Tuesday, December 29, 2009

Time's Arrows

Picture several scientists at a New Year’s Eve social gathering. They would provoke amusement among the guests by wishing them "Happy Arrow of Time" instead of the more conventional "Happy New Year." The scientific term arrow of time is an expression describing the relentless forward direction of the flow of time, helping us distinguish the past from the future.

Someone may ask if the forward flow of time and our awareness of the distinctions of past and future are worth contemplating, obvious as they seem. Most evident is our ability to remember the past but not the future. This is called the psychological arrow of time.

Two other arrows are less obvious to the non-scientist, but they describe an overlay of necessary conditions in the universe in which we operate. The two conditions are the thermodynamic arrow of time and the cosmological arrow of time.

The thermodynamic arrow of time is related to the second law of thermodynamics, also called the law of entropy. Briefly, this law describes the natural tendency of our universe to move toward a state of increasing disorder (entropy) in which energy is continually being transformed to a less useful state. The direction of this arrow of time is established by the direction in which disorder increases. Check out one of my previous posts on this topic for examples of increasing entropy:

Related to the thermodynamic arrow is the cosmological arrow of time. As the universe expands, time moves forward. In 1998 scientists were amazed to discover the universe’s rate of expansion was not slowing, as had been thought, but was actually accelerating. Suddenly the speculation that the universe would some day stop expanding and perhaps begin contracting under its own gravity was shown to be impossible. There would be no “Big Crunch” and there would be no reversal of the arrow of time!

Our “gut feeling” that time proceeds in a certain direction is connected, then, to our observation that (a) disorder is increasing, and (b) the expansion of the universe is ongoing. Light conversation at the coffee table and a friendly “Happy New Year” certainly has its place to enhance our social health. But more serious discussions involving the arrow of time may help us understand the kind of universe God designed for man’s benefit. Reversal of either the law of entropy or the expanding universe would preclude life on earth. There is an upside to the law
of entropy. The Creator had humanity in mind when He designed this operating system.

Thursday, December 24, 2009

One Time Dimension

To titillate their readers, science fiction writers often use the idea of time travel to the past or future. Examples abound, as popular past TV shows such as The Twilight Zone and movies such as Back to the Future have demonstrated.

Is there any reality in what these writers envision? They imagine time occurring in more than one dimension. But our universe is currently locked into only one dimension of time. Here and now, every effect has a previous cause. In travel to the future, events (effects) would not have to be preceded by a cause in the past. And travel to the past would necessitate a time reversal with causes following their effects instead of preceding them.

The timeline of our universe constantly moves forward. Scientists speak about a forward-moving Arrow of Time. But they also say that nothing in the laws of physics actually forbids a reversal of the direction of time. In our universe, however, this does not occur because God created our cosmos in the beginning to operate in one time dimension. The Arrow of Time moves in only one direction.

Science researchers acknowledge that more than one time dimension could exist. The Triune God, who created our universe transcendently from outside our cosmos, is not limited to one time dimension as we are. We may say, therefore, that human experience in this created cosmos has been purposefully limited by the Creator. For the redeemed in Christ, this limitation will be lifted at the onset of the New Creation described in Revelation 21.

The forward-moving Arrow of Time describes several necessary conditions imposed on our universe which make our physical life possible. It is a topic for a future post.

Monday, December 21, 2009

Time Limits

As each new year approaches we become more contemplative, curious, and sentimental about the subject of time. Greetings cards from friends and family frequently contain expressions of disbelief that time passes so quickly.

Time is also a scriptural and a scientific concept. The Genesis creation account asserts there was a beginning. The beginning refers not only to the creation of space, matter, and energy, but also to the beginning of time itself. The New International Version passages in I Corinthians 2:7, II Timothy 1:9, and Titus 1:2 all reference actions, intentions, and characteristics of God before the beginning of time, or before time began.The New Testament, especially the Book of Revelation, suggests future events with indications that time as we now experience it will end at the onset of the New Creation. Christ, existing before the creation of the universe, is described as the Alpha and Omega, an indication of His eternal nature. Humanity, however, thinks in terms of beginnings and endings within our own frame of created time. Our universe had a beginning, and therefore, a beginning to our time dimension.

