A Theory of Everything

1. A Theory of Everything Atomic Structure

2. 1. Be able to describe the history of the discoveries that lead to our current understanding of the atom. That is the topic of this chapter.

3. The elements of fire, air, earth, and water are not made of atoms, but are continuous. Matter is infinitely divisible Matter is not infinitely divisible Matter is not infinitely divisible Atoma (sg. atomon) "indivisible units" 2. What is an atom? From where did the concept of an atom arise? Leucippus or Leukippos (first half of 5th century BC) Aristotle (384 BC – 322 BC) Democritus (ca. 460 BC - 370 BC). Student of Leucippus

4. Alchemy In the history of science, alchemy refers to both an early form of the investigation of nature and an early philosophical and spiritual discipline, both combining elements of chemistry, metallurgy, physics, medicine, astrology, semiotics, mysticism, spiritualism, and art all as parts of one greater force. The best-known goals of the alchemists were the transmutation of common metals into gold or silver; the creation of a "panacea or the elixir of life," a remedy that supposedly would cure all diseases and prolong life indefinitely; and the discovery of a universal solvent http://en.wikipedia.org/wiki/Alchemy 2. What is an element? Title: The alchemist Painter: Sir William Fettes Douglas (1822 - 1891)

5. In 1803, the Englishman John Dalton, an instructor and natural philosopher, used the concept of atoms to explain why elements always reacted in a ratio of small whole numbers—the law of multiple proportions—and why certain gases dissolved better in water than others. He proposed that each element consists of atoms of a single, unique type, and that these atoms could join to each other, to form chemical compounds. http://en.wikipedia.org/wiki/Atom 3. What was Dalton's contribution to our understanding of the atom? What is an element? What is a molecule? What is a compound? John Dalton (1766 – 1844)

7. 3. What is the "billiard ball” model of the atom?

8. 4. What is a cathode ray tube? 1. Control Grid 5. Cathode 2. Anode6. Cathode ray beam 3. Deflecting coils 7. Focusing coil 4. Heater 8. Fluorescent screen

9. Sir Joseph John “J.J.” Thomson (1856 – 1940) First experiment In his first experiment, he investigated whether or not the negative charge could be separated from the cathode rays by means of magnetism… Thomson concluded that the negative charge was inseparable from the rays. 4. What did J.J. Thompson find out about the atom's structure?

10. Sir Joseph John “J.J.” Thomson (1856 – 1940) Second experiment In his second experiment, he investigated whether or not the rays could be deflected by an electric field (something that is characteristic of charged particles). Previous experimenters had failed to observe this, but Thomson believed their experiments were flawed because they contained trace amounts of gas. Thomson constructed a cathode ray tube with a practically perfect vacuum, and coated one end with phosphorescent paint. Thomson found that the rays did indeed bend under the influence of an electric field, in a direction indicating a negative charge. 4. What did J.J. Thompson find out about the atom's structure?

11. Sir Joseph John “J.J.” Thomson (1856 – 1940) Third experiment In his third experiment, Thomson measured the charge-to-mass ratio of the cathode rays by measuring how much they were deflected by a magnetic field and how much energy they carried. He found that the charge to mass ratio was over a thousand times higher than that of a hydrogen ion (H+), suggesting either that the particles were very light or very highly charged. 4. What did J.J. Thompson find out about the atom's structure?

12. Sir Joseph John “J.J.” Thomson (1856 – 1940) Third experiment Thomson's conclusions were bold: cathode rays were indeed made of particles which he called "corpuscles", and these corpuscles came from within the atoms of the electrodes themselves, meaning that atoms are in fact divisible. The "corpuscles" discovered by Thomson are identified with the electrons which had been proposed by G. Johnstone Stoney. 4. What did J.J. Thompson find out about the atom's structure?

