What Is the Relationship between Earth Science and Geology?
In this chapter we shall try to explain what the fundamental problems in the other they make the various relatively simple compounds found in rocks, earth, etc. as a science, now reduced essentially to what are called physical chemistry. physical science works with earth science. earth science is the study of earth systems and the systems in space. Brief and Straightforward Guide: What Is the Relationship between Earth Science and other related data, which in consonance with the physical analysis of the.
A muscle is a very large number of fibers close together, containing two different substances, myosin and actomyosin, but the machinery by which the chemical reaction induced by acetylcholine can modify the dimensions of the muscle is not yet known.
Thus the fundamental processes in the muscle that make mechanical motions are not known. Biology is such an enormously wide field that there are hosts of other problems that we cannot mention at all—problems on how vision works what the light does in the eyehow hearing works, etc.
The way in which thinking works we shall discuss later under psychology. Now, these things concerning biology which we have just discussed are, from a biological standpoint, really not fundamental, at the bottom of life, in the sense that even if we understood them we still would not understand life itself.
But you can have life without nerves. Plants have neither nerves nor muscles, but they are working, they are alive, just the same. So for the fundamental problems of biology we must look deeper; when we do, we discover that all living things have a great many characteristics in common.
The most common feature is that they are made of cells, within each of which is complex machinery for doing things chemically. In plant cells, for example, there is machinery for picking up light and generating glucose, which is consumed in the dark to keep the plant alive. When the plant is eaten the glucose itself generates in the animal a series of chemical reactions very closely related to photosynthesis and its opposite effect in the dark in plants.
In the cells of living systems there are many elaborate chemical reactions, in which one compound is changed into another and another.
To give some impression of the enormous efforts that have gone into the study of biochemistry, the chart in Fig. Here we see a whole series of molecules which change from one to another in a sequence or cycle of rather small steps. It is called the Krebs cycle, the respiratory cycle.
The Feynman Lectures on Physics Vol. I Ch. 3: The Relation of Physics to Other Sciences
Each of the chemicals and each of the steps is fairly simple, in terms of what change is made in the molecule, but—and this is a centrally important discovery in biochemistry—these changes are relatively difficult to accomplish in a laboratory. If we wanted to take an object from one place to another, at the same level but on the other side of a hill, we could push it over the top, but to do so requires the addition of some energy.
Thus most chemical reactions do not occur, because there is what is called an activation energy in the way. In order to add an extra atom to our chemical requires that we get it close enough that some rearrangement can occur; then it will stick. However, if we could literally take the molecules in our hands and push and pull the atoms around in such a way as to open a hole to let the new atom in, and then let it snap back, we would have found another way, around the hill, which would not require extra energy, and the reaction would go easily.
Now there actually are, in the cells, very large molecules, much larger than the ones whose changes we have been describing, which in some complicated way hold the smaller molecules just right, so that the reaction can occur easily. These very large and complicated things are called enzymes. They were first called ferments, because they were originally discovered in the fermentation of sugar.
In fact, some of the first reactions in the cycle were discovered there. In the presence of an enzyme the reaction will go. An enzyme is made of another substance called protein. Enzymes are very big and complicated, and each one is different, each being built to control a certain special reaction.
The names of the enzymes are written in Fig. Sometimes the same enzyme may control two reactions. We emphasize that the enzymes themselves are not involved in the reaction directly. They do not change; they merely let an atom go from one place to another. Having done so, the enzyme is ready to do it to the next molecule, like a machine in a factory.
Of course, there must be a supply of certain atoms and a way of disposing of other atoms. Take hydrogen, for example: For example, there are three or four hydrogen-reducing enzymes which are used all over our cycle in different places. It is interesting that the machinery which liberates some hydrogen at one place will take that hydrogen and use it somewhere else. The most important feature of the cycle of Fig.
So, GTP has more energy than GDP and if the cycle is going one way, we are producing molecules which have extra energy and which can go drive some other cycle which requires energy, for example the contraction of muscle.
- What Is the Relationship between Earth Science and Geology?
- Earth science
The muscle will not contract unless there is GTP. An enzyme, you see, does not care in which direction the reaction goes, for if it did it would violate one of the laws of physics. Physics is of great importance in biology and other sciences for still another reason, that has to do with experimental techniques.
In fact, if it were not for the great development of experimental physics, these biochemistry charts would not be known today. The reason is that the most useful tool of all for analyzing this fantastically complex system is to label the atoms which are used in the reactions. They are different isotopes. We recall that the chemical properties of atoms are determined by the number of electrons, not by the mass of the nucleus.
