Since When We Existed on this Earth?

 

Recently I wrote an essay on the Chinese Calender for Chinese New Year of the Dragon.

This afternoon on the third Day of the Chinese New Year, 2024 I thought I should pen a artiticle on: 

 How old are we since when we existed on this Earth? 

 By “we” I mean the group of animals zoologically called Homo sapiens that we proudly called ourselves as our present day modern human beings. The answer is probably we are twice as old as we once thought.

Let us recap in summary form what I wrote earlier. “Mya” below means “million years ago.”

 30 Mya: Old-world / new-world monkey split.

25 Mya: Old-world monkey / apes split. Also, Drosophila melanogaster / D.

obscura split

 15 Mya: Apes migrate to Asia.

6 -7 Mya: Sahelanthropus

 5 - 4 Mya: Common ancestors of chimps and humans. Formation of current

Galapagos Islands

History on the Emergence of human-like and humans:

3.6 Mya: Panama Isthmus rise / Lucy fossil / Australopithecus afarensis

footprints

 2.5 Mya: Tool use

1.8 Mya: Homo habilis out of Africa

1.6 Mya: Homo erectus in Asia

 600,000 years ago. Human / Neanderthal split.

500,000 years ago.  Homo erectus use fire

 355,000 years ago. Homo heidelbergensis footprints

200,000 years ago. Anatomically modern human

250,000 – 160,000 years ago. Homo sapiens arose.

120,000 years ago. Homo language possible

100,000 years ago. Wolf / dog split

79,000 – 15,000 years ago.  Start of Wisconsin glaciations

50,000 years ago. Humans migrate from Asia to Australia

 45,000 years ago. Megafauna extinction in Australia

30,000 years ago. Human migration from Asia to North America

14,000 – 10,000 years ago. Domestication of dog and Megafauna extinction in North America

12,000 years ago. Early agriculture

8,000 years ago. Domestication of cattle

6,000 years ago. Domestication of horse

3,000 years ago. Iron tools were found to be used by humans.

Let us now go back to 1856 to the west German valley of the Neander River called Neanderthal in German. Their labourers were clearing out a limestone cave when they came across some bones. News of this discovery came to the ears of a professor teaching at a college. He succeeded in getting to the site and recovered a set of about fourteen bones including a skull.

They were clearly human bones, but they showed some differences from those of modern humans. The bones had prominent bony ridges over the eyes. It also showed a backward sloping forehead, a receding chin, and very odd prominent teeth. He immediately classified the discovery as the “Neanderthal man” That caused an uproar among paleoanthropologists and biological anthropologists. They questioned if they were actually remains of some kind of ancient and primitive ancestors of modern human beings or was it the remains of modern humans with some kind of anatomical disorders?

Later, the same discoveries were also made of the same skulls and bones elsewhere in other parts of Europe, in the Middle East and Africa. It was obvious that it was not some kind of anatomical or bony disorder among humans everywhere. It became accepted that the Neanderthal man was indeed a somewhat primitive type of human creature that existed, probably even Adam and Eve were created in the same image as God. Paleoanthropologists promptly termed such beings as Homo neanderthalensis and gave modern human creatures as Homo sapiens, the term “sapiens” to mean “sapient” or “knowing” Unfortunately zoologists classified both as animals belonging to genus “Homo”.

Here are how scientists crudely classified us (Homo sapiens) as belonging to the Animal Kingdom as the descendants of the Homo genus:

• Kingdom - Animalia.
• Phylum - Chordata.
• Class - Mammalia.
• Order - Primates.
• Family - Hominidae.
• Genus - Homo.
• Species - Homo sapiens.

Nevertheless, eventually the difference between the Neanderthal man and modern human sapiens seemed so little that anthropologists and zoologists began to think of us as members of two subspecies. Neanderthal man may have originated from earlier and still more primitive ancestors as long as 3.6 million years ago (see list above).

As far as we know all these human-like species are also known as Hominins under a broader hominid, but not all hominids are hominins. Hominins (the tribe Hominini) are all modern and extinct humans and their immediate ancestors. Hominids (the genus Hominidae) are all hominins and great apes (including gorillas, chimpanzees, and orangutans), and all their immediate ancestors.

However, according to the Smithsonian Museum of Natural History, “human evolution is the lengthy process of change by which people originated from apelike ancestors. Scientific evidence shows that the physical and behavioural traits shared by all people originated from apelike ancestors and evolved over a period of approximately six million years.

One of the earliest defining human traits, bipedalism -- the ability to walk on two legs -- evolved over 4 million years ago. Other important human characteristics -- such as a large and complex brain, the ability to make and use tools, and the capacity for language -- developed more recently. Many advanced traits -- including complex symbolic expression, art, and elaborate cultural diversity -- emerged mainly during the past 100,000 years.

Humans are primates. Physical and genetic similarities show that the modern human species, Homo sapiens, has a very close relationship to another group of primate species, the apes. Humans and the great apes (large apes) of Africa -- chimpanzees (including bonobos, or so-called “pygmy chimpanzees”) and gorillas -- share a common ancestor that lived between 8 and 6 million years ago. Humans first evolved in Africa, and much of human evolution occurred on that continent. The fossils of early humans who lived between 6 and 2 million years ago come entirely from Africa.

Most scientists currently recognize some 15 to 20 different species of early humans. Scientists do not all agree, however, about how these species are related, or which ones simply died out. Many early human species -- certainly most of them – left no living descendants. Scientists also debate over how to identify and classify species of early humans, and about what factors influenced the evolution and extinction of each species.

Early humans first migrated out of Africa into Asia probably between 2 million and 1.8 million years ago. They entered Europe somewhat later, between 1.5 million and 1 million years. Species of modern humans populated many parts of the world much later. For instance, people first came to Australia probably within the past 60,000 years and to the Americas within the past 30,000 years or so. The beginnings of agriculture and the rise of the first civilizations occurred within the past 12,000 years”.

According to another source, “the immediate ancestors of humans were members of the genus Australopithecus.  The australopithecines (or australopiths) were intermediate between apes and people.  Both australopithecines and humans are biologically similar enough to be classified as members of the same biological tribe--the Hominini.  All people, past and present, along with the australopithecines are hominins.  We share not only the fact that we evolved from the same ape ancestors in Africa but that both genera are habitually bipedal, or two-footed, upright walkers.  By comparison, chimpanzees, bonobos, and gorillas are primarily quadrupedal, or four-footed. 

Over the last decade, there have been several important fossil discoveries in Africa of what may be very early transitional ape/hominins, or proto hominins.  These creatures lived just after the divergence from our common hominid ancestor with chimpanzees and bonobos, during the late Miocene and early Pliocene Epochs.  The fossils have been tentatively classified as members of three distinct genera--Sahelanthropus, Orrorin , and Ardipithecus .  Sahelanthropus was the earliest, dating 7-6 million years ago.  Orrorin lived about 6 million years ago, while Ardipithecus remains have been dated to 5.8-4.4 million years ago.  At present, the vote is still out as to whether any of these three primates were in fact true hominins and if they were our ancestors.  The classification of Sahelanthropus has been the most in question.

