Sunday, February 24, 2013

Solar System Stability

The recent 100-year meteor strike on February 15 may have triggered some apprehension about the stability of our Solar System, the abode of humans in the cosmos. By marked coincidence, Asteroid 2012 DA14 passed Earth from a different direction on the same day, coming within 17000 miles, closer than nearby earth communications satellites. The object was much larger than the Russian meteor but posed no danger to Earth dwellers. These two recent events cause us to reflect on the nature of our Solar system. How predictable and how stable is it? Do we live in a chaotic solar system characterized by space debris bombarding Earth like a target at a celestial shooting range? The two recent events notwithstanding, let us consider the remarkable stability of our multi-billion year old Solar System.

The picture of our Solar System with its central Sun surrounded by eight orbiting planets and millions of much smaller objects has been presented to us from our childhood as an orderly and predictable system. Modern man, created uniquely in the image of God, has inhabited planet Earth only for a few tens of thousands of years. The Solar System as part of the cosmos, however, has been present for the last several billion years, roughly one third of the time elapsed since the event described in Genesis 1:1: In the beginning God created the heavens and the earth. The events of the six creation “days” of Genesis 1:3-31 followed long after the verse 1 beginning.

Let us answer the questions posed in our first paragraph. Is our Solar System a chaotic system? One common definition of chaos is “complete disorder and confusion.” On February 15 some may have answered, “Yes,” but that would be completely false. Mathematicians have attempted to answer the question for centuries, including French astronomer Laplace in 1773. He made a serious attempt to offer mathematical proof of the fundamental stability of the Solar System. He came close in his attempt. Isaac Newton in 1687 “believed that divine intervention might occasionally be necessary to put the solar system back in order and prevent its dissolution.” Ivars Peterson’s volume Newton’s Clock…Chaos in the Solar System states, “The Solar System has apparently survived for more than four billion years in some semblance of its present form…None of this work (speaking of computer modeling) provides evidence that the Solar System is falling apart.” (italics mine)

Another modern usage of chaos gives a different picture. “Chaos theory” describes the underlying order of a complex system in which even tiny initial changes could yield a widely diverging result far down the road. For example, the popular example of the fluttering butterfly wing at one geographic location (the Butterfly Effect) triggers a chain of events which ultimately could generate a hurricane at some distant place on the earth. In theory, The Butterfly Effect may be more than science fiction. A chaos theory scenario involving our billions of years old Solar System may be worth contemplating without being accused of bowing at the altar of pure science fiction. Ivars Peterson writes: “In the case of the Solar System, the question is whether the multifarious influences of every body on every other body shift the planets from their essentially unchanging orbits only slightly and temporarily, or whether these effects can eventually lead to radical, irreversible changes…”

Peterson’s most significant observation relates to the ongoing mystery surrounding the long standing stability of the Solar System: “…The problem of the Solar System’s stability has fascinated and tormented astronomers and mathematicians for more than 200 years. Somewhat to the embarrassment of contemporary experts, it remains one of the most perplexing, unsolved issues in celestial mechanics.” Our current vision of this apparent stability could relate to our intuitive recognition of the initial and ongoing work of God.

Whether or not we believe, as Isaac Newton believed, that God’s ongoing intervention was necessary to periodically restore planets’ orbits to their places, virtually everyone could agree that our universe is a divinely ordered place. In over four billion years, the potentials of chaos theory have not brought about disaster on our planet. The Solar System in which we reside is a beautiful and unique place.

Monday, February 18, 2013

Meteors of the Century

The term “….. of the century” conjures up reverent awe. In a culture immersed in literary superlatives, we may have difficulty distinguishing the literary from the literal. Consider 100-year weather, geological, astronomical, or historical events--are they real, or are they assigned truth status only by a journalist? Some events gain 100-year status less easily than others because they are not subject to human judgment. Most scientists agree the Russian meteor fall of February 15, 2013 in Chelyabinsk is not subject to opinion. It was unanimously acclaimed as the largest recorded object to strike the earth in over 100 years. In 1908 Earth was struck by a similar but much larger object which leveled 80 million trees over 825 square miles in a remote region of Siberia. Neither blast caused any human deaths.

