Sgc Lecture 1.pdf

1/16/18

The Known Universe ü https://www.amnh.org/our-research/ hayden-planetarium/digital-universe

BC1754: Stars, Galaxies and Cosmology

The scale of things….
 
 Reduce the size of the solar system by a factor of 10 billion; the Sun is now the size of a large grapefruit (14 cm diameter).



 How big is Earth on this scale? A.  an atom B.  a ball point C.  a marble D.  a golf ball

Earth viewed by Voyager 1, 4 billion miles or 6.4 billion kilometers away


 


The scale of the solar system

On the 1-to-10-billion scale, a few minutes to walk to Neptune.



 ü  On a 1-to-10billion scale: ü  The Sun is the size of a large grapefruit (14 cm). ü  Earth is the size of a ball point, 15 meters away.

How far would you have to walk to reach Alpha Centauri, one of the closest stars to the Sun?

A.  B.  C.  D. 

1 mile 10 miles 100 miles the distance across the United States (2500 miles)

1

1/16/18

Scale of the Solar System w/ Bill Nye the Science Guy ü http://www.youtube.com/watch? v=97Ob0xR0Ut8

How far into our Galaxy can we see with our eyes?

•  The Milky Way is one of about 100 billion galaxies. •  1011 stars/galaxy x 1011 galaxies = 1022 stars

There are as many stars as grains of (dry) sand on all Earth’s beaches.

How large is the Universe?

ü http://cds.cern.ch/record/1002700?ln=en ü https://apod.nasa.gov/apod/ap140112.html

2

1/16/18

Some Basic Information….. Professor Putman Office: Pupin 1318 Office Hours: Mon. 11-12 in 1318 Pupin or email to make another time Email: [email protected] (do not expect an immediate response)

All information is on Canvas.

Reading ü Readings are noted in the Syllabus ü Book: 21st Century Astronomy: Stars and Galaxies, Fifth or fourth edition, by Kay, Palen & Blumenthal ü Strongly recommended

Teaching Assistant: Aliya Babul Office Hours: Tues. 4-5 after class in 514 Altschul or email to make another time Email: [email protected] Who are you?

Lectures

Grades

ü Focus on comprehension and key points

ü 30% - Homework

ü Abbreviated lecture notes will be posted

ü 5% - In-class

ü Regular in-class activities, ABCD questions (bring this every day)

ü 20% - Exam 1 (Feb. 13)

ü Sit in the front 2/3 of the classroom ü Laptop use is discouraged ü Phones should be off ü Start time is 2:40; come in the back if you are late ü Don’t pack up until class is finished

Homework ü  Will be made available on Canvas ü  Assigned and due approximately every 1.5 weeks (~7 HWs) ü  Hand in at the beginning of class on the due date ü  -5 points if handed in after class on the same day, -10 points for each day late (max 6 days)

ü 20% - Exam 2 (March 27) ü 25% - Final Exam (TBD) No make-up exams. Let me know at least a month before if there is a problem with an exam date. This class is typically not heavily curved. No extra credit is planned.

In-Class ü In class activities every week (or two) ü Question and ABCD card participation ü Most likely a weekly Exit Poll

ü  Make sure you write up the HW on your own. ü  Familiarize yourself with the Columbia Academic Integrity Information: https://www.college.columbia.edu/academics/ academicintegrity

3

1/16/18

Math and Units

Exams

Basic high school math background required (algebra and geometry) Metric system:

-  -  -  -  - 

ü Combination of short answer and multiple choice ü Not exactly cumulative, but the course builds on itself (i.e., need to know earlier material to understand later)

length: metric system: 1000 mm = 100 cm = 1 m 1000 m = 1 km You are 1.5-2 m tall. Manhattan is 21.5 x 3.7 kilometers (13.4 x 2.3 miles) Distance to sun is 150 million km. Wavelength of visible light: 500 nm = 500x10-9 m

Scientific notation 0.001= 10-3 Dist. to sun 150,000,000,000 m= 1.5x1011 m

Geometry and Proportional Circle circumference, C = 2πr, or C α r

•  • 

Announcements ü Relevant readings are the first chapter ü If you have taken either UN1404 or UN1420 you should not be in this course ü Feel free to send me pictures or videos relevant to class ü HW#1 is posted and will be due next Thursday Jan. 25th at the beginning of class ü Syllabus is subject to change

What is Cosmology?

Look over Math Tools 1.1-1.2 and Appendix 1 in the book Come and talk to us if you need help

BC1754: 
 Stars, Galaxies and Cosmology ü What is a star? ü What is a galaxy? ü What is cosmology?

What is Cosmology?

A.  Having wide international sophistication

x Cosmopolitan A.  Having wide international sophistication

B. The study of the origin and structure of the universe

B.  The study of the origin and structure of the universe

C. The study of treating the hair, nails, and skin for aesthetic improvement

The study of treating the hair, nails, and skin for xC.Cosmetology aesthetic improvement

D. The study of objects and matter outside the earth's atmosphere and of their physical and chemical properties

The study of objects and matter outside the xD.Astronomy earth's atmosphere and of their physical and chemical properties

4