The earliest australopithecines very likely did not evolve until 5 million years ago or shortly thereafter (during the beginning of the Pliocene Epoch) in East Africa.  The primate fossil record for this crucial transitional period leading to australopithecines is still scanty and somewhat confusing.  However, by about 4.2 million years ago, unquestionable australopithecines were present.  By 3 million years ago, they were common in both East and South Africa.  Some have been found dating to this period in North Central Africa also.  As the australopithecines evolved, they exploited more types of environments.  Their early proto-hominin ancestors had been predominantly tropical forest animals.  However, African forests were progressively giving way to sparse woodlands and dry grasslands, or savannas.  The australopithecines took advantage of these new conditions.  In the more open environments, bipedalism would very likely have been an advantage.

By 2.5 million years ago, there were at least 2 evolutionary lines of hominins descended from the early australopithecines.  One line apparently was adapted primarily to the food resources in lake margin grassland environments and had an omnivorous diet that increasingly included meat.  Among them were our early human ancestors who started to make stone tools by this time.  The other line seems to have lived more in mixed grassland and woodland environments, like the earlier australopithecines, and was primarily vegetarian.  This second, more conservative line of early hominids died out by 1 million years ago or shortly before then.  It is likely that all the early hominins, including humans, supplemented their diets with protein and fat rich termites and ants just as some chimpanzees do today”.

Let us not go too far back into the timeline into the evolution of humans on Earth for which we are still uncertain. Let us remain to the time of the first discovery on the Neanderthals that underwent milder evolutionary changes where at some time and some places were similar to us although their fossils were fewer for us to study how they descended and exited from other hominins.  

But we know their old skeletons are almost similar to ours and by judging from them modern humans must have developed around 40,000 years ago which I estimate was the time when Adam and Eve were created in the same image as God at least 500,000 years ago. All other hominids may have been destroyed by God long before God recreated a new model resembling His likeness as Adam and Eve.

See my other write up on

“Creation or Evolution? The Bible vs. Science” here:

https://scientificlogic.blogspot.com/2022/07/creation-or-evolution-bible-vs-science.html

Judging from my point of view, Adam and Eve may have been created in northern Africa after their descendants started to migrate eastwards out of Africa after being chased out of the Garden of Eden, though I am uncertain.

The latest Neanderthal skeletons are about 35,000 years old suggesting some of them may still exist after modern Adam and Eve were created or evolved. This means modern man and the Neanderthal man were both on Earth together for some time till God decided to get rid of “children of gods” in the Great Flood during Noah’s time during the last great glaciation some 20,000 years ago. This may suggest that the Neanderthals and the modern Homo sapiens lived together for only about five thousand years before the Neanderthals species were wiped out from the surface of this Earth.

Presumably, when the two subspecies encountered each other they compete with food and habitats, and according to what I understand on the evolution of life on Earth, the Neanderthals lost out as one of the biological laws on the “Survival of the Fittest” "Survival of the fittest” was a phrase used by Herbert Spencer that originated from Darwinian evolutionary theory as a way of describing the mechanism of natural selection.

Herbert Spencer first used this phrase, after reading Charles Darwin's On the Origin of Species, in his Principles of Biology (1864), in which he drew parallels between his own economic theories and Darwin's biological ones.

One reason for the demise of the Neanderthals was we believe the Neanderthals were stockier, stronger and heavier than the modern humans at that time, but less agile than its human animal counterparts besides the moderns were brainier and more intelligent, and more ingenious and creative. Their modern counterparts may have been able to invent weapons such as slings, bows and arrows that were able to attack the Neanderthals from a distance instead of a close encounter with the Neanderthals who were stronger. Eventually the Neanderthals may have lost every battle and diminished in numbers until the modern Homo sapiens began to rule over this Earth.

But there is a problem here. A published report in February 1988 by a team of French and Israeli anthropologists raises questions about early human creatures’ relationship to the Neanderthals. Their findings in an Israel cave of skeletal remains of some thirty human beings that seems to be Homo sapiens sapiens. Stone tools found with these remains were examined for age using an analytical procedure called “thermoluminescence” that in simple language means “production of light on heating” that the skeletons were 90.000 years old.

If this was correct, this would imply that modern human creatures split off from the neanderthal creatures more than twice as long as was previously thought, and this means that much more time for the development of differences that did not show up in the fossil bones. We may conclude that the Neanderthal creatures and the modern man arose differently as Adam and Eve in the Garden of Eden as I would strongly believe and accept some 500,000 years ago. In other words, we are entirely different animal species than those creatures, the Neanderthals.

If the Neanderthals and humans coexisted not for 5,000 years but for 500,000 years then why should we, human creatures, take so long to wipe out the Neanderthals until God decides to wipe out all the “children of various gods” in the Noah Great Flood. This would suggest to me, on the contrary, the Neanderthals were smarter than we thought. They would have put up a better fight than human creatures during those times.

I think we, as scientists along with other biological evolutionists, and paleoanthropologists need to tackle this question on hominid origin on Earth. But it is a sad thought that we ourselves may no longer exist within the next 350 years at most from the way we produce, consume, congest, and pollute to give way to the humbler creatures that do not require these, yet they thrive abundantly.  It shall be these humbler and meeker creatures that shall once again regain and inherit this Earth.

It shall be programmed in them through the handiwork of her Creator who shall regain her original glory once again.

Read this biological reality in Matthew 5:5:

“Blessed are the meek, for they shall inherit the earth” where the lower and meeker life like bacteria, plants, and other organisms that were the first to appear on Earth and human creatures the last to surface, but we shall also be the first to be wiped out from this Earth.

The explanation is here:

Humanity left in Isolation or Destroyed?

https://scientificlogic.blogspot.com/2023/12/humanity-in-isolation.html
 

lim ju boo

 (An 2,469 essay)

The Role of Free Radicals in Human Life Spans

 

In Psalm 90:10 of the King James Version of the bible it clearly says:

"The days of our years are threescore years and ten; and if by reason of strength they be fourscore years yet is their strength labour and sorrow; for it is soon cut off, and we fly away". 

“You do not know what will happen tomorrow. For what is your life? It is even a vapor that appears for a little time and then vanishes away” (James 4:14).

