Moon Phases And some basic ideas about science and the scientific method

Who can tell me… What the moon looks like when you observe it? What the moon looks like when you observe it?

How were you able to draw the moon? It’s not visible from here in the class room! It’s not visible from here in the class room! You did it from memory? You did it from memory? But let’s say we want to know what the moons of Jupiter would look like from Jupiter? But let’s say we want to know what the moons of Jupiter would look like from Jupiter? Would doing it from memory help? Would doing it from memory help? What we really want… What we really want…

Is what scientists call a THEORY In this case a theory that can predict what (any) moon should look like when observed. 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! Regardless of where the moon is and where it is observed from!

THEORY In the context of science, the word THEORY has special meaning. The FreeDictionary says: In the context of science, the word THEORY has special meaning. The FreeDictionary says: the·o·ry \`thē-ə-rē, `thir-ē\ Noun, plural the·o·ries the·o·ry \`thē-ə-rē, `thir-ē\ Noun, plural the·o·ries 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. 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. 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. 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. 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. 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. 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

Conjecture and Hypothesis also have only one meaning when used in a scientific sense con·jec·ture con·jec·ture 1. Inference or judgment based on inconclusive or incomplete evidence; guesswork. 1. Inference or judgment based on inconclusive or incomplete evidence; guesswork. 2. A statement, opinion, or conclusion based on guesswork. 2. A statement, opinion, or conclusion based on guesswork. hy·poth·e·ses hy·poth·e·ses 1. A tentative explanation for an observation, phenomenon, or scientific problem that can be tested by further investigation. 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. 2. Something taken to be true for the purpose of argument or investigation; an assumption. 3. The antecedent of a conditional statement. 3. The antecedent of a conditional statement.

It’s a fact… You can NOT prove a theory to be true! You can NOT prove a theory to be true! In math, you can prove a theorem to be true – that is something different In math, you can prove a theorem to be true – that is something different

By the way… Galileo Galilei (1564 – 1642) is credited with formalizing what we now call the scientific method Galileo Galilei (1564 – 1642) is credited with formalizing what we now call the scientific method

Models When scientists develop theories, they usually create a model to describe the physical observations they make When scientists develop theories, they usually create a model to describe the physical observations they make Models don’t have to be perfect, they only have to be good enough to cover the domain of the theory Models don’t have to be perfect, they only have to be good enough to cover the domain of the theory

Let’s play a game You are scientists and your job is to develop a theory You are scientists and your job is to develop a theory You make an accidental observation You make an accidental observation From those observations you will make a hypothesis From those observations you will make a hypothesis From the hypothesis you will create more experiments From the hypothesis you will create more experiments And repeat until you have a theory And repeat until you have a theory Remember, among other things a theory must have predictive value! Remember, among other things a theory must have predictive value!

Here’s the universe and your accidental observation ? TRUE

Your turn…

Can you… think of a theory that everyone was sure was correct but 228 years later was shown to not be correct? think of a theory that everyone was sure was correct but 228 years later was shown to not be correct?

Newton’s theory of gravity, 1687

Einstein’s theory of general relativity, 1915

What we came here for… Develop a theory that will predict what the moon will look like each day of the lunar cycle Develop a theory that will predict what the moon will look like each day of the lunar cycle AND… AND… Where to find the moon in the sky given we know what it looks like Where to find the moon in the sky given we know what it looks like

How to measure and record your data Going to measure distance in fist widths Going to measure distance in fist widths This is about 10 degrees This is about 10 degrees We’re going to practice this in a few minutes We’re going to practice this in a few minutes Going to use the sun as your reference point Going to use the sun as your reference point Going to do this for 4 weeks Going to do this for 4 weeks

NEVER, EVER… Look at the sun without specially designed eye protection!

What to record for your data Position of the moon relative to the sun Position of the moon relative to the sun Appearance of the moon Appearance of the moon Date/time observation made Date/time observation made Sun Moon 6 fists March 99, PM

Bonus items Sketch in the appearance of the markings on the moon 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 Indicate in which direction(s) the sun and moon are (E, SE, S, SW, W) when you observed them

How to measure Use one hand to cover the sun Use one hand to cover the sun Measure in fists from the sun to the moon Measure in fists from the sun to the moon Measure 3 times, record each, and average them Measure 3 times, record each, and average them If they are far apart in the sky If they are far apart in the sky From horizon to horizon is 180 degrees or 18 fist widths… 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. 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.) Remember horizon means straight in front of you, not the visible horizon (like tree tops, roofs, etc.)

Hints Moon will rise today (17 Mar 08) at 2:38PM Moon will rise today (17 Mar 08) at 2:38PM Each day it rises about an hour later (3:50PM on Tuesday, 3:59 PM on Weds) Each day it rises about an hour later (3:50PM on Tuesday, 3:59 PM on Weds) You will not get data every day You will not get data every day Clouds, bed time, and ???? Clouds, bed time, and ???? Think about what your theory is, and the model that you might use to demonstrate the theory Think about what your theory is, and the model that you might use to demonstrate the theory