The Learn Tracker
...life-long learning: structured, organized, searchable...
920
Lectures Watched
Since January 1, 2014
Hundreds of free, self-paced university courses available:
my recommendations here
Peruse my collection of 275
influential people of the past.
View My Class Notes via:
Receive My Class Notes via E-Mail:

VIEW ARCHIVE

Contact Me via E-Mail:
edward [at] tanguay.info
Notes on video lecture:
The Milky Way and Its Black Hole
Notes taken by Edward Tanguay on March 8, 2016 (go to class or lectures)
Choose from these words to fill the blanks below:
flashes, mirror, heavy, 375, Minerva, seconds, 2007, Moon, outside, 12, minutes, 1500, past, heavier, million, 16, gas, four, 28, time, lag, Centauri, massive, staggering, 384, JAXA, quickly, Selenological, black
•
as you look far away in the universe, you are looking into the         
•
International Space Station
•
only very recent that humans have developed technology to have a station                the earth
•
floating above the Earth at an altitude of        kilometers
•
the diameter of the Earth is     ,000 kilometers
•
suggests that moving out away from the Earth is not a very easy thing to do
•
travel to the moon
•
      ,400 kilometers
•
Kaguya
•
nickname for SELENE (                           and Engineering Explorer)
•
launched on September 14,         
•
picture:
•
went to the other side of the moon
•
took pictures of Earth rise
•
because distances are so large in space, we use          to describe how far away objects are
•
light takes 1.3 seconds to reach the         
•
Moon is 1.3 light-seconds away
•
the Apollo astronauts put a              on the Moon
•
we can shoot a laser to it and it returns 2.6                later
•
Sun
•
1.5 10^8 kilometers away
•
8.3 light-               away
•
Hayabusa
•
an unmanned spacecraft developed by the Japan Aerospace Exploration Agency (        ) which returned a sample of material from a small near-Earth asteroid named 25143 Itokawa to Earth for further analysis
•
20 light-minutes away from the Earth (more than two times the distance to the Sun)
•
the command sent to the probe to deploy the                lander arrived to late, since it took 20 minutes to get there
•
there is a 40-minute        for making decisions of how the probe should interact with its environment
•
it had to decide as much as it could on its own
•
Neptune
•
         light-hours away
•
Voyager
•
human-made object that is the farthest from Earth
•
    -light-hours away
•
we are still communicating with it
•
closest star
•
Proxima                 
•
4.2 light-years
•
Voyager will have to travel for over 10,000 years to get to Proxima Centauri
•
Milky Way galaxy
•
we are in a galaxy which is a disc and when we look at the Milky Way we see the disc from the inside
•
we are     ,000 light-years away from the center of the galaxy
•
it's only          light-years thick
•
our solar system is revolving around the center of the our galaxy
•
at a speed of 220 km/s
•
something is pulling us to the center of the galaxy
•
we know this to be a            hole
•
with infrared light we can see through the dust and debris in space to see the motion of stars at the center of the galaxy
•
something is pulling a star, and after it passes through, it speeds on               
•
it takes 20 years for a star to orbit around this very            object
•
by studying the motion of these stars, you can determine how                the object is
•
the answer is                     : the object in the middle of the Milky Way galaxy is four million times heavier than our Sun
•
nothing can be that heavy except for a black hole
•
black hole at center of the Milky Way
•
four                times our solar mass
•
other galaxies have                black holes
•
it can consume objects including        around it
•
even the speed of light is not enough to escape the force of gravity from the black hole
•
just before gas enters the black hole, it                in light
The Milky Way and Its Black Hole