It wasn’t…

Worse than that, in the third grade we had to learn about “conversion of units.” I figured it was good source of test problems. So I couldn’t escape from learning it. I admit it was difficult in the beginning. “The strange rule” said if we are to measure with a bigger scale, then we had to divide the number by ten and vice versa. Why was 120 cm equal to 1.2 m? If we knew that it was 120 already why did we bother to say it was also 1.2 in another unit? I got confused whether I should multiply the number by ten or divide by ten? (At least it was easy to multiply or divide by ten instead of another number, so I kept silent.)

In time, I realized that people used the unit to measure almost anything. Length is measured in meters, mass is in kilograms, time is in seconds. Wherever there was quantity, there was also a base-unit associated with it. Of course I never asked what a “second” was, because our teacher said everyone accepted this unit of time. Since it was a world-accepted “standard measure,” I subconsciously got the impression that the universe had a clock* and that people calibrated their time accordingly. In the same way, one kilogram was an absolute quantity in my mind by which every other mass can be measured.

As we grew up, more and more types of measures and units entered our lives: Volt, Joule, Ampere, Newton, and many others. Dealing with the “old” units of length and time was a piece of cake then. However, my faith in “standard measures” as universal remained unchanged until high school.

I was quite surprised in high school when our chemistry teacher told us that our very fundamental units of measures were actually not absolute. They were not fundamental in the sense that they, too, were defined in terms of other quantities. In fact, there is a history of “what to define as a unit” and “how to measure it.”

Let’s take time, for instance. We measure years by days and days by hours. Have we ever thought about why a year is 365 days and one day is 24 hours? Can’t we divide a year into 400 days or a day into 25 hours? Is this an artificial choice or a natural timing? It all depends on how we define a year and a day. We can identify a year by a full rotation of the earth around the sun. Also we can distinguish the beginning of day and night clearly. These are definite intervals of time dictated through our observations, and so there is not much choice other than setting one year at 365 days. Is there a similar fact behind the relation of day to hours? Not at all! It was in ancient Egypt, around 2000 BC, that days for the first time were sliced into 24 pieces of time. In the age of Babylonians, however, a day was designed to be 60 hours. Perhaps the reason for such division of the day (into 24 or 60) hours was that 24 or 60 are nice numbers which are divisible by many integers; the same reason why a full-angle is 360 degrees instead of 2π.

In the Middle Ages, for Muslims, measurement of astronomical phenomena was a very serious affair. They were very concerned about accurate timing. Determining the changing time of the five daily prayers and the beginning and ending of the month of Ramadan was more than a custom, it was a religious duty. And such calculations required high precision. This precision was exemplified in year 1000 AD by the Muslim scholar al-Biruni who gave the times of the new moons in terms of days, hours, minutes, seconds, thirds, and fourths after noon Sunday.

In the West, the first accurate time measurements were made by Roger Bacon in thirteenth century. In 1657, Christian Huygens invented the pendulum clock, which uses swinging weights to keep time. Later, Hyugens and William Clement refined the design so that clocks were accurate up to seconds. Another problem with older clocks was that although they worked fine in the local region, they lost accuracy at different parts of the globe and were thus unsuitable for navigation. The reason for the lack of accuracy was that earth’s rotation around the sun on its axis (which definitely affects the period of the pendulums) was not uniform. Several adjustments were made in the nineteenth century for better accuracy by improving the design to compensate for thermal expansion of the metal rods and air drag, which globalized the measurement of time. In 1956, the “second” was redefined in terms of the earth’s revolution around the sun, according to data gathered in year 1900. As the scientists were not completely satisfied, they re-defined the second (as the atomic second) a decade later. In 1967, the Thirteenth General Conference on Weights and Measures defined a second of atomic time in the International System of Units as:

The duration of 9,192,631,770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the caesium-133 atom.

Measuring the length was another important task for ancient peoples. Among the earlier civilizations, the most accurate system was developed by Indus Valley Civilization. While their contemporaries were using parts of the body for measurement, as early as 2600 BC, the Indus civilization had a much finer unit system that accounted even for millimeters. Most societies continued to use their own length scale until eighteenth century.

