1/26/05 Atoms and Stars, Class 3 1

Atoms and StarsIST 2420

and IST 1990

Class 3: January 26

Fall 2005

David Bowen

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Handouts• PowerPoint notes

• Passbacks for Temperamental Can

• At end of class, for ISP 3340 only, Essay Questions

Names• Initial by your name on signin list

• Go through class names again

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Due this week

• Report for Lab 1o Assignments go in the “IN” folder

For next week…• Reader Pp 105 – 125 (positive evidence)

• Manual Pp 6 - 12

• Turn in Report for today’s Lab 2

• Essay 1 Due February 9

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From last weekFrom the statement of Pope John Paul II to Pontifical Academy of Sciences, 1996:

“… new knowledge has led to the recognition of the theory of evolution as more than a hypothesis. It is indeed remarkable that this theory has been progressively accepted by researchers, following a series of discoveries in various fields of knowledge. The convergence, neither sought nor fabricated, of the results of work that was conducted independently is in itself a significant argument in favor of the theory.” Quoted in Stephen Jay Gould, Rocks of Ages, 1999, Pp 81-82. (Later says the creation of man and man’s mind lie outside of science.) http://www.jesuitsinscience.org/Newsletter97/papal.htm

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Statements of Major Religions Regarding Evolution in Science

Classes

• http://www.don-lindsay-archive.org/creation/voices/#part3

• Jewish, Episcopalians, Catholics, Lutherans, Methodists, Presbyterians, Unitarian- Universalists

• Also major scientific groups, teacher’s associations have statements there

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Applying Aspects of Science• “Fair play” argument

o Science is not fair to ideas that do not have experimental support

• Argument that gaps or problems with evolution mean Creation Science / Intelligent Design win by eliminationo Never 100% agreement in science (Flat Earth

Society); theories must be falsifiable, have positive evidence (could modify evolution or develop third theory)

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Readings• James B. Conant, “The Development of

the Concept of Atmospheric Pressure”o To let water run out of barrel, need

hole at topo Aristotle: The earth is full.

Something else must move to make way for water. “Nature “abhors” a vacuum.

o Today, we say pressure pushes up against water, holds it in place.

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Pressure• Force per unit area (e.g. pounds per square

inch)• Same in all directions• Acts perpendicularly to a surface• Effect can be from a difference in pressure• (Heated air / steam (a) expand and/or (b)

increase pressure on container, cooling does the opposite: contract and/or lower pressure)

• Later, apply to Temperamental Can

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Readings (cont’d)o 1638: Galileo, from workmen,

vacuum pump will not raise water more than 34 feet (made a poor hypothesis – breaking wire).

o 1644: Torricelli (Galileo’s student) in hypothesized “sea of air:” like ocean although made of air. Atmospheric pressure holds water in, but only so much (34 feet)

o Mercury 13.5 × denser, 30 inches

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Readings (cont’d)o 1647: Blaise Pascal reasoned that pressure

less at high altitude, similar to increasing ocean pressure with depth.

o 1648: Pascal’s brother-in-law carried inverted mercury tube to mountain Puy-de-Dôme, saw it was less, then halfway when halfway down the mountain, constant at top.

• “…one cannot say … nature abhors a vacuum more at the foot of the mountain than at its summit.”

o 1654: Otto von Guericke, Magdeburg spheres

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Readings (cont’d)o 1657: Robert Boyle put mercury column

inside a vacuum pump, mercury fell when air pumped out, later used for experiments inside vacuum

o Some points about this sequence of events:• A discovery (inverted mercury tube) becomes an

instrument for further discoveries (barometer, altimeter, vacuum apparatus). “Science is cumulative or progressive.”

