Transcript Constellations

You have 5 minutes to check your Answers to
the Black Hole Discussion Questions
1. We could not compress the aluminum foil-covered balloon when it was inflated
because the air inside the balloon was resisting the pressure we exerted upon it. Our
pressure simulated gravity pulling the matter in the star toward its center and the air
within the balloon simulated the outward flowing energy from thermonuclear fusion.
These two factors balance each other out, so the star stays at equilibrium.
2. If a real star were the size of the balloon, then the black hole would be much, much
tinier than our model black hole. A real black hole that has formed from a massive
star is smaller than the tip of a pencil!
3. Building the star with more layers of gas (represented by the foil) would make the
star more massive. It would also result in the formation of a more massive black hole,
since there would be more material with which to form the black hole.
4. Although they have a different size, since they are made from the exact same
amount of material, the model star and the model black hole have the same mass.
However, since the model black hole is smaller, it has more material contained in less
volume, and therefore has a higher density than the model star. This would also be
true for a real black hole, which would be even smaller and much, much denser.
5. Since both the star and the black hole have essentially the same
mass, but the latter had a much smaller volume, the black hole is
much, much denser than the star. The same amount of matter is
crammed into a much smaller space. This is true for both the model
and in real life. In real life the star is much, much huger and the black
hole much, much smaller, so the difference in density is even greater.
6. Black holes do not suck up nearby material. If the Sun were
magically converted into a black hole, Earth's orbit would not change!
Earth would continue to “fall around” the black hole, but not fall into it.
However, life on Earth would cease to exist, seeing as it is dependent
on the sun’s light and heat, which would no longer be emitted.
More detail in case you are curious: Material generally falls into a black
hole when it collides with other material orbiting the black hole. The
collision alters the material's orbit. Instead of orbiting a comfortable
distance from the black hole, the material is now orbiting too close to
the black hole – within the boundary of its event horizon. Then the
black hole's enormous gravity traps the material in a one-way spiral to
oblivion.
Reminder: Our sun is not massive enough to become a black hole
!
What do you see in this picture?
Could you find Orion?
Can you find any pictures in
these stars?
What is the name for a picture
made of stars?
Constellations
• What is a
constellation?
• A group of stars that
seems to form a
picture
A group of stars that seems to form a picture
The word “seems” is important because the stars
in the constellation have no actual relationship to
one another. They just look that way from our
point of view, here in our solar system.
If you were in a
different
position relative
to Orion, you
wouldn’t see
the same
pattern at all!
Every culture since ancient times has
made up their own
constellations and stories to go along
with them.
Chinese constellations
Native American (Ojibway) Constellations
Hawaiian constellations
Norse Constellations
The International Union of Astronomers
recognizes 88 “official” constellations.
Most are from ancient Greek times, but
some, especially those in the southern
hemisphere, were made up more
recently by western astronomers.
These are used as a “roadmap” to the
sky.
But you can also make up your own constellations,
like we did in class.
It’s like
looking for
pictures in the
clouds!
It’s also cool to learn about
the “official” ones!
Your Task:
• Make a picture of your assigned
constellation.
• Learn the myth behind it well enough to
tell it when we go into the StarLab.
• Instructions in communicators!
• Links on School Web Page (This Month in
Science)
• Ignore the Homework on the bottom, but
you should each choose your own star.