But there can be, for example in carbon, six neutrons or seven neutrons, together with the six protons which all carbon nuclei have. Now, we return to the description of enzymes and proteins. Not all proteins are enzymes, but all enzymes are proteins.
There are many proteins, such as the proteins in muscle, the structural proteins which are, for example, in cartilage and hair, skin, etc. However, proteins are a very characteristic substance of life: Proteins have a very interesting and simple structure. They are a series, or chain, of different amino acids.
There are twenty different amino acids, and they all can combine with each other to form chains in which the backbone is CO-NH, etc. Proteins are nothing but chains of various ones of these twenty amino acids. Each of the amino acids probably serves some special purpose. Some, for example, have a sulfur atom at a certain place; when two sulfur atoms are in the same protein, they form a bond, that is, they tie the chain together at two points and form a loop.
Another has extra oxygen atoms which make it an acidic substance, another has a basic characteristic. Some of them have big groups hanging out to one side, so that they take up a lot of space. One of the amino acids, called proline, is not really an amino acid, but imino acid.
There is a slight difference, with the result that when proline is in the chain, there is a kink in the chain. If we wished to manufacture a particular protein, we would give these instructions: In this way, we will get a complicated-looking chain, hooked together and having some complex structure; this is presumably just the manner in which all the various enzymes are made. One of the great triumphs in recent times sincewas at last to discover the exact spatial atomic arrangement of certain proteins, which involve some fifty-six or sixty amino acids in a row.
Over a thousand atoms more nearly two thousand, if we count the hydrogen atoms have been located in a complex pattern in two proteins. The first was hemoglobin. One of the sad aspects of this discovery is that we cannot see anything from the pattern; we do not understand why it works the way it does.
Of course, that is the next problem to be attacked. Another problem is how do the enzymes know what to be? A red-eyed fly makes a red-eyed fly baby, and so the information for the whole pattern of enzymes to make red pigment must be passed from one fly to the next. This is done by a substance in the nucleus of the cell, not a protein, called DNA short for desoxyribose nucleic acid.
This is the key substance which is passed from one cell to another for instance sperm cells consist mostly of DNA and carries the information as to how to make the enzymes.
First, the blueprint must be able to reproduce itself. Secondly, it must be able to instruct the protein. Concerning the reproduction, we might think that this proceeds like cell reproduction. Cells simply grow bigger and then divide in half. Must it be thus with DNA molecules, then, that they too grow bigger and divide in half?
Every atom certainly does not grow bigger and divide in half! No, it is impossible to reproduce a molecule except by some more clever way. Schematic diagram of DNA. The structure of the substance DNA was studied for a long time, first chemically to find the composition, and then with x-rays to find the pattern in space.
The result was the following remarkable discovery: The DNA molecule is a pair of chains, twisted upon each other. The backbone of each of these chains, which are analogous to the chains of proteins but chemically quite different, is a series of sugar and phosphate groups, as shown in Fig.
Thus perhaps, in some way, the specific instructions for the manufacture of proteins are contained in the specific series of the DNA. Attached to each sugar along the line, and linking the two chains together, are certain pairs of cross-links. Whatever the letters may be in one chain, each one must have its specific complementary letter on the other chain. What then about reproduction? Suppose we split this chain in two. How can we make another one just like it? This is the central unsolved problem in biology today.
The first clues, or pieces of information, however, are these: There are in the cell tiny particles called ribosomes, and it is now known that that is the place where proteins are made. But the ribosomes are not in the nucleus, where the DNA and its instructions are. Something seems to be the matter. However, it is also known that little molecule pieces come off the DNA—not as long as the big DNA molecule that carries all the information itself, but like a small section of it.
This is called RNA, but that is not essential. It is a kind of copy of the DNA, a short copy. The RNA, which somehow carries a message as to what kind of protein to make goes over to the ribosome; that is known. When it gets there, protein is synthesized at the ribosome. That is also known. However, the details of how the amino acids come in and are arranged in accordance with a code that is on the RNA are, as yet, still unknown. We do not know how to read it.
Certainly no subject or field is making more progress on so many fronts at the present moment, than biology, and if we were to name the most powerful assumption of all, which leads one on and on in an attempt to understand life, it is that all things are made of atoms, and that everything that living things do can be understood in terms of the jigglings and wigglings of atoms. Astronomy is older than physics. In fact, it got physics started by showing the beautiful simplicity of the motion of the stars and planets, the understanding of which was the beginning of physics.
But the most remarkable discovery in all of astronomy is that the stars are made of atoms of the same kind as those on the earth. Atoms liberate light which has definite frequencies, something like the timbre of a musical instrument, which has definite pitches or frequencies of sound.