• Uncertain nature of early scientific communication (private letter for Pascal, book for Boyle)

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Temperamental CanAll connected by pressure, some by *

1. Imploding upside-down can

2. Right-side up can that did nothing

3. * Inverted cup that held water

4. * Inverted cup with card that held water

5. Water running out of can, stopped with thumb

6. * Gurgling can

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Temperamental Can (Cont’d)• * - upside down layer of water is unstable if

too large, breaks up, allows air in

• Grading – original data sheet with procedure and observations, explanations clearly separated. Consistent presence of hypotheses when asked for.

• Many mentioned a special role for oxygen, which was not the case here - Oxygen not used in burning, inert like Nitrogen (20/80)

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Background: History of Science

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History of Science (cont’d)• Greeks (Aristotle, Plato and others)

o General theories preferred, consistent with known facts but no dedicated experiments

• “Saving the phenomena”

o Plato: essential forms are universal, have a greater degree of reality. Led to alchemy.

o Aristotle: heavens and earth follow different laws; also four elements: fire, air, earth, water

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History of Science (cont’d)

• Romanso Christians came to dominateo Concerned with God’s will, perfection of God

• India?

• Arabs / Muslims – study world to study God

• Chinese

• Mongols, Vandals, Goths etc. conquered but also transferred information

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History of Science (cont’d)

• Southern Europeo Specializationo System: theory & experiment, esp. Francis Bacon

• Northern Europe

• USo Science generates technology

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Lab 2 - Density• Manual, Pp 30 – 34• Observations and Queries separate• Exercise 1

o Pick three spherical objects (aluminum, brass, lead)

o Describeo Measure weight of displaced

water & recordo Use postal scales

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Lab 2 – Density (cont’d)

• Use weight in decimal poundso Convert ounces to decimal pounds by dividing

ounces by 16 (ounces per pound)

o Example: 1 lb 3 oz = lb = 1.3875 lb or 1.39 lb

o Calculators supplied for use in class

16

31

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Lab 2 – Density (cont’d)

• Exercise 2o Weight in air? Weight in water?o Weights in water and air – use LCD fish scaleo Weight in air should be the larger of the twoo Query 3

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Lab Reports

1. Cover Sheeto Your nameo Experiment, number and titleo Lab dateo Names of group

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Lab Reports (cont’d)

2. Data sheeto Procedure – what you dido Observations and measurementso If you copy it over or type it, include the

original also

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Lab Reports (cont’d)

3. Answers to questions, explanations, hypotheses, theories, tables, calculations

Main ideas:

• Keep data separate from the resto What you dido What you saw and/or measured

• Good detail in procedure and observations

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Observations and Explanations

• Procedure and Observation: I did “A” (procedure) and then I saw and/or measured “B” (observation)o Be specific. Object is to let someone else do

exactly the same thing.o Sketches are goodo Keep on a separate sheet of paper

• Explanations – hypotheses, theories

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Observations and Explanations(cont’d)

• Explanations can be wrong but observations still valido Keep them clearly separatedo Write details of observations – may be other

aspects importanto Louis Agassiz – observation of a fish

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Review of Essay Assignment

• Due February 9• Topic: We have studied the process by which

Aristotle's view that nature abhors a vacuum was replaced by the sea of air hypothesis. Following Copi's seven step account of the scientific method, explain how this transition took place. Draw on material from the reading, class discussion, and the laboratory experiments. Also write about what this tells us about the scientific method.

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Essay Assignment (cont’d)

• 3 to 4 pages, 12-point Times Roman, double-spaced, 1” margins top and bottom, 1½” left and right.

• Content: 40%. Reading and understanding course materials, applying them to topic, consistent point of view

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Essay Assignment (cont’d)

• Form: 40%. Title page, Introduction (roadmap), Body (organized, transitions between topics, detail to support general points), Conclusion (review content, draws to an end)

• Mechanics: 20%. Spelling, grammar, punctuation. Use spell-check and grammar-check (note on passive) or dictionary.

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ISP 3360 – break time

ISP 3340 starts

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ISP 3340

• Pictures for Moodle?

• Handout: Essay 1 Questionso Due February 23o Title page must list topic and descriptive title

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End for ISP 3340

Lab