Chapter 1 Physics Outline

Daniel Sims physics Chapter 1 notes 1. What is physics a) Albert Einstein and Stephen hawking are two famous physicists b) Physics uses math as it's primary language c) Many inventions made with the aid of physics • atomic bombs • computer chips • Graphite-epoxy materials used in guitars and golf clubs • CDs • Computer games • Movie recording and playback • Lasers d) There are physicists in everywhere • Men and women who work at universities • at two-year colleges • high-schools • industrial and government labs • hospitals • wall street 1.2.Physics: the search for understanding a) Physics – a branch of knowledge that involves the study of the physical world. • The study of objects can range from subatomic particles to the universe • they study matter and energy and their relation to each other • They ask questions about what they see • to answer these questions they will make observations, do experiments, and create models or theories • This questioning leads to descriptions for many phenomena and various predictions • This leads to a better understanding of the universe • Some of their work only other physicists will care about however, some of there work changes our daily life like the invention of the computer b) The wanderers: mars • Mars is among the brightest plants in the night sky. • Ancient people observed celestial objects in order to define time of year and help in travel. • Mars is one of the five “wanderers” • the “wanderers” generally followed an eastern course through the constellations, yet, unlike the stars, they also moved westward for periods of time. • The deep red color of mars cause the Babylonians to associated it with disaster and the romans to name it after their god of war • Records of the motions of mars help develop the early concepts of the solar system. c) Are the stars and planets like the earth? • 2500 years again Greek philosophers tried to determine what the world was made of by making observations of everyday occurrences • believed that all matter on or near earth was made up for four elements: earth, water, air, fire

each element thought to have it's place by it's heaviness the order of the four elements follow • fire • air • water • earth • Motion was thought to occur because an element traveled in straight line towards its own natural place • Since the motion of the celestial objects did not fit the Greek belief, the Greeks added a fifth element called quintessence • In the twelfth century the writings made their way to europe and accept as truth • this theory remained unchallenged until Galileo Galilei d) Galileo and scientific Methods • in 1609 built a telescope • he found that the moon was not a perfect sphere but had mountains • he could find the height of these mountains buy the shadow they casted • found four moons circling the planet Jupiter • found that the milky way was made of far more stars then anyone thought before • As a result he argued that earth and the other plants actually circled the sun • As he studied he formed a systematic method of observing, experimenting, analyzing called the scientific method • Rather then writing his result in Latin, the language of scholars he wrote them in native Italian so that any educated person could read and understand • Considered to be the father of modern experiment • The scientific method used every since • knowledge, skill, luck, imagination, trail and error, educated guesses, and great patience all play a part. e) Mars in recent times • people found mars to look much like earth • astronomers found what appeared to be vegetation cycles similar to earth's seasons and dark areas believed to be seas • Strange marking on the surface of mars were misinterpreted as being channels or canals possibly made by intelligent beings • this interpretation became so prevalent that a 1938 radio drama depicting a Martian invasion of earth causing widespread panic in the US • Rockets capable of reaching out neighboring planet were developed in 1960s both the US and USSR sent probes to orbit mars to pictures and return data. • Mars trips in 1964 • US Mariner 4 – first photos from 1,898 to 9846 km above the surface • USSR Zond 2 – failed to send back data • Mars trips in 1969 • US mariner 6 – examination of Martian equatorial region from an altitude of 3430 km • US mariner 7 – examination of martian southern hemisphere and south polar ice cap from an altitude of 3430 • Mars trips in 1971 • USSR mars 2 – Martian orbit • USSR mars 3 – Lander on Martian surface •

US mariner 9 - photographs of entire Martian globe from orbit • Mars trips in 1973 • US mars 5 – Martian orbit • Mars trips in 1975 • US viking 1 – panoramic views and close-up photos from the Martian surface • US viking 2 – Automated experiment on the Martian surface • Mars trips in 1988 • USSR Phobos 2 – Martian orbit • Mars trip in 1993 • US mars observer – lost during mission • 1996 • US global surveyor – record of surface features, atmospheric data, and magnetic properties from Martian orbit • US mars pathfinder – Surface landing and release of a mobile vehicle to explore ares vallies • was surrounded by protective airbags, landed on mars on july 1997. • the mission cost less then the production of one hollywood movie. • A 10kg rover named sojourner, was released to explore nearby rocks • the exploration was broadcaster on the Internet • 1998 • US Mars surveyor orbiter – to map Martian surface and weather patterns and act as a communications satellite between landers rovers and earth • 1999 • US Mars surveyor lander – to land at the Martian south pole to sample and analyze the surface • 2001 and beyond • To replace communications relay satellited with new orbiters; to continue analyses of Martian atmosphere and surface with orbiters and landers • To return Martian rock and soil sample to earth b) Why study Mars? • Probes comfirmed that the climate is very different • Mars is an ideal laboratory for scientists interested in geology and atmospheric physics • from the study of mars scientists may learn more about the types of conditions that could lead to dramatic environmental change • these studies could tell us why mars grow so cold • Water was found to aid in any human exploration the search goes on to find the waters that were in the floods that shaped the surface of mars • if there is live on mars it would have to live without oxygen, store water for a long time, live underground from protection from radiation and temperature. c) Who will study mars • the mars exploration team made of of many members these members include • physics, chemists geologists and astronomers • technicaians • graphic designers • managers • they are all cretive curious interested in myseries and in solcing problems • they took science and math classes •

working as a team they were able to do more thus the reward was greater • the internet allows a student to look at the whole processes d) Is physics important • the mars mission was based on physics • rocket engines • gyoscopic directional controls • precision clocks • solar panel • nuclear power source • camers, computer radio, transmitters and receivers • science and technology is in constant interaction • some scitific results produce new tech • faster lighter computers • artificial limbs • all of the mars team members used problem solving • this skill allowed them to go on with the project in a perdicament • they also had team work skills • to make presentations to communicate what they have learned to coworkers, their friends and the general public • the goal of this course is to show the student the way physicists view the world and to give you an understanding of the physical world around you. • We will be prepared to answer these questions • how do we know • why do we believe it • what's the evidence for that •