ASTRONOMY 110 Honors Foundations of Astronomy Office Hours: Paul Coleman:MWF (8:30-9:30 & 10:30-11:30) Watanabe 423 pcoleman@ifa.hawaii.edu Course details and notes: http://www.ifa.hawaii.edu/users/gruff/default/Coleman.html

Cell phones on vibrate please! Phasers on Stun!! Cell phones on vibrate please!

ASTRONOMY 110 H a survey of astronomy Required TEXT: Provided by Instructor… (plus updates)

Possible Grading Schemes: 2 – 3 midterm exams + final + etc. Weekly quizzes + optional final + etc. No work at all Wheel of misfortune !! Homework Extra curricular extra credit Imaginarium visit Faulkes telescope observing Evening lecture(s) Stargazing A research paper bad grade good grade

ASTRONOMY 110H a survey of astronomy Every Week: Monday: Return quiz from previous week – Update on your progress Wednesday: Collect homework and give solutions Friday: Quiz, Solution, and Homework and Reading assignment

90 – 100 A 80 – 89.9 B 70 – 79.9 C 60 – 69.9 D < 59.9 F plus or minus grades also

Homework problem: Send an E-mail to Dr. Coleman before next Wednesday Aug 30… Tell him the magic word

The Scientific Method Question Hypothesis Prediction Test Result a tentative explanation Prediction Test Result confirm, reject, or modify should be the same no matter who conducts the test

Hallmarks of Good Science Science seeks explanations for observed phenomena that rely solely on natural causes. Science progresses through the creation and testing of models of nature that explain the observations as simply as possible. Occam’s Razor A scientific model must make testable predictions that could force us to revise or abandon the model. Theory -- a model which survives repeated testing

Bad Scientific Practice pseudoscience – masquerades as science, but does not follow the scientific rules of evidence nonscience – establishes “truths” through belief

Looking back in time Light, although fast, travels at a finite speed. It takes: 8 minutes to reach us from the Sun 8 years to reach us from Sirius (8 light-years away) 1,500 years to reach us from the Orion Nebula The farther out we look into the Universe, the farther back in time we see!

Address: Earth How would the Universal post office find us?

Moon An object which orbits a planet.

Star A large, glowing ball of gas that generates heat and light through nuclear fusion

Planet A moderately large object which orbits a star; it shines by reflected light. Planets may be rocky, icy, or gaseous in composition.

Asteroid A relatively small and rocky object which orbits a star.

Comet A relatively small and icy object which orbits a star.

Solar (Star) System A star and all the material which orbits it, including its planets and moons

Nebula An interstellar cloud of gas and/or dust

Galaxy A great island of stars in space, all held together by gravity and orbiting a common center

Universe The sum total of all matter and energy; that is, everything within and between all galaxies

Microscopic “building blocks” of all chemical elements Atom Microscopic “building blocks” of all chemical elements

Where do we come from? The first (and simplest) atoms were created during the Big Bang. More complex atoms were created in stars. When the star dies, they are expelled into space…. to form new stars and planets! Most of the atoms in our bodies were created in the core of a star!

and Shakers… Movers… “We never get to go anywhere” “It costs too much to go anywhere” Nothing could be further from the truth… During this one hour lecture, all of us will have traveled some 48,600 miles through space as our planet sails around the sun at 18 miles per second! During the half-minute we’ve been looking at this slide, we have traveled ~400 miles. We are whizzing through space in at least four different directions! Why don’t we feel the motion?

Motion I Face the rising sun in the morning. That's our first direction of celestial movement. Let's begin our fantastic cosmic voyage and see what is really going on. We are going to investigate four directions that we are moving, all at the same time.

r Circumference = 2pr

Motion I 1042 mph !!!! Circumference = 2pr ~ 25000 miles Time = 24 hours 1042 mph !!!!

Motion II r = 1 AU = 1.5 x 1011 meters

Motion II We are zooming around the sun at 64,800 mph!!!

West N

r 226 million years to make one revolution around the Milky Way. The last time we were here, dinosaurs ruled the earth. Our orbital speed around the galaxy is an astonishing 135 miles per second Our Sun is but one of some 100 billion stars that makes up our home galaxy, the Milky Way. It takes our sun about 226 million years to circle the Milky Way. Motion III

Motion III With the measured distance to the Galactic Center we calculate a speed of about 486,000 mph. Look a little above the horizon about 20 degrees west of directly south – you are traveling in that direction! The center of the Galaxy is located between the two constellations Scorpius and Sagittarius. 90 degrees away from this direction (toward Dorado) is the direction we are going as we orbit the galaxy at 135 miles per second.

Motion IV Look South around midnight in june, you'll see the beautiful Southern Cross low on the horizon. Right above it is the constellation Centaurus. That's the direction our solar system and galaxy is headed at more than a million miles per hour!

Take your pick: Earth’s rotational speed = 1042 mph Earth’s orbital speed = 64,800 mph Sun’s orbital speed = 486,000 mph Milky Way’s speed = 1,000,000 mph (Not to mention the expansion of the universe!) In the ~20 minutes so far for this talk, we have moved about 350 miles east and about 21,600 miles around the sun. Our solar system has moved 162,000 miles around the galaxy and we've moved about 340,000 miles closer to Hercules. For a grand total of about 420,000 miles traveled! Too bad we don't get frequent flyer miles for this.