This will be your first short week, that’s right you only have school for three days! WOW... what a deal for you! Guess I will have to give you extra homework to do over those two days off so you wont forget your math huh.... if you don’t like that idea you better talk to me or I will be sending you home with homework for those two days!
THIS WEEK: After scoring it big with our friendship bracelets and now how to make a gazillion on Ebay.... you will really need math to count all that loot you’ll be making! This short week we will be learning about types of fractions and start working with fractions with addition, and subtraction! Oh how do you spell fun? FRACTIONS!
CALCULATOR !!! As we start getting into fractions, trust me you are going to want a fraction calculator. How do you know if your calculator can do fractions, good question.... look to see if it has an ABC button on it.. If so easy peasy... you have a fraction calculator. If not and $$ is tight for you, talk to me and I will give you $5.00 towards the purchase of a calculator, they usually cost about 12 or 13 buckaroos!
The Milky Way has a halo of dark matter that makes up over 90% of its mass. Yes, 90%. That means that all of what we can see (with the naked eye or telescopes) makes up less than 10% of the mass of the Milky Way. Now, it doesn’t have a halo like those old cartoon characters that die, sprout wings and play a harp in the clouds. The halo is actually invisible, though we know it exists by running simulations of what the Milky Way would look like and how fast stars inside the galaxy’s disk orbit the center. The heavier it is, the faster they should be orbiting. If you assume that the galaxy is made up only of matter that we can see, then you get a rotation rate for the stars that is well below what it should be, so the rest is made up of what is elusively called “dark matter,” or matter that only interacts gravitationally (so far as we know) with “normal matter”.
As galaxies go, the Milky Way is a middleweight. The largest galaxy known, IC 1101, has over 100 trillion stars, and other large galaxies can have more than a trillion stars. Smaller galaxies like the aforementioned Large Magellanic Cloud, have about 10 billion stars. The Milky Way has between 200-400 billion stars, but when you look up into the night sky the most you can see from any one point on the Earth is about 2,500. We aren’t stuck with this many stars forever, though, because the Milky Way is constantly losing stars – through supernovae – and producing stars, netting about seven stars per year
You may not think so by looking at it, but the Milky Way is full of dust and gas. And when I say full of dust, I mean that we can only see out about 6,000 light years into the disk of our own galaxy in the visible spectrum, and the galaxy is about 100,000 light years across! The dust and gas makes up a whopping 10-15% of the “normal matter” in the galaxy, with the remainder being stars. The thickness of the dust deflects visible light, as is explained here but infrared light can pass through the dust, which makes infrared telescopes like the Spitzer Space Telescope extremely valuable tools in mapping and studying the galaxy. Spitzer can peer through the dust to give us extraordinarily clear views of what is going on at the heart of the galaxy and in star-forming regions.
We can’t take a picture of the Milky Way from above (yet) because we are inside the galactic disk, about 26,000 light years from the galactic center. This means that any pretty pictures you see of a spiral galaxy with elegant arms that is supposedly the Milky Way is either a picture of another spiral galaxy or the rendering of a talented artist. Imaging the Milky Way from above is a long, long way off; however, this doesn’t mean that we can’t take breathtaking images of the Milky Way from our vantage point!
Most galaxies have a supermassive black hole at the center. Ours is no exception. The center of our galaxy is called Sagittarius A* (pronounced “A-star”), and it houses a black hole with a mass of 40,000 Suns that is 14 million miles across (about the size of Mercury’s orbit). But this is just the black hole itself. All of the mass trying to get into the black hole – called the accretion disk – forms a disk that has a mass of 4 million Suns, and would fit inside the orbit of the Earth. Though like other black holes, Sgr A* tries to consume anything that happens to be nearby, star formation has been detected near this black hole behemoth.
On a clear night, out in the country away from the city lights, you will see a bright, but diffuse, band through the sky. It will make a complete arc overhead (actually it appears as a great circle on the sky with the earth as the center).
Next time you are out in the country, look at this band of light and think about how it looks. This was named by the Greeks as: "Galaxies Kuklos" or The Milky Circle. The Romans changed the name to "Via Lactea" or The Milky Road or as we now call it "The Milky Way."
However, it was not until the the middle of the 18th century that people first came up with the idea that The Milky Way was actually a galaxy of stars. And it was not until the 19th and 20th centuries that scientists understood that The Milky Way is just one of many such galaxies in the universe.
1) Our galaxy has a black hole with a mass of 40,000 Suns that is 14 million miles across, write out the mass in expanded form_____ and 14 million in standard form________.
2) Why is it difficult to take a picture of the Milky Way_______________? And how far are we from it’s galactic center________?
3) What makes it difficult to see into the Milky Way_________ and how far into it can we see_________?
4) The dust and gas makes up a whopping 10-15% of the “normal matter” in the galaxy, is the remainder of the galaxy made of_________?
5) How many stars are in IC1101_______?
6) How many stars are in the Milky Way_______ and how many can you see from the earth_____? Write out the number of stars in the Milky Way you can see from the earth in expanded form__________.
Fri, Oct 28 Carroll College (exhibit.) Spokane, Wash. 6 p.m.
Fri, Nov 11 Eastern Washington Spokane, Wash. TBA
Mon, Nov 14 Washington State Spokane, Wash. 9 p.m.
Sat, Nov 26 Western Michigan (Ronald McDonald House Charities) Spokane, Wash. (Spokane Arena) 1 p.m.
Wed, Nov 30 Notre Dame Spokane, Wash. 8:15 p.m.
Sat, Dec 03 Illinois Champaign, Ill. 12:15 p.m.
Sat, Dec 10 Michigan State Spokane, Wash. 6 p.m.
Thu, Dec 15 Oral Roberts Spokane, Wash. 6 p.m.
Sat, Dec 17 Arizona (Battle In Seattle) Seattle, Wash. (KeyArena) 1 p.m.
Tue, Dec 20 Butler Spokane, Wash. 6 p.m.
Thu, Dec 22 Air Force Spokane, Wash. 6 p.m. Wed, Dec 28 Portland * Spokane, Wash. 6 p.m.
Sat, Dec 31 Xavier Cincinnati, Ohio 5 p.m.
Thu, Jan 05 Pepperdine * Spokane, Wash. 6 p.m.
Sat, Jan 07 Santa Clara * Spokane, Wash. 5 p.m.
Thu, Jan 12 Saint Mary's * Moraga, Calif. 8 p.m.
Sat, Jan 14 Loyola Marymount * Los Angeles, Calif. TBA
Thu, Jan 19 San Francisco * Spokane, Wash. TBA
Sat, Jan 21 San Diego * Spokane, Wash. 5 p.m.
Thu, Jan 26 Portland * Portland, Ore. 8 p.m.
Thu, Feb 02 BYU * Provo, Utah 7 p.m.
Sat, Feb 04 Pepperdine * Malibu, Calif. TBA Thu, Feb 09 Saint Mary's * Spokane, Wash. 8 p.m.
Sat, Feb 11 Loyola Marymount * Spokane, Wash. 5 p.m.
Thu, Feb 16 Santa Clara * Santa Clara, Calif. 8 p.m.
Sat, Feb 18 San Francisco * San Francisco, Calif. TBA
Thu, Feb 23 BYU * Spokane, Wash. 8 p.m. Sat, Feb 25 San Diego * San Diego, Calif. TBA
As always, you are amazing, incredible people with the whole world waiting to be changed by YOU!Mr. Rott