Brilliant agnostic scientist Steven Hawking acknowledges the beginning of our time dimension at the Big Bang singularity. He claims we experience life in real time, but his writings and the writings of other thinkers focus more on the concept of “imaginary” time. They claim imaginary time is actually more “real” in the sense that there would be no beginning or end. Their writings wander to esoteric topics like no boundary conditions, sum over histories, and the possibility of tiny, tightly curled extra dimensions.

At least one secular writer, Gevin Giorbran, writing about imaginary time, stated, “But I have found it interesting that Christian friends have told me the bible actually says this is a period when we will find out more and more about God.” Giorbran claimed a blend of his “spiritual and scientific beliefs” as he contemplated these issues. I do not quote Hawking or Giorbran as authoritative on these issues. Their thoughts, however, merit consideration.

Some Christians believe the New Creation may be an extension of the time dimensions and real time experiences in which we are now embedded. In the passage in I Corinthians 2:7-9 which uses the phrase “before time began,” the Apostle Paul acknowledges the inconceivability of these truths to us who live in our present universe: “No eye has seen, no ear has heard, no mind has conceived what God has prepared for those who love him.”

We can be sure God, as the Creator, had a special purpose in mind for this universe. This purpose was not for us to live forever in a universe running down under the Law of Entropy. It is more reasonable, according to scripture, to see our universe as a means of banishing sin and corruption finally and forever.

Tuesday, December 15, 2009

Descriptive or Explanatory?

Our many recent posts on the electromagnetic spectrum have been long on description, but perhaps short on explanation. We explained some of the physical characteristics of these waves: their electromagnetic nature, their wavelength, their similarity to particles, and their speed. It is more difficult to explain the many different ways in which they affect our environment, including how and why they affect humans. We're tempted to dismiss such questions with "That's just the way it is."

Microwaves offer a good discussion example. These are waves ranging from 0.3 cm up to about 30 cm. It is easy to explain that they are shorter than radio waves, but longer than light. Explaining why many hundreds of different microwave lengths are useful for some purposes, but not others, is more difficult, however. Scientists have figured out how to use microwaves to manage air traffic, observe development and movement of weather systems with Doppler radar, and measure the excess speed of drivers on the highway. Discovering how these systems work is challenging but rewarding for the non-scientist.

For several decades. we have heated our foods quickly in microwave ovens. Microwaves heat the water molecules in beverages or the water molecules in foods such as vegetables and meat by causing the molecules to vibrate rapidly. The faster the speed of vibrating molecules in a substance, the warmer it becomes. Cell phones send information by microwaves to nearby towers. The information may be briefly converted to electrical impulses and finally to audible sound waves from the hand-held receiver, all in a fraction of a second.

Visible light, which enables us to image our environment in detail with trillions of "data points" each millisecond our eyes are open, provokes a different type of "how" or "why" question: Why does a wavelength of 430 trillion hertz look red, while very slightly shorter wavelengths look orange or yellow? Scientists explain "what" happens better than they explain the subjective human experience of red, orange, yellow, green, blue, or violet, depending on exceedingly slight variation in the light's wavelength. The subjective human enjoyment of color vision cannot be reduced to an easy physical explanation.

Our God has produced a material universe and an operating system which enables us to enjoy it. Our enjoyment is expanded when we grasp even a few of its operating principles. Our awe and wonder, in turn, become part of the enjoyment. As we make a study of how our universe operates and how we have expanded our knowledge to make these operations serve our needs, it becomes more difficult to deny the work of God, the Intelligent Designer.

Wednesday, December 9, 2009

Light Talk

In my childhood days I recall the anxious voice of my mother announcing to the family that a “long distance” call from an out-of-state relative had arrived. The ensuing conversation was often tense and terse, with no time for light banter. The three-minute talking time limit approached quickly; the basics of the call’s purpose had to be handled quickly, because money for this calling luxury was in short supply.

Even after factoring in cost of living increases in past decades, long-distance calling rates were many multiples of today’s rates because the copper cable medium carrying our call was expensive and limited in its capacity. In the 1930s or 1940s there was no phoning luxury as inexpensive as today’s “unlimited long distance calling.”

School children and young adults may have difficulty achieving a sense of wonder at the applications of modern technology. Recent posts on the electromagnetic spectrum--how it works and how its energy is transmitted--may be far less interesting than contemporary society’s focus on consumerism. Instead of curiosity about how things work, today’s consumers are more focused on how new products work for them, focusing on the marketing claims of the blizzard of new products and how to acquire them.

