Week of September 28, 2015

This week starts out with a (TOTALLY!) TOTAL LUNAR ECLIPSE! Check out the Cool Science feature at the bottom of this blog entry for details.

This Week in AP Physics
We will complete our experiment on Inertial Mass vs Gravitational Mass as well as assignment 1 by Tuesday. Next we’ll explore the fundamentally important Newton’s Laws of Motion with some charmingly-delivered notes, assignment 2, and an experiment for which you will write a formal lab report. This report will be due on Thursday, October 8 (hardcopy due at the start of class, upload to TurnItIn.com by 3:00 of that day. Remember to write using Google Drive and share your document with me at alhsgb@gmail.com… Note that I do not use that for email correspondence.)

This Week in Physics
We will take our unit 1 test and will then begin a much quicker topic, two-dimensional motion, in unit 2. When asked, please take notes on Podcast 1 – Vectors vs. ScalarsPodcast 2 – Vector Diagrams, Podcast 3 – Introduction to Vector Addition, and Podcast 4 – Vector Addition Sample Problem. We will go over these briefly in class and will then do assignment 1.

Cool Science of the Week
Indeed there will be a lunar eclipse to start our week! On Sunday night (beginning at 9:07 pm and peaking at 10:47 pm) if you head outside – and if the weather cooperates – you’ll be in for a pretty cool sight…a bright red moon! A lunar eclipse happens when the moon passes into Earth’s shadow, preventing the moon from getting the full blast of sunlight that allows it to look white and bright. Interestingly, there is still a little bit of light that bends (refracts) through Earth’s atmosphere and strikes the moon. This light is reddish because the atmosphere has filtered out higher energy light (the colors blue and green.) What remains streaming behind the Earth is a red shadow. As the moon passes into this shadow, it will appear bright red, and it’s a pretty awesome sight. It is said that the moon during a lunar eclipse is experiencing all the sunsets and sunrises of Earth at the same time.

You may also hear news reporters brag that this will be a SUPERMOON! This sounds very impressive, but I’ll let you decide for yourself. The moon’s orbit is elliptical, which means that there are orbital locations that are closer to Earth than others. When the moon is at (or near) its closest orbital point, some people term it a supermoon. Is it so super? Well, it is about 16% brighter than the average full moon…but the average moon only reflects 7% of the sun’s light…so supermoon will reflect about 8.1% of the sun’s light. Is that enough to notice? Additionally, a supermoon appears 7% bigger than the average full moon, which is 0.5 angular degrees in our 180 degree sky. Doing the math, 7% of 0.5 degree makes the supermoon 0.535 degrees big. I don’t think I’m going to notice the difference, but it sure sounds exciting when people talk about it on the news! 🙂 This may make you wonder (if all this supermoon business is so unimpressive) why the moon really does seem bigger sometimes. I think I’ve written enough for now, but I can share it with you in class if you’d like to know.