom is the hydrogen atom. It consists of one proton and one electron. The electron orbits around the proton and the average distance from proton to electron is called the Bohr Radius. This distance is approximately 5.29 X 10^-11 metres.

Thus, if we scale up the size of the proton to the size of a basketball, the electron would orbit around the proton at an average distance of 1.60 X 10^4 metres = 16000 metres = 16 km.* If I held a basketball sized hydrogen proton in my living room, its associated electron would be somewhere around Richmond in the south, Burnaby to the east, the North Shore mountains to the north, or out over the Pacific Ocean to the west at any given moment.

This is the simplest of atomic models. The typical distance between two helium protons is
2.5 X 10^-15 metres. In our scaled up model, this distance becomes about 0.755 metres. Thus our basketball model helium atom would have two basketballs separated by 75 cm in my living room in downtown Vancouver and two electrons whizzing around in an orbit which again would include portions of Richmond and Burnaby.

The nuclear radius of Uranium is around 15 X 10^-15 metres. This involves 92 protons interacting together in this nucleus. In the model we have been discussing, that is 92 basketballs in my living room taking up about 4.5 metres of space. The cloud of 92 electrons would be similarly scattered in orbits far beyond the protons themselves. By the way, electrons are small, but present science has not given us a very good idea of their actual diameter.

Even the massive granite of a mountain (like the Stawamus Chief monolith near Squamish BC) is a complex interaction of molecules in which individual atoms are linked together by molecular bonds and share electrons between atoms. There are spaces between the protons and electrons and the whole thing is a spinning, buzzing, hive of activity despite the fact that we see it as a lump of rock simply sitting there since the mountain range was formed.

What do we do with this sense of space and solid objects? It is beyond our comprehension. There is something beautiful, mystical, and spiritual about it. It fills me with awe. It causes me to praise a creator who could create all of this and understand all of its complexities.
He counts the stars
and calls them all by name.
How great is our Lord! His power is absolute!
His understanding is beyond comprehension!
Psalm 147:4, 5 New Living Translation
*Basketball model: 254 mm Basket ball = 2.54 X 10-1 metres; 0.8418 X 10-15 metres proton; 5.29 X 10-11 metres average proton/electron distance (2.54 X 10-1 / 0.8418 X 10-15) X 5.29 X 10-11 metres; 3.02 X 1014 X 5.29 X 10-11 metres 1.60 X 104 metres = 16000 metres = 16 km.

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