13. Sir Joseph John “J.J.” Thomson (1856 – 1940) Physics 1906 Thomson imagined the atom as being made up of these corpuscles swarming in a sea of positive charge; this was his plum pudding model… Thomson's discovery was made known in 1897, and caused a sensation in scientific circles. http://en.wikipedia.org/wiki/J._J._Thomson 4. What did J.J. Thompson find out about the atom's structure?

14. 4. What is the "plum pudding" model of the atom?

15. 5. What was the Geiger-Marsden experiment (Gold foil experiment/ Rutherford experiment) The Geiger-Marsden experiment (also called the Gold foil experiment or the Rutherford experiment) was an experiment done by Hans Geiger and Ernest Marsden in 1909, under the direction of Ernest Rutherford He+2 He+2

16. 1911 Ernest Rutherford (1871 – 1937) Chemistry 1908 “It was almost as incredible as if you fired a fifteen-inch shell at a piece of tissue paper and it came back and hit you.” The plum-pudding model is incorrect. The positive charge(s) must be concentrated in the center. 5. What was the contribution of Rutherford? What is the "planetary" model of the atom?

17. 6. Consider the planetary model of an atom. What parts of an atom were known at this time? What is the charge on each? What is the mass of each? What is atomic number? Mass number? Isotopes? Particle Mass Relative Mass Charge Relative Charge Electron 0.10953 x 10-31 kg 0 -1.60219 x 10-19 C -1 Proton 1.674 x 10-27 kg 1 1.60219 x 10-19 C 1 Neutron 1.677 x 10-27 kg 1 0 0

18. Niels Bohr (1885 - 1962) Physics 1922 • Postulated (1913): • Electrons orbit in distinct paths analogous to planets. • Only certain radii (shells) occur. • Electrons absorb energy to move to outer shells and release energy when they move to inner shells • Electrons do not release energy in a shell. How are the electrons organized? 7. What was the contribution of Bohr? What is the Bohr model? Be able to show how electrons fill in this model.

19. l is wavelength mv is momentum Louis de Broglie (1892 – 1987) Physics 1929 Why are only certain electron paths allowed? Electrons travel as waves (with no mass) and as particles (with mass.) This is the wave-particle duality of ALL matter. (1924) 8. Who was de Broglie? What is the relationship between waves and particles? How did de Broglie's work help to explain why electrons are only found at fixed distances?

20. Erwin Schrodinger (1887 – 1961) Physics 1933 Y Equation for Wave Theory (1926) 8. What was the contribution of Schrodinger?

21. Max Born (1882 – 1970) Physics 1954 Y Is a probability amplitude (1926) The Schrödinger equation defines the behaviour of y , but does not interpret what yis. Schrödinger tried unsuccessfully to interpret it as a charge density. In 1926 Max Born, just a few days after Schrödinger's fourth and final paper was published, successfully interpreted as a probability amplitude, although Schrödinger was never reconciled to this statistical or probabilistic approach. http://en.wikipedia.org/wiki/Schr%C3%B6dinger%27s_equation 8. What was the contribution of Born?

22. Orbitals are probabilities of finding an electron at any given time. 1926 8. What is the electron cloud model? What is an orbital? What is the orbital model? Be able to describe this model.

24. This doesn’t make sense! How can an electron be a particle and a wave at the same time? Packer, J. I. 1961 (reprinted 1991). Evangelism and the Sovereignty of God. InterVarsity Press, Downer’s Grove, IL.

25. Our aim in the present study is to think out the nature of the Christian’s evangelistic task in the light of this agreed presupposition that God is sovereign in salvation. Now, we need to recognize right at the outset that this is no easy assignment. All theological topics contain pitfalls for the unwary, for God’s truth is never quite what man would have expected; and our present subject is more treacherous than most. This is because in thinking it through we have to deal with an antinomy in the biblical revelation, and in such circumstances our finite, fallen minds are more than ordinarily apt to go astray.

