Wright State University Lake Campus/2016-1/Phy1060/log
Today we talked about parallax.
Today we did a lab on energy, temperature and blackbodies.
Dailly journal[edit | edit source]
1/11 Monday[edit | edit source]
- Almost all the students registered
- Reminder to keep usernames confidential on all wikis.
- See also w:Wikipedia:Username policy
- Advice: Download these pdf copies of the study guides in case Wikiversity goes down at a inopportune time.
1/13 wed[edit | edit source]
Copy this into your user page and paste:
*[[Wright State University Lake Campus/2016-1/Phy1060]]
1/19 tues Angular size lab[edit | edit source]
- See Important announcement below
- Today's 1- page report: Comment on Physics and Astronomy Labs/Angular size
- Place small images under your username on Wright_State_University_Lake_Campus/2016-1/Phy1060#Class_Roster
- Does the class know how to comment on a quiz question?
- Draw an image for
Important announcement[edit | edit source]
Tuesday's and Thursdays are lab days and I need to take attendance. Usually this will be in the form of a 1-page report on blank typing paper. Leave a 3/4 inch margin all around and do not include your real identity inside that space.
- At the very top (inside the 3/4 inch margin where it can be deleted): First last name and date.
- At the very bottom (also in the margin where it can be cut): Name of today's lab and real name.
- In the lower right hand corner, but outside the margins where it will be seen by viewers, you are strongly encouraged to write "I release to public domain - username" This way you or I can post to commons. I will not post handwritten diagrams without your permission.
- Within 24 hours you need to start a journal inside your log's .S personal subpage. Write a one sentence summary of every lab that you attend.
You need to follow the aforementioned instructions so that I can give you a good lab grade
1/20 wed[edit | edit source]
1/22 Fri[edit | edit source]
ques 8 Wikipedia_Sidereus_Nuncius
2/1 Mon: What to put in your dot-S sublog[edit | edit source]
- One option is being used at Wright State University Lake Campus/2016-1/Phy1060/log/BAhrns15
- Any other options the class knows about?
- Another suggestion is to copy/paste this text into your dot-S log subpage:
==Work accomplished== <small>Describe each contribution, list date and permalink. Use either # or * to create a list.</small> ==Lab journal== <small>Only for labs, which occur on Tuesdays and Thursdays. A one sentence (with or without verb) is all you really need. (But it would be good practice to write a bit more).</small>
- At the minimum you want to make about 6 contributions, two before each upcoming test. You must not do all these at the last minute. Record them and refer them using a permalink. To create a permalink look on Tools on the left sidebar and select "Permanent Link". You will see an address "https:// ... oldid=######". Just copy and paste that link after you describe your contribution. You might make several edits to achieve one accomplishment. Be sure to date your accomplishment. Easy contributions to make involve finding grammatical errors in quizzes or astronomy pages and either correcting or documenting them. Other equally easy tasks involve suggesting new questions or short essays to help students understand the question and remember the answer to a quiz question. One good multiple choice question would count towards a large portion of your required effort.
- I will be monitoring your efforts to give you an idea of when you have completed this minimum effort.
- The easiest way to get an A in this course is to do above 90% on the exams (after one test is dropped) and do a bare minimum on the writing part. Extra effort on the wiki writing will help you a tiny bit. But ...
- An extraordinary effort that truly helps Wikiversity or Wikipedia could get you an A even with mediocre test scores. I strongly suggest that if this is the path you choose to take, that you stay in close contact with me as I oversee your work to make sure you are not getting into trouble.
2/4 Thur[edit | edit source]
I might be a few minutes late today. Go to Second Journal of Science and write a handwritten summary of Wikipedia:Astronomical spectroscopy. Don't write it in your .S log, but on actual paper. You may work in groups, but each person needs a different summary.
2/11 Thur[edit | edit source]
- If you have not already done so, today you must go to your .S subpage and create a work accomplished page for all You may copy the following script:
- The entire class will write a description of the parallax experiment. You may write in your .S journal if you prefer to work alone, or you may work in groups of 2 or 3 and write on a white sheet of paper. If you write in the .S journal, sign your username to the sheet provided.
- Now divide up into two groups and "stage" the lab so we can take pictures. Pick one of the two activities. The photographers will meet with me as the "actors and directors" prepare for the photography.