When we are listening to several different tones we can tell them apart, but when we look with our eyes at a mixture of colors we cannot tell the parts from which it was made, because the eye is nowhere near as discerning as the ear in this connection. However, with a spectroscope we can analyze the frequencies of the light waves and in this way we can see the very tunes of the atoms that are in the different stars.
As a matter of fact, two of the chemical elements were discovered on a star before they were discovered on the earth. Helium was discovered on the sun, whence its name, and technetium was discovered in certain cool stars. This, of course, permits us to make headway in understanding the stars, because they are made of the same kinds of atoms which are on the earth. Now we know a great deal about the atoms, especially concerning their behavior under conditions of high temperature but not very great density, so that we can analyze by statistical mechanics the behavior of the stellar substance.
Even though we cannot reproduce the conditions on the earth, using the basic physical laws we often can tell precisely, or very closely, what will happen. So it is that physics aids astronomy. Strange as it may seem, we understand the distribution of matter in the interior of the sun far better than we understand the interior of the earth.
What goes on inside a star is better understood than one might guess from the difficulty of having to look at a little dot of light through a telescope, because we can calculate what the atoms in the stars should do in most circumstances. One of the most impressive discoveries was the origin of the energy of the stars, that makes them continue to burn.
One of the men who discovered this was out with his girlfriend the night after he realized that nuclear reactions must be going on in the stars in order to make them shine. She was not impressed with being out with the only man who, at that moment, knew why stars shine. Well, it is sad to be alone, but that is the way it is in this world. Furthermore, ultimately, the manufacture of various chemical elements proceeds in the centers of the stars, from hydrogen.
How do we know? Because there is a clue. The proportions are purely the result of nuclear reactions. By looking at the proportions of the isotopes in the cold, dead ember which we are, we can discover what the furnace was like in which the stuff of which we are made was formed.
Astronomy is so close to physics that we shall study many astronomical things as we go along.
First, meteorology and the weather. Of course the instruments of meteorology are physical instruments, and the development of experimental physics made these instruments possible, as was explained before.
However, the theory of meteorology has never been satisfactorily worked out by the physicist. It turns out to be very sensitive, and even unstable. If you have ever seen water run smoothly over a dam, and then turn into a large number of blobs and drops as it falls, you will understand what I mean by unstable.
You know the condition of the water before it goes over the spillway; it is perfectly smooth; but the moment it begins to fall, where do the drops begin? What determines how big the lumps are going to be and where they will be? That is not known, because the water is unstable. Even a smooth moving mass of air, in going over a mountain turns into complex whirlpools and eddies. In many fields we find this situation of turbulent flow that we cannot analyze today. Quickly we leave the subject of weather, and discuss geology!
The question basic to geology is, what makes the earth the way it is? The most obvious processes are in front of your very eyes, the erosion processes of the rivers, the winds, etc. Ptolemy flourished ce applied the theory of epicycles to compile a systematic account of Greek astronomy. He elaborated theories for each of the planetsas well as for the Sun and Moon. His theory generally fitted the data available to him with a good degree of accuracy, and his book, the Almagestbecame the vehicle by which Greek astronomy was transmitted to astronomers of the Middle Ages and Renaissance.
It essentially molded astronomy for the next millennium and a half. Ptolemy's equant modelIn Ptolemy's geocentric model of the universe, the Sun, the Moon, and each planet orbit a stationary Earth. For the Greeks, heavenly bodies must move in the most perfect possible fashion—hence, in perfect circles.
In order to retain such motion and still explain the erratic apparent paths of the bodies, Ptolemy shifted the centre of each body's orbit deferent from Earth—accounting for the body's apogee and perigee—and added a second orbital motion epicycle to explain retrograde motion.
The equant is the point from which each body sweeps out equal angles along the deferent in equal times. The centre of the deferent is midway between the equant and Earth. Greek physics Several kinds of physical theories emerged in ancient Greeceincluding both generalized hypotheses about the ultimate structure of nature and more specific theories that considered the problem of motion from both metaphysical and mathematical points of view.
Attempting to reconcile the antithesis between the underlying unity and apparent multitude and diversity of nature, the Greek atomists Leucippus mid-5th century bceDemocritus late 5th century bceand Epicurus late 4th and early 3rd century bce asserted that nature consists of immutable atoms moving in empty space. According to this theory, the various motions and configurations of atoms and clusters of atoms are the causes of all the phenomena of nature. Epicurus, bronze bust from a Greek original, c.
Courtesy of the Soprintendenza alle Antichita della Campania, Naples In contrast to the particulate universe of the atomists, the Stoics principally Zeno of Citiumbridging 4th and 3rd centuries bce, Chrysippus [3rd century bce], and Poseidonius of Apamea [flourished c.
