For this assignment, you may work in pairs. Use the following estimates:
- The Milky Way galaxy's disc has a radius of about 100,000 light
years (LY).
- The Earth's diameter is about 12,700 kilometers
- The Sun's diameter is about 1,392,000 kilometers
- The Radius of the star VV Cephei is about 1800 times that of the
sun
- It will turn out to be useful to notice that 1.8 meters is about 6
feet, thus 1800 millimeters or 180 centimeters is 6 feet.
- Use Wikipedia to find the distance between the Earth and Sun, and
search for any other facts (there shouldn't be many of them) you might
need. Use Google Calculator if you wish, for conversions, and
arithmetic. Hint: as of this writing (the entry does change over time)
you can use the "Orbit and rotation" section of
http://en.wikipedia.org/wiki/Earth to find the average Earth-to-Sun
distance.
- Earth and Sun
- How many times larger than Earth's diameter is the Sun's
diameter? ______.
- If we round this to the nearest 10, the Sun is roughly ______
times the diameter of the Earth.
- If instead if want just a rough estimate, then rounding to the
nearest 100, we can say the Sun is roughly ______ times bigger than
the Earth in Diameter
- After finding out how far the Earth and Sun are, give a rough
round figure for how many times bigger than the Sun's diamater
this distance is:
"The distance from the Sun to the Earth is about ______ times the
diameter of the Sun". Rounded to the nearest 10: ______. Rounded to
the nearest 100: ______.
Solve on scratch paper first, show only your Final draft clean,
clear solution steps below:
- Sun and VV Cephei
- If the Sun were 1 millimeter in diameter (a spec whose width is
that of the smallest "metric system" notches on your ruler) then VV
Cephei would be a sphere whose diameter is _____ meters or about _____
feet.
- If the Sun were 1 centimeter (just under a half an inch, or
about a small marble) in diameter then VV Cephei would be a sphere
whose diameter is _____ meters or about _____ feet.
Solve on scratch paper first, show only your Final draft clean,
clear solution steps below:
- Now suppose we want to scale things so that the Earth is the
size of that marble: the Earth is 1 centimeter in diameter. Use the
"rounded to the nearest 100" figures for how many times bigger the
Sun's diameter is than Earth's, and how many Suns-diameter's worth
correspond to the Earth-to-Sun distance. To give the corresponding size
or length for:
- How big the Sun would be in meters? ______ In feet ______.
- How far away in feet would this (model of) the Earth be from our
model of the Sun? ______ feet (or ______ (fraction) of a mile)
(include fractions)
- How big would the diameter of VV Cephei be? about ______ feet
or about ______ miles
Solve on scratch paper first, show only your Final draft clean,
clear solution steps below:
- Suppose finally that we shrink the Milky Way down to the size
of the Earth. The Earth is roughly spherical while the Milky Way is
roughly a flat disk so we need to clarify the meaning: suppose we
shrunk our Galaxy, the Milky Way, down so the diameter of it's disk
(namely 100,000 light years) would become instead the same as the
diameter of the Earth (or that the radius of the flat disk of the
Galaxy would be the length of Earth's radius). You may wish to
type "1 light year in kilometers" into Google.
- How big would VV Cephei be? It would be a sphere whose diameter
is roughly ________ (include units).
- How about the sun? ______.
Solve on scratch paper first, show only your Final draft clean,
clear solution steps below: