Big Bang Theory & SigFigs! woohoo!

Some classes got to homework today and some did not; if you didn't have homework today, rest assured, everyone will tomorrow.  Tuesday HMWK (due Thursday):  read p. 231-236, 238-241, and problems #1-6 on p. 237, # 2-7 on p. 241.
EXAMS upcoming!!  Friday 5/4: Astronomy exam.  TGT review game here
Friday 5/11 cumulative exam.  skim/review notes and materials from this whole year.
5/15 or 5/16: essay final (I will provide a question from each chapter this semester; you choose which you want to answer)
Sig figs practice problems may be found here and here.  <-- these pages include answers.
Notes for today / tomorrow here and below (some classes were truncated due to Freeman not being used to short class periods again haha)
The Big Bang Theory - evidence from Doppler effect, cosmic microwave radiation, implications of whether the universe will expand forever, stop, or re-collapse.

Significant figures rules & practice: why / how to round
Accuracy vs. precision - accuracy is correctness, precision is the degree of closeness of a measurement; a descriptor of how small the units or increments used to measure something are.

Significant figures:
Report answers with the smallest number of significant figures used in calculation so as to avoid displaying more precision than exists.
Sig figs are:
nonzero numbers AND ...
zeroes IF they
*are between two nonzero digits
*are to the right of the decimal AND to the right of a nonzero digit
BUT NOT IF they
-are to the left of all nonzero digits
-are to the right of nonzero digits but not to the right of a decimal.

Doppler, Light Speed, Distances in Space

Classes on their 2nd/3rd dose of Freeman during this testing schedule will experience:
Solar System Scale - we walked off the solar system to scale and found out that the outer planets are much farther away from the Sun than they appear on paper.
Powers of Ten video (see it on youtube - if this link works)
Distances in space notes
** the only number you're asked to memorize here is the speed of light, c.  (see below or in notes)
Star types (I) notes
Notes on the Doppler Effect (these were connected to the Absorption Spectra notes)
Discussion of the Electromagnetic Spectrum - wave lengths and energies of different EM waves, all of which move at ~ 3.00x10^8 m/s in a vacuum:... plus how the ROYGBIV is situated between (lower energy) longer infrared waves and (higher energy) UV rays - Red is by infrared, and violet is by UV so you can tell which has lower and higher E (and their relative wavelengths) (SEE IMAGES BELOW)
Watched some "fun science" videos with Charlie (hopefully this link works)
Worked on Astronomy Vocabulary (something I typically expect you to get from the reading, but I should apparently do more often.
Some classes got to start a video regarding solar system and planet formation, depending on how long they took to work math problems.
EXTRA MATH / number concept and Challenge problems HERE to help you review.
After classes (next time) finish the video, we will address significant figures and scientific notation so that you never need to ask, "how do I round this?"  again, and WHY you round.
 - it's easy (based on specific, clear rules) but will take practice to perfect.

see the sun? how?

pinhole sun viewers, solar filter film, a "sun spotter" telescope, and even a reflecting (newtonian) telescope are in full swing to view the sun in the 2nd class meeting this week.  We'll spend more time working on conversions using light speed, A.U.s, and distances in space, and explain the workings of a telescope - and different kinds which solve various problems with viewing the sky.
Some classes will finish with enough time to watch some fun They Might Be Giants "here comes science" videos.
There should be no doubt of what a sunspot looks like after you get to see it firsthand, and we'll take mini-trips to track the sunspots we've found over the next few classes (my classes have not seen any sunspots in the past 4 years that I've taken them outside to look!!!)  Neat to see a more "active" sun.
NASA STEREO view of the sun webpage
NASA Current view of the sun webpage  <-- see REAL TIME images of the sun!!! ...from the Solar Helical Observatory Telescope (SOHO)  (see below too)

Above:  Today's sun (visible light)

Below:  Showing wavelengths of light at 1 million degrees C.  This is the sun's corona (atmosphere) and is brighter where there is more activity on the sun's surface.

Add caption

More SUN! light speed too!

Today: finished notes on the Sun (part II)
Noted planetary distances from the sun in A.U.s  
Used A.U. figures from the sun to determine distance from sun in km (using conversion factors)
Calculated time for light to reach Earth from Sun using light speed in space (300,000,000 m/s)
Calculated time for signals to travel from Earth to distant planets and back  (as if you were talking with a buddy on Saturn, or controlling the Mars rovers on earth and waiting for video confirmation of what you did...)
Some classes had time to make a telescope.

Astronomy! HMWK for Friday. ALL classes Library tomorrow!

*** All classes meet in the library computer lab Thursday***
Thursday in the computer lab:  You have two options for what to do today; both are for points but the textbook stuff is required and due tomorrow.
1. Work on Friday's homework: Read p. 218-228, p. 222#1-6 and p. 228#1-7.

www.glencoe.com/ose

Access code: EE058E574E

(best results usually with Internet Explorer)

2. Work on Optional Assignment(s):

(there are three available right now)  see the following:

1. Persuasive energy efficiency presentation to your parents (due Friday, the 13th)

2. Presentation about the current/upcoming Mars Mission  (Present in class Friday, the 13th)

3. PHET: blackbody radiation -   (due next Friday, the 20th)

Yesterday classes got back tests and we discussed/had notes&readings regarding historical perspectives of the universe.
Today we explored a bit about our sun; specifically its temperature, composition, and our relative location to it. We also started to look at how we know what we know about the universe: assumptions about light that we receive and that the rules of the universe must be the same here as in distant places (again, uniformitarianism).
outline of Notes from yesterday
Notes from today: Sun
Notes from today: absorption spectra, emission spectra, and Doppler
Notes for Friday and Monday: Sun Pt II

Tomorrow's review practice problems

https://docs.google.com/document/d/1tCePAWyF6MZ845u2Zfqr8EAKhLhD-dvA22zGCxKozOA/edit

Many of the questions come from this page - you can use it to check your answers for many of them - use "ctrl + f" on your keyboard to "find" or search.