1. Astronomy A205 Dr. Edward Rhoads LD 156P 317-278-1134 erhoads@iupui.edu Homepage: http://www.physics.iupui.edu/Astronomy/RhoadsAstro/A205/Stars/A2 05syllabus.htm

2. Goal: To understand what Science is, what it does, and as to how Astronomy is useful to our society. Objectives: 1.To understand what goes into Scientific Models 2.To understand what is meant by Scientific Theory 3.To Brainstorm uses for Astronomy

3. What is Science? To attempt to gain an understanding work on the following example: You are buying a house. The house is $80,000. You make a 20% down payment The loan is 5% interest for 30 years.

4. The model to construct You type this information into a website which estimates your mortgage payment and it claims that the monthly payment will be $343.60 per month. However, if you pay more each month you can pay it off in less time. The next page has a table which gives you the amount you need to pay each month in order to pay off the loan in that number of years. What you need to construct is a model you feel does a best job of paying off the loan (one you might decide to later use in real life) AND how much you will pay total on that house including the down payment.

5. # years$/month 14530.5 13558.8 12591.9 11631.3 10678.8 9737.1 8810.2 7904.6 61030.7 51208 41474 31918 22808 15479 # years$/month 30343.6 29348.7 28354.3 27360.4 26367 25374.1 24382 23390.7 22400.2 21410.7 20422.4 19435.4 18450 17466.3 16484.9 15506.1

6. Assumptions Assumptions are values we assume to be true or that their effect on the final result is negligible. What have we assumed here?

7. Assumptions Constant interest rates Constant payment each month Monthly interest, and payment made after interested compounded

8. Omissions Omissions are anything that we left out. Either we forgot Or didn’t know about it Or just assumed that it would have no influence on the outcome What are some things we have omitted from our models?

9. Omissions Insurance Property tax Escrow Lenders fees Home improvement costs Moving costs Utilities Income from home if you rent some of it out INFLATION There are always other unknowns.

10. Question is Which “model” is now the best one? Are the other ones “wrong”?

11. Error Bars Error Bars are just the value we expect the true value to deviate from our model. The lower the error bar the more accurate our model. What this does is allow us to estimate a range of values we know the “true” answer should fall into.

12. In Science: Usually not a “right” or “wrong” answer. There are answers that are highly accurate, moderately accurate, and not very accurate. Okay, occasionally there is a “crackpot” idea also, but those are rare and usually ignored by most – however….

13. Science: Is the ongoing work to attempt to understand what we do not know using what we do know. We do this by attempting to best address the “error bars” both known and unknown that we may encounter in order to establish the most accurate set of ideas (otherwise known as “models” or “theories”) that we possibly can.

14. What is a “theory” a)Some random guess. b)What some scientist thinks the answer should be off the top of his head. c)Some unproven and/or un-provable idea which is the most educated guess someone can make. d)The “model” which most accurately explains what we can observe and find in experiments, and has been proven to be accurate time after time after time.

15. What is Astronomy used for? With a neighbor, brainstorm as many things that you can think of that Astronomy has been, or could be, used for. Include even historical reasons, and possibly future ones.

16. Conclusion Science is about using as many facts as possible to take the next step in understanding the unknown. Many “theories” are in fact well thought out and very well proven using as many tests, observations, and experiments we can think of. Astronomy, in addition to being very fun and cool, and having lots of pretty pictures, is a very useful science and will only become more useful as mankind heads into the future.

17. Questions?