1. 4/12/06Atoms and Stars, Class 131 Atoms and Stars IST 2420 and IST 1990 Class 13 Winter 2006 Instructor: David Bowen Course web site: www.is.wayne.edu/drbowen/aasw06 IST 1990 Moodle: techtools.culma.wayne.edu/moodle My new cell-phone number: 248-376-9848 (the number to call during 5 – 6 PM office hours)

2. 4/12/06Atoms and Stars, Class 132 Agenda Assignments, passbacks, initial signin sheet Pick up: oNotes for Class 13 oFinal Where-Is Upcoming assignments oWindows Calculator for Final Review of readings Emphasizing main points one more time Updates: natural disasters & bird flu Lab 11: The Orbiting Bottle

3. 4/12/06Atoms and Stars, Class 133 Changes in Lab Schedule Changes to Syllabus lab schedule: oLab 11 tonight oWe will not do Lab 4 (we went over the content last class)

4. 4/12/06Atoms and Stars, Class 134 Upcoming … April 19 (last regular class) oEssay 2 due oReview for Final Exam April 26: nothing that night but the Final Exam Opportunities for extra help: o5 – 6 PM next week (April 19) oReview Session next week during class o5 – 6 PM before Final (April 26) oTelephone, email, set up a time

5. 4/12/06Atoms and Stars, Class 135 Semester is Ending! If you have been relying on being able to turn work in late, it is time to get going oAlternatives: D, E, I, X, drop – see counselor! Getting ready for Final: oRead Information Sheet carefully – a lot of information there oLook at Final Topics carefully oUse Review Session! Final Where-Is probably April 12

6. 4/12/06Atoms and Stars, Class 136 16 ths on the Final Options for doing the math for converting 16ths (inches, ounces) to decimal (inches, pounds) oWindows calculator oLab calculator (I will pass from person to person)

7. 4/12/06Atoms and Stars, Class 137 Windows Calculator Start  Programs  Accessories  Calculator If it looks very different, click View  Standard Click on keys or use Keypad or Numeric Keypad on right of keyboard oMake sure Num Lock is lit before using Numeric Keypad

8. 4/12/06Atoms and Stars, Class 138 Experiment 11 Most reports did say that the formula for the ellipse was trusted more than the experimental measurement oThe power of authority oAlso, not trusting your techniques oBut in this case, the authority was not trustworthy Many said no use in repeating measurements oResults would be the same No! Every technique has a limit, will have variations when you push that limit It is never easy, but scientists will eventually come down on the side of experiment

9. 4/12/06Atoms and Stars, Class 139 Experiment 7 Should find V of block  V of displaced water (Archimedes was correct) oCan be large error because of small height of displaced water Should find S.G of wood  % below water oLarge error in estimating % below water Dumbbell – should find W in air  W in water + W displaced water oErrors were larger than I thought, may be a problem

10. 4/12/06Atoms and Stars, Class 1310 Later Evidence for Atoms (Q10d) 1895 Boltzmann and Gibbs with Statistical Mechanics – success of Atomic Theory But Atoms still seen as perhaps just a theoretical convenience, perhaps no actual existence 1905 Einstein analyzed Brownian motion to find density of atoms oExperimentally confirmed oMore convincing

11. 4/12/06Atoms and Stars, Class 1311 Later Evidence for Atoms (Q10d) 1911, Rutherford discovered electron and nucleus, components of atoms oAtomic Theory adopted oBut atoms are not elemental (they have parts), even though atoms are still called elements Similar definitive evidence since then Individual atoms seen in 1970s (~)

12. 4/12/06Atoms and Stars, Class 1312 Readings – Big Bang Emails on Big Bang #1 from George Gale (1999) oKansas school board rejected Big Bang and radioactive dating along with evolution o“Young earth creationists” – 6,000 years in past for age of earth Vs 4.5 billion years from radioactive dating (Q14) o(DB) 6,000 years ago is a reasonable scientific date for writing and the development of records

13. 4/12/06Atoms and Stars, Class 1313 Evidence for Big Bang #2, Neil De Grasse Tyson o“Theories” instead of “Laws” – humble now o1929 Edwin Hubble, galaxies receding, further galaxies receding faster oGravitational lenses – focused object receding faster than focusing object (further away) o“Time dilation” from Einstein’s Special Theory of Relativity – time slows down if motion faster

14. 4/12/06Atoms and Stars, Class 1314 Evidence for Big Bang o“Time dilation” from Einstein’s Special Theory of Relativity – time slows down if motion faster Distant supernovae do explode and age more slowly compared to near ones (Big Bang says moving faster) oCosmic Microwave Background predicted, discovered 1965 A peak location and spectrum (shape of intensity Vs wavelength) that matches measurements Has a distant source – we see it heated when passes through matter

15. 4/12/06Atoms and Stars, Class 1315 Evidence for Big Bang oCosmic Microwave Background predicted, discovered 1965 (cont’d) Molecular “thermometers” show background radiation hotter from distant (older) galaxies oAlso consistent with mix of atomic species Consistent with accelerator laboratory experiments oBut background radiation too uniform “Inflationary universe” explains this, and more (DB: some non-uniformity observed this year)