Knowledge of our Solar System captivates many. If Earth, our own planet, fails to supply enough fascination, there is much to know about the other seven planets—their appearance, size, movement, and the conditions present. Most images of our Solar System do not highlight the presence of millions of additional bodies apart from the sun and its planets, such as asteroids and meteoroids. Technically, asteroids are chunks of rock or metal larger than one meter in size. Meteoroids are similar but have a diameter smaller than one meter. On the spectrum of rock size, the Russian object was a multi-ton asteroid possibly 15 m in diameter which entered earth’s atmosphere at a shallow angle and exploded about fifteen miles above the surface. The blast injured over 1000 people, damaged 4000 buildings and caused over $33 million damage according to estimates, primarily from broken glass.

A meteor strike on this planet is an occasion triggering awesome reflection for many reasons. We contemplate what kind of cosmos this is. In particular, in what sort of solar system do we abide? Over one million asteroids exist larger than one km diameter in the orbit between Mars and Jupiter. Smaller rocks exist there in the uncounted millions. In contrast, even in the sparsely populated region of the inner planets, there are yet tens of thousands of near earth asteroids (NEA) which buzz the regions of Mars, Earth, Venus, and Mercury. An International Astronomical Union (IUA) publication “A Chronology of Milestones” captivates attention with its statistics. Of the near earth asteroids the IAU publication states, “Due to gravitational perturbations caused by planets as well as non-gravitational perturbations, a continuous migration brings main belt asteroids closer to the Sun, thus crossing the orbits of Mars, Earth, Venus, and Mercury.”

People prone to worry could become overly concerned about earth’s sometimes violent weather such as thunderstorms and hurricanes, earth’s periodic geologically harsh manifestations such as volcanoes and earthquakes, and yes, even the possibility that earth may someday receive a fatal asteroid strike such as the massive one theorized to have caused the extinction of the dinosaurs 66 million years in the distant past. Ongoing discoveries of sizable near earth asteroids are filling reference books as research data is added to our knowledge. Specifically, near earth asteroids (NEA) including some deemed to be potentially hazardous (PHA) have proliferated from 1970 to 2013 progressively, from 27 NEA (10 PHA), to 53 (17), to 134 (42), to 877 (215), to 8694 (1221). Potentially harmful asteroids (PHA) are defined as coming within 19.5 lunar distances (LD) of earth (7.5 million km). It is significant to note that no human has ever been killed by a potentially harmful asteroid (PHA) in recent recorded history, even though we note two highly significant asteroid impacts in 1908 and 2013.

When scientists describe man’s Solar System abode, it is apparent that God has provided a home on Earth which wonderfully provides for the existence of man. Asteroids and meteoroids are part of the Solar System formed over millions of years in preparation for the recent arrival of humans. The earth as a solid body is also the product of a developing planet whose resources were in place when created man first arrived. God commanded that man should subdue the earth. Man quickly learned how to use the earth’s agricultural and mineral resources to provide for his need of food and shelter. Genesis 1:31 is a passage which concludes the record of the sequence of earth preparation culminating in the arrival of man. After six days of creation events Earth was ready to provide for the needs of man. The Earth, by God’s gracious providence, has continued to provide resources to fulfill man’s needs up until this very moment in history.

Friday, February 15, 2013

Storms of the Century

So-called hundred year storms occur with increasing frequency, sometimes every ten years, we joke. Hundred year storms are not a predictable phenomenon, because weather systems do not depend on long-range statistical predictions. The science of probability is far from exact. The early February New England snowstorm was touted in many reports as “The Big One.” The storm turned out to be significant, but its impact was downgraded to one of the top snow producers of all time. We may wonder how a few tenths of an inch of total snowfall makes a difference when we rank the severity and impact of a major snowstorm. In Boston, this snow-producer ranked #5. Ski resorts in northern New England eagerly anticipated a better season than last year’s financial disaster.