A list of 10 of the oldest people mentioned in the Bible were:

1. Methuselah: He is often regarded as the longest-lived person in the Bible, living for 969 years according to the Book of Genesis (Genesis 5:27).
2. Jared: Jared, the father of Enoch, lived for 962 years (Genesis 5:20).
3. Noah: The famous ark builder lived for 950 years (Genesis 9:29).
4. Adam: The first man in the Bible, Adam, lived for 930 years (Genesis 5:5).
5. Seth: Seth, the son of Adam and Eve, lived for 912 years (Genesis 5:8).
6. Kenan (Cainan): Kenan, also known as Cainan, lived for 910 years (Genesis 5:14).
7. Enosh: Enosh, the son of Seth, lived for 905 years (Genesis 5:11).
8. Mahalalel: Mahalalel lived for 895 years (Genesis 5:17).
9. Lamech (father of Noah): Lamech, the father of Noah, lived for 777 years (Genesis 5:31).
10. Shem: Shem, one of Noah's sons, lived for 600 years (Genesis 11:10-11).

Despite that, I often read claims by people that we can avoid old age and death through healthy lifestyles such as good nutrition, exercise, rest and sleep besides avoidance of smoking and alcoholism and obesity promotes good health and extends human life span through the absence of diseases. This may be true in limited ways though we may have limited scientific knowledge and evidence to show that. There is also a limit on how long we can live.

Nevertheless, in 1935, a scientist named Clive McCay published a startling discovery that rats with severely restricted diets lived up to 33% longer than previously known possible. Over the last few decades, similar experiments have been carried out on countless species, from worms to rodents and even primates. 

The specifics vary from study to study, but many show results just as surprising as those that McCay discovered so many years ago. The exact manner by which calories are reduced changes across studies, but the animals’ calorie intakes are generally reduced by as much as half their normal levels. Depending on the species, the most promising results have shown lifespan extensions between 50 and 300%.

If these results hold water, then they could have important implications for our own longevity. However, these studies are not without controversy. Many scientists are concerned that calorie restriction will not benefit humans, or that it could even result in long-lasting harm. Is calorie restriction a silver bullet against aging, or something that should be kept in the laboratory? 

At first glance, calorie restriction is a counter-intuitive way to approach longevity. Here, we use this term to refer to up to a 50% reduction of calories from a normal diet, not simply a lack of overeating. Consuming so much less food than a normal diet seems like it should reduce your lifespan, not extend it. To better understand where this idea comes from, it’s necessary to first understand how aging – the process by which our bodies function less well over time – works. There are two classic theories that could potentially shed some insight into this process: the rate of living theory, and the free radical theory.

The rate of living theory arose from the observation that larger animal species tend to have longer lifespans than small ones. One way to explain this observation is through the concept of metabolic rate, which refers to how quickly an animal expends energy for the body’s day-to-day functioning. This includes energy needed for processes like breathing, maintaining body temperature, and circulating blood. Since larger animals have also been observed to have lower metabolic rates, this theory suggests that slower metabolic rates – i.e., slower “rates of living” – are associated with longer lifespans to quote a source from the Internet.

This is only the second theory on life spans. But we have another more interesting theory to offer.

In chemistry a molecule is made up of more than one atom. Each atom in a molecule is attached to other atoms by a pair of electrons. Thus, a carbon atom may be attached to four different hydrogen atoms by four different hydrogen atoms by four different electron pairs, under some circumstances a hydrogen atom may break free taking its electron with it. What is left of the original molecules is a carbon atom with only three hydrogen atoms. Where the fourth hydrogen atom should be is a single electron unattached to anything.

A molecular fragment containing that single electron is a radical. That single electron is very active, tending to tear strongly at other molecules in order to grasp an atom with which it can make up an electron pair again. This happens so rapidly that a radical, even if formed does not last long and may just snatch up the atom that broke loose before it can quite get away. Nevertheless, if a radical can last long enough to wander about a bit and seize an atom from some other molecule, it is spoken of during its brief existence as a ‘free radical’.

Free radicals can form within living cells. Energetic radiation such as cosmic rays, X-rays or ultraviolet light from the Sun can produce them. So can certain chemicals. These free radicals can last long enough to damage neighborhood molecules. When these damaged molecules happen to be proteins, enzymes, or worse of all, the deoxyribonucleic acid (DNA) molecules in the genes, the cells suffer. Some portions of the cell machinery may be knocked awry.

The body has ways of preventing or correcting damage by free radicals. Substances such as vitamin C and vitamin E can give up electrons easily, and in so doing they can satisfy the appetite of the free radicals and prevent them from taking other molecules. The body also has corrective mechanisms that can repair molecules damaged by free radicals.

Nonetheless, not all free radical damage can be averted or repaired. This means that as life goes on, injury to the cells does take place and it does add on. With the years, more and more cells are crippled, and various necessary portions of the body machinery become more and more rickety and ineffective.

There are some scientists who think it is this accumulating damage that causes old age that makes it certain we all die in the end, even in the absence of disease, infection, and accidents.   

If this is so, then we might live longer if we could find some more powerful means than the body itself for preventing free-radical damage. For instance, there are some plants such as the creosote bush that have an unusually long-life span. The creosote bush (Larrea tridentata) is called chaparral as a medicinal herb that contains a plentiful supply of the compound nordihydroguaiaretic acid (NDGA). This can short -circuit free radicals by handing them an electron and perhaps does this more efficiently than vitamin C and E do.

A biochemist at the University of Louisville, John P. Richie, Jr. has tested this possibility by feeding NDGA to female mosquitoes. Such mosquitoes normally live for an average of 29 days, but with NDGA they lived for an average of 45 days. That’s an increase of 50 percent. If this worked similarly on human beings, it might increase our average lifespan from 75 years to 113 years.

It is unlikely that anyone will try to feed human beings NDGA as a nutrition-medical experiment, but Richie’s observation seems to support the free radical theory of aging.

 There may be other less problematic ways of preventing free radical formation or encouraging their removal so that human life span can significantly be extended.

But the question that we must face is whether we want to do this even if this is possible. Any extended life span will obviously increase the population, which will make it necessary to lower the birth rate than would be advisable. Mankind will end up with an ageing population that no country would desire. This means there will be fewer and fewer young people. Governments, business, and all the machinery that runs society will need to be conducted for longer and longer periods by older and older people and what young people that are left will have to wait for longer and longer periods of time to take over. Does this matter and make sense?

It probably does. It would not be just young people, but they are new people who are biologically, economically and socially better people with better brains who might just be in a better position to tackle problems in new and creative ways. Society in command by long-lived oldsters with a declining infusion of the young and new might tend to decay and become static. In truth it might well be that oldsters give way to the young and new for the survival of the fittest of the human species. The advantage that we may gain by living longer could be paid for by the decline of humanity.  It is just one of the biological rules in evolution on the survival of the fittest.

 

The Origin of Homo sapiens Languages

 

The origin of languages is uncertain.

The Tower of Babel in Genesis 11:1–9 explains why the peoples of this world started to speak different languages when at that time there was probably just one language till the people in biblical times tried to build a tower to reach heaven till God broke them apart into confusion.  

