Title: Moon%20Phases
1Moon Phases
- And some basic ideas about science and the
scientific method
2Who can tell me
- What the moon looks like when you observe it?
3How were you able to draw the moon?
- Its not visible from here in the class room!
- You did it from memory?
- But lets say we want to know what the moons of
Jupiter would look like from Jupiter? - Would doing it from memory help?
- What we really want
4Is what scientists call a THEORY
- In this case a theory that can predict what (any)
moon should look like when observed. - Regardless of where the moon is and where it is
observed from!
5THEORY
- In the context of science, the word THEORY has
special meaning. The FreeDictionary says - theory \the-?-re, thir-e\ Noun, plural
theories - 1. A set of statements or principles devised to
explain a group of facts or phenomena, especially
one that has been repeatedly tested or is widely
accepted and can be used to make predictions
about natural phenomena. - 2. The branch of a science or art consisting of
its explanatory statements, accepted principles,
and methods of analysis, as opposed to practice
a fine musician who had never studied theory. - 3. A set of theorems that constitute a systematic
view of a branch of mathematics. - 4. Abstract reasoning speculation a decision
based on experience rather than theory. - 5. A belief or principle that guides action or
assists comprehension or judgment staked out the
house on the theory that criminals usually return
to the scene of the crime. - 6. An assumption based on limited information or
knowledge a conjecture.
A set of statements or principles devised to
explain a group of facts or phenomena, especially
one that has been repeatedly tested or is widely
accepted and can be used to make predictions
about natural phenomena
6Conjecture and Hypothesis also have only one
meaning when used in a scientific sense
- conjecture
- 1. Inference or judgment based on inconclusive or
incomplete evidence guesswork. - 2. A statement, opinion, or conclusion based on
guesswork. - hypotheses
- 1. A tentative explanation for an observation,
phenomenon, or scientific problem that can be
tested by further investigation. - 2. Something taken to be true for the purpose of
argument or investigation an assumption. - 3. The antecedent of a conditional statement.
7Its a fact
- You can NOT prove a theory to be true!
- In math, you can prove a theorem to be true
that is something different
8By the way
- Galileo Galilei (1564 1642) is credited with
formalizing what we now call the scientific method
9Models
- When scientists develop theories, they usually
create a model to describe the physical
observations they make - Models dont have to be perfect, they only have
to be good enough to cover the domain of the
theory
10Lets play a game
- You are scientists and your job is to develop a
theory - You make an accidental observation
- From those observations you will make a
hypothesis - From the hypothesis you will create more
experiments - And repeat until you have a theory
- Remember, among other things a theory must have
predictive value!
11Heres the universe and your accidental
observation
2
?
TRUE
4
6
12Your turn
13Can you
- think of a theory that everyone was sure was
correct but 228 years later was shown to not be
correct?
14Newtons theory of gravity, 1687
15Einsteins theory of general relativity, 1915
16What we came here for
- Develop a theory that will predict what the moon
will look like each day of the lunar cycle - AND
- Where to find the moon in the sky given we know
what it looks like
17How to measure and record your data
- Going to measure distance in fist widths
- This is about 10 degrees
- Were going to practice this in a few minutes
- Going to use the sun as your reference point
- Going to do this for 4 weeks
18NEVER, EVER
Look at the sun without specially designed eye
protection!
19What to record for your data
- Position of the moon relative to the sun
- Appearance of the moon
- Date/time observation made
Moon
Sun
6 fists
March 99, 2008 4PM
20Bonus items
- Sketch in the appearance of the markings on the
moon - Indicate in which direction(s) the sun and moon
are (E, SE, S, SW, W) when you observed them
21How to measure
- Use one hand to cover the sun
- Measure in fists from the sun to the moon
- Measure 3 times, record each, and average them
- If they are far apart in the sky
- From horizon to horizon is 180 degrees or 18 fist
widths - So you can measure up from the horizon for both
and subtract from 18. - Remember horizon means straight in front of you,
not the visible horizon (like tree tops, roofs,
etc.)
22Hints
- Moon will rise today (17 Mar 08) at 238PM
- Each day it rises about an hour later (350PM on
Tuesday, 359 PM on Weds) - You will not get data every day
- Clouds, bed time, and ????
- Think about what your theory is, and the model
that you might use to demonstrate the theory