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 Universe
 Ptolemy

Look to the Stars
 Astrology
 Calendars (Mayan, Aztec, Druids)

Emergence of Modern Astronomy
 Copernicus
Mechanistic Universe

Kepler

Galileo

The Telescope

Heresy
Motion

Mass (m)
F=ma

Speed (s)

Velocity (v)

Acceleration (a)

Force (F)
Universal Laws of Motion

Isaac Newton

Newton’s Laws of Motion
“If I have seen far, it is by standing on the shoulders of giants”
-- Sir Isaac Newton

What is space?
 – the bucket problem (absolute space)
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.