According to the story, a united human race speaking a single language and migrating eastward, comes to the land of Shinar. There they agree to build a city and a tower with its top in the sky. Yahweh (God) observing their city and tower, confounds their speech so that they can no longer understand each other, and scatters them around the world.

According to historians the origin of human languages lies so far back in human prehistory. The Homo sapiens to my knowledge arose between 250,000 to 160,000 years ago, and probably primitive Homo language became possible only 120,000 years ago after fire was first discovered by lightning burning bush forests and bushes.

Flint blades burned in fires roughly 300,000 years ago were found near fossils of early but not entirely modern Homo sapiens in Morocco. Fire was used regularly and systematically by early modern humans to heat treat silcrete stone to increase its flake-ability for the purpose of toolmaking approximately 164,000 years ago at the South African site of Pinnacle Point. Evidence of widespread control of fire by anatomically modern humans dates to approximately 125,000 years ago, and probably the origin of human languages started much later although we have no direct historical trace when language started, and neither can comparable processes be observed today. Despite this, the emergence of new sign languages in modern times—Nicaraguan Sign Language, for example may potentially offer insights into the developmental stages and creative processes necessarily involved.  

The time range for the evolution of language or its anatomical prerequisites extends, at least in principle, from the phylogenetic divergence of Homo (2.3 to 2.4 million years ago) from Pan (5 to 6 million years ago) to the emergence of full behavioural modernity some 50,000–150,000 years ago.

Few dispute that Australopithecus probably lacked vocal communication significantly more sophisticated than that of great apes in general, but scholarly opinions vary as to the developments since the appearance of Homo some 2.5 million years ago. Some scholars assume the development of primitive language-like systems (proto-language) as early as Homo habilis, while others place the development of symbolic communication only with Homo erectus (1.8 million years ago) or with Homo heidelbergensis (0.6 million years ago) and the development of language proper with Homo sapiens, currently estimated at less than 200,000 years ago.

Nevertheless. when the Cro-Magnon men painted their colorful animals deep in the caves of the present-day France and Spain 25,000 years ago, what language did the speak? Would you believe that there are scientists who are seriously trying to answer that question?

How can one possibly find out? Ancient people may leave behind bones and their tools and even their art, but they don’t leave behind any records of their language. They’d have to be able to write to do that, and writing was invented only 5,000 years ago.

In a way, though, they do leave records of their languages, because languages aren’t completely independent of one another. There are similarities between, for instance, among such languages as Portuguese, Spanish, Catalan, Provençal, French, Italian, and perhaps Romanian. They are all called Romance languages, because they are all similar, not only to each other such as Malay and the Indonesian languages, or Chinese, Japanese and Korean languages. But to the old Roman language we call Latin.

This is not a mystery. Latin was once the common language of Western Europe in the days of the Roman Empire. After the fall of that empire and the temporary decline of education and other aspects of civilization, the Latin dialect in different parts of what had been the empire drifted apart and eventually developed into new languages. We can still detect similarities in vocabulary and grammar, however.

Suppose, then, we had only this Romance language, but that Latin had died out so completely that we have no record of it whatsoever. Might it not be possible, then. To go through the various Romance languages, study all the similarities, and construct a common language from which all might have developed? And if one did, might that constructed language not be something like Latin?

If we want to go even further back, there are similarities between Latin and Greek. The ancient Romans recognized this and adapted the more sophisticated grammatical principles that had been used in Greek and applied them to their own language. Must there not have been, then, an older language from the Greek and Latin both developed?

The surprising answer to this question came when the British began to seize control of India in the 1700s. The prime purpose was to engage in trade that would enrich Great Britain, but there naturally were scholars among the British who were interested in Indian civilization for its own sake. Among these was Sir William Jones, who studied an old Indian language, Sanskrit, which like Latin, was no longer in use but had given rise to later variations.

Sanskrit survived in ancient epics and religious writings, however, and as Jones studied it, he found similarities in its vocabulary and grammar to both Greek and Latin. Furthermore, and this was the great surprise, there were similarities to the Teutonic languages, such as Gothic, Old High German, and Old Norse. He even found similarities to Persian and to the Celtic language.

In 1786, he convinced therefore, that there was an “Indo-European” family of language that stretched from Ireland to India and that probably stemmed from a single source. We might imagine that about 7,000 B.C.E. there was an “Indo-European tribe” that lived perhaps in what is now Turkey. It spread outwards in all directions, carrying with it its languages which evolved in different places as groups became isolated from each other. By studying all the similarities, might it not be possible to work up a kind of common language, a “Proto-Indo-European” that might indeed resemble what the original tribe spoke in 7.000 B.C.E?

This is made more possible because in the 1800s the rules for the manner in which language changed with time were worked out by, among others, the Grimm brothers who are better known today for the fairy tales they collected.

There are other language families that are not Indo-European. There is the Semitic group which includes Arabic, Hebrew, Aramaic and Assyrian. There is the Hamitic group which includes certain early languages of Egypt, Ethiopia, and North Africa. There is the Ural-Altaic group, which includes Turkish, Hungarian, and Finnish so that if Turkey was the original home of the Indo-Europeans, the vicissitudes of history have arranged to have a non-Indo-European language spoken there today.

Then there are the variety of languages spoken by Native Americans; by black Africans; by the Chinese and in their different dialects, and by people in the Far East and different parts of Southeast Asia.

Chinese is part of the Sino-Tibetan language family, a group of languages that all descend from Proto-Sino-Tibetan. The relationship between Chinese and other Sino-Tibetan languages is an area of active research and controversy, as is the attempt to reconstruct Proto-Sino-Tibetan.

The main difficulty in both of these efforts is that, while there is very good documentation that allows for the reconstruction of the ancient sounds of Chinese, there is no written documentation of the point where Chinese split from the rest of the Sino-Tibetan languages. This is actually a common problem in historical linguistics, a field which often incorporates the comparative method to deduce these sorts of changes. Unfortunately, the use of this technique for Sino-Tibetan languages has not as yet yielded satisfactory results, perhaps because many of the languages that would allow for a more complete reconstruction of Proto-Sino-Tibetan are very poorly documented or understood.

Therefore, despite their affinity, the common ancestry of the Chinese and Tibeto-Burman languages remains an unproven hypothesis. Categorisation of the development of Chinese is a subject of scholarly debate. One of the first systems was devised by the Swedish linguist Bernhard Karlgren in the early 1900s. The system was much revised, but always heavily relied on Karlgren's insights and methods.

Besides the Chinese languages there are also the languages of the Polynesians, the Indonesians and the rising national language of Malaysia, by the Aborigines in Australia, and so on, and on.

There are even languages that have no known connection to any other, such as ancient Sumerian and modern Basque.

