"Annenberg Media" "¶" "AT THIS POINT," "WE'VE LEARNED A LOT ABOUT ELECTRICITY." "WE KNOW ABOUT FORCES AND CHARGES AND VOLTAGES" "AND ELECTRIC CURRENTS AND SO ON," "AND THE QUESTION ARISES, WHAT'S ALL THAT ABOUT?" "WHAT'S REALLY IMPORTANT ABOUT ALL THAT STUFF?" "LET ME GIVE YOU AN EXAMPLE." "REMEMBER VAN MARUM'S GIANT MACHINE" "THAT WAS MADE AT THE END OF THE 18th CENTURY." "IT COULD DEVELOP A VOLTAGE OF 100,000 VOLTS." "IT USED A BANK OF 100 LEIDEN JARS" "TO STORE ENERGY IN," "AND IT COULD STORE 2,000 JOULES OF ENERGY." "AND SO THE QUESTION IS, IS THAT IMPRESSIVE?" "AND THE ANSWER IS REALLY NO." "2,000 JOULES OF ENERGY" "IS ABOUT 1/2 OF 1 FOOD CALORIE," "OR TO PUT IT IN PURELY ELECTRICAL TERMS," "THIS LITTLE 9-VOLT TRANSISTOR RADIO BATTERY" "CAN STORE 10 TIMES AS MUCH ELECTRICAL ENERGY" "AS VAN MARUM'S BANK OF 100 LEIDEN JARS," "AND YET, THAT MACHINE COULD HURL A LIGHTNING BOLT" "A DISTANCE OF 2 FEET," "AND THE BATTERY CERTAINLY CAN'T DO THAT." "AND SO THE QUESTION IS, WHAT REALLY IS IMPORTANT?" "VOLTAGE, OR ELECTRIC POTENTIAL," "IS A MEASURE OF THE POTENTIAL ENERGY OF AN ELECTRIC CHARGE" "SUCH AS, FOR EXAMPLE," "THE ELECTRONS THAT MAKE UP THE ATOMS IN YOUR BODY." "YOU MIGHT ASK THE QUESTION," "WHAT IS THE POTENTIAL BINDING ELECTRONS TO YOUR BODY?" "IT BETTER BE MUCH MORE THAN I CAN DEVELOP WITH THAT MACHINE" "BECAUSE IF IT ISN'T," "THE MACHINE WOULD BE DEVASTATINGLY DANGEROUS." "IT COULD RIP US TO SHREDS." "SO, ARE ELECTRONS BOUND TO YOUR BODY" "MUCH MORE STRONGLY" "THAN I CAN DEVELOP A POTENTIAL WITH THAT MACHINE?" "THE ANSWER IS NO." "THE BINDING POTENTIAL OF AN ELECTRON IN YOUR BODY" "IS ONLY 3, 4, 5 VOLTS." "I CAN DEVELOP 100,000 VOLTS WITH THAT MACHINE." "ONCE AGAIN, WE'RE LEFT WITH CONFUSION" "ABOUT WHAT'S IMPORTANT IN ELECTRICITY." "THE BASIC ELEMENTS OF ELECTRICITY ARE VERY SIMPLE." "IF I CAN IMAGINE POINT ELECTRICAL CHARGES" "IN A VACUUM," "THEN THERE ARE POSITIVE CHARGES AND NEGATIVE CHARGES," "AND THEY ATTRACT OR REPEL EACH OTHER" "WITH A FORCE THAT VARIES INVERSELY" "AS THE SQUARE OF THE DISTANCE BETWEEN THEM." "THAT'S ALL IT IS," "AND YET IT TOOK THOUSANDS OF YEARS" "TO FIGURE THAT OUT." "EVEN TODAY, WHEN WE UNDERSTAND IT WELL," "IT'S STILL CONFUSING TO LEARN." "THE REASON THAT'S TRUE" "IS BECAUSE THESE ELEMENTS OF ELECTRICITY," "POINT CHARGES IN A VACUUM," "NEVER EXIST IN THE REAL WORLD." "ELECTRICITY ALWAYS EXISTS IN MATTER," "AND SO IN ORDER TO UNDERSTAND ELECTRICITY," "WE MUST FIRST UNDERSTAND