Gravity and the Rise of Modern Astronomy Flashcards
Whose model was supported by the church on 1609?
Ptolemy
What was Galileo the first to do?
To direct a telescope to the night sky and report the results.
What did Galileo discover?
Saw the mountains and craters on the moon.
The four moons of Jupiter.
Sunspots
Thousands more stars
Observed a complete set of phases of Venus
What was Newton’s concept of universal Gravitation?
They is an attractive force between all masses.
What did Newton design?
The first useful reflecting telescope.
What did Newton discover?
That white light could be spread out into its spectral components.
What is an Orrerie?
A clockwork model the solar system.
What is Newton’s first law?
In an inertial frame of reference, an object will maintain its velocity unless acted upon by a force.
What is Newton’s second law?
A force on a body accelerates it, the acceleration being inversely proportional to the body’s mass. F=ma
What is Newton’s third law?
If something exerts a force on a body, the body exerts a force back, an equal and opposite force.
What is proportional to the force of attraction between two masses m1 and m2?
Proportional to the product of the masses and the inverse square of the distance d between them.
What does Gravity control?
Not only the solar system but the large scale structure of the universe: Universal gravity.
How does Earth’s gravity compare the the gravity in the rest of the Solar system?
It has the strongest gravity of anywhere you could stand in the solar system.
What is a tide?
A distortion in the shape of one body induced by the gravitational pull of another nearby object.
What is a tidal force?
A force that varies in strength and/or direction over an object causing it to deform
What is the underlying cause of our tides?
Attraction of the sun and the moon on the Earth varies over the Earth, it is the difference of attraction that raises the tides.
Why does the tidal bulge move around the Earth?
Because the Earth rotates on its axis and relative to the Earth, the Sun and moon move around.
What are the consequences of the double tidal bulge?
Because of the rotation of the Earth and the friction between the water and land, the tidal bulge occurs ahead of the direct line to the moon.
hat is the total tide a sum of?
The sum of the moon tide and the sun tide.
What happens at Spring tides?
Forces add
What happens at Neap tides?
Forces partially add
What cause the Spring and Neap tides?
The tidal component caused by the sun.
What is the consequence of the precession of the Earth’s axis?
The pole star changes
What varies because the precession of the Earth’s axis?
The equator tilt
