Transcript What is Physics? - Tri-City

What is Physics?
Chapter 1
Pg.5-13
The Search for Understanding
 Physics – branch of knowledge that involves that
involves the study of the physical world.
 It studies a variety of things from the atom and
subatomic particles to the universe
 The important part of any science is questioning
and investigation.
 Why??
 Best question you can ask in any area.
 Has led to a number of useful discoveries
 Atomic bomb, computer chips, golf clubs, etc.
The Wanderers
 Observations made about the ancient night sky:
 5 very bright objects
 Follow set patterns of movement across the night
sky throughout the year.
 Used to map out time and seasons.
 Seem to move westward for a period of time, then
move back eastward
 What are they??
Early Science
 Around 2500 years ago, people were
making observations of the earth, sun, moon
, and other celestial bodies and trying to
figure out what they were. What they were
made of.
 Matter was thought to have four elements:
earth, water, air, fire.
 We know this is not true now, combine those
our and all we get is this guy 
 Motion was only straight line motion;
elements moved toward their actual place.
Early Science
 People observed the “wanderers” did not follow
this set pattern.
 Observations showed them to be perfect
spheres and that they circled earth forever.
 This meant they could not be made of the four
basic elements; a 5th element was added
“quintessence.
 Up to this point there was no set way to observe
and experiment
Galileo Galilei: “the father of modern experimentation
 Italian astronomer
 Developed first telescope
 First guy to really use “scientific
method”
 Discovered:
 Planets has orbital moons
 Moons had surface features
 Multiple stars
 Galileo argued that the planets
circled the sun vs the common
belief that the Earth was the
center of the universe.
Mars “the wanderer”
 Mars is interesting because it looks a lot like Earth.
 Once thought to have ice caps, rivers, lakes, a
viable atmosphere, and even channels (made
by intelligent life)
 War of the Worlds by Wells
 Book about a Martian invasion, read on the radio,
people freaked out.
 Colonization of mars?
Colonization of Mars?
 Well the truth is that Mars would be hard to colonize,
virtually impossible
 It is a dead planet
 Anything thought to be water only exists in small amounts
 The average temperature ranges from 30 to -140 degrees
 There is no atmosphere
 And for the bargain price of $250,000 you can buy a ticket
on the Virgin Mobile space shuttle to Mars……..oh yeah it’s
a one way flight