Since last week I have been reviewing weather records from many past decades. I have also reviewed my personal recollections of significant winter storms. These recollections reinforce my suspicion that most blizzards primarily affect limited regional areas. While historic regional storms are significant, truly monster storms impacting broad geographical regions fall into a different category.

Such is the Superstorm of 1993. The storm rightly deserves the accolade “Storm of the Century” from fascinated weather historians. Personal recollections imprint such events on our memory. In that category, I recall traveling several miles from our New Jersey home to shovel off my father’s flat-topped garage roof before the 30 inches of heavy snow collapsed it. Syracuse, New York, a city a few miles from my birthplace, received 43 inches during that storm. Historic details of that monster blizzard and incredible statistics of the superstorm consign my personal recollections to insignificance.

A careful search of the literature should convince readers that this was the most severe winter storm ever to strike the United States in terms of overall scope. Stu Ostro, senior meteorologist at the Weather Channel wrote this in his blog entry about that 1993 Superstorm in 2008: “With 26 states and estimates of 100 million people being affected, a severe impact on travel, hundreds of fatalities, and billions of dollars of damage and other economic losses, there’s not been a winter storm in historical weather records before or since, at least in the U. S., to match the overall scope and effects of the one on March 12-13, 1993.”

The catalogue of that storm’s statistics is overwhelming. Following is a partial and inadequate listing. The storm extended from the Gulf of Mexico, Florida, and even Cuba, to southern Canada, impacting states in the south with record cold, wind, snowfall, thunderstorms, and tornadoes. The storm in the Gulf of Mexico capsized one ship, causing seven deaths, and generated ocean storm surges resulting in drowning of several coastal Florida residents. Then heavy, southern snows fell in extremely cold conditions, especially in the Appalachians, extending even to Chattanooga, TN with snowfalls of 2-4 feet. Unprecedented snowfalls continued north with depths also measured in feet. When the total snowfall across the 26 states affected was totaled, the figure came to a staggering 12.91 cubic miles, greater than measured in any other snowfall.

In a triumph of weather forecasting, meteorologists had predicted the potential for this event as many as 7-10 days in advance. Five days before the storm our country was warned of a historic weather event of enormous impact. Forecasters had seen unusual jet stream patterns, some dipping far to the south, merging over the Gulf of Mexico, and permitting an outbreak of extremely cold air ushered down from Canada. As it interacted with warm, moist air, the superstorm developed explosively. Many southern residents were unable to grasp the possibility of such an unusual late winter outbreak.

Since the recent New England blizzard some commentators are immersed in a feeding frenzy of alarmism that such events signal global warming is upon us with a vengeance. Are we to believe that cold waves and blizzards point to a conclusion that global warming is increasingly manifest? Yes, we are told, for global warming merely amplifies the extremes of weather. Superstorm 1993, the most extensive winter storm of the 20th century, struck long before current global warming apprehension had gripped national psyche. In the next to last year of the 19th century our country experienced the Great Blizzard of 1899 which gripped Florida and other southern states with snow and the only sub-zero temperatures ever recorded in the Sunshine State. On its northward passage, this storm dropped the temperature in Cape May, NJ, to 0˚F, along with 34 inches of snow, both all time records for that area. The Great Blizzard of 1899 was not dependent on global warming to fuel its intensity.

In addition to my still-present youthful excitement over a robust snowfall, the positive benefits of blizzards far outweigh the negatives in the long run. Applying common wisdom in walking, shoveling, or driving illustrates the point. In the scope of God’s care for the human race created in His image, we offer Him thanks for the provision of plentiful fresh water for support of Earth’s seven billion souls.