16. 4/12/06Atoms and Stars, Class 1316 Evidence for Big Bang oBut required mass is missing (DB: dark matter is being discovered – see update) #3: Gregg Esterbrook oModern science chance-based, seems not to require God, also predicts death of the universe o1999 conference at Berkeley CA Astronomer Allan Sandage: majesty of Big Bang helped make him a believer Ian Barbour: physical law seems to favor life (Anthropic Principle)

17. 4/12/06Atoms and Stars, Class 1317 Evidence for Big Bang #3: Gregg Esterbrook (cont’d) oConsilience by E.O.Wilson: can reconcile technical and spiritual, along with other books oCreation “ex nihilo” consistent with latest Big Bang theories o(Q14) Parallel between God creating existence from “waters” with H being most abundant element (DB) Water necessary for life (at least life like us), life on earth did come from life in water o“Existence may be … prewired … for life” oIf we came late, still may be early in time span of universe

18. 4/12/06Atoms and Stars, Class 1318 Evidence for Big Bang #4: Thomas Diana oMore and more can be explained without the action of God oAncients had gods, each with own area oGeocentric theory – we were at center of universe oNow we are displaced from central position oQuantum Mechanics lets Big Bang be created from empty space (quantum fluctuations)

19. 4/12/06Atoms and Stars, Class 1319 Evidence for Big Bang #4: Thomas Diana (cont’d) oAt one point, science said life impossible without extraordinary coincidences in physical constants (Anthropic Principle) Now inflationary theory of universe makes this less necessary oHow to retain belief? (Q14) Not a belief in anthropomorphic God, but one that transcends as science transcends the ordinary Scientific mastery of universe results in separation

20. 4/12/06Atoms and Stars, Class 1320 Evidence for Big Bang #4: Thomas Diana (cont’d) oHow to retain belief? (Q14) Scientific mastery of universe results in separation Separation has led some to seek immanent God –“immanent” (Theology): present throughout the universe, as opposed to transcendent (existing apart from the universe) We can achieve this – experience power greater than ourselves –Rituals –Gazing at starlit sky – experience not diminished by knowledge

21. 4/12/06Atoms and Stars, Class 1321 The Big Bang… Big Bang, expansion of universe 3-D analogy to a rising loaf of raisin bread oExpansion with no center (but this bread has edges, unlike the universe) ohttp://www.is.wayne.edu/drbowen/aasw05/BigBangAnalogies.htmhttp://www.is.wayne.edu/drbowen/aasw05/BigBangAnalogies.htm 2-D analogy to the surface of an expanding balloon ohttp://www.astro.ucla.edu/~wright/Balloon2.htmlhttp://www.astro.ucla.edu/~wright/Balloon2.html

22. 4/12/06Atoms and Stars, Class 1322 The Big Bang… Big Bang, expansion of universe 3-D analogy to a rising loaf of raisin bread oExpansion with no center (but this bread has edges, unlike the universe)

23. 4/12/06Atoms and Stars, Class 1323 The Big Bang… 2-D analogy to the surface of an expanding balloon oNo edge but cannot go off the balloon surface (DB) (Q14) Universe originally light, no matter oHad to cool off for matter to exist

24. 4/12/06Atoms and Stars, Class 1324 Brain Candy… Wormhole A theoretical possibility within Einstein’s General Theory of Relativity (1916) oA shortcut through 4-D space-time that could dramatically speed travel between points connected by the wormhole, and into the future oRequires an undiscovered form of exotic matter with negative energy density – a “white hole,” contrasts with a black hole oWormhole could collapse on the traveler http://en.wikipedia.org/wiki/Wormhole

25. 4/12/06Atoms and Stars, Class 1325 Wormhole From Wikipedia (see link on previous slide)

26. 4/12/06Atoms and Stars, Class 1326 Update Inflation: Universe expanded “exceeding quick” in first trillionth of a second, to size of grapefruit Produces “Anthropic Principle” Now expansion of universe is accelerating o Einstein’s cosmological constant

27. 4/12/06Atoms and Stars, Class 1327 Readings: Black Holes (Hewitt) (Q3) Black hole: escape velocity at surface > speed of light, so cannot escape (Black Hole is dark) oSpace collapses nearby, draws in anything nearby DB: can see light as indrawn objects are destroyed oCan also be seen by gravitational effect on neighbors oDB: Burned-out star collapses, forms Black Hole Nuclear fuel burns out, star collapses Black Hole can draw in other matter Theoretically possible for reappearance of this matter as white hole, but this is unknown

28. 4/12/06Atoms and Stars, Class 1328 Readings: Global Warming (Q12) Light comes in to earth from sun oSome absorbed on surface, warming earth oRest reflected, exits to space oGreenhouse gases in upper atmosphere trap reflected light, some returned and further heats earth Amount of warming now about 1ºF but projected to rise rapidly oBy 2100, projections = 2.5ºF to 10.4ºF

29. 4/12/06Atoms and Stars, Class 1329 Atmosphere, Climate and Change by Thomas Graedel and Paul Crutzen, Scientific American Library, 1997.

