1. Last week: Temperature
Definition:
-Temperature is a measure for hotness and coldness and can be felt or measured with a thermometer.
-Temperature measures how fast the molecules in a material are moving

2. weight force on three masses
Context: How much sugar do you put in your coffee? How hard do I have to push to move a car? What is the weight gallon of water, a gallon of air, or a gallon of helium?
Definitions:
- Mass is the amount of matter in an object, i.e. its energy content (nuclear).
Inertial mass is sluggishness of an object, its resistance to acceleration.
Gravitational mass is proportional to the weight of an object, the gravitational pull on the object.
Discussion: (1) experimental observation: Inertial mass = Gravitational mass = Mass
The U.S. National Prototype Kilogram, which currently serves as the primary standard for measuring mass in the U.S.
Lecture demos:
sluggishness,
weight force on three masses

3. weight force = mass * gravity
Discussion continued …
2) Measuring mass: With a scale or balance.
Units of mass: kg
Units of weight force: lbs or Newton
Mass of an object on the Moon =
Mass of the object on earth =
Mass of the object anywhere in the universe
i.e. its sluggishness is the same everywhere.
However the weight force is different since
Gravity of earth: g = 9.8 m/s2
Gravity on the moon = (1/6) gravity on earth
Therefore: Weight force is the same everywhere on earth, but
Weight force on the moon = (1/6) weight force on earth
weight force = mass * gravity
W = m g

4. Beam stays horizontal if: Left mass * left distance =
Discussion continued …
2) Measuring mass: With a balance.
Lecture demo:
Masses suspended from a balanced beam –
50gram , 20cm to the left of the center
balances 20gram, 50cm to the right
Beam stays horizontal if:
Left mass * left distance =
Right mass * right distance
Lecture demo:
Triple beam balance

5. Energy = mass * (speed of light) 2
Discussion continued …
3) Creating and destroying matter (mass)
Energy (light) -> matter + antimatter
-> energy (light + heat)
High-energy cosmic rays impacting Earth's atmosphere (or any other matter in the solar
system) produce minute quantities of matter and antimatter, such as an electron – positron pair.
A positron has the same weight as an electron, but
is made of anti-matter and
has the opposite charge.
Nuclear reactors and nuclear bombs convert
matter into energy.
Energy = mass * (speed of light) 2
E= m c 2
Evidence for antimatter in a bubble chamber photo (Fermilab). The magnetic field in this chamber makes negative particles curl left and positive particles curl right. Many electron-positron pairs appear as if from nowhere, but are in fact from photons, which don't leave a trail. Positrons (anti-electrons) behave just like the electrons but curl in the opposite way because they have the opposite charge. Lecture demo

6. Discussion continued …
4) A model for the creation and destruction
of matter:
The soliton machine
= an array of pendulums on an elastic string Lecture demo
Small regular waves represent heat, light, X-rays.
Full left twist (solitons) represents matter.
Full right twist (antisoliton) represents antimatter.
A soliton can not be created by itself, the creation of a soliton always requires the creation of an anti-soliton, like matter can not created by itself. The creation of matter requires the creation of anti-matter.
Force between solitons is attractive, like gravity.
Why is there so little antimatter in our universe?

7. What, if the other universe is mostly antimatter?
Discussion continued …
5) When solitons hit the system boundary they turn into anti-solitons. So if matter hits the boundary of the universe, does it turn into antimatter?
Does the universe have a boundary? Can our universe collide with another universe?
What, if the other universe is mostly antimatter?

8. Discussion continued …
6) Benchmark masses
Mass of
- 1 quart of water ~ 1kg ~ 2 pounds on Earth
- a person ~ 70kg ~ 150 pounds on Earth
a car ~ 1000kg ~ 2000 pounds on Earth
More examples

9. Mass Definitions: Mass is the amount of matter
in an object, i.e. its total energy content
(nuclear + chemical + thermal energy).
E=m c2
Inertial mass is sluggishness
of an object, its resistance to acceleration.
F=m a (Newton’s 2nd law)
Gravitational mass is proportional
to the weight of an object,
the gravitational pull on the object.
W = m g
Inertial mass = Gravitational mass = Mass
The U.S. National Prototype Kilogram, which currently serves as the primary standard for measuring mass in the U.S.