26. What is an antinomy? The Shorter Oxford Dictionary defines it as ‘a contradiction between conclusions which seem equally logical, reasonable or necessary.’ For our purposes, however, this definition is not quite accurate; the opening words should read ‘an appearance of contradiction.’ For the whole point of an antinomy – in theology, at any rate – is that it is not a real contradiction, though it looks like one. It is an apparent incompatibility between two apparent truths. An antinomy exists when a pair of principles stand side by side, seemingly irreconcilable, yet both undeniable. There are cogent reasons for believing each of them; each rests of clear and solid evidence; but it is a mystery to you how they can be squared with each other.

27. You see that each must be true on its own, but you do not see how they can both be true together. Let me give an explain. Modern physics faces an antinomy, in this sense, in its study of light. There is cogent evidence to show that light consists of waves, and equally cogent evidence to show that it consists of particles. It is not apparent how light can be both waves and particles, but the evidence is there, and so neither view can be ruled out in favour of the other. Neither, however, can be reduced to the other or explained in terms of the other; the two seemingly incompatible positions must be held together, and both must be treated as true. Such a necessity scandalized our tidy minds, no doubt, but there is no help for it if we are to be loyal to the facts.

28. It appears, therefore, that an antinomy is not the same thing as a paradox. A paradox is a figure of speech, a play on words. It is a form of statement that seems to unite two opposite ideas, or to deny something by the very terms in which it is asserted…

29. A Theory of Everything Nuclear Physics and Radioactivity

30. Chemistry involves the electrons in atoms. Radioactivity involves the nucleus of atoms.

31. 1. We know that the atom is made of electrons that are found in orbitals. We also know that the nucleus is made of protons and neutrons. Since the protons are positive, they should repel one another. Why does a nucleus not disintegrate? What are four fundamental interactions between particles in nature? Describe their effect, strength, and range. Physicists hold that there are four fundamental interactions between particles in nature: • Gravity • The Strong Nuclear Force • The Weak Nuclear Force • Electromagnetism

32. 1. We know that the atom is made of electrons that are found in orbitals. We also know that the nucleus is made of protons and neutrons. Since the protons are positive, they should repel one another.

33. 1. We know that the atom is made of electrons that are found in orbitals. We also know that the nucleus is made of protons and neutrons. Since the protons are positive, they should repel one another. Why does a nucleus not disintegrate?

35. There is an optimum number of neutrons for each element. Atoms with more or fewer than this number tend to be unstable. 2. Not all nuclei are stable. Why? Make a list of reasons.

36. Henri Becquerel (1852 – 1908) Physics 1903 I studied uranium ore and accidentally discovered radioactivity. One wraps a Lumière photographic plate with a bromide emulsion in two sheets of very thick black paper, such that the plate does not become clouded upon being exposed to the sun for a day. One places on the sheet of paper, on the outside, a slab of the phosphorescent substance, and one exposes the whole to the sun for several hours. When one then develops the photographic plate, one recognizes that the silhouette of the phosphorescent substance appears in black on the negative. If one places between the phosphorescent substance and the paper a piece of money or a metal screen pierced with a cut-out design, one sees the image of these objects appear on the negative. … One must conclude from these experiments that the phosphorescent substance in question emits rays which pass through the opaque paper and reduces silver salts. 3. How did we come to our current understanding of radioactivity? What was the contribution of Henri Becquerel?

37. Marie Curie (1867 - 1934) Pierre Curie (1859 - 1906) Physics 1903 We studied uranium. We found that purified uranium was less radioactive than the ore from which it was taken. We then isolated 10mg of this more radioactive substance from 8 tons of ore. We named it radium. We also made compounds of radium and found that radioactivity is not a characteristic of chemical bonds. It is associated with the nucleus. We also isolated polonium. Marie named for her homeland of Poland. 3. What was the contribution of the Curies?

