Welcome to Astronomy! Introduction to the Universe Astro 1105/1107 Prof. Julia Kregenow.
-
date post
15-Jan-2016 -
Category
Documents
-
view
224 -
download
0
Transcript of Welcome to Astronomy! Introduction to the Universe Astro 1105/1107 Prof. Julia Kregenow.
![Page 1: Welcome to Astronomy! Introduction to the Universe Astro 1105/1107 Prof. Julia Kregenow.](https://reader036.fdocuments.in/reader036/viewer/2022062314/56649d625503460f94a441bb/html5/thumbnails/1.jpg)
Welcome to
Astronomy!
Introduction tothe
Universe
Astro 1105/1107Prof. Julia Kregenow
![Page 2: Welcome to Astronomy! Introduction to the Universe Astro 1105/1107 Prof. Julia Kregenow.](https://reader036.fdocuments.in/reader036/viewer/2022062314/56649d625503460f94a441bb/html5/thumbnails/2.jpg)
A large, glowing ball of gas that generates heat and light through nuclear fusion
Star
![Page 3: Welcome to Astronomy! Introduction to the Universe Astro 1105/1107 Prof. Julia Kregenow.](https://reader036.fdocuments.in/reader036/viewer/2022062314/56649d625503460f94a441bb/html5/thumbnails/3.jpg)
GalaxyA great island of stars in space, all held
together by gravity and orbiting a common center
M31, The Great Galaxy in Andromeda
![Page 4: Welcome to Astronomy! Introduction to the Universe Astro 1105/1107 Prof. Julia Kregenow.](https://reader036.fdocuments.in/reader036/viewer/2022062314/56649d625503460f94a441bb/html5/thumbnails/4.jpg)
Universe
The sum total of all matter and energy; that is, everything within and between
all galaxies
![Page 5: Welcome to Astronomy! Introduction to the Universe Astro 1105/1107 Prof. Julia Kregenow.](https://reader036.fdocuments.in/reader036/viewer/2022062314/56649d625503460f94a441bb/html5/thumbnails/5.jpg)
Your Goals: Brief Survey
What do you want to learn about astronomy?
Write down a few things.
![Page 6: Welcome to Astronomy! Introduction to the Universe Astro 1105/1107 Prof. Julia Kregenow.](https://reader036.fdocuments.in/reader036/viewer/2022062314/56649d625503460f94a441bb/html5/thumbnails/6.jpg)
My Goals: on Syllabus
On course website: www.astro.cornell.edu/academics/courses/astro105/
Please read it carefully!
![Page 7: Welcome to Astronomy! Introduction to the Universe Astro 1105/1107 Prof. Julia Kregenow.](https://reader036.fdocuments.in/reader036/viewer/2022062314/56649d625503460f94a441bb/html5/thumbnails/7.jpg)
Homework for TOMORROW
• Read Syllabus online -- quiz tomorrow!– The syllabus is our CONTRACT
• Register on “MasteringAstronomy” website – Instructions on our course webpage www.astro.cornell.edu/academics/courses/astro105/
– Enroll in our course: (ID# given on syllabus)
• First online assignment due tomorrow 10:30am– “Introduction to MasteringAstronomy” (see HW page)
![Page 8: Welcome to Astronomy! Introduction to the Universe Astro 1105/1107 Prof. Julia Kregenow.](https://reader036.fdocuments.in/reader036/viewer/2022062314/56649d625503460f94a441bb/html5/thumbnails/8.jpg)
SOME REALLY BIG IDEAS
ScienceLight
Lookback timeGravity
Star stuffExpanding universe
Space is big. And empty.
![Page 9: Welcome to Astronomy! Introduction to the Universe Astro 1105/1107 Prof. Julia Kregenow.](https://reader036.fdocuments.in/reader036/viewer/2022062314/56649d625503460f94a441bb/html5/thumbnails/9.jpg)
Chapter 1Our Place in the
Universe
![Page 10: Welcome to Astronomy! Introduction to the Universe Astro 1105/1107 Prof. Julia Kregenow.](https://reader036.fdocuments.in/reader036/viewer/2022062314/56649d625503460f94a441bb/html5/thumbnails/10.jpg)
How did we come to be?
Pg. 4
![Page 11: Welcome to Astronomy! Introduction to the Universe Astro 1105/1107 Prof. Julia Kregenow.](https://reader036.fdocuments.in/reader036/viewer/2022062314/56649d625503460f94a441bb/html5/thumbnails/11.jpg)
The Universe is Dynamic
Everything is moving
Some terminology:
Expansion
Revolve vs. Rotate
![Page 12: Welcome to Astronomy! Introduction to the Universe Astro 1105/1107 Prof. Julia Kregenow.](https://reader036.fdocuments.in/reader036/viewer/2022062314/56649d625503460f94a441bb/html5/thumbnails/12.jpg)
What motion does the Earth undergo?
