Transcription

1 She didn t quite know what the relationship was between lunatics and the moon, but it must be a strong one, if they used a word like that to describe the insane. Paolo Coelho, Veronika Decides to Die

2 HW1 is on-line now and due 1 week from today at the beginning of class. Super blood wolf moon.

3 Super comes from the Moon being near to its closest point to the Earth.

4 Blood moon: 4 total lunar eclipses in a row without a partial eclipse (NOT 4 months in a row though!) is called a tetrad of eclipses. This occurred in In 2013, two Christian pastors wrote a book, describing this event in terms of the apocalypse: using the term blood moon.

5 The Earth is roughly spherical (round in 3 dimensions)

6 What is science? Google says, the intellectual and practical activity encompassing the systematic study of the structure and behavior of the physical and natural world through observation and experiment. more concise (by me): understanding the world around us using observations, experiments, and deductive reasoning.

7 The scientific method A way to distinguish between ideas (theories/hypotheses) to determine which is likely correct.

8 The scientific method Do an experiment or make an observation. Determine an explanation (theory) for the observation. From the theory, make predictions. Make further observations to test the prediction. Eliminate or refine the theory.

9 Observation Many people are wearing MSU logo sweatshirts to class today. Now you try to make a theory why this is.

10 Observation Many people are wearing MSU logo sweatshirts to class today. Now you try to make a theory why this is. Now consider a way to test whether or not your idea is correct.

11 Observation More people are driving SUV/Trucks than cars, and at an increasing rate. Why?

12 Selection effects and biases. What if I were to survey owners why they bought an SUV and I want the answer to be For off-road capability. What could I do to make that the answer? There can be selection effects depending on how the sample is chosen or there can be biases based on weaknesses in the data or the method of getting the data.

13 Compare these two sentences: I believe that people who work full time should make a decent wage. I infer that employees work better when they are given a two hour lunch break. How are these two sentences similar or different?

14 Belief (according to Google) 1. an acceptance that a statement is true or that something exists. "his belief in the value of hard work" 2. trust, faith, or confidence in someone or something. "a belief in democratic politics" Me: Typically a value statement. Inference (according to Google) A conclusion reached on the basis of evidence and reasoning. there should be no inference drawn from the fact that he chooses not to be a witness

15 How is science done? science uses evidence to understand/infer how nature/the world/the Universe works.

16 We begin by examining what we know about the Earth and the Moon

17 If you were a bazillion miles above the Earth s north pole and looked down and watched the Moon, what would you see?

18 The Moon goes around the Earth! Much faster than the Earth goes around the Sun. The Moon orbits once about every 28 days.

19 NOTE: There is a Moon phase simulator on the internet that is a link on my web page for this course. Phases of the Moon are NOT caused by the Earth's shadow. The Moon is always half-lit by the Sun. Phases are caused by the portion of the lit side of the Moon that is visible to us.

20 How the Moon appears to us on Earth How it would appear if you were a bazillion miles above the north pole

21 Lunar Orbit. We see a Full Moon once every 29.5 days. But the Moon actually goes around the Earth once every 27.3 days! Why are these numbers different?

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23 The same is true for an Earth day! If you keep time by the stars, your sidereal day is different from the solar day by nearly 4 minutes.

24 Definition: Sidereal vs Solar Sidereal: One complete revolution according to the stars. Solar: One complete revolution according to the Sun. This will be very funky for some planets!

25 The Earth only goes around 1 star, our Sun. Other stars are much farther away. The position of the Earth relative to the Sun changes during the year, but our solar system, compared to other stars, is (very, very, nearly) stationary.

26 Eclipses Solar Eclipse: The Moon is between the Sun and the Earth. Can only occur during New Moon. The Moon's shadow only covers small regions of the Earth. Partial Eclipse: The Moon only covers part of the Sun. Lunar Eclipse: The Earth is between the Sun and the Moon. Can only occur during Full Moon. Can also have partial eclipse.

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28 why don't solar and lunar eclipses happen once every lunar orbit?

29 why don't solar and lunar eclipses happen once every lunar orbit? Because the Moon's orbit is tipped compared to the Earth's. An eclipse only happens if a New or Full Moon occurs when the Moon is on the Earth's orbital plane (called the ecliptic).