Dr. Hoge

NS 1300 – Spring 2010

Is the Big Bang in trouble? The Big Bang is the unifying theory of cosmology,

right?

But, we are finding that the Big Bang theory cannot answer all of the questions we have.

So, we need a new theory.

What does this mean, and why such a fuss?

What are the questions the Big Bang can’t answer?

The Ordered Universe

Earth as the Center of the UniversePtolemy

Look to the StarsAstrologyCalendars (Mayan, Aztec, Druids)

Emergence of Modern AstronomyCopernicus

Mechanistic Universe

Kepler

Galileo

The Telescope

Heresy

Motion Mass (m)

Speed (s)

Velocity (v)

Acceleration (a)

Force (F)

F=ma

Universal Laws of Motion

Isaac Newton

Newton’s Laws of Motion

What is space? – the bucket problem (absolute space)

“If I have seen far, it is by standing on the shoulders of giants”-- Sir Isaac Newton

Space-Time d = vt

d is distance

(displacement is different from distance)

v is velocity

t is time

Speed is change in distance over time (magnitude)

Velocity is speed plus direction (vector)

(scale is important)

Newton’s 1st Law – Law of Inertia A moving object will continue moving in a straight

line at a constant speed, and a stationary object will remain at rest, unless acted on by an unbalanced force.

A motorist wishes to travel 40 kilometers at an average speed of 40 km/hr. During the first 20 km, an average speed of 40 km/hr is maintained. During the next 10 km, however, the motorist goofs off and averages only 20 km/hr. To drive the last 10 km and average 40 km/hr, the motorist must drive:

a) 60 km/hr c) 90 km/hr

b) 80 km/hr d) faster than light

Newton’s 2nd Law The acceleration produced on a body by a

force is proportional to the magnitude of the force and inversely proportional to the mass of the object.

A force is a push or a pull

F = ma

Newton’s 3rd Law For every action there is an equal and

opposite reaction.

Friction

Gravity○ FG = M1 X M2 / d2

○ Center of gravity?

Projectile Motion It’s not rocket

science,oh wait, yes it is

Momentum

P = mv

Linear Momentum

Angular Momentum

Conservation of Momentum

Gravity

Newton’s Gravity

Einstein’s Gravity

Wherefore Art Thou, Gravity? General Relativity

Gravitational Field

Quantum Gravity

Graviton

Can String Theory Unite Them?

Is Superman Possible? Cartoon Laws of Physics

Roller Coaster Physics

The Physics of Baseball

NASCAR Physics

Physics of Martial Arts

Movie Physics

Physics of Superheroes

Quiz 1. T or F, force equals mass times velocity.

2. T or F, momentum equals mass times acceleration.

3. T or F, gravity is an example of Newton’s 3rd law.

4. If I say the force of gravity pulling on you is the force, what is the reaction force?

5. T or F, gravity is nothing more than the acceleration of

spacetime.