Neither the atomic theory nor Stoic physics survived the criticism of Aristotle and his theory. In his physicsAristotle was primarily concerned with the philosophical question of the nature of motion as one variety of change. He assumed that a constant motion requires a constant cause; that is to say, as long as a body remains in motion, a force must be acting on that body.
He considered the motion of a body through a resisting medium as proportional to the force producing the motion and inversely proportional to the resistance of the medium. Aristotle used this relationship to argue against the possibility of the existence of a void, for in a void resistance is zero, and the relationship loses meaning.
He considered the cosmos to be divided into two qualitatively different realms, governed by two different kinds of laws. In the terrestrial realm, within the sphere of the Moonrectilinear up-and-down motion is characteristic.
Heavy bodies, by their nature, seek the centre and tend to move downward in a natural motion. It is unnatural for a heavy body to move up, and such unnatural or violent motion requires an external cause.
Light bodies, in direct contrast, move naturally upward. In the celestial realm, uniform circular motion is natural, thus producing the motions of the heavenly bodies. Archimedes 3rd century bce fundamentally applied mathematics to the solution of physical problems and brilliantly employed physical assumptions and insights leading to mathematical demonstrations, particularly in problems of statics and hydrostatics.
He was thus able to derive the law of the lever rigorously and to deal with problems of the equilibrium of floating bodies. Illustration of Archimedes' principle of buoyancy. Here a 5-kg object immersed in water is shown being acted upon by a buoyant upward force of 2 kg, which is equal to the weight of the water displaced by the immersed object. The buoyant force reduces the object's apparent weight by 2 kg—that is, from 5 kg to 3 kg.
Islamic and medieval science Greek science reached a zenith with the work of Ptolemy in the 2nd century ce. The lack of interest in theoretical questions in the Roman world reduced science in the Latin West to the level of predigested handbooks and encyclopaedias that had been distilled many times.Plate Tectonics Explained
Social pressures, political persecution, and the anti-intellectual bias of some of the early Church Fathers drove the few remaining Greek scientists and philosophers to the East. There they ultimately found a welcome when the rise of Islam in the 7th century stimulated interest in scientific and philosophical subjects. Most of the important Greek scientific texts were preserved in Arabic translations. Although the Muslims did not alter the foundations of Greek science, they made several important contributions within its general framework.
When interest in Greek learning revived in western Europe during the 12th and 13th centuries, scholars turned to Islamic Spain for the scientific texts. A spate of translations resulted in the revival of Greek science in the West and coincided with the rise of the universities. Working within a predominantly Greek framework, scientists of the late Middle Ages reached high levels of sophistication and prepared the ground for the scientific revolution of the 16th and 17th centuries.
Mechanics was one of the most highly developed sciences pursued in the Middle Ages.
The problem of projectile motion was a crucial one for Aristotelian mechanics, and the analysis of this problem represents one of the most impressive medieval contributions to physics. Because of the assumption that continuation of motion requires the continued action of a motive forcethe continued motion of a projectile after losing contact with the projector required explanation. Aristotle himself had proposed explanations of the continuation of projectile motion in terms of the action of the medium.
The ad hoc character of these explanations rendered them unsatisfactory to most of the medieval commentators, who nevertheless retained the fundamental assumption that continued motion requires a continuing cause.
According to this view, there is an incorporeal motive force that is imparted to the projectile, causing it to continue moving. Buridan employed this concept to suggest an explanation of the everlasting motions of the heavens. During the s certain Oxford scholars pondered the philosophical problem of how to describe the change that occurs when qualities increase or decrease in intensity and came to consider the kinematic aspects of motion.
Dealing with these problems in a purely hypothetical manner without any attempt to describe actual motions in nature or to test their formulas experimentally, they were able to derive the result that in a uniformly accelerated motion, distance increases as the square of the time.
Thomas Aquinaswhich had clearly theological consequences. Many of these condemned propositions had scientific implications as well. The scientific revolution During the 15th, 16th, and 17th centuries, scientific thought underwent a revolution. A new view of nature emerged, replacing the Greek view that had dominated science for almost 2, years. Science became an autonomous disciplinedistinct from both philosophy and technologyand it came to be regarded as having utilitarian goals.
By the end of this periodit may not be too much to say that science had replaced Christianity as the focal point of European civilization.
Out of the ferment of the Renaissance and Reformation there arose a new view of science, bringing about the following transformations: Astronomy The scientific revolution began in astronomy. Relying on virtually the same data as Ptolemy had possessed, Copernicus turned the world inside out, putting the Sun at the centre and setting Earth into motion around it. To achieve comparable levels of quantitative precision, however, the new system became just as complex as the old.
