Homework 8 is ready.

Homework 8 is ready, a smorgasbord of hoops calculations on your home planet.

By the way, what is your caption for this photo? What is #3 thinking?

Special lecture section meeting today

Asteroid Encounter, Feb. 15

We will hold our class meeting today, Feb. 15, at the Pegasus Ballroom. Get there as early as you can -- I expect it to be crowded. We have seating set aside in the back.

1. Be there at our regular time, 1:30 - 2:20 PM.
2. Extra credit, 4 points on semester grade if you attend 1:30 - 2:20 PM.
3. We will take attendance and have two questions on iClicker 2, so be sure to bring it.
4. Sit in back near me.
5. I will be wearing a bright red shirt!
6. One question will be running for the first ten minutes, 1:35 - 1:40 PM.
7. I will stand up when the second question is ready, 2:10 - 2:20 PM.

Homework 7 for Kepler's laws

You can now work on Homework 7, concerning orbits and gravity and Kepler's three laws.

Special meeting in Pegasus Ballroom, Student Union, 1:30 - 2:20 PM, this Friday.

I am up to lecture L10 for iClicker 2 data uploads. Good.

Uploading iClicker 2 data

I am uploading a few lectures worth if iClicker 2 data right now.

So if you see your Grades page changing, fear thou not!

Variations in g on our moon

An interesting look at variations in the gravitational field of our moon, from the GRAIL spacecraft.

Mercator projections of free-air gravity, topography, and Bouguer gravity. Frames in (A) highlight the area surrounding the Korolev impact basin, at center. Frames in (B) show the western limb of Oceanus Procellarum. Details of free-air and Bouguer gravity are the same as in Fig. 1. Topography is from a LOLA 1/64° grid.

Cf., Zuber et al., Science 8 February 2013: Vol. 339 no. 6120 pp. 668-671.
DOI: 10.1126/science.1231507

Free-air gravity adjusts the value of g for altitude above sea level; Bouguer gravity also corrects for the mass of the rock piled up to that altitude.

1000 mGal = 1000 milliGalileos = 1 cm/sec². So the variations are small but telling.

Enjoy.

-1

By the way, if your grades page shows a "-1" for the ..Exam 1 scantron score, that means you forgot to bubble in the test form A, B, C or D, or maybe you messed up the PID.

It happens.

So if that happened to you: I will have to dig through the gigantic pile of exams to find yours and figure out what went wrong. Then I can get the true score figured out, but it will take some time.

Exam 1 grades are UP.

The scantron scores are now up. Together with your iClicker 2 points, they add up to the full score, "Midterm exam 1" on your grades page.

Your exam 1 iClicker grade

I just uploaded two items to the gradebook:

1. 
   ..Exam 1.39, which is either 0, 1 or 2 points. Two points for correct answer, one point for partial credit (my dicision), zero for incorrect.
2. Your Exam 1.39 answer, which shows the number you actually typed in for your answer. If you did not send an answer, or if it was a letter, e.g., A, then I entered -1 to signify no numeric answer. I cannot post text in the gradebook, so I am sorry about this -1 substitution.

I have not heard yet from anybody about the scantrons, but hopefully by tomorrow (Friday) we will get those data.

What an exam!

OK, the scantrons are in test scoring. Hopefully by tomorrow or Friday we will get results.

I will post the iClicker 2 points tomorrow.

For now, I am going to catch up on my ZZZZZ.

I recommend the same philosophy to all of you guys. :D

Fiasco Day

I have to apologize for cussing and carrying on about the lecture hall's equipment yesterday, and for having such a short lecture.

Now it also turns out that the my podcasting software did not record audio yesterday!

Big disasters.

Two comments:

1. The portion of midterm exam 1 concerning yestrday's lecture is relatively small, and would have been small even if the lecture went the normal length. After all, there have been 10 other lectures. So do not stress out about it.
2. I will make a replacement version of the podcast this afternoon and publish it to iTunes U this afternoon. It will not have any of your guys' questions from the floor, but I will walk you through the material we did cover. The iClicker 2 questions will be in there, too.

Office hours at 10 AM!

Homework 6 ready

There is a short homework assignment ready now in Webcourses2. It is Homework 6.

Homework 5 is ready.

Your homework assignment #5 is ready. It is due at the start of lecture on Monday.

Side note: When we have homework assignments, they are always due at the beginning of the next lecture, 1:30 PM.