As early as seventeenth century, with the advances in the accurate measurement of time, pendulum motion was suggested to measure standard length. In the eighteenth century, there were two main approaches for measuring the standard unit of length. One suggested defining the meter as the length of a pendulum with a half-period of one second. The other suggested defining the meter as one ten-millionth of the length of the Earth’s meridian along a quadrant, which is the distance from the equator to the North Pole. In 1791, the French Academy of Sciences selected the choice based on the meridian. After several changes in the definition in 1960, the International Bureau of Weight and Measure organized the 11th CGPM (General Conference on Weights and Measure), during which the meter was redefined as 1,650,763.73 wavelengths of the orange-red emission line in the electromagnetic spectrum of the krypton-86 atom in a vacuum. The final decision came from the 17th CGPM as: “a meter is defined as 1/299,792,458 of a light-second.”

Figure 1. Historical International Prototype Meter bar, made of an alloy of platinum and iridium, was the standard from 1889 to 1960.

As for the measurement of mass, the situation is even more complicated since scientists cannot even agree on what mass is. There are mainly two different understandings of mass based on its features. One is called inertial mass (related to the quantity of a material); the other is gravitational mass (related to gravitational pull and acceleration). Whether these two concepts are equivalent or not is still in debate though in modern theories like Einstein’s general relativity, these two definitions are equivalent. We can, therefore, leave these philosophical discussions about the concept of mass to the scientists and go back to its measurement.

Just like the measurement of time and length, scientific mass measurement gained a boost after the French Revolution. At first, a gram, defined as the absolute mass of 1 cm3 of water at 0o C, was chosen as the standard. In 1799, scientists made a slight modification to the unit of mass by re-setting the definition at 4oC since it is the temperature at which water is most stable. Later, officials noticed that this unit was too small to be a standard of everyday commercial materials, which usually appear in large amounts. In 1889, the International Prototype Kilogram (IPK), made of an alloy of 90% platinum and 10% iridium (by weight), was designed to define the standard mass (Figure 2). After the first production, several more stable replicas of IPK have been produced to replace the older ones. Today every government who subscribes to this standard must have an exact copy of IPK, and these replicas must be returned to Paris periodically as they may get rusted or dirty with time.

Figure 2. Shown above is a computer-generated image of the International Prototype Kilogram (IPK). The IPK is made of a platinum-iridium alloy and is stored in a vault at the BIPM in Sèvres, France.

These facts may sound very odd to some, as it did to me when I first heard of them. I asked myself: If all these measures are defined in terms of something else, what is the point of defining them in the first place? For example, if we can agree to use the second as some interval of time, why do we bother to count the number of oscillations of Cesium. The answer is: We cannot agree unless we use a reference time which is geography-free, climate-free, and politics-free. Only then we will be sure that I, here in Western Pennsylvania, a person on the top of Everest, or a person in a submarine under the Pacific Ocean will call the same interval of time a “second.” In other words, the oscillation of the cesium isotope was believed to be free from all possible deficiencies that are results of physical location (Australia or America), environmental change (the Amazon Forests or the Sahara Desert), and politics.

In short, sand-clocks for measuring time (think of what kind of sand in what shape of glass tube) or the arm of a king as a length unit (imagine a king who seized the throne at 13 and died at 60), or weighing with iron cylinders (common in small grocery stores in some countries) is too unreliable, too unstable, too local, and of course, inaccurate to create a standard. Especially in this age of globalization, a consensus on measurement is absolutely necessary.

It seems a bit ironic that a simple-looking concept of science, measurement, could cause such controversy. A simple way to keep track of numbers that belong to different kind of quantities evolved into an area of serious research through time. Perhaps then, I should have not worried that much about my bad math grades on a subject which troubled the scientist themselves. After all, my grades were just my teacher’s own measurement.**

O. S. Caglayan has a PhD in mathematics. He is a freelance writer. He lives in Pittsburgh, Pennsylvania.

* This famous quotation attributed to Newton was opposed by Leibnizian view of time: “The universe is the clock.” The scientist as philosopher, Friedel Weinert, Springer; 1 edition (May 27, 2004)

