Scholarships and Awards for Majors in Physics and Astrophysics 20 Awards available, $1,000 - $10,000 recognizing Academic achievement, Potential for excellence in research, Overall excellence and achievement. Free Pizza Information Session: Feb. 29, 5:30 pm, PAN110 Information and application: Application Deadline: March 28, 2016 Undergraduate Research (UROP) $1500/project Benefit: a strong letter for the above awards and applications to graduate schools

Getting ready for the first paper By now, I sincerely hope that you have the records of your lab partners’ UMNx500 ID's. The information is required to fill-in your choices of topics for both papers. On 2/26 (F) evening after all students finish their first lab period of the third assigned lab, an will be sent out. Then you have to send me your choices of the topics for the paper #1, along with the UMx500 ID’s of your lab partners of each topic. I will assign and you the topic for your paper #1. Before 8 AM on 3/1 (Tu), your choice of the topic should be made.

Important dates (part of the list) Peer Review (first paper): March 8 (Tuesday) If you are late for the class, most likely you will not be allowed to participate in the peer-review. By missing the grades of the first draft and peer-review, your maximum score will be 80% of the paper #1. Due time for the revised first scientific paper along with the peer review report and first draft: noon, March 11 (Friday) No Lab Week: March 7-11 (the week before Spring Break) Next week lecture will be “key components of writing a scientific paper.

Another excellent suggestion from a student Upon receiving one student’s suggestion, the following message was sent to you yesterday morning: To effectively use the lecture time, please make sure that you have a pen and a piece of paper to write down the answer(s) of the question(s) for all future lectures. Once I call your name or pick you (after raising your hand), you have to show us that you have one piece of paper with your answer. Previously a few students got to the white board and tried to figure out the answer(s) by reading the question(s) on the PPT. It is not a good idea to have the rest of students waste their time waiting for your answer(s).

Expected equation for thermal expansion: Before using “black box” software, it is wise to estimate the parameters the old- fashion graphical way first The initial guess yields intercept/slope

Least-Square Fit Black Box: Excel spreadsheet LSQFit Read the documentation! Don’t worry about detailed understanding of the inner workings yet. Step 1 is to enter data manually into LSQFit or copy from another spreadsheet. Step 3 is to interpret the results. a, b,  a,  b,  2, reduced  2, M, etc. Step 2 is to “fill down” columns E through O to complete LSQFit on the input data.

LSQFit spread sheet Step 3 is to interpret. Given the initial set of data along with the LSQFit results, on your paper write down the fitting results (a and b) with proper values of errors. Three students has been picked to write their answers on the white board.

Fitting data to a straight line Fitting to this equation, Write down your answer in your paper with proper values of errors. Use the calculator in your phone. Two students have been picked to write their answers on the white board. yields

Fitting data to a straight line Fitting to this equation, yields Answers:

LSQFit spread sheet What are the meanings of  2, N, M, reduced  2 ? We will not discuss Cov(a,b), r ab, and S x /S.

Analyses Question: Are there problems associated with this set of data? Once the fitting is done, in general, it is good idea to exam the quality of fitting through analyses.

Analyses The fitting results shown in this figure look very good.

Analyses However, from the  i -plot shown on the right, one immediately realizes that there is a problem. Question: What is the problem?

Analyses i Randomness (good);  i too small. Question: error bars too large or small? Good data: randomness; most data having  i between -1 and +1 Once the fitting is done, in general, it is good idea to exam the quality of fitting through analyses. Fitted errors: Measured errors:  i

Analyses Each Geiger counter output, there is error which we do not measure. Thus the lab manual suggests that you analyze data with respect to a well-established distribution function ( ), then vary  i such that  2 has a value of about what?

Plotting data using Excel program Enter the data in one Excel spread sheet, previously discussed data

Plotting data using Excel program Enter the data in one Excel spread sheet, from previously discussed data Please raise you hand high, if you already know how to get this figure from the given set of data using Excel or other programs.

Plotting data using Excel program Height light B column (x) and C column (y). Click on “Insert” tab

Plotting data using Excel program Click on “Scatter” tab Select this choice Under “Insert” tab

Plotting data using Excel program A scattered data plot will show in the Excel sheet. Click on the plot to get the “Chart Tools” For a single set of data, let us remove the unnecessary legend. Clicking on “Series1” Then select “Delete”

Plotting data using Excel program Select “Layout” tab, Click on “Chart Title” Pick “Above Chart” Then type the title of the figure accordingly

Plotting data using Excel program Similarly, Select “Layout” tab, Click on “Axis Titles” Pick “Horizontal Axis Title” and then “Vertical Axis Title” for the latter one select “Rotated Title” Type the “Axis Titles” of the figure accordingly

Plotting data using Excel program Adding error bars. In “Layout” tab, Click on “Error Bars” Pick “More Error Bars Options”

Plotting data using Excel program This screen will show up to “format error bars” Select “Custom” then click on “Specify Value”

Plotting data using Excel program This screen will show up. You have to input the locations of positive (negative) error value in your spread sheet. They are in the column D (highlighted) Input =Sheet1!$D$2:$D$16 for both positive (negative) error values. Then Click “OK” Sheet1 $D$2 $D$16

Plotting data using Excel program Even though the error bars on x are not given, the final plot will show. Click on one of the horizontal “error bars” and then hit “delete”

Plotting data using Excel program In most cases, this will be your final plot. In some cases, you have more than one set of data and would like to use “open” legend instead of “solid” one. Use the following instructions. Right click on one of the data point.

Plotting data using Excel program The select “Format Data Series”

Plotting data using Excel program In the new screen Select “Maker Fill” In another new screen, Pick “No fill”.

Plotting data using Excel program Here is our final plot.

Plotting data using Excel program But the plot of this type is not uncommon in both lab-books and submitted papers. Can you tell us what are the problems?

Plotting data using Excel program If the axis labels are too small, you should click on one of the number, e.g., “1” in the horizontal axis, all the numbers in the horizontal axis will be in a box. Then you can change the font size properly, e.g. from 8 to 12. Repeat it for the vertical axis label.

Plotting data using Excel program