If all of these were studied, might it be possible to work out an original language from which we all descended? It would be an enormous task, but to the linguists it would be a fascinating job.

The topic was discussed at a 1969 conference of historical linguistics by Vitaly Schevoroshkia of the University of Michigan who has been doing research on this subject. It would be a useful endeavor too because if we could work out how human language evolved, it is possible we would work out at the same time the migrations and wanderings of the early Homo sapiens.

The Traditional Calendar of the Chinese then and now

 

The Traditional Calendar of the Chinese then and now

On Saturday, January 27, 2024, I posted an article in this blog called:

“Chronometry: The Measurement of Time, Seasons and Year by the Chinese” here:

https://scientificlogic.blogspot.com/2024/01/

I promised I shall post another version about the Chinese calendar just before Chinese New Year of the Dragon in just two days’ time that falls this Friday, 10 February 2024.  

This article is especially written in red to signify prosperity for a New Year for the Chinese. 

According to Isaac Asimov, the Chinese probably began some millennia BC to reckon the passage of time by days and by approximate lunar synodic months. After a time, as 12 such months got out of step with the seasons, they seem, like the inhabitants of early Mesopotamia, to have let in every now and then an embolistic year with a thirteenth or intercalary month. By the thirteenth century BC they appear to have worked out that the year was about 365.25 days and the synodic month about 29.53 days, better values perhaps than those arrived at by any contemporaries in other places. By the early part of the first millennium AD, they had 365.242815 days for the tropical year, 365.255989 days for the sidereal year and 29.530585 days for the synodic month (see Needham, 1959), again values nearer the mark than those used elsewhere at that time.

From at least 104 BC, when Emperor Wei-ti instituted a revised calendar, and possibly for a few centuries before, the Chinese had a luni-solar calendar basically like the Babylonian standardized calendar which was adopted in the early fourth century BC. There were many official variations in the calendar from 104 BC until AD 1912 when the Gregorian calendar was adopted by the new Republic, but the changes were relatively minor. This calendar had months (yüeh) of 29 or 30 days in rough alternation (a system going back no doubt to the second millennium BC); it had ordinary years of 12 months and so of 354 or less commonly 355 days and embolistic years with an intercalary month (jun yüeh) and so of 383, 384 or 385 days. The Chinese embolistic year, as in the Babylonian standardized calendar, occurred seven times in a cycle of 19 years and in about the same positions within the cycle as in Babylonia, namely the third, the fifth or the sixth, the eighth, the eleventh, the thirteenth of fourteenth, the sixteenth or the seventeenth and the nineteenth years.

The cycle of 19 years and 235 lunar months was called chang (the Metonic cycle of the West). In rounded days it totalled 6940 days which was about two-fifths of a day longer than 19 tropical years at that time and 235 lunations which of course did not quite match. Later, perhaps early in the first millennium AD, a longer cycle pu (four chang cycles with 1 day left out of one of them) was introduced. Such a pu cycle was only 0.6 day longer than 76 tropical years. It was the same as the cycle proposed by Kallippos circa 334 BC. These similarities suggest a borrowing by one set of calendar makers from the other, in which case history suggests that the Babylonians and perhaps the Greeks had temporal priority. Careful observes, recorders and analysts could, of course, arrive at all these matters independently and the Chinese may well have done so.

There are some differences between Babylonian and Chinese calendrical systems which should be noted. First, whereas the Babylonians began the year with the new Moon (strictly, in their case, the first visible crescent after sunset) about the time of the Spring Equinox, the Chinese began it with the new Moon mid-way between the Winter Solstice and the Spring Equinox. Second, whereas the Babylonian calendar let in the intercalary month usually after the twelfth month (though occasionally after the sixth), the Chinese let it in after various non-Winter months in accordance with a rule which will be explained later.

There are similarities and differences in the arbitrary divisions of the day by the Babylonians and the Chinese. At one time, as we have seen, the Babylonians divided the day (reckoned from sunset) into twelve equal divisions, each a beru (they later substituted the Egyptian 24 ‘temporal hours’), and the Chinese from the fourth century BC divided the day (ordinarily reckoned from midnight but for this operation from 11 p.m.) into twelve equal shih periods. However, whereas the Babylonians divided the beru into sixtieths and the fraction into further sixtieths, the Chinese divided the shih into eights called kho, equal to 15 minutes of our time. The Chinese also divided the day into hundredths, each also called a kho, but which were 14 minutes 24 seconds of our time.

At a very early date, at least early in the first millennium BC, the Chinese divided the Equator into twenty-four segments, each 15˚ of longitude in extent. The period taken by the Sun to traverse such a segment is called a chhi. It averages 15.23 days but because of the variable apparent velocity of the Sun (least in the northern Summer and the greatest in the northern Winter) the period may be as long as about 15.74 days or as short as about 14.72 days. The Chinese rounded the periods to whole days to produce five or six chhi of 16 days and nineteen or eighteen of 15 days. Those chhi usually spanning the middle of a lunar month were called chung-chhi (chung is ‘middle’) and those usually spanning the ends of neighbouring months were chieh-chhi (chieh is ‘nodal’ or ‘at a junction’). Each chhi had its own name, thus Li-chhun (the beginning of Spring) was the period during which the Sun was between 315˚ and 330˚ of Equatorial longitude, that is, at least approximately, in the second half of the Western sign Aquarius; Yu-shui (the rains) when the Sun was between 330˚ and 345˚, that is, in the first half of Pisces; Ching-chih (awakening of insects) when the Sun was between 345˚ and 360˚, that is, the second half of Pisces; Chung-fen (Spring Equinox) when the Sun was between 360˚(0˚) and 15˚, that is the first half of Aries; and so on. The chhi system was very early in origin, say second millennium BC (Needham, 1959) and so predated the Near Eastern Zodiacal signs by 30˚ extent. Much later, about AD 600, pairs of 15˚ segments were combined to form signs of the Zodiac which had by then been borrowed from Babylonia through India but given distinctive Chinese animal names which had been used for other duodenary cycles.

The new year began with the new Moon nearest to the beginning of Li-chhun which occurred on or about 5 February (Gregorian). As a month is 29 or 30 days, New Year’s Day occurred between about 20 January and 19 February. After an ordinary year of 354 or 355 days, New Year’s Day moved forward by about 11 days in terms of Gregorian dates. When it moved forward to a date between 20 January and 30 January, the year's beginning had to be embolistic (otherwise the following year would begin with the new Moon next but one nearest the beginning of Li-chhun). It is this rule which determines which years in the 19- year cycle is embolistic. Further the intercalary month in the embolistic year is that one which ended before the beginning of a chieh-chhi (information from Professor Ho Peng- yoke). This could be any of the non-winter months as the chhi tend to be shortest in winter, but it would most likely be a summer month when the chhi tend to be longest. This rule for selecting the intercalary month is similar in principle to that used by the Hindus in selecting their intercalary chandra masa; it is likely, however, to have yielded a slightly different result as the Hindus were using Signs 30 ̊ in extent and were anchoring them to a fixed and not a precessing First Point of Aries; the Chinese located the beginning of Chung-fen at the precessing First Point of Aries.

