Sky, History, Light & Matter - Study Guide
- What do we absolutely know for certain?
- How do sciences operate and evolve?
- What is the most important characteristic of a scientific theory,
distinguishing it from other kinds of theories?
- What is the cause of the most basic and obvious changes in the
appearance of celestial objects?
- If you are stuck on Earth, how can you tell the Earth is rotating?
- Why does the amount of daylight change throughout the year?
- Why do we see different stars at night at different times of the year?
- What is the celestial sphere, what are its features, and why is it useful?
- What is the source of and relationship between our time divisions?
- Which of our largest time divisions (year, month, week, day) is not
"natural," that is, not based on some orbital/rotational characteristic?
- What causes the Earth's seasons?
- What are solstices and equinoxes?
- What is precession and what are its effects?
- Why do planets sometimes appear to have retrograde motion?
- If the Earth's rotation was not tilted relative to the Sun, what would be the consquences?
- What causes the Moon to appear in phases?
- When can we see particular phases of the Moon?
- How much of the Moon can we see from Earth?
- Does the Moon rotate?
- What causes lunar and solar eclipses?
- What phase must the moon be in for a lunar eclipse to occur? ...for a Solar eclipse?
- Why or why not do solar and lunar eclipses occur each once a month?
- Which kind of eclipse do we see most often? Why?
- What causes tides on Earth? Where?
- When are tides strongest and weakest?
- What are tides on Earth doing to the Earth's rotation and to
the Moon's orbit around us?
- What did ancient Greeks and pre-Renaissance Europeans believe
about how the Earth is situated in the Universe? Why?
- How did ancient Greek astronomers explain the motions of celestial objects?
- How did ancient Greek astronomers explain retrograde motion?
- What caused the switch from a geocentric to a heliocentric view of the Universe?
- How did Aristotle's notion of natural movement for earthly
elements compare to our current notion of inertia?
- Which ancient Greek believed that the Earth revolves around
the Sun, rather than the Sun around the Earth? Why?
- Which ancient Greek accurately determined the size of the Earth?
- Which ancient Greek used epicycles to tune a fairly accurate
geocentric model of the Universe?
- What prediction did the Ptolemeic system make for the phases of Venus?
- Copernicus likely got his heliocentric idea from reading about which ancient Greek?
- What prediction did the Copernican system make for the phases of Venus?
- Was Copernicus' heliocentric model of the Solar System more accurate
than the contemporaneous descendant of Ptolemy's geocentric model?
- On what basis might you have chosen Copernicus' heliocentric model
over Ptolemy's geocentric model for the motions of the planets and the Sun?
- Why was the shift away from a geocentric Universe so profound?
- How was Brahe able to compile the most accurate (up to that time)
positions of astronomical objects?
- Even though Brahe had the most accurate astronomical data,
why did he still believe the Earth was at rest?
- Who used Brahe's accurate planetary positions to make a very
accurate heliocentric model of the Solar System?
- What was the physical basis of Kepler's planetary orbital laws?
- What kind of orbits do planets have about the Sun?
- How do planetary orbital velocities change during their orbits around the Sun?
- How do planetary orbital periods vary with their average distance from the Sun?
- How did Galileo's Law of Inertia differ from Aristotle's?
- What observational discoveries of Galileo could have been used
to kill off the Ptolemeic geocentric picture?
- What do the phases of Venus look like from Earth?
- What do the phases of Venus tell you about the Ptolemeic vs Copernican systems?
- What are Kepler's three Laws of planetary orbits?
- What are Newton's three Laws of motion?
- What is the relationship between Kepler's Laws and Newton's Laws?
- What is the difference between weight and mass?
- Can something with mass be weightless? How or why not?
- Can an object with mass be weightless while under the influence of gravity?
- Do the physical laws that apply on Earth apply elsewhere?
- What does the force of gravity depend on?
- How does your acceleration in response to a gravitational force differ
from your acceleration in response to other kinds of forces?
(recall Leaning Tower vs. struggling with piano on ice rink)
- What are various kinds of energy?
Light & Matter
- What is light?
- What are the wave-like behaviors of light?
- What are the particle-like properties of light?
- How does the energy of light relate to other properties of light?
- How does the energy of an X-ray compare to that of a radio wave/photon?
- Does light have mass?
- What do E, m and c correspond to in E=mc2?
- What does E=mc2 mean when applied to light?
- Does light respond to gravity?
- How do we get most of our information from the Universe?
- How do we use light to learn about the Universe?
- What are the three kinds of light spectra?
- How does light interact with "normal" matter?
- What kind of radiation spectrum is emitted by a hot solid? A hot, diffuse gas?
- Where do spectral lines come from?
- Can a naked (fully ionized) atomic nucleus emit emission lines?
- How do emission line spectra tell us about the (quantized) structure of atoms?
- How can light spectra tell us what kinds of elements are interacting
with the light we are seeing?
- Is the speed of light the ultimate speed limit?
- How does the speed of light in space/vacuum depend on light's frequency/wavelength?
- What are molecules made up of?
- What are atoms made up of?
- What are protons and neutrons made of?
- How do protons, neutrons, atomic nuclei, atoms and molecules stay put together?
- What determines the chemical (electrical) properties of atoms?
- How do atoms (and molecules) absorb and give off energy?
- What force(s) hold together a grain of sand, chairs, people, the Earth,
the Moon to the Earth, the Earth to the Sun ...
- What particles are considered fundamental, that is, not made up of even more
- Where is the vast majority of the mass in normal matter?
- How solid is an atom?
- Why is our sky blue?
- How does our blue sky relate to the red/orange Sun, Moon, and clouds on the
horizon? (at sunrise, sunset, moonrise, moonset)
- How does the thermal radiation from an object change when you heat it?
(What are the Stefan-Boltzmann and Wien Laws?)
- Of the three kinds of spectrum, what kind is a thermal spectrum?
- How can we use light to determine whether a light source is moving or not?
- How and why does the brightness of something decrease with increasing distance?
- Why do astronomers want telescopes to be large? There are two main reasons.
- What is the difference between refracting and reflecting telescopes?
- Why are some telescopes sent into space as satellites?