** The author is indebted to his dear elementary school teacher Muazzez Ozalp for instilling in him the love of science.

References

1. G. J. Toomer. Ptolemey’s Almagest (Princeton, New Jersey: Princeton University Press, 1998)
2. The History of Time (Leofranc Holfrod-Strevens).
3. al-Biruni (1879). The chronology of ancient nations: an English version of the Arabic text “Vestiges of the Past”. London: W.H. Allen, 147-149. OCLC 9986841.
4. Matthew Bennett, Michael F. Schatz, Heidi Rockwood and Kurt Wiesenfeld, Proc. R. Soc. Lond. A 2002 458, 563-579.
5. Ian Whitelaw. A Measure of All Things: The Story of Man and Measurement, St. Martin’s Press, 2007.
6. http://physics.nist.gov/cuu/Units/meter.html
7. www.bipm.org/eng/home

In this issue we examine diverse topics from astronomy to art, from dialogue to genetics. On reading the lead article, you will be filled with hope that once those “who are spiritually alert with faith, hope, and tenacity” roll up their sleeves ready for work, the true message of Islam will be revealed to everyone in the world, for Islam is “a combination of systems that is perfectly compatible with human nature and rich enough to meet all the material and spiritual needs of humanity.”

Although we see it every day as the source of light and heat above us, most of us do not know that the sun is like an “enormous piano with ten million notes.” “The Trembling Sun” expounds on how helioseismologists gather important information about the sun’s core by studying the echoes that appear on the sun’s surface from the energy produced by these ten million notes.

From the macrocosmic sounds of the sun we move on to studying the marvelous microcosmic world of seeds in “Tiny, With A Great Mission,” which is a contemplative piece on how seeds are equipped with all the necessary information, how are they programmed to become the plant they are meant to be, and so on. In “Will and Balance in Nourishment,” we learn that there is no limit to the absorption of foods that have high calories (lipids, carbohydrates, and proteins), and that this can lead to being overweight. However, in the absorption of minerals, the rules of dynamic balance occur in our intestines, regardless of our will, by the help and mercy of God. The former becomes a test of our appetite, while the latter is a measure divinely installed in our body to protect us from various malfunctions. A similar protective mechanism is found in the DNA, our genetic coding. “A Miraculous Mechanism: DNA Repair” lists various precautions to prevent DNA damage, such as detection by sensor proteins, the damage checkpoint process, and apoptosis.

We are grateful to the authors for their contributions, and owe a special thanks to Ozge Ozturk, Hacer Sartepe, and Sermed Ogretim for their help in producing this issue.

The sound of the sun

Sound waves are seismic waves which cause up-down and forward-backward movements. According to some scientists with poetic hearts the sound of the sun is like the sound of the heart beat. When a human’s heart beats, it makes varying sounds by contracting and relaxing, and cardiologists use these sounds to determine if there is a problem with the heart. Like the cardiologists who listen to our hearts, helioseismologists (scientists who research the sun’s seismic waves) listen to the sounds of the sun to learn more about its structure and mysteries. The power produced by these sounds makes the sun oscillate like a bell or tremble like someone suffering from a high fever. Another interesting point is that millions of different sounds have been discovered to emanate from the sun and every sound oscillates on a distinct frequency and displays a different pattern on the sun’s surface. If we compare the sun to a piano, a piano has 88 metal wires which produce sounds with varying tones, whereas the sun produces ten million notes. So the sun is like an enormous piano with ten million notes producing sounds at roughly five-minute intervals which create harmonic acoustics resembling the heart beat.

Scientists are trying to decipher these ten million different sounds, which brings us to another interesting point; we cannot hear the sound frequencies because they are too low (between 1–4 millihertz) for the human ear (the lowest range of human hearing is 20 Hz). 1–4 millihertz equals to a time span of 200–1,000 seconds, meaning that the sun oscillates once every 3–16 minutes. Even if our hearing ability was suitable, the sound would not reach us because there is no air or layer of gas between the earth and the sun to convey sound. If we could increase the sounds of the sun by 20,000–40,000 times, the sound humans would hear would only resemble a whisper. The sun is like a musical instrument that plays a continuous concerto of ten million notes every day in the sky above us, and we do not even perceive it. Can you imagine the astronomical music if we were to include the galaxy’s 200 million stars?

