1. It has been discovered in recent years that over 90 percent of the mass and e
ID: 1522343 • Letter: 1
Question
1. It has been discovered in recent years that over 90 percent of the mass and energy in the universe is "dark" that is, not visible to our present instrumentation. Discuss in detail the implications this discovery has for science and scientific philosophy.
2. Below are listed the characteristics for four telescopes. Answer the following questions:
a) How much brighter (or fainter) will point sources appear to be when viewed through Telescope 2 compared to Telescope 1?
b) Compare the theoretical resolving power of Telescope 2 to Telescope 3.
c) If an eyepiece with a focal length of 0.5 cm is used with each of the telescopes listed below, which telescope will have the highest magnification?
d) What is the value of that highest magnification from part (c)?
e) Sketch the optical system of Telescope 5.
Telescope Type Diameter of primary Lens/mirror Focal Length of primary lens/mirror
1 Refractor 20cm 200cm, 2 Prime Focus Reflector 100cm 400cm ,3 Newtonian Reflector 50cm 250 cm ,4 Cassegrain Reflector 40 cm 300 cm
3. Briefly discuss a discovery made in astronomy as a result of an astronomer being able to:
a) measure precise positions of celestial objects.
b) measure precise brightnesses of celestial objects.
c) precisely measure the spectra of celestial objects.
4. Compare and contrast the first four planets in order from the sun with the next four planets(5 through 8).
5. Breifly describe each of the following:
a) a meteor (b) a comet (c) a meterorite (d) a satellite (e) an asteriod
6. What observations and/or measurements would you have to make in order to determine each of the following:
(a) the circumference of the earth (b) the mass of the Earth (c) the temperature of the Sun
(d) the distance to the Sun (e) the luminosity of the Sun
7. Discuss the evidence for the fact that the universe is now believed to be dynamic and changing, as opposed to an earlier view that it was static and unchanging (the "immutability of the heavens").
Explanation / Answer
There is a lot of the implications this discovery has for science and scientific philosophy.Groping in the darkness, you stumble upon a book of damp matches. You strike one; it quickly flares, then fizzles out. Again, you try; again, a flash and fizzle. But in that moment,you realize that you can glimpse a bit of your surroundings.
The next match strike lets you sense faint walls far
away. Another flare reveals a strange shadow, suggesting the
presence of a big object. Yet another suggests you are moving—or,
instead, the room is moving relative to you. With
each momentary flare, a bit more is learned
In some sense, this situation recalls our puzzling predicament
on Earth. Today, as we have done for centuries, we gaze
into the night sky from our planetary platform and wonder
where we are in this cavernous cosmos. Flecks of light provide
some clues about great objects in space. And what we
do discern about their motions and apparent shadows tells us
that there is much more that we cannot yet see.
Astronomers currently study dark matter by its effects on the bright matter
that we do observe. For instance, when we watch a nearby
star wobbling predictably, we infer from calculations that a
“dark planet” orbits around it. Applying similar principles to
spiral galaxies, we infer dark matter’s presence because it accounts
for the otherwise inexplicable motions of stars within
those galaxies
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