- Physics and Astronomy Labs/Parallax. Our first goal will be to photograph students setting this lab up and writing a description of the lab. Write your descriptions using pencil on a piece of paper. You may work in groups of 1, 2 or 3 as you write. Then form groups of 3,4, or 5 to "stage" the setting up of the lab for a photograph.
- Physics and Astronomy Labs/Hooke's law and Young's modulus. Here, you will document how we wind and unwind the string, and how we measure the force using a spring scale.
2/16 Thur: Newton's dark secrets[edit | edit source]
2/23 Tues: Angular size to find distance to wall[edit | edit source]
2/23 Thur: Parallax[edit | edit source]
3/8 Tues: Black body using Nebraska materials[edit | edit source]
3/22 Tues: Nebraska HR diagram (help with the upcoming exam[edit | edit source]
What happens when one moves vertically on the HR diagram? How do low mass stars change during "birth"?
3/23 Wed: More help with exam[edit | edit source]
- Talk:Astronomy college course/Introduction to stellar measurements/questions (supplement to Astronomy college course/Introduction to stellar measurements/questions
- Discuss open clusters:
- Young and small
- In the disk where most of the gas is
- Small clusters tend to drift apart for two reasons
- 1. Small clusters have less gravity; they "evaporate". Random motion causes these stars to interact and some of them gain enough speed to escape from the gravity.
- 2. Nearby clouds exert gravitational forces. It is FALSE to say the feel significant forces only due to gravitational forces with each other. But they do feel significant attractions due to giant molecular clouds. These clouds are very dense and massive.
- 3. The moving cluster method can be used to find distance: Over a few years, the evaporation is effectively zero, so the cluster does not change its size. But the angular size does change, and they can use math to calculate the distance using the doppler effect for speed and the change in angular diameter due to the fact that the object is moving away from them. Hint: A distant object that is moving away at high speeds does not change its angular size very rapidly.
3/24 more help with exam[edit | edit source]
- Write the horizontal and vertical labels for an hr diagram. Also label the main sequence, and the "large and small corners".
- A star that is increasing its temperature while maintaining constant luminosity is getting closer to what corner?
- Be sure that on the HR diagram you can label: Hot and cold stars, luminous and dim stars, large and small stars. Also know whether a star is getting bigger or smaller as it moves either horizontally or vertically.
- The story of the white dwarf
- Found as a perturbation in the orbit of a nearby star. See File:Sirius.Trajectory.png
- Three reasons we know they are small:
- 1. location on the HR diagram: temperature-Luminosity (Hot star that is dim, since hot stars give off much energy per square foot, they must have very few square feet: About the temperature of the sun, but only about the size of the earth. See File:H-r diagram-black white.png and File:Hertzsprung-Russel_StarData.png.
- 2. The spectral lines are red shifted (Gravitational NOT Doppler). We know the white dwarf is not moving away from us because it is orbiting another star that is not moving away at high speed. What else could cause this shift? General relativity and the idea of photons (Einstein). See File:Gravitational_red-shifting2.png and File:Redshift blueshift.svg
- 3. The quantum theory of solids says that the electrons prevent further collapse -- believe it or not, the same theory that explains the density of metals also describwes the density of a white dwarf. See the image at w:Bohr–Einstein debates#Post-revolution:_First_stage as well as File:Nuvola di elettroni.svg and and file:H2OrbitalsAnimation.gif
3/30 Wednesday[edit | edit source]
Finish the story of the white dwarf with Quantum theory of solids.
- The story of the Neutron star
- Accidental discovery of a rapid pulsating radio source using a primitive w:radio telescope. See Wikipedia:Pulsar. Big things don't do things rapidly. A neutron star rotating that fast (with a hotspot) would fly apart. For a picture of this telescope see http://www.bigear.org/vol1no1/burnell2.gif
- A brilliant theoretical astrophysicist calculated a small size that most people did not believe (like the quantum theory of solids, but a much more advanced calculation) See Wikipedia:Chandrasekhar limit.
- The energy output of the crab nebula could be explained by a rotating mass that was slowing down, but only if it was a few kilometers in diameter. and note the disorganization in having two articles on this subject.
3/31 Thursday: Bach, resonances and Danse Macabre (Saint Saens)[edit | edit source]
- Finish resonance lab with Bach and Dance Macabre: Wright_State_University_Lake_Campus/2016-1/Phy2400/log#3.2F29_Solutions_to_questions_13.2C_14.2C_15
- Start Astronomy_college_course/Scale_model_of_the_solar_system