Science, Computing and Society Computer Science 129 Science, Computing and Society

GRE/GMAT WORDS Corroborate – to confirm Ephemeral – lasting a short time Laconic – using few words Mitigate – to make less severe

The Scientific Method Wikipedia Definition: Scientific method is a body of techniques for investigating phenomena and acquiring new knowledge, as well as for correcting and integrating previous knowledge. It is based on gathering observable, empirical, measurable evidence, subject to the principles of reasoning

Steps in the Scientific Method Define the question Gather information and resources Form hypothesis Perform experiment and collect data Analyze data Interpret data and draw conclusions that serve as a starting point for new hypotheses Publish results Steps 3 – 6 are iterative (repeating)

Scientific Method What are we hoping to get from using the Scientific Method? INFORMATION!

CHAPTER 0 - INTRODUCTION WHAT IS INFORMATION? WHAT IS A BIT? BINARY DIGIT LIKE BASE TEN HAS 0-9, BINARY DIGITS USE 2 NUMBERS, 0 AND 1 BIT = INFORMATION

CHAPTER 0 - INTRODUCTION ANY CHOICE FROM TWO EQUALLY LIKELY POSSIBILITIES IS A BIT LIGHT SWITCH HANDS ON A CLOCK TURNING CLOCKWISE OR COUNTERCLOCKWISE COIN TOSS COMPUTERS TRANSLATE THESE INTO 0 OR 1, OR A BIT

CHAPTER 0 - INTRODUCTION INFORMATION IS THE SUBSTANCE FROM WHICH ALL THINGS ARE MADE QUANTUM PHYSICS HELPS US TO UNDERSTAND THE RELATIONSHIP BETWEEN INFORMATION AND EXISTENCE

CHAPTER 0 - INTRODUCTION QUANTUM MECHANICS DEPARTS FROM CLASSICAL PHYSICS

CHAPTER 0 - INTRODUCTION Classical physics is physics based on principles developed before the rise of quantum theory. (In contrast, modern physics refers to the physicist's world view wrought by the revolutionary quantum theory.) A physical system on the classical level is a physical system in which the laws of classical physics are valid.

CHAPTER 0 - INTRODUCTION Among the branches of theory included in classical physics are: Classical mechanics Newton's laws of motion Object at rest remains at rest unless force applied Change of momentum is equal to the force applied For every action there is an equal and opposite action Classical electrodynamics (Maxwell's Equations) Classical thermodynamics 1st Conservation of energy 2nd Entropy (chaos) Special theory of relativity and General theory of relativity (gravity)

CHAPTER 0 - INTRODUCTION QUANTUM PHYSICS IS VERY DIFFERENT FROM CLASSICAL PHYSICS ATOMS DO NOT OBEY NEWTONS LAWS MORE LIKE ALICE IN WONDERLAND ELECTRONS – IN LARGE SCHEME THEY HAVE A DEFINED LOCATION ELECTRON IN SUBATOMIC WORLD THEY ARE NOT IN ANYPLACE AT ONCE BUT SMEARED

CHAPTER 0 - INTRODUCTION ELECTRONS CAN JUMP THROUGH OBJECTS (BASEBALL THROWN AT WALL BOUNCES – ELECTRON COULD BOUNCE OR SHOW UP ON OTHER SIDE – CALLED TUNNELING – USED IN TRANSISTORS AND ALL ELECTRONICS)

CHAPTER 0 - INTRODUCTION ELECTRONS BEHAVE SOMETIMES LIKE PARTICLES, SOMETIMES LIKE WAVES LIGHT THOUGHT TO TRAVEL IN WAVES, SOMETIMES SEEMS TO BE A STREAM OF PARTICLES

CHAPTER 0 - INTRODUCTION TO ILLUSTRATE THIS STRANGE BEHAVIOR WE WILL LOOK AT THE DOUBLE SLIT EXPERIMENT. http://www.youtube.com/watch?v=DfPeprQ7oGc WATCH THE ABOVE VIDEO – THERE WILL BE QUESTIONS ON THE MIDTERM FROM THIS 5 MINUTE VIDEO

CHAPTER 0 - INTRODUCTION REMEMBER IN MATH THAT IF THE TOP OF TWO WAVES IN THIS EXAMPLE ARE ADDED YOU GET (+1) + (+1) =+2, IF THE TOP OF ONE IS ADDED TO THE BOTTOM THEY CANCEL EACHOTHER OUT (+1) + (-1)=0

CHAPTER 0 - INTRODUCTION MARBLES THROUGH A SINGLE SLIT = SINGLE LINE MARBLES THROUGH A DOUBLE SLIT = DOUBLE LINE

CHAPTER 0 - INTRODUCTION WAVE THROUGH SINGLE SLIT = MORE INTENSITY IN A SINGLE LINE WAVE THROUGH DOUBLE SLIT = INTERFERENCE PATTERN OF MANY BANDS

CHAPTER 0 - INTRODUCTION ELECTRONS THROUGH A SINGLE SLIT = SINGLE LINE ELECTRONS THROUGH A DOUBLE SLIT WITH NO OBSERVER= INTERFERENCE PATTERN ELECTRONS THROUGH A DOUBLE SLIT WITH AN OBSERVER = DOUBLE LINES (CREEPY!)