MATTER." "BUT MATTER IS ESSENTIALLY ELECTRICAL IN NATURE," "AND SO IN ORDER TO UNDERSTAND MATTER," "WE MUST FIRST UNDERSTAND ELECTRICITY," "AND THAT'S THE CRUX OF THE DILEMMA" "THAT WE WANT TO SPEAK ABOUT TODAY." "AT FIRST GLANCE," "TRYING TO SEE ELECTRICITY IN ITS TRUE LIGHT" "SEEMS AS RISKY AS A NIGHT OUT ON THE LAS VEGAS STRIP." "ELECTRICITY HAS NUMEROUS QUANTITIES" "CHARGE, POTENTIAL, AND FIELD, TO NAME A FEW" "AND WITH SUCH A BEWILDERING VARIETY," "IT'S HARD TO KNOW WHICH QUANTITY TO BET ON." "WHAT'S NEEDED IS A WAY TO EXPLAIN" "HOW EVERYTHING FITS TOGETHER," "A WAY TO STACK THE DECK" "IN FAVOR OF GOOD SENSE AND CLARITY." "WHAT'S NEEDED IS A SURE-FIRE METHOD BEHIND THIS MADNESS," "THE CAUSE BEHIND THE EFFECT, OF ELECTRICITY." "WHAT'S NEEDED IS A CHANGE OF SCENE." "ON THE SURFACE, THE ELECTRICAL CONNECTION" "BETWEEN LAS VEGAS AND THESE NEVADA HILLS" "ISN'T IMMEDIATELY OBVIOUS." "FOR ONE THING, SURVEYORS DON'T GAMBLE." "THERE'S NOTHING RANDOM" "IN THE DETAILED PRECISION OF THEIR MAPS," "NOR IN THEIR MEASUREMENTS" "THAT DETERMINE THE HEIGHT ABOVE SEA LEVEL" "OF EACH POINT ON A PREDETERMINED GRID." "A LINE IS DRAWN, CONNECTING ALL POINTS" "A CERTAIN HEIGHT ABOVE SEA LEVEL" "AND THEN REPEATED FOR OTHER HEIGHTS" "AT REGULAR INTERVALS." "TO A PRACTICED EYE," "THE RESULTING CONTOURS OF CONSTANT HEIGHT" "GIVE A CLEAR REPRESENTATION OF THE REAL LANDSCAPE." "BY THE SAME TOKEN," "THE CONTOURS ON THIS MAP" "GIVE A CLEAR REPRESENTATION OF AN ELECTRIC FIELD." "THESE ARE CONTOURS OF CONSTANT ELECTRIC POTENTIAL," "AND THEY, TOO, REPRESENT A TERRAIN" "THAT HAS ITS UPS AND DOWNS." "WHEN REAL GROUND GOES UP AND DOWN," "THE PRUDENT TRAVELER WANTS TO KNOW ABOUT IT" "BECAUSE GOING UPHILL CAN BE HARD WORK," "AND EXACTLY THE SAME IS TRUE FOR ELECTRIC POTENTIAL." "MOVING UP THE INCLINE OF POTENTIAL IS HARD WORK." "AND THE STEEPER IT IS, THE HARDER IT IS TO CLIMB." "OF COURSE, IF THE POTENTIAL ISN'T CHANGING," "IT TAKES NO WORK AT ALL," "AND IF THE POTENTIAL DECREASES," "THE FIELD IS DOWNHILL ALL THE WAY." "IN THIS ANALOGY, ELECTRIC POTENTIAL IS ELEVATION," "AND ELECTRIC FIELD IS THE DOWNWARD SLOPE." "TO PUT IT IN MORE MATHEMATICAL TERMS," "THE ELECTRIC FIELD IS A NEGATIVE DERIVATIVE" "OF THE POTENTIAL." "OR, IN OTHER WORDS," "THE POTENTIAL IS MINUS THE INTEGRAL" "OF THE ELECTRIC FIELD." "THE ELECTRIC FIELD OF A SINGLE POINT CHARGE" "IS PROPORTIONAL TO 1/r-SQUARED." "SO ITS INTEGRAL IS PROPORTIONAL TO 1/r." "FOR A SINGLE