Module 2A Flashcards
Scientific Method
empirical method for acquiring knowledge
The scientific method consists of two parts:
The experimental method (doing experiments), and
The protocol (advisory principles needed to do science).
experiment
logical procedure that attempts to prove or disprove an
hypothesis, directly or indirectly. It uses qualitative and quantitative
observations. It must be repeatable.
A measurement is
quantitative observation.
Galileo’s Law of Falling Bodies,
excluding aerodynamic factors, objects of dissimilar mass,
released from the same height off the ground, will hit the
ground at the same time.
Physics is not like
math.
hypothesis.
scientifically vetted, tentative explanation of a physical phenomenon
A scientific theory
is a proven hypothesis. It is a fact
physical law or physical principle.
A scientific theory of general applicability
conserved physical quantities.
is one that can neither be created nor destroyed.
Its amount (within a closed system under observation) is fixed.
Mass is
conserved (classically speaking).
Energy is
conserved (classically speaking).
Charge is
conserved.
Linear Momentum
conserved (for isolated systems).
Angular Momentum is.
conserved (for isolated systems).
Noether’s theorem
For every symmetry seen in nature, there is a corresponding conserved physical quantity (and vice-versa).
principal physical conclusion of rotational symmetry.
If after a rotation, an object looks the same, its physics is the same.
advisory principles
does not carry the weight of a real physical law, but nevertheless, by dint of its repeated value and use, implies strongly that the “advice” it confers should be heeded.
Occam’s Principle.
Whenever there are two competing hypotheses, chances are the simpler of the two is the correct one.
Principle of Falsifiability
In order for an hypothesis to be considered scientific, it must be possible to show it is false, if in fact it is false.
heliocentric mode
the Sun was the center of the solar system, and that the Earth was the third planet orbiting the Sun,
geocentric model
the Earth was the center of the solar system, and the Sun, Moon, and the planets orbited Earth.
prograde motion),
West to east
retrograde motion).
east to west
Planetary retrograde motion
is thus all an illusion.
zodiacal constellations,
The constellations that the Sun “passes through” on its yearly journey around Earth