Scientists gather important information about the sun’s core by studying the echoes that appear on the sun’s surface from the energy produced from these ten million notes. The solar oscillations are divided into three categories called the p, g, and f modes. The p mode is the pressure of acoustic waves, g mode is gravity and the f mode refers to the surface-gravity waves. There are ten million of the p and f modes alone and the combination of these modes produce ten million different sounds.

In Bediüzzaman’s Risale-i Nur, his explanation of the letter “Lam” in the verse 36:38 in chapter Ya Sin in the Qur’an, affirms that everybody obtains understanding of this chapter according to his or her own spiritual senses and every chapter of the Qur’an contains thousands of aspects from which everyone benefits according to his or her own depth of understanding, from the common public to scholars, from scholars to the philosopher of the cosmos. In The Words, Nursi goes on to say, “Precise and wise scholars consider li to be causal and adverbial. They understand that since the All-Wise Maker operates behind the veil of apparent causality, He has tied the planets to the sun by His law of gravity and causes them to revolve with distinct but regular motions according to His universal wisdom. To produce gravity, He has made the sun’s movement on its axis an apparent cause. Thus a resting place means that “the sun moves in the place determined for it for the order and stability of its own (solar) system.” Like the Divine laws, that motion produces heat, heat produces force, and force produces gravity. … The sun is a light-diffusing tree, and the planets are its moving fruits. But unlike trees, the sun is shaken so that the fruits do not fall. If it were not shaken, they would fall and be scattered. They also may imagine the sun to be a leader of a circle reciting God’s Names, ecstatically reciting in the circle’s center and leading the others to recite. Elsewhere, I expressed this meaning as follows: ‘The sun is a fruit-bearing tree; it is shaken so that its traveling fruits do not fall. If it rested, no longer shaken, the attraction would cease, and those attracted to it would weep through space” (Twenty-fifth Word).

It is interesting that the sun’s oscillation, which modern science discovered in the 1960s, was mentioned much earlier by Bediüzzaman. In fact he went further and even explained the wisdom and necessity of the sun’s oscillation as a law of gravitation keeping the earth and the other surrounding planets in orbit. This is a subject which has only recently begun to be researched by scientists of the present. If we were to look further into the history of the valuable discoveries of Imam Rabbani, Ibrahim Haqqi of Erzurum, Ulug Bey, and many other scholars, we would be sure to encounter many other scientific facts.

References

1. “Solar Ellipticity Fluctuations Yield No Evidence of g-Modes,” J. R. Kuhn, K. G. Libbrecht and R. H. Dicke, Nature 319, 128 (1986).
2. “The Excitation and Damping of Solar Oscillations,” K. G. Libbrecht, B. D. Popp, J. M. Kaufman and M. J. Penn, Nature 323, 235 (1986).
3. “What do Observations Tell us about the Excitation of Solar Oscillation Modes?” K. G. Libbrecht, Proceedings of IAU Symposium 123, Advances in Helio- and Astroseismology (1988).
4. “Seismology of Solar Oscillation Line Widths,” J. Christensen-Dalsgaard, D. O. Gough, and K. G. Libbrecht, Astrophys. J. Letters 341, L103 (1989).
5. “Frequencies of Solar Oscillations,” K. G. Libbrecht, M. F. Woodard, and J. M. Kaufman, Astrophys J. Supp. 74, 1129(1990).
6. “Advances in Helioseismology,” K. G. Libbrecht and M. F. Woodard, Science 253, 152 (1991).

Hibernators are intensely active in summer. A part of that activity is building temporary burrows for summer use only. Ground squirrels, (Spermophilus citellus) for example, can build hundreds of such temporary shelters over a single summer, on average 15 shelters in a 10m2 area of open field. These shelters have only the one nest compartment, usally between 30 and 50cm below ground level. By contrast, their shelters for hibernation, sometimes as much as 3m below ground level, are intended for long, repeated use and contain a number of compartments-one for storing large quantites of food (usally dry seeds), one for use as a ‘toilet’, and a third for sleeping.