We must be careful not to be diverted from the worship-enhancing potential of becoming well-informed about the physical laws which govern the activities of our everyday life and in turn, the Creator who authored those laws. In previous posts we have mentioned the empowerment experienced by scientists since the onset of the scientific revolution. Rather than giving glory to the Creator, many began to bask in their own discovery achievements rather than giving glory to the lawgiver.

One such discovery achievement is the fiber optics technology perfected in the past three decades. It is likely that your phone conversations, cable television, and internet are transmitted mostly by ordinary light traveling through a tiny glass fiber core surrounded by cladding and protected by a buffer coating. Laser light in the infrared EMS light band is sent through the fiber. Traveling at 300,000 km/sec (7 ½ times around the world in one second), the light signal experiences what is termed “total internal reflection,” bouncing off the cladding of the cable many times on its way but remaining within it.

Laser light pulses within the hair-diameter fiber carry digital information--billions of bits per second. Receiving station technology converts the bits to intelligible sound, an image, or other information. The next time you speak on the phone, be aware that as many as 50,000 other conversations may be transmitted by your cable simultaneously. These conversations are literally “light talk.” Samuel F. B. Morse’s first telegraph message, sent between Washington, D. C. and Baltimore in 1844, read, “What Hath God Wrought?” This question now has a vastly expanded significance.

Friday, December 4, 2009

Subduing the Spectrum

Many people at or beyond retirement age fondly remember the excitement of mailing in 25 cents and a cereal box top, then waiting anxiously for the promised item to arrive by return mail. My personal favorite was the “Lone Ranger Atomic Bomb Ring” from 1947, just two years after Hiroshima. This remarkable promotion came with instructions as follows: “Twist tail fin--slide it off…Go into dark room and wait until your eyes are accustomed to darkness. Look into lens—and SOCKO! You’ll see brilliant stabs of flashing light caused by released energy of atoms split to smithereens inside atom chamber.”

This hyped promise was actually quite accurate--more so than the disappointing pirate treasure finder’s ring I ordered later. The “stabs of flashing light” were caused by alpha particles, bundles of two protons with two neutrons, shooting out from the nuclei of a tiny quantity of radioactive isotope polonium 210 embedded inside the ring. When the particles struck a zinc sulfide screen, peering into the ring we could see flashes of light. I learned to appreciate the remarkable science of this toy as an adult. The polonium atoms randomly disintegrated on their own, forming lead and helium. The small amounts of radioactive elements and isotopes in our environment behave in a similar way. Using this scientific knowledge for beneficial purposes is a way to “subdue the earth,” God’s directive to man in Genesis 1:28.

The story of radioactive materials is somewhat more complicated. Radioactive elements emit one or more types of ionizing radiation: the previously mentioned alpha particles, beta particles (electrons), and gamma rays--extremely high energy electromagnetic radiation. Gamma radiation has the shortest wavelength of the electromagnetic spectrum. In just over 100 years, scientists have discovered how to harness this radiation for man’s benefit.

The “ionizing” radiation of alpha particles, beta particles, gamma rays, and X-rays has become useful in treating disease and making food safer. Ionizing radiation breaks down the DNA molecule in cancer cells, damaging them fatally. Normal, healthy cells may avoid such damage when doses of radiation are correctly meted out to cancer victims. Radioactive elements such as cobalt 60 can kill microbes in food, retarding spoilage and increasing shelf life. Irradiated foods are gaining acceptance because the process is safe, leaving no residual radiation.

Near the end of the 19th century, little was known about how to use the many types of electromagnetic energy for the benefit of man. Since then we have experienced a flood of discoveries. Without this knowledge, life as we now know it would be impossible. God’s instructions to man in Genesis 1:28 are finally finding fulfillment, thousands of year after He gave them.

The Lone Ranger Atomic Bomb Ring was completely harmless. Polonium 210 emitted virtually no gamma radiation or beta particles as do many radioactive elements. Alpha particles do not even pass through a sheet of paper, much less the casing of the Lone Ranger ring. The cost of that relic was only fifteen cents plus one box top and the price of a postage stamp--three cents at that time. What a small price to pay for piquing my interest in the wonders of how God’s created world works. In 1947, the best was yet to come.