![Page 13: Welcome to Astronomy! Introduction to the Universe Astro 1105/1107 Prof. Julia Kregenow.](https://reader036.fdocuments.in/reader036/viewer/2022062314/56649d625503460f94a441bb/html5/thumbnails/13.jpg)
What motion does the Sun undergo?
![Page 14: Welcome to Astronomy! Introduction to the Universe Astro 1105/1107 Prof. Julia Kregenow.](https://reader036.fdocuments.in/reader036/viewer/2022062314/56649d625503460f94a441bb/html5/thumbnails/14.jpg)
There are over 100,000,000,000 stars in our galaxy.
??
![Page 15: Welcome to Astronomy! Introduction to the Universe Astro 1105/1107 Prof. Julia Kregenow.](https://reader036.fdocuments.in/reader036/viewer/2022062314/56649d625503460f94a441bb/html5/thumbnails/15.jpg)
Thought QuestionSuppose you tried to count the more than 100 billion stars in our galaxy,
at a rate of one per second…
How long would it take you?
![Page 16: Welcome to Astronomy! Introduction to the Universe Astro 1105/1107 Prof. Julia Kregenow.](https://reader036.fdocuments.in/reader036/viewer/2022062314/56649d625503460f94a441bb/html5/thumbnails/16.jpg)
Unit Conversion
Convert 100 Billion seconds to years
Seconds -> Minutes -> Hours -> Days -> Years
![Page 17: Welcome to Astronomy! Introduction to the Universe Astro 1105/1107 Prof. Julia Kregenow.](https://reader036.fdocuments.in/reader036/viewer/2022062314/56649d625503460f94a441bb/html5/thumbnails/17.jpg)
Lookback Time
• We see objects as they were in the past:
• Light travels at a finite speed (300,000 km/s).
• The farther away we look in distance, the further back we look in time.
• Allows us to study the history of the Universe.
![Page 18: Welcome to Astronomy! Introduction to the Universe Astro 1105/1107 Prof. Julia Kregenow.](https://reader036.fdocuments.in/reader036/viewer/2022062314/56649d625503460f94a441bb/html5/thumbnails/18.jpg)
Example: Our nearest neighbor.
This photo shows the Andromeda Galaxy as it looked about 2 1/2 million years ago.
Question: When will be able to see what it looks like now?
M31, The Great Galaxy in Andromeda
Fig. 1.4
![Page 19: Welcome to Astronomy! Introduction to the Universe Astro 1105/1107 Prof. Julia Kregenow.](https://reader036.fdocuments.in/reader036/viewer/2022062314/56649d625503460f94a441bb/html5/thumbnails/19.jpg)
Light-year: the distance light travels in one
year.
(But how far is that?)
![Page 20: Welcome to Astronomy! Introduction to the Universe Astro 1105/1107 Prof. Julia Kregenow.](https://reader036.fdocuments.in/reader036/viewer/2022062314/56649d625503460f94a441bb/html5/thumbnails/20.jpg)
• Scientific Notation
• Multiply and Divide powers of 10
• Convert Units
• Rearrange an equation to solve for another variable
• Plug numbers in for variables in an equation and calculate
Math Skills Summary
![Page 21: Welcome to Astronomy! Introduction to the Universe Astro 1105/1107 Prof. Julia Kregenow.](https://reader036.fdocuments.in/reader036/viewer/2022062314/56649d625503460f94a441bb/html5/thumbnails/21.jpg)
• Scientific Notation– e.g. 300,000,000 = ?– e.g. 4x10-5 = ?
• Multiply and Divide powers of 10– e.g. 108 / 10-5 = ?
• Convert Units– e.g. How many inches in a mile?
• Rearrange an equation to solve for another variable– e.g. b = L / 4d2. Solve for d.
• Plug numbers in for variables in an equation and calculate– e.g. L = 3.8x1026 watts, d = 1.5x1011 m, b = ?
Math Skills Summary
![Page 22: Welcome to Astronomy! Introduction to the Universe Astro 1105/1107 Prof. Julia Kregenow.](https://reader036.fdocuments.in/reader036/viewer/2022062314/56649d625503460f94a441bb/html5/thumbnails/22.jpg)
(show coolpics.ppt)