The Scientific Revolution
State and describe Newton's three laws of motion.
1. An object in motion stays in motion and an object at rest stays at rest unless acted on by an unbalanced force. (A ball will continue to roll down a slope unless something stops it.)
2. Force equals mass times acceleration (You applying force to a basketball and a boulder will cause them to accelerate; however it requires more force to accelerate the boulder)
3. For every action there is an equal and opposite reaction. (If I lean on a wall, I exert an action force on it. The wall then exerts a reaction force back on me so I do not fall through it)
Name Aristotles 4 Causes and the question each one tries to answer.
Formal: What is is?
Material: What is it made of?
Efficient: Who/What made it?
Final: What is its purpose?
Name three physical effects of special relativity.
1. Time dilation: if you move fast, time passes more slowly for you
2. Length Contraction: if something moves faster, it will appear shorter
3. Simultaneity: two events may occur at the same time in one frame, but not in another (it is frame dependent)
Three physical effects of quantum mechanics
Three physical effects of quantum mechanics include the photoelectric effect, wave-particle duality causing electrons to interfere with themselves in double-slit experiments, and quantum tunneling.
Why did Galileo catch so much trouble for espousing heliocentrism while earlier proponents did not?
Galileo spoke against the Pope in his writings about heliocentrism and was therefore the target of the Catholic Chruch.
Who modified the telescope for astronomical uses?
Newton
What effect relating to Earth's orbit did the Greeks predict, yet fail to observe? Why was this good evidence for geocentrism?
The predicted but failed to observe stellar parallax.
This was good evidence for geocentrism because it seemingly proved that the Earth was not moving because there was no observable proof that it was.
The two postulates of special relativity
1. Physics works the same in all inertial frames of reference
2. The speed of light in a vacuum is the same for all inertial observers
Three physical effects of general relativity
1. Gravity is not a "real" force.
2. Gravitational Lensing
3. Gravitational time dilation
Who proposed elliptical planetary orbits? Why was this a controversial proposal?
Kepler. This was controversial because many held the idea that the heavens needed to be perfect and therefore must be in perfect circles. If orbits were not perfect circles, this would contradict the idea that the heavens were perfect.
Galileo observed the phases of ______, which meant ______ orbited ___ ____ and not _______.
Venus; Venus; the Sun; Earth
Name four ancient uses of Astronomy.
1. To predict the seasons for agriculture
2. To aid in navigation
3. For religious and ceremonial purposes
4. To keep track of time
What is a photon?
A photon has no mass, moves at the speed of light, and exhibits both wave-like and particle-like properties. Einstein used them to explain the photoelectric effect.
According to general relativity, which two frames are identical?
There is no observable difference between an accelerating frame and a frame in a gravitational field.
If I race a turtle, who is going to win?
Me you fools. A tortoise would beat me, but I am absolutely crushing that turtle.
Daily Double
Based on Newton's Law of Gravitation, what would happen to the gravitational field on Earth is our planet suddenly shrunk to 1/3 of the current radius, but the mass remained constant?
It would multiply 9 times
What are epicycles and why were they introduced?
Epicycles refer to small circles a planet makes in its larger circular orbit. They were introduced to explain planetary retrograde.
What is tunneling?
Tunneling refers to a particle spontaneously appearing on the opposite side of a barrier despite not traveling through the barrier.
If Alice and Bob are twins, and Bob travels to deep space at very high speeds and the returns to earth, will Alice and Bob be the same age? If not, who will be younger? Why?
Alice and Bob will not be the same age. Alice will think Bob is younger and Bob will think Alice is younger. Alice is correct, Bob is younger. This is because Bob's frame is not inertial and is therefore less valid than Alice's inertial frame.
Give an example of natural selection affecting the characteristics of a species.
The finches in the Galapagos are an excellent example. The finches on the island with nuts all tended to have larger beaks. This is because these beaks were well equipped to break open nuts, which was necessary for survival on this island. The birds that had small beaks and could not open the nuts to get food, died out and did not reproduce, therefore the small-beaked finches were not as commonly found on the island with nuts as the primary food source.
Why is Galileo's modification of the telescope important for history?
It allowed him to adequately observe space, which led to the realization that the Earth is not the center of the universe or our solar system once and for all.
What was science typically referred to as?
Natural Philosphy
Why is it unlikely you will tunnel through a wall?
As the size of an object increases, the likelihood of tunneling decreases.
How did Einstein use photons to explain the photoelectric effect?
He did this by explaining that the light waves that bounce off the metal also act like particles. This means that all of a photon's energy is thrust into the electron causing it to be ejected from the photon, creating the photoelectric effect.
Who is most often credited with proposing heliocentrism? How was his book received by the church?
Copernicus. Despite the fact that he waited until the year he passed away to publish his book for fear of being berated by the church, the church had no significant problem with his book and willingly accepted it.