It has been stated above, following various authorities but particularly Needham (1959) and de Saussure (1920) on this occasion, that the Chinese lunar month began with the new Moon. In modern astronomical usage ‘new Moon’ refers to the conjunction, yet one may reasonably imagine watchers for the first visible crescent, such as the Babylonians, the Greeks, the early Romans and the Jews, not to mention some other Semitic peoples, referring to that apparition as the new Moon, as we tend to do. The early Egyptians by contrast used the day (ending at dawn) of the last visible crescent before sunrise as the last day of the lunar calendar month and began the new month on the next day. The term ‘new Moon’ can thus have several meanings: the first visible crescent, the conjunction or even the disappearance of the ‘old Moon’. We have sought to establish, with no great success, what criterion the Chinese used for the beginning of the lunar calendar months. We suspect that there were changes with the passage of time.

The Chinese engaged in a great deal of minor tinkering with their calendar over the two millennia for which we have records. Professor Ho Peng-Yoke kindly extracted for us  some relevant information given in Li-fa t`ung-chih written by Chu Wen-hsin and not yet translated into English. From 104 BC when Emperor Wei-ti reformed the existing lunar or perhaps luni-solar calendar there were until its official replacement in AD 1912 by the Gregorian calendar forty-two further reforms, not to mention many regional variants.

Professor Ho Peng-Yoke says that in the Chinese mind to promulgate a calendar is to exercise the right of a ruler. Chu Wen-hsin in addition to giving the dates of introduction of the forty- two variants of the T`ai-ch`u calendar produced by or for Wei-ti in 104 BC (some lasted only a couple of decades and others a couple of centuries) also states the average duration of the years in each. Quite early the years approximated on average 365.25 days, but the average shrank, in zig-zag fashion, to about 365.2423 days in the mid-seventeenth century. We suspect that the criterion for the first day of the month may also have changed from time to time.

Sivin (1969) cites two early first millennium AD treatises which dealt with the beginning of the month. The first discussing the calendar prior to 104 BC says that ‘the new moon visible on the last day of the calendar month and the old moon visible on the first day are omens of the ruler’s laxity or overstrictness’. Isaac Asimov inclined to interpret this as meaning that the first day of the calendar month should have occurred on a day between those on which the old moon was visible (before sunrise) and the new moon was visible (after sunset), but it may have some other implication. The second treatise quoted by Sivin speaking of the T`ai-ch`u calendar of Wei-ti says the calendar ran slightly behind the phenomena so that the new moon occurred earlier than the calendar predicted. The conjunction would take place on the last day of the month in some cases and the moon would appear on the first day in other cases.

To check what might be happening in the Kuei-mao calendar (AD 1742 to 1911), Issac Asimov took more or less at random a run of 26 months from 2 December 1880 as set out in A Sino- Western Calendar for Two Thousand Years:1-2000 AD by Hsueh Chung-san and Ou-yang (1955). He compared the dates of the first days of these 26 months as given in that work with the times and dates of conjunction (converted to ‘Peking Mean Time’) as set out in the Nautical Almanac for the years 1880, 1881 and 1882. Eleven of these Chinese months began on the day of conjunction, 15 on the day after but none of the day before (the day being reckoned from midnight). On eight of the eleven occasions when the first calendar month day coincided with the day of conjunction, conjunction occurred before midday in ‘Peking Mean Time’; on twelve of the fifteen occasions when the first day of the month occurred on the day after conjunction, conjunction occurred after midday. There is an obvious tendency here, akin to one to be found in Indian calendrical practice. There are, however, some fairly marked departures from the tendency, for example 27 May 1881 was the first day of a calendar month although the conjunction occurred at about 3.50 p.m. on that day and 20 June 1882 was the first day of a calendar month although the conjunction occurred at about 8.05 a.m. on the day before. Further using data from The Nautical Almanac for the relevant year.  Isaac Asimov had no difficulty in generating months of roughly alternating 29 and 30 days with their first days on the day of conjunction. At this time the Chinese would have had data almost as precise as those in The Nautical Almanac, certainly good enough for this purpose. It is almost as though the Chinese at this time in trying to avoid under shooting the day of conjunction quite often over-shot it. There is, however, another possibility. They may have been aiming at the first visible crescent. To check this possibility, Isaac Asimov worked out from a table in Norton’s Star Atlas and Reference Book times of sunset in Peking on the first days of the 26 calendar months, and in qualitative way tried to estimate the probability of a visible crescent after sunset on the first day of these calendar months. Asimov took into account the obliquity of the Ecliptic to the horizon, the latitude of the Moon and the rapidity with which the Moon was separating from the Sun. He concluded that on one occasion there was very probably, perhaps certainly, a first visible crescent after sunset on the first day of the calendar month, that on 2 or 3 other first days visible crescent was possible but that on the remaining 22 or 23 first days of the month a first visible crescent was impossible or highly improbable. On no first day could there have been a last visible crescent before sunrise on the first day of the calendar month.

All the foregoing is better evidence for the day of conjunction if the conjunction is early in the day, or the day after, if the conjunction is late in its day, then it is for the first visible crescent. It is all fairly clear evidence against the day after the last visible crescent as the first day of the calendar month.

Emboldened by the exercise just described, Asimov dipped back much earlier into the data in A Sino-European Calendar for Two Thousand Years. The data for the first century AD have many gaps and hence seemed suspect as well as not readily usable. The data for the late second century seemed more confidently stated (though, of course, this does not mean that they were more accurate). No issues of The Nautical Almanac were available for the epoch, but Bickerman provides appropriate dates and times of conjunction. Bickerman’s data have been obtained by projection back from modern data on rules which have been improved since they were used to generate his data; this may well be a weakness in the next exercise.

Isaac Asimov comparisons were necessarily much rougher than for the period 1880-2. He had no data on the Moon’s position north or south of the Ecliptic nor on the rate at which the Moon was separating from the Sun. Hence, Asimov constructed a nomograph based on Schoch’s values for Babylon but adapted for the latitude of Peking and incorporating in a somewhat qualitative way variations arising from other relevant considerations which entered into the making of this nomograph. It was so rough that he did not believe that the use of space would be justified. More important to mention is the result of its application to the 1880-2 data already investigated. The nomograph gave essentially the same results as his earlier more careful investigation, though slightly more generous in respect of probable and possible first crescents on the first day of the month.