30. 4/12/06Atoms and Stars, Class 1330 New York Times, “Computers Add Sophistication, but Don’t Resolve Climate Debate,” Science Times Pg D3 8/31/04

31. 4/12/06Atoms and Stars, Class 1331 Global Warming (cont’d) Largest effect in Antarctic oSnow reflects most, sea water least oArctic ice disappearing oPolar bears in danger oEskimos suing US The New Yorker, cover, 12/12/05

32. 4/12/06Atoms and Stars, Class 1332 Global Warming (cont’d) What to do? Options: oNothing. Live with it. (Physical and ecosystem consequences not known) Humans can adapt quickly, natural world cannot – evolution is slow, but humans are free of evolution oCosmetic actions. Cite uncertainty, call for more research Will never have 100% certainty Options: o“Invisible hand” of market Trade CO 2 permits

33. 4/12/06Atoms and Stars, Class 1333 Global Warming (cont’d) Options (cont’d): oLimit CO 2 production Increase energy efficiency, use waste energy, switch to low-carbon fuels (natural gas) away from coal and petroleum oRemove CO 2 once it is generated Sequestration – pressurized underground or under deep ocean (DB) Recent poll says US thinks scientists are confused about Global Warming. NOT! oDeliberate confusion caused by industry groups opposed to controls – citing 2 or 3 out of 2,500

34. 4/12/06Atoms and Stars, Class 1334 Readings: Icecaps and Hurricanes Evidence for Global Warming: Thawing icecaps Coral bleaching Hurricanes Melting glaciers Desertification Rising sea levels

35. 4/12/06Atoms and Stars, Class 1335 DB: That’s not all… Many worldwide resource issues – “the human footprint” oWater (drinking, irrigation, industrial), food, farmland, population (6 billion  9 billion), living in unsafe places, petroleum, trash, development Managing the human footprint will be a major, continuing issue

36. 4/12/06Atoms and Stars, Class 1336 Re-emphasizing Main Points Two pillars of science oExperiment: makes science reliable Scientists led astray by logic (Aristotle) and belief (Inquisition) Experiments base science on direct experience oTheory: makes science valuable Once you have a reliable theory, it tells you the answer in advance, can use it as technology Two quotes from Copi, Reader Pg 8

37. 4/12/06Atoms and Stars, Class 1337 Re-emphasizing Main Points I want experiments in course to: oGive you direct experience oIllustrate experiments in class oIllustrate social nature of science within the lab groups

38. 4/12/06Atoms and Stars, Class 1338 Updates Bird flu: oSome concern over transmission via domestic pets in rich countries Natural disasters: oHurricane season of 2005: with better measurements, more hurricanes oIn addition to hurricanes, warm Gulf of Mexico also important in tornado formation Tornadoes generated when warm air from Gulf meets cold air from Northwest

39. 4/12/06Atoms and Stars, Class 1339 Updates (cont’d) Plate tectonics: oDetermines location of mineral resources and fossil fuels Mineral resources brought near surface by old zones of rising magma Fossil fuels generated when organic matter covered over before it rots, “cooked” when drawn down to warmer depths (but not hot – like baking a turkey) then brought back near surface so we can find it –Temperatures increase going down into the earth Plate tectonics does both of these

40. 4/12/06Atoms and Stars, Class 1340 Updates (cont’d) Tenth planet? oIn Class 5, mentioned “tenth planet” 2003 UB313 nicknamed “Xena,” larger than Pluto oThat size based on inference from brightness oNew direct measurement says Xena about the same size as Pluto oInference from brightness fooled because Xena is highly reflective oNow, Pluto and Xena will probably be accepted as planets or demoted, as a pair oMeaning of “planet” still being debated

41. 4/12/06Atoms and Stars, Class 1341 Uncertainty Principle (Repeat) No practical effect at macroscopic level oA philosophical problem with The Mechanical Universe and with “The God’s eye view” or The Clockwork Universe over age of universe Important at atomic and molecular level oUncertainties are large on atomic scale oWhat underlies our reality is strange

42. 4/12/06Atoms and Stars, Class 1342 Lab 11: Orbiting Bottle Swing bottle on string oMeasure distance from finger to middle of water, convert to decimal feet (÷ inches by 12) oMeasure weight of bottle, convert to decimal pounds oTime ten “orbits” or circles (count from zero!) oMeasure angle down from horizontal oUse formulae Large hand motion to get bottle moving, then small hand motions to sustain motion during measurements

43. 4/12/06Atoms and Stars, Class 1343 Orbiting Bottle String pulls in two directions, H and V Two formulae for F H 1.F V (up) balances W (down), then angle determines F H 2.Inward force to move bottle in circular orbit Two should agree, roughly

44. 4/12/06Atoms and Stars, Class 1344 SET Course information: Me: David Bowen Courses: oIST 2420, Atoms and Stars, 4 Credits, Section 001, CRN 24609 oIST 1990, Science and Religion, 2 or 4 Credits, Section 004, CRN 24607 Lab afterwards