Before hibernation, animals prepare themselves for the hardship of the very long period of cold by storing up large amounts of fat in adipose tissue under the skin, up to some 40 % of total body weight. These fats are composed of fatty acids which typically have ten or fewer than ten carbon atoms and are consturcted with some double bonds between the carbon atoms of the chain and their esters with glycerides. These compounds provide the ideal energy source needed during hibernation because lipids yield twice the energy yielded by carbohydrates and proteins. Moreover, these fatty acids need very little oxygen in their degradation/conversion to energy.

Blood circulation and homeostasis during hibernation are not well understood. The animal steadies body temperature at around 2°C to 5°C: in mammals the body temperature remains about 1°C above environmental temperature. Usally, when body temperature falls to this level, metabolic rate is increased or the animal awakes, but during hibernation this does not happen. Metabolic rate at 5°C is usually 2-5% of the rate at normal body temperature. For example, the active heart rate of the genus Myotis of bats is between 500 and 700 beats per minute. During hibernation the rate goes down to 20 beats per minute at 5°C, and 8 beats at -7°C. Two consistent and characteristic changes are found in blood during hibernation: an increased production of herapin, which may be contributing to a reduction in the risk of blood clotting during very slow circulation, and an increase in serum magnesium, for which there is no explanation as yet.

Many different types of respiratory patterns have been observed during the state of hibernation. We will mention only one example here: The hedgehog, at a body temperature of 5°C, does not breathe at all for an amazing 56 minutes.

In controlled observations, it has been found that animals which hibernate show improved retention of learned behaviour compared to non-hibernating animals. Again, it is not at all clear why this should be so.

Hibernation is not a prolonged period of constant torpor. There are periodic arousals during winter caused by the accumulation of metabolic end products or having a full bladder. The awakening process is often assisted by shivering, especially when the body temperature is very low. Awakening is a costly process because it takes as much energy to wake up as it does to stay in hibernation for ten days. The ground squirrel, Spermophilus citellus gains around 150-200 g of fat before hibernation. That is more than enough for the energy being used up during sleep; the excess is needed for the wakening up intervals which occur fortnightly.

A number of hypotheses have sought to explain how hibernation is triggered-changes in weather and climate, temperature, humidity and change of diet are among the suggestions. Apart from these causes, a protein was isolated from the blood of a hibernator bear in the USA in the 1980s which, when injected into rats appeared to induce sleeping behaviour in summer. Today it remains uncertain if this protein is the only stimulator of hibernation. If it is, we still need to know what other conditions are related to the protein level and its effect and how the level of protein is maintained at the right level during the animal’s life cycle.

What is already securely known about hibernation establishes it as a truly amazing physiological phenomenon. It tells us that the body temperature of some hibernators will passively adjust ambient tempeature from between 2°C to 32°C without causing awakening. The inevitable question is what advantage such behaviour affords the hibernating animals. Some small animals, because of their high metabolic rates are faced with an acute need for a continuously available supply of food and water. Controlled investigations show that dormant animals at cool temperatures lose much less weight than the non-dormant ones. It has also been shown that small animals can survive for at least a hundred days on the energy derived from ten grams of fat. Hibernation is, in other words, a survival technique, an adaptation to the conditions of poor or non-existent food supply during the winter months.

That is, however, something of a mechanical explanation which, even as a mechanical explanation, is far from satisfactory. The secondary question immediately arises of why this particular adaptation and not another-why not migration, for example, to areas where winter does not affect food supply so drastically? There are many birds and other animals which take this option.

A more satisfying explanation must surely consider what adaptability itself is, how it relates to the variety of life-forms, to the individuation of species and kinds, and to the overwhelming intution (which must touch any truly objective observer) that, at levels of subtlety and intricacy which defy comprehension, the survival and provision of each and every living form is minutely arranged and co-ordinated to create a whole that is thoroughly interconnected. The value of that whole is manifested in many different aspects-beauty, variety, efficiency, the rich warmth of life. Is it not impossible to resist the impression of a wonderful generosity within and behind the world of living forms?