Isacc Asimov took for investigation two runs of 25 months beginning on 16 January AD 150 and on 21 January AD 155. He concluded that there were perhaps fourteen occasions when there was probably a first visible crescent on the first day of the month, sixteen occasions when there was a possible first visible crescent, twenty occasions when a first visible crescent was highly improbable or impossible and no occasion on which there could have been a last visible crescent before sunrise on that day. If these inferences are correct, the Chinese in the second century AD were using either the day of the predicted but not observed first visible crescent and often undershooting it or the day of conjunction and often overshooting it.

Nomograph constructed for estimating the likelihood of a first visible crescent at certain intervals between conjunction and sunset and for various times within the year, at the latitude of Peking. The band of ‘possible’ first visible crescent allows for the occurrence of some unfavourable conditions, for example, the Moon being south of the Ecliptic, whereas the band of ‘probables’ assumes all conditions are favourable.

Sivin’s reports and  two dubious studies suggest to Issac Asimov  and he should not wish to use a stronger word, (i) that the Chinese for at least some two millennia or more were aiming at the day of conjunction, (ii) that at first, they tolerated but with some dismay both last visible and first visible crescents on the first day of the calendar month, later they became intolerant of last visible crescents on that day and (iv) still later they tried to minimize first visible crescents but suffered a few of them in preference to undershooting the day of conjunction. Perhaps in this last suggested phase they used the rule ‘First day of the calendar month if the conjunction is before midday and next day if it is after midday’ but through inadequacies of data or obsessions about alternating months of 29 or 30 days (which is doubtful) or on some other considerations (which have not been able to locate) sometimes broke the rule.

Issac Asimov should then like to turn to some cycles of years other than the chang cycle of 19 years (like the Metonic cycle) and the pu cycle of 76 years (like the cycle proposed by Kallipos). These were based on considerations other than those of adjusting a lunar year to the tropical year by periodic intercalary months.

First, the Chinese had a duodenary cycle of years based, like that in India, on Jupiter’s progress among the fixed stars. As Jupiter’s sidereal period is 11.86 years, the planet moves eastward each tropical year about 30.354˚. This is slightly greater than a Babylonian Sign of the Zodiac. Each of the 12 Jupiter years was given one of the names of the twelve ‘terrestrial branches’ which shall be discussed below, and which were also bestowed on the Signs of the Zodiac when they were adopted very much later.

Second, they had a sexagenary cycle not based on five Jupiter cycles as in India and not confined to the years, indeed it seems to have been employed first, in perhaps the late second millennium BC, for a cycle of days and was not applied to the years until near the end of the first millennium BC. The manner of its generation is peculiar (though the same principle of generating a cycle is to be found in the Meso-American calendars). Successive items in two lists, the ten ‘celestial stems’ (chih) and the twelve ‘terrestrial branches (kan), are paired. Let capital letters stand for the members of the chih list, thus A, B, C, D, …, J, and minuscules for the members of the kan list, thus a, b, c, d, …, l. Then a sixty-item set of pairs may be generated to produce

Aa, Bb, Cc, Dd, Ee, Ff, Gg, Hh, Ii, Jj

Ak, Bl, Ca, Db, Ec, Fd, Ge, Hf, lg, Jh

Ai, Bj, Ck, Dl, Ea, Fb, Gc, Hd, Ie, Jf

And so on.

The sixtieth pair is Jl and the sixty-first Aa thus beginning a new cycle.

According to Needham (1959) the origins of the chih and the kan lists are obscure.

He suggests that the former may have begun as the names of the 10-day period (obtained by dividing the ‘full’ lunar month into thirds). The latter seem to have been associated with the 12 lunar months which almost make up a year, with the twelve shih into which the day is divided and later with the 12 years in the Jupiter cycle. We shall list the twelve kan with the animal names in Chinese and English long associated with them.

Tzu (rat), chhou (ox), yin (tiger), mao (hare), chhen (dragon), ssu (snake),

wu (horse), wei (sheep), shen (monkey), yu (cock), hsii (dog) and hai (pig)

In accordance with this list the Chinese have: (i) the ‘hour’ (strictly double hour or shih) of the rat, of the ox, of the tiger and so on; (ii) the day of the rat, of the ox, of the tiger and so on, qualified by the appropriate chih term in the sexagenary cycle, thus chia-tzu or tzu or ping-tzu, for days which are 12 apart; (iii) the month of the rat, of the ox, and so on, although they are more usually known as the first, the second, the third and so on year of some named Emperor’s reign.

Twelve double hours (shih) make a day. A sexagenary cycle of days comes close to 2 lunar synodic months rounded to 29 or 30 days (say 59 days for the pair). A sexagenary cycle of months comes out to rather less than 5 years, assuming that intercalation is being employed. A sexagenary cycle years (averaging about 365.25 days) comes out a little longer (21914.5 days) than five Jupiter cycles (21662.95 days). Perhaps these near coincidences (the deviations of which would not be so evident at first) were enough to convince the early Chinese calendar-makers that the sexagenary cycles could be applied to the days, the months and the years. Whatever be the case they applied them. It would be roughly analogous were we to say the Sun hour of the Moon day of the Twia-month of the Wooden year or the Januarius hour of Februarius day of the Martius month of the Aprilis year or better still the Aries hour of the Taurus day of the Gemini month of the Cancer year.

Though this very ancient calendar was officially abolished on the establishment of the Republic of China in AD 1912, it lingered on in China and in Chinese communities abroad. Unfortunately, not many Malaysians or Singaporeans are aware of this. They only know about the cycles of Zodiac years of the various years that comes and goes in cycles like this Rabbit Years that has just two days left to give way to the Year of the Dragon on 10 February 2024.

 The Chinese calendar in its basic form has had a slightly longer run than the essentially Roman calendar which we use, though both have had a shorter run than the Egyptian civil calendar especially if we count its continued modified forms among the Copts and Ethiopians, among the Persians and among the Parsees in India. Calendars are hard both to make and to unmake, partly because conventions and traditions are so important in them whatever hard core of adjusted astronomical fact, they have in them. It is difficult to distinguish independent creations and borrowings when comparing practices in the Far East and the Near East. There are clear instances of borrowings, sometimes through India but sometimes along the trade-route north of India. The concept of the Zodiac almost certainly moved from the Near East to the Far East through India.

Gunpowder and silk came from China to the West through the Near East perhaps on the northern route. The seven-day planetary week came temporarily into China from Hellenistic sources possibly through India but perhaps through the northern route from northern Persian regions. Sunday in the short-lived Chinese week was Mit, possibly from Mithra, the Sun god. The 360˚ division of the circle also seems to have drifted from Mesopotamia, though in China it was corrected for a time to 365.25˚, on the assumption that it was based on the average daily rate of the Sun’s progress amongst the fixed stars. There is clear evidence of Chinese innovation. As have claimed the Chinese could easily have discovered the Metonic Cycle without influence from the Near East. It is also important to recognize that while astronomers in the Near East, including the Greeks, and in India adopted an orientation for celestial location based on the Ecliptic, the Chinese from the outset adopted an orientation based on the Celestial Equator and Poles, the reference frame now adopted internationally by astronomers.