38. Marie Curie (1867 - 1934) Physics 1903 Chemistry 1911 I was born in Poland and lived there until I was 24. My early years were marked by the death of my sister Zofia and, two years later, the death of my mother. Because I was female, and because of Russian reprisals following the Polish 1863 uprising against Tsarist Russia, I was denied admission to a regular university. At age 18 I took a post as a governess. From my earnings I supported my elder sister Bronisława, who was studying medicine in Paris. In 1891 I went to join my sister in Paris. At age 18 I took a post as a governess. From my earnings I supported my elder sister who was studying medicine in Paris. I joined her at the University 1891 where I studied mathematics, physics and chemistry. I graduated first in my class. A year later, I obtained my master's degree in mathematics. In 1903, under the supervision of Henri Becquerel, I received her DSc becoming the first woman in France to complete a doctorate. At the University of Paris, also, I met and married Pierre Curie. Our interest in magnetism drew us together. On April 19, 1906, Pierre was killed in a street accident as he was leaving a publisher's office. He had gone there to review proofs of an article, and found the business closed due to a strike. Heading back across the street in heavy rain, he was struck by a horse-drawn vehicle and fell under its wheels, fracturing his skull. I was the first woman to be awarded a Nobel Prize. Eight years later, I received the Nobel Prize in Chemistry. They said that it was, "in recognition of her services to the advancement of chemistry by the discovery of the elements radium and polonium, by the isolation of radium and the study of the nature and compounds of this remarkable element". I was the first person to win or share two Nobel Prizes. I remain the only woman to have won two Nobel Prizes I am one of only two people who have been awarded a Nobel Prize in two different science fields. 3. What was the contribution of the Curies?

39. Ernest Rutherford (1871 – 1937) Chemistry 1908 Radioactivity was first discovered in 1896 by Henri Becquerel. Different types of decay can occur, but Rutherford was the first to realize that they all occur with the same mathematical approximately exponential formula. As for types of radioactive radiation, it was found that an electric or magnetic field could split such emissions into three types of beams. Rutherford coined the terms alpha and beta to describe the two distinct types of radiation emitted by thorium and uranium. http://en.wikipedia.org/wiki/Radioactive_decay http://en.wikipedia.org/wiki/Ernest_Rutherford 4. What are the types of radioactive emissions?

40. Ernest Rutherford (1871 – 1937) Chemistry 1908 [The term transmutation] was first consciously applied to modern physics by Frederick Soddy when he, along with Ernest Rutherford, discovered that radioactive thorium was converting itself into radium in 1901. At the moment of realization, Soddy later recalled, he shouted out: “Rutherford, this is transmutation!” Rutherford snapped back, “For xxx's sake, Soddy, don't call it transmutation. They'll have our heads off as alchemists.” http://en.wikipedia.org/wiki/Nuclear_transmutation 4. What are the types of radioactive emissions?

41. 22688Ra 22286Rn + 42He The Strong Nuclear Force 5. What is alpha decay?

42. 10n 11p + 0e- 13755Cs 13756Ba + 0e- The Weak Nuclear Force In β−  decay, the weak interaction converts a neutron (n0) into a proton (p+) while emitting an electron (e− ) and an antineutrino (νe) 6. What is beta decay?

43. Electromagnetic Radiation Photons 7. What is gamma decay?

44. Electromagnetic Radiation Photons 7. What is gamma decay?

45. Alpha particles may be completely stopped by a sheet of paper, beta particles by aluminum shielding. Gamma rays can only be reduced by much more substantial barriers, such as a very thick layer of lead. 4. What are the types of radioactive emissions?

47. 8. What is a half-life?

48. 8. What is a half-life? http://www.kayelaby.npl.co.uk/atomic_and_nuclear_physics/4_6/4_6_1.html

49. Today's accepted age of the Earth of 4.55 billion years was determined by C.C. Patterson using Uranium-Lead dating on fragments of the Canyon Diablo meteorite and published in 1956. 8. What things have been dated using radioactive materials?

50. Willard F. Libby (1918 – 1980) Chemistry 1960 146C 147N + 0e- Half-life = 5,730 years Up to 60,000 years old Carbon-containing materials 8. What is carbon dating? What kinds of things are dated by this technique?