POINT CHARGE," "THE DIRECTION OF THE FIELD IS PRETTY OBVIOUS," "BUT WHAT ABOUT MORE COMPLICATED SITUATIONS?" "WHAT DOES THE ELECTRIC FIELD FOR THIS POTENTIAL LOOK LIKE?" "BECAUSE IT TAKES NO WORK TO MOVE A CHARGE" "ALONG A CURVE OF CONSTANT POTENTIAL..." "THERE'S NO COMPONENT OF FIELD IN THAT DIRECTION." "SO THE FIELD IS PERPENDICULAR TO EACH EQUIPOTENTIAL" "AT EVERY POINT." "AND THAT'S HOW IT ASSUMES ITS FAMILIAR SHAPE." "THE FAMILIAR SHAPE OF EVEN THE MOST RUGGED TERRAIN" "ISN'T ALL PEAKS AND VALLEYS." "SOME REGIONS ARE PERFECTLY FLAT AND HORIZONTAL." "A LAKE IS A REGION" "OF CONSTANT HEIGHT ABOVE SEA LEVEL," "JUST AS A REGION OF CONSTANT ELECTRIC POTENTIAL" "IS CREATED BY A CONDUCTOR IN AN ELECTRIC FIELD." "AND SINCE ELECTRIC POTENTIAL" "IS THE SAME EVERYWHERE ON THE SURFACE OF A METAL," "THE ELECTRIC FIELD IS ALWAYS PERPENDICULAR" "TO THAT SURFACE." "OUT IN THE HILLS, IT'S HARD TO FIND MUCH" "THAT'S PERPENDICULAR TO ANYTHING," "BUT IN THE CITY, IT'S EASY." "HERE IT'S EASY TO FIND ELECTRICITY AT WORK" "AND AT PLAY." "ALTHOUGH THIS PROLIFERATION OF LIGHT AND COLOR" "IS PROBABLY NOT WHAT THE PIONEERS OF ELECTRICITY" "HAD IN MIND," "THEY NEVERTHELESS LAID THE FOUNDATION FOR IT." "BEN FRANKLIN DID HIS PART BY BRINGING ELECTRIC POTENTIAL" "OUT OF THE HEAVENS AND DOWN TO EARTH." "THOMAS EDISON, THINKING MORE ABOUT WORK THAN PLAY," "CAPTURED ELECTRICITY IN GLASS AND MADE IT YIELD LIGHT." "THE EVENTUAL PROLIFERATION OF NEON SIGNS" "WAS PROBABLY NOT EVEN IMAGINED BY GEORGES CLAUDE," "THE FRENCH PHYSICIST" "WHO DEVELOPED A PRACTICAL NEON LIGHT IN 1909." "THOSE FIRST NEON LIGHTS" "WERE PUT TO WORK IN THE GRAND PALAIS IN PARIS," "NOT AS DECORATION, BUT AS HOUSELIGHTS." "THE REDDISH GLOW OF THOSE LIGHTS" "WAS SEEN AS A DRAWBACK BY EVERYONE," "EVERYONE BUT JACQUES FONSEQUE, A PUBLICIST." "IN THAT RED GLOW, HE SAW GREAT POSSIBILITIES." "HE PERSUADED CLAUDE TO SELL HIM THE RIGHTS," "AND BY 1912," "PARIS HAD THE WORLD'S FIRST NEON SIGN," "AND THE WORK HAD BARELY BEGUN." "ELECTRIC POTENTIAL IS THE ABILITY TO DO WORK" "BY MAKING ELECTRIC CHARGES FLOW," "AND NO MATTER WHERE THEY GO," "THEIR POTENTIAL" "IS MEASURED IN VOLTS." "BUT HOW BIG IS A VOLT?" "AND HOW MANY VOLTS DOES IT TAKE" "TO DO A JOB?" "A FLASHLIGHT BATTERY IS RATED AT 1 1/2 VOLTS." "WITH ONLY 2 OF THEM," "ONE CAN DO WORK WORTH MILLIONS." "WHEN NECESSARY, 12 VOLTS IS ENOUGH TO START THE GETAWAY CAR," "AND 110 VOLTS, ENOUGH TO LIGHT A BULB OR TWO," "OR SEND A CROOK