In contrast to Platonic instrumentalism, Copernicus asserted that to be satisfactory astronomy must describe the real, physical system of the world.
Copernican systemCopernican system, 18th-century French engraving. The astronomer is shown between a crucifix and a celestial globe, symbols of his vocation and work.
By the time large-scale opposition to the theory had developed in the church and elsewhere, most of the best professional astronomers had found some aspect or other of the new system indispensable.
Thus, it was widely read by mathematical astronomers, in spite of its central cosmological hypothesiswhich was widely ignored. The tables were more accurate and more up-to-date than their 13th-century predecessor and became indispensable to both astronomers and astrologers. The Adler Planetarium and Astronomy Museum, Chicago, Illinois During the 16th century the Danish astronomer Tycho Braherejecting both the Ptolemaic and Copernican systems, was responsible for major changes in observation, unwittingly providing the data that ultimately decided the argument in favour of the new astronomy.
Using larger, stabler, and better calibrated instruments, he observed regularly over extended periods, thereby obtaining a continuity of observations that were accurate for planets to within about one minute of arc—several times better than any previous observation. Engraving of Tycho Brahe at the mural quadrant, from his book Astronomiae instauratae mechanica The engraving depicts Brahe, in the centre with arm upraised, and the work of his observatory at Uraniborg, on the island of Ven.
In the background, assistants perform astronomical observations, work in Brahe's study, and do chemical experiments. The hound at his feet symbolizes loyalty. Courtesy of the Joseph Regenstein Library, University of Chicago Engraving of Tycho Brahe's model of the motion of the planet Saturn, from his Astronomiae instauratae progymnasmataprinted in Prague.
What is the relationship between earthscience and physical science
Tycho's geocentric model put the Earth at the centre A of the universe, with the Sun B revolving around it, and the planets revolving around the Sun.
The Adler Planetarium and Astronomy Museum, Chicago At the beginning of the 17th century, the German astronomer Johannes Kepler placed the Copernican hypothesis on firm astronomical footing. Converted to the new astronomy as a student and deeply motivated by a neo- Pythagorean desire for finding the mathematical principles of order and harmony according to which God had constructed the world, Kepler spent his life looking for simple mathematical relationships that described planetary motions.
His painstaking search for the real order of the universe forced him finally to abandon the Platonic ideal of uniform circular motion in his search for a physical basis for the motions of the heavens. Kepler, JohannesJohannes Kepler, oil painting by an unknown artist, ; in the cathedral of Strasbourg, France. With these two laws, Kepler abandoned uniform circular motion of the planets on their spheres, thus raising the fundamental physical question of what holds the planets in their orbits.
The impending marriage of astronomy and physics had been announced. In Kepler stated his third law, which was one of many laws concerned with the harmonies of the planetary motions: Kepler's theory of the solar system.
A powerful blow was dealt to traditional cosmology by Galileo Galileiwho early in the 17th century used the telescopea recent invention of Dutch lens grinders, to look toward the heavens. In Galileo announced observations that contradicted many traditional cosmological assumptions. He observed that the Moon is not a smooth, polished surface, as Aristotle had claimed, but that it is jagged and mountainous.
Earthshine on the Moon revealed that Earth, like the other planets, shines by reflected light. Like Earth, Jupiter was observed to have satellites; hence, Earth had been demoted from its unique position. The phases of Venus proved that that planet orbits the Sun, not Earth. Removing Earth from the centre destroyed the doctrine of natural motion and place, and circular motion of Earth was incompatible with Aristotelian physics.
Although in his youth he adhered to the traditional impetus physics, his desire to mathematize in the manner of Archimedes led him to abandon the traditional approach and develop the foundations for a new physics that was both highly mathematizable and directly related to the problems facing the new cosmology.
Interested in finding the natural acceleration of falling bodies, he was able to derive the law of free fall the distance, s, varies as the square of the time, t2. Combining this result with his rudimentary form of the principle of inertiahe was able to derive the parabolic path of projectile motion. Galileo, oil painting by Justus Sustermans, c. He was principally concerned with the conceptions of matter and motion as part of his general program for science—namely, to explain all the phenomena of nature in terms of matter and motion.
This program, known as the mechanical philosophy, came to be the dominant theme of 17th-century science. Although matter tends to move in a straight line in accordance with the principle of inertia, it cannot occupy space already filled by other matter, so the only kind of motion that can actually occur is a vortex in which each particle in a ring moves simultaneously.