Interactions of Energy and Matter

in the Oceans, Atmosphere, solid Earth, Sun, and stars and galaxies,

and in physics, chemistry, biology, and mathematics

© Bob Field 2003

1. Oceans

Water temperatures rise when sunlight is absorbed. Warm waters are buoyant. Variations in sunlight and season affect water circulation and the availability of nutrients and minerals for sea life. Ice floats in water, keeping the sea from freezing from the bottom up. The oceans profoundly influence climate and the evolution of the Earth's surface including life itself. The diversity, abundance, and distribution of marine life depend on the interaction of sunlight with seawater and on the influence of gravity. Thermal conduction, convection, radiation, evaporation, condensation, and precipitation transfer energy between the oceans and the atmosphere.

2. Atmosphere

Air temperatures rise when sunlight is absorbed by the atmosphere or by the surface of the sea and land. Variations in sunlight affect wind patterns, precipitation, and local and global climates. Global climate is strongly influenced by the scattering of light back to space by air molecules and by cloud droplets condensed from water evaporated from the oceans by absorbed sunlight. Global climate depends on the radiation of infrared energy from the Earth's surface and its absorption and re-radiation by the atmosphere. The Earth's rotation and the variations of density with temperature produce a circulation of air that redistributes thermal energy globally to compensate for the variation of sunlight with latitude and season.

3. Solid Earth

Heat was trapped in the planet when it formed. Radioactive decay continues to replace some of the heat being lost to space as it leaves the interior of the planet. Rock is a poor thermal conductor, and convection of less dense molten rock is important for heat transfer and the formation of continents and shallow waters that are vitally important to sea life. Gravity is the force that made the molten Earth into a near sphere.

4. Sun

No wonder that ancient people worshipped the Sun. Thermonuclear fusion in the core of the Sun releases energy in the form of lethal gamma rays. Nuclear forces are very short range and fusion can only occur when nuclei are packed very tightly, which occurs naturally inside the Sun due to the extreme gravitational force of the Sun's great mass. Gamma rays and other electromagnetic radiation interact strongly with the interior matter of the Sun. This heats the Sun to millions of degrees and traps and transforms the radiation gradually over thousands of years into mostly benign visible and infrared light that the Sun's surface radiates into space. Unbearably intense at the Sun's surface, the solar energy spreads out in space and is tolerable and beneficial when it arrives at the Earth's surface.

The Sun's gravity is responsible for the formation of the Earth. The Sun's gravity confined dust and gaseous material in compact orbits around the Sun for hundreds of millions of years. Collisions slowly formed the Earth and other planets. Eventually, nearly all of the stray material was safely confined to well-separated nearly circular orbits. The pull of the Sun still keeps the Earth in a nearly circular orbit where it can receive a continuous supply of nearly constant solar energy.

5. Stars & Galaxies

What good are stars besides making wishes on? The Sun is great for us, but stars are even more important. Our solar system would be nothing more than hydrogen and helium gases if it weren't for the stars that lived and died billions of years ago. Thermonuclear fusion in young stars transforms hydrogen into helium. The radiation released in the core exerts an outward pressure as it interacts with the gases in the star's interior. This force keeps the star from collapsing under its own weight by balancing the force of gravity for billions of years. When the hydrogen is depleted, gravity is unopposed and the star contracts, increasing temperatures and pressures until fusion resumes with the helium nuclei. The subsequent radiation pressure once again balances gravity until the helium runs out.

The Big Bang produced hydrogen and helium in great abundance, but did not produce any significant amount of carbon, nitrogen, and oxygen, which together with hydrogen form the bulk of the oceans, atmosphere, and living things. Over time, vast amounts of larger nuclei are produced inside stars by fusion. When some stars die, they explode, ejecting an abundance of elements into space, where they are available for incorporation in the next generation of solar systems to form. Our relatively young solar system collected these elements along with silicon, calcium, aluminum, sulfur, sodium, iron, and many other vital to the chemistry and biology of Earth. And naturally it was the collective gravitational pull of all the stars in our galaxy that confined the mass of our yet-to-be-formed solar system within range of these explosions.

6. Physics

Physicists investigate the fundamental interactions between energy and matter. Matter interacts over long distances by the relatively weak but always attractive force of gravity. Electromagnetic forces, which may attract or repel, are stronger, but tend to be neutralized by the attraction of opposite charges (positive and negative). Although electromagnetic forces tend to be dominant over atomic and molecular distances rather than astronomical distances, the Earth's weak magnetic field obviously has a global effect. Electrical forces hold atoms and molecules together in relatively stable forms that happen to be changeable within limits by interaction with energy that is readily available on our planet. The strength of these forces is essential for orderly change. Nuclear forces are very powerful but inherently short-ranged. They hold nuclei together despite the powerful repulsion of closely packed positively charged protons. Enormous energy is released when nuclei undergo transformations. Physics explores and explains the generation, absorption, and scattering of light and other forms of energy as well as the motions of atoms, molecules and macroscopic particles from dust to stars.

7. Chemistry

Chemists investigate the structure and behavior of atoms and molecules. The electrical forces associated with the transfer or sharing of electrons between or among atoms or molecules are the foundation of chemical processes. These processes are influenced by a variety of factors including the transfer of heat to or from a substance, the exposure to light, and the proximity to the influence of other molecules. Nearly everything that happens on our planet and among its inhabitants can be considered chemistry. Some of the most interesting and important chemical processes involve water, oxygen, carbon dioxide, and carbon compounds. Living systems exchange solids, liquids, and gases with their environment. Metabolic processes in living cells transform energy and matter to create and destroy proteins, carbohydrates, nuclei acids, and lipids.

8. Biology

Biology involves living systems that interact with each other and with the environment. Like chemical processes, biological processes involve the transfer or sharing of electrons among atoms and the interaction of atoms and molecules with electromagnetic energy. Most of the mysteries of life have been found to have biochemical explanations, but the complexity of life has not revealed whether there is more to life than extremely sophisticated chemistry. One can only hope. Biological systems inevitably must transfer materials and energy to and from the environment in order to function. Sunlight and materials with chemical energy stored from previously absorbed sunlight provide the energy for metabolic processes. Materials exchanged with the environment include gases, liquids, and solids. Organisms are parts of ecosystems and are organized at the cellular level and often as multicellular forms with higher levels like tissues, organs, and systems of organs, each with specialized functions. Ultimately energy that is released appears as heat that must be dissipated by conduction or convection. As important as thermal insulation and burning calories is to the warm-blooded sea otter, ironically the failure to remove heat efficiently has also resulted in the deaths of many sea otters.

9. Mathematics

Scientists use a variety of tools to explore the natural world. They use their eyes and ears and they develop instruments that can sense forms of energy more precisely or in ways that are beyond the ordinary senses. Measurements in field studies and experiments in laboratories provide information about the interactions of energy and matter under a variety of natural or controlled conditions. Mathematics is another tool available to scientists to help interpret data and to predict what may occur under conditions that have never been observed directly. Mathematical models allow scientists to design new experiments or new instruments for making observations. These models are often cheaper and faster to build and may make the difference between success and failure for a research project. Some of the most interesting mathematical functions involve power laws such as inverse square decreases in energy fluxes, variations of area and volume with the square and cube of a linear dimension, exponential growth and decay rates, and sinusoidal variations in periodic processes. Integral and differential calculus allow one to sum the contribution of multiple diverse elements and to determine the rates of change of natural processes.