FLEEING INTO THE NIGHT." "HOWEVER, CRIME DOESN'T PAY." "EVEN WITH A ONE-ARMED BANDIT, THE GAME CAN GO TOO FAR." "[GUNSHOT]" "WHEN THAT HAPPENS, NOBODY WINS." "ON AUGUST 6, 1890, AT 6:40 A.M." "AT AUBURN STATE PRISON, NEW YORK," "MR. WILLIAM KEMMLER WAS THE FIRST PERSON IN THE WORLD" "TO DIE BY ELECTROCUTION." "IT TOOK APPROXIMATELY 17 SECONDS" "AND SEVERAL THOUSAND VOLTS," "BUT THE ELECTRIC CHAIR" "WASN'T THE FIRST USE OF HIGH VOLTAGE." "IN THE 18th CENTURY," "VAN MARUM'S GIANT ELECTROSTATIC GENERATOR" "COULD GENERATE 100,000 VOLTS." "SO COULD THE SMALLER WIMSHURST MACHINE" "AND THE VAN DE GRAAFF GENERATOR," "AND IN THE MODERN PHYSICS LABORATORY," "THIS TANDEM VAN DE GRAAFF PARTICLE ACCELERATOR" "USES 3 MILLION VOLTS." "BUT HIGH VOLTAGES" "ARE NOT CONFINED TO EXOTIC LABORATORIES." "EVERY DAY, POWER LINES CARRY ELECTRICITY" "AT HUNDREDS OF THOUSANDS OF VOLTS" "ACROSS THE LAND TOWARD THE CITY," "WHERE NEON LIGHTS USE ABOUT 10,000 VOLTS" "TO DO THEIR WORK," "AND PART OF THAT WORK IS TO HOLD THIS TOWN TOGETHER." "OCCASIONALLY, THEY EVEN HELP BIND PEOPLE TOGETHER." "BUT ELECTRICITY IS ALSO RESPONSIBLE" "FOR AN ALTOGETHER DIFFERENT TYPE OF BINDING." "THE ATOM ITSELF," "THE BASIC BUILDING BLOCK OF EVERYTHING" "WE SEE, FEEL, OR SMELL," "IS HELD TOGETHER BY THE FORCE OF ELECTRICITY." "AND THAT BOND BETWEEN THE ELECTRON AND THE ATOM" "HAS A DEFINITE VOLTAGE." "THAT VOLTAGE HOLDS THE WORLD TOGETHER." "AND SO WHAT IS THE VOLTAGE OF THE ATOM ITSELF?" "IN EVERY ATOM," "THE ELECTRIC FORCE BINDS NEGATIVELY CHARGED ELECTRONS" "TO A POSITIVE NUCLEUS." "THE NUCLEUS IS SO SMALL," "IT CAN BE THOUGHT OF AS A POINT POSITIVE CHARGE," "EVEN THOUGH IT REALLY CONSISTS OF NEUTRALLY CHARGED NEUTRONS" "AND POSITIVELY CHARGED PROTONS." "EACH ELECTRON HAS EXACTLY ENOUGH NEGATIVE CHARGE" "TO BALANCE THE POSITIVE CHARGE OF ONE PROTON." "THE RESULT MAY BE A PERFECTLY NEUTRAL ATOM." "THIS PICTURE, OR ANY PICTURE OF AN ATOM," "IS ONLY A MODEL," "BUT AS A MODEL, IT IS A GUIDE TO FACT," "AND ONE SUCH FACT OF GREAT IMPORTANCE" "IS THAT THE DISTANCE FROM THE NUCLEUS" "TO THE OUTERMOST ELECTRON OF ANY ATOM" "IS ALWAYS ABOUT 1 ANGSTROM UNIT, 100 MILLIONTH OF A CENTIMETER." "FROM THE POINT OF VIEW OF THAT OUTERMOST ELECTRON," "THE OTHER ELECTRONS VIRTUALLY BALANCE THE ELECTRIC CHARGE" "OF ALL THE PROTONS IN THE NUCLEUS EXCEPT ONE." "SO, THE OUTERMOST ELECTRON" "DETECTS VERY NEARLY THE ELECTRIC FIELD," "AND THE ELECTRIC POTENTIAL DUE TO ONE PROTON," "ABOUT