What is this? PH1600: Lecture 1A Grand Tour of the Universe

PH1600: Introductory AstronomyLecture 1: A Grand Tour of the Heavens

School: Michigan Technological UniversityProfessor: Robert Nemiroff

TAs: Ashley Ames & Martin BoluytTerm: Fall Semester 2008

No formal book: Only lectures, Wikipedia pages, & APOD pagesGood background reading book:

The Cosmos by Pasachoff & FilippenkoOnline Course WebCT pages: courses.mtu.edu

Physical Class Time: Monday & Wed 10:05 – 10:55 am Physical Class Location: Rekhi G005 (Basement)

This class can be taken online ONLY, class attendance is not required!

Goal: A Beautiful & Free Astronomy Course

Beautiful space pictures are used to liberally illustrate space themes

All course material is freely available over the Internet

Still, this course is rigorous, college-level, accurate and up-to-date

Beautiful Space Pictures

Usually chosen from the daily updated Astronomy Picture of the Day (APOD: apod.nasa.gov)

Includes the most recent astronomy images, not yet available in printed text books

Includes the most beautiful astronomy images, which help define our time

Free Astronomy Course

Text taken from freely available wikipedia.org

In astronomy, wikipedia is often more up-to-date than textbooks

Information is free, but diplomas cost money to receive college credit, you need to

register at a university and pay money!

You are responsible for…

Lecture material Wikipedia pages (cited in lectures)

Anything on those pages can appear on quizzes or tests, even if I never mention them during my lecture(s)

Use only wikipedia.org pages as they appeared on September 1, 2008

APODs posted during the semester September 1 – December 15 inclusive APOD review every week during lecture

Completing the Quizzes Chapter 1 quiz now online

Wikipedia entries of today

Universe Electromagnetic Spectrum Light Year

Cosmic Questions

What does “universe” mean? How big is the universe? What is the largest thing in the universe? What is the smallest thing in the

universe? How old is the universe?

These will all be addressed during this course! Here, though, are some quick answers:

Cosmic Answers:

There are many definitions to “universe” Earth, visible universe, causally connected brane,

etc. Wikipedia entry: Universe http://en.wikipedia.org/w/index.php?

title=Universe&oldid=235892226 Size of visible universe: 13.7 billion light years in

radius Largest thing: Superclusters (100 million light

years across Smallest thing: electron, photon, neutrino, other

fundamental particles Universe Age: 13.7 Billion light years

Light Year: Slow Light is a Time Machine

“Light year” is a unit of distance The distance light travels in one year

An object one light year away is seen as it was one year ago. Etc! You can only see the past We can almost see back to the beginning of

the universe Light could circle the Earth about 7.5

times in one second Wikipedia entry: light year

Speed of light: example calculation

c = speed of light = 3 x 108 meters/sec

Q: The sun is (about) 8 light minutes away – how far is that in meters?

A: distance = velocity x timed = c t = (3 x 108 m/sec)x(8 min)x(60 sec/min) = 1.44 x 1011 meters

Light is more colorful than we can see.

Visible light: red to blue ROY G BIV

Almost visible light: infrared to ultraviolet Entire Electromagnetic Spectrum:

Radio waves, microwaves, infrared, visible (red, blue), ultraviolet, X-rays, gamma-rays

Different animals perceive light differently The Sun is green

Wikipedia entry: Electromagnetic Spectrum

The Very Large Array of Radio Telescopes Credit: Dave Finley, AUI, NRAO, NSF APOD: 2006 May 14

Jets from Radio Galaxy 3C296 Credit & Copyright: AUI, NRAOAPOD: 2002 February 26

A Year of Resolving Cosmology Credit: WMAP Science Team, NASAAPOD: 2003 December 31

The Galactic Center in InfraredCredit: 2MASS Project, UMass, IPAC/Caltech, NSF, NASAAPOD: 2006 July 16

The Coma Cluster of GalaxiesCredit & Copyright: Jim Misti (Misti Mountain Observatory)APOD: 2006 March 21

Dark Sun SizzlingCredit: TRACE Project, Stanford-Lockheed Inst., NASA APOD: 2006 July 12

SN 1006: Supernova Remnant in X-RaysCredit: J. Hughes (Rutgers) et al., CXC, NASAAPOD: 2005 December 26

Fermi's First LightCredit: NASA, DOE, International LAT Team APOD: 2008 August 28

The Sky at Night

All stars seen are in our Milky Way Galaxy, most are near our Sun

Stars Sirius, Polaris, etc.

Constellations Orion, Ursa Major (Big Bear), etc.

Asterisms Big Dipper, Little Dipper, etc.

Planets Venus, Jupiter, etc.

Central Plane of our Galaxy

Sirius: The Brightest Star in the NightCredit & Copyright: Juan Carlos CasadoAPOD: 2000 June 11

Ceci n'est pas un MeteoreCredit & Copyright: Laurent Laveder (PhotoAstronomique.net)APOD: 2006 August 19

Dusk of the PlanetsCredit & Copyright: Jerry Lodriguss APOD: 2002 April 29

Raining PerseidsCredit & Copyright: Fred Bruenjes

APOD: 2007 August 12

Astronomy Pictures of the Day (APODs) from the past week…

APODs reviewed today:Monday, 2008 September 1 throughWednesday, 2008 September 3

Web site: apod.nasa.gov