26-30
King of Castille, Leon, and Galicia.
Funded a group of scholars to recalculate the positions of the planets - “If I had been present at the creation, I would have recommended a simpler design for the universe.”
Alphonso X the wise (1221-1284)
After Tycho’s death Kepler inherits
the data set and published them (Rudolphine Tables)
“Kepler’s First Law allows planets to move on orbits that are:”
A. Elliptical Epicycl.
B. Circular or elliptical.
C. ”Elliptical but not circular.
D. Circular but not elliptical.
B. Circular or elliptical.
By 1630 general acceptance of Kepler’s model, but no one knew why it worked. Newton invented calculus and explained many fundamental principles in physics with it.
Newton’s three laws of motion: new physical foundation for the universe.
Newton’s Universal Theory of Gravity: describes how gravity acts.
Isaac Newton (1642-1727)
If a deep space rocket suddenly stops its engine it will...
A. Decelerate.
B. Suddenly Accelerate.
C. Continue with same speed.
D. Very slowly decelerates until stops.
A. Decelerate.
B. Suddenly Accelerate.
C. Continue with same speed.
D. Very slowly decelerates until stops.
Cities develop and become wealthy from trade (Venice, Milan, Rome, Florence). Ambitious, wealthy merchants develop power and influence. “L’Umo Universale” - refined taste, knowledge of classics, history & philosophy, appreciation of art (music, painting, architecture, sculpture). Rich merchant families patronize art & sciences (Medici, Montefeltro, etc.).
The renaissance (14th-!7th century)
The orbit of each planet around the Sun is an ellipse with the Sun at one focus.
Kepler’s First Law
Question: Earth’s orbit: ellipse close to circular, 1.7% difference in closest and furthest distance from the Sun.
According to Kepler’s Second Law of Planetary Motion, a planet with an orbit like Earth’s would:
A. Move faster when further from the Sun.
B. Move faster when closer to the Sun
C. Experience a dramatic change in orbital speed from month to month.
D. Experience no change in orbital speed over the course of the year.
An object moves at constant velocity unless a net force acts to change its speed or direction.
Newton's First law of motion
If a spaceship ignites two rockets instead of one, it will accelerate:
A. Two times slower.
B. Two times fast.
C. At the same rate.
D. Four times faster
A. Two times slower.
B. Two times fast.
C. At the same rate.
D. Four times faster
Minor cleric working for the Catholic church. The tables of planet positions were becoming increasingly inaccurate Copernicus spent years studying different models of the Solar System’s layout. The model could be much simpler if the Sun was in the center, and Earth would just be one of the orbiting planets. Conceptually, this was a huge change. The new model was simpler, but not more accurate - the orbits were still circular.
The Copernican Revolution Begins Copernicus (1474-1543).
The planet sweeps out equal areas in equal times.
The areas swept out in 30-day periods are all equal.
Kepler’s Second Law:
Average distance between Earth and the Sun 1 AU = 1.49x10^8 km = 92.95 million miles = 8.32 light minutes
Astronomical Unit
Force = mass x acceleration
Newton's second law of motion
If Force is 2x greater,
but the mass is the same, the acceleration will be 2x greater.
Danish aristocrat and astronomer
Tycho Brache (1546 - 1601)
More distant planets orbit slower, following the relationship: P^2= Y^3.
P - orbital period [year].
a - semi-major axis [AU].
Kepler Third Law
Kepler’s Laws of planetary motion are based on detailed observations made by which astronomer?
A. Isaac Newton.
B. Tycho Brache.
C. Galileo Galilei.
D. Nicholas Copernicus.
B. Tycho Brache.
For any force, there is always an equal & opposite reaction force.
Newton's third law of motion
If Force is the same, but the mass is the two times greater, the acceleration will be...
expressed
Brache witnesses a dying star, proves the Greek idea of heavenly perfection and stability wrong. New Standard in Observational Data: Very accurate measurements (1/60 of 1 degree).
Uraniborg
What is an ellipse?
Aplane curve surrounding two focal points, such that for all points on the curve, the sum of the two distances to the focal points is a constant
Additional Important Argument
Discovery Moons of Jupiter Galileo discovers four moons orbiting Jupiter.
Aristotle said that every object naturally moves toward its resting place. Was he right and which of Newton’s Law Addresses this?
A. Yes - Newton’s 1st law.
B. No - Newton’s 1st l.
C. Yes - Newton’s 2nd Law.
D. No - Newton’s 2nd law.
Aristotle said that every object naturally moves toward its resting place. Was he right and which of Newton’s Law Addresses this?
Tells us the strength of the gravitational attraction between the 2 objects.
Universal Law of Gravitation