AN ANGSTROM AWAY." "ITS ELECTRIC POTENTIAL WORKS OUT TO JUST A FEW VOLTS." "AND BECAUSE ITS CHARGE IS NEGATIVE," "SO IS ITS POTENTIAL ENERGY," "CONVENIENTLY MEASURED IN UNITS CALLED ELECTRON VOLTS." "THOSE FEW ELECTRON VOLTS, MINUS A LITTLE KINETIC ENERGY," "IS WHAT HAS TO BE OVERCOME TO TEAR AN ELECTRON" "FROM AN ATOM." "ABOUT THE SAME IS NEEDED" "TO REMOVE AN ELECTRON FROM A MOLECULE" "OR FROM A HUNK OF SOLID METAL." "CONSIDERABLY LESS HAS TO BE OVERCOME" "TO TEAR DOLLARS AWAY FROM LAS VEGAS TOURISTS." "WHILE THE GAMBLER'S ATTRACTION FOR MONEY IS GREAT," "THE BOND BETWEEN ANY ONE DOLLAR AND THE GAMBLER" "IS VERY SLIGHT INDEED." "BUT SOME OF THE OTHER BONDS MADE HERE" "ARE MORE LONG-LASTING IN NATURE." "AT LEAST IN SOME CASES, THE TIE IS VERY STRONG." "BUT WHEN A FEW VOLTS TIE AN ELECTRON TO AN ATOM," "HOW STRONG IS THAT BOND?" "SINCE A VAN DE GRAAFF GENERATOR CAN BUILD UP 100,000 VOLTS," "IT SEEMS THIS MACHINE OUGHT TO BE CAPABLE OF IONIZING" "EVERY BIT OF ORDINARY MATTER IN SIGHT," "BUT IT ISN'T." "SOMETIMES, VOLTAGE ALONE ISN'T ENOUGH." "IN FACT, IF AN ATOM AND A VAN DE GRAAFF" "ENGAGE IN A SIMPLE TUG 0F WAR FOR ONE ELECTRON," "THE ATOM ALWAYS WINS" "BECAUSE A TUG OF WAR IS A QUESTION OF FORCE," "NOT VOLTAGE." "IN OTHER WORDS," "WHAT MATTERS IS THE DERIVATIVE OF THE POTENTIAL ENERGY," "NOT JUST HOW BIG IT IS." "HERE'S A VAN DE GRAAFF DOME AND AN ATOM." "THEY'RE COMPETING FOR AN ELECTRON" "THAT MIGHT BE BOUND TO THE VAN DE GRAAFF" "BY TENS OF THOUSANDS OF VOLTS." "BUT ZOOMING IN BY 10, 100," "1,000 TIMES," "THE ELECTRON'S POTENTIAL ENERGY DUE TO THE ATOM" "IS SEEN TO BE MUCH SMALLER, BUT VERY MUCH STEEPER." "IN FACT, THE HORIZONTAL SCALE HAS TO BE EXPANDED 10, 100," "1,000, 10,000," "100,000 TIMES JUST TO SEE THE SLOPE." "THE ATOM'S FORCE IS 100,000 TIMES STRONGER" "THAN THE VAN DE GRAAFF," "AND THAT'S NO CONTEST AT ALL." "AND IT'S NOT MUCH OF A CONTEST" "WHEN THE HOUSE DETERMINES THE ODDS." "THAT'S WHY THE SMART PLAYERS" "PREFER TO LEAVE LITTLE TO CHANCE." "BENJAMIN FRANKLIN WAS SUCH A PERSON." "HE EVEN FOUND A WAY" "TO TAKE SOME OF THE RISK OUT OF THUNDERSTORMS," "AND IN FACT, HIS INVENTION OF THE LIGHTNING ROD" "SPARED MANY A CHURCH, BARN, AND HOME" "FROM FLAMING DESTRUCTION." "[THUNDER]" "WHERE DOES THE LIGHT IN LIGHTNING COME FROM?" "AS IN ANY SPARK," "THE MOLECULES OF AIR ARE MOMENTARILY IONIZED," "LEAVING A GAS OF POSITIVE MOLECULAR IONS" "AND NEGATIVE ELECTRONS CALLED A PLASMA." "VERY