On this note, let me wish all the Chinese the world over a very Happy and Prosperous New Year of the Dragon. 

Our First Glimpse of the DNA Molecule

 

Our First Glimpse of the DNA Molecule

 The idea of atoms as indivisible particles dates back to ancient Greece. The ancient Greek philosopher Democritus (around 460–370 BCE) proposed the concept of "atomos," suggesting that matter could be divided into indivisible particles. However, this idea was not widely accepted, and it took many centuries for the atomic theory to be revived and developed into the modern atomic theory.

The concept of molecules emerged later in the 19th century. Amedeo Avogadro, an Italian scientist, proposed Avogadro's law in 1811, which stated that equal volumes of gases, at the same temperature and pressure, contain the same number of molecules regardless of their chemical nature and physical properties. This laid the groundwork for understanding molecules as distinct entities.

The development of the atomic and molecular theories was a gradual process, involving contributions from multiple scientists over the centuries. John Dalton's atomic theory in the early 19th century and subsequent advancements in chemistry and physics contributed to our modern understanding of atoms and molecules. The discovery and understanding of atoms and molecules have been ongoing and continue to evolve with scientific research and technological advancements. But no man has ever seen a molecule, let alone an atom untilTop of Form January 1989 when scientists got their first direct look at a very important molecule that changed the biological and medical world.  

For a long time, scientists have been peeping through microscopes at objects too small to be visible through the naked eyes. They have been doing this for four hundred years. The method scientists used was to use lenses that forced light to bend, and in so doing they were able to focus and enlarge images of objects that reflect light. The invention that was able to do this was the microscope.

As the advances in optics progressed over the period, they were able to magnify objects up to 2,000 times as currently with light microscopes. I have several microscopes that are able to do this as microscopy bedsides astronomy is my hobby.

More than 2,000 times, scientists ran into the physical limits of light that comes in waves. Images more than 2,000 times are just magnified without showing further details just like we use a pair of binoculars to magnify trees seen from a distance without being able to see the details of the leaves.

These waves are tiny, but those objects under a microscope were tiny too. If the objects were tinier than the light waves that view them, then the light waves will skip over them so that details of the object could not be seen.

In order to overcome this problem scientists in their ingenuity used shorter light waves such as ultraviolet light. This “ultramicroscopy”, shall we call it temporarily, seems to solve the problem, at least for a while. However, shorter waves could not be focused properly.

In 1923 a French scientist by the name of Louis de Broglie pointed out that subatomic particles exist in wave form too. In 1925 an American scientist named Clinton J. Davisson was able to detect such waves produced by electrons. These electron waves are much shorter than ordinary light waves. They were about the same length as X-rays. But X-rays are extremely difficult to focus, whereas electrons and their waves could be focused easily using magnetic fields.

The first device used to focus electron waves and enlarge the image of objects using this method was constructed in 1932 by a German scientist called Ernest Ruska. This was then the first “electron microscope” which was a crude one initially. However, over the years it was improved and refined until it could magnify up to 300,000 times, a vast improvement over the light microscope that could magnify only up to 2,000 times.

Initially in such a prototype electron microscope the electrons had to pass through an object to produce an enlarged image. This means scientists needed to work with very thin slices of materials for the electrons to pass through. Then they managed to overcome this problem by producing a very thin, sharp beam of electrons and play that beam over the surface by scanning it to produce an enlarged image. This gave rise to the first scanning electron microscope.

Now, a still newer version of electron microscope produced by electrons is called “tunneling effect” and this invention gave rise to a “scanning tunneling electron microscope” that may have reached the limits of its magnification of a million times. This invention gave scientists the ability to peep for the first time ever at a molecule – the molecule of deoxyribonucleic acid (DNA). This was first seen by Miguel B. Salmeron and others at the Lawrence Livermore Laboratory in California in early 1988.

DNA is now so familiar to everyone, even to the non-scientists because it is their chemical footprints of life – you, me and all living creatures that thrive and creep on the surface of this Earth are composed of DNA. Every living cell contains a set of DNA molecules that are constantly replacing themselves, passing the newly created molecules on to daughter cells. Such sets also occur in sperm and egg cells so that they can pass on from parents to children into the generations. Every species of life has their own sets of DNA although there are tiny differences in the sets of different individuals of the same species

But what does DNA matter to life? Its significance to life was first recognized in 1944 that caused scientists to search how these molecules could produce molecules exactly like themselves, somewhat like identical twins.

It was not until 1953 that a British scientist, Francis H.C. Crick, and his American colleague, James D. Watson worked this out. We know that when X-rays pass through molecules they tend to bounce to the side. Photographs of such X-rays produce dots where the X-rays bounce. We call this “X-rays diffraction patterns”. This pattern makes it possible to deduce the shape of molecules. What a beautiful ingenuity of scientists!

 After a long period of time and careful studies they finally found that the DNA molecule consisted of two complex strands of atoms twined together in a double helix like the shape of bedsprings or a winding staircase. They saw each strand had a complicated shape, and the two strands fitted each other precisely.

When DNA forms another molecule like itself, the two strands unwind and each one picks up small groups of atoms from the cell fluid or surrounding area, and puts them together into a new strand that fits exactly upon the original one. In other words, each strand serves as a model to create a new partner for itself. Finally, each DNA molecule produces two DNA molecules exactly alike.

This discovery brought Watson, Crick and another scientist Maurice Wilkins to win the Nobel Prize in Physiology or Medicine in 1962 for their discovery of the molecular structure of DNA, which helped solve one of the most important of all biological riddles. The Nobel Prize for their work was considered a hallmark in very fine scientific reduction. They described the double helix of the DNA molecule so precisely in every detail even though molecules of DNA are far too small.

Thirty years after the discovery of DNA by Watson and Crick, the first picture of the DNA molecules was photographed by the scanning tunnelling electron microscope and no further arguments were required. There was evidence of a double helix so visible to the eyes with the aid of a scanning tunnelling electron microscope. The molecules coil themselves as theoretically expected. From the image it became possible to work out the distance between two successive coils. It turns out to be 5.08 × 10^-6 (0.00,000,508) millimetres – so incredibly small.

Miguel B. Salmeron and his group were planning to refine the method further to see whether they could even see finer details of the strand. The use of the scanning tunnelling electron microscope will enable scientists to look at images of smaller molecules if not atoms. Molecules such as in metals and semiconductors to organic molecules and biological samples are targets of electron microscopy in areas such as molecular immunology in cancer research.

We wish our scientific counterparts every success in their endeavour.

List of 30 Power Point Presentations

 

Scientific Logic: Search results for list of PowerPoint presentations