QUICKLY, THE ELECTRIC FORCE BETWEEN IONS AND ELECTRONS" "CAUSES THEM TO RECOMBINE INTO NEUTRAL MATTER," "GIVING OFF THEIR EXCESS ENERGY IN THE FORM OF LIGHT." "BUT LIGHTNING CAN BE TAMED." "IN A NEON TUBE, FOR INSTANCE," "THE SAME PROCESS CAN BE SLOWED TO A CONTINUOUS GLOW." "BUT THE ELECTRIC FIELD IN A NEON SIGN" "OR A VAN DE GRAAFF MACHINE OR EVEN A STORM CLOUD" "CAN'T IONIZE MATTER." "SO HOW DO THEY CAUSE SPARKS TO FLY?" "THE ANSWER IS THAT THEY DO IONIZE THE AIR," "BUT NOT IN A DIRECT TUG OF WAR." "THE AIR AROUND THE VAN DE GRAAFF BULB" "ALWAYS CONTAINS A FEW ACCIDENTAL ELECTRONS." "THE ELECTRIC FIELD OF THE VAN DE GRAAFF" "ACCELERATES SUCH AN ELECTRON UNTIL IT HITS ANOTHER MOLECULE." "THEN IT STARTS OVER AGAIN." "IF THE DISTANCE BETWEEN ATOMS IS LARGE ENOUGH" "AND THE FIELD IS STRONG ENOUGH," "THE ELECTRON CAN BUILD UP ENOUGH KINETIC ENERGY" "TO KNOCK ANOTHER ELECTRON OFF WHEN IT HITS." "IF THAT HAPPENS, BOTH ARE ACCELERATED," "CAUSING MORE IONIZATION" "IN A CHAIN REACTION THAT CREATES A SPARK." "SO, A VAN DE GRAAFF MACHINE OR A NEON SIGN" "IONIZES THE AIR NOT BY SHEER ELECTRIC FORCE," "BUT BY COLLISIONS." "WHILE THAT'S NOT EXACTLY CHEATING," "IT'S A TRICK, NONETHELESS." "BUT THEN, THIS TOWN'S FULL OF TRICKS," "TRICKS OF THE TRADE SCIENTIFICALLY DESIGNED" "TO IONIZE THE TOURISTS' POCKETBOOKS." "IT'S ALSO FULL OF ENERGY," "AND THE ENERGY OF THE PEOPLE SEEMS TO RISE BY THE HOUR." "ELECTRIC ENERGY, ON THE OTHER HAND," "GOES UP WITH VOLTAGE AND WITH CHARGE." "SO, THE QUESTION OF HOW MUCH ENERGY" "AN ELECTRIC DEVICE CAN DELIVER" "DEPENDS NOT ONLY ON ITS VOLTAGE," "BUT ALSO ON HOW MUCH CHARGE IT HAS AVAILABLE." "THE VAN DE GRAAFF" "AND THIS GIANT ELECTROSTATIC GENERATOR" "BOTH REACH VERY HIGH VOLTAGES BEFORE SPARKS DISCHARGE THEM." "BUT EVEN VAN MARUM'S 100 LEIDEN JARS" "COULDN'T STORE NEARLY AS MUCH CHARGE" "AS THERE IS IN AN AUTOMOBILE BATTERY." "EVEN THOUGH IT HAS A FAR LOWER VOLTAGE" "THAN THOSE MACHINES," "IT STORES SO MUCH CHARGE IN CHEMICAL FORM" "THAT IT'S VASTLY MORE USEFUL." "IN FACT, A COMMON RADIO BATTERY" "STORES 10 TIMES THE ENERGY OF VAN MARUM'S GENERATOR." "A BATTER IS A STOREHOUSE OF ENERGY," "BUT ON ANY GIVEN DAY," "DESPITE ANY GIVEN NUMBER OF BATTERIES," "MUCH MORE ENERGY IS ACTUALLY STORED RIGHT HERE." "YET ONLY A SMALL FRACTION" "OF THIS WATER'S VAST POTENTIAL ENERGY" "IS CONVERTED TO ELECTRICAL ENERGY." "THAT ENERGY TRAVELS ACROSS THE DESERT" "TO THE CITY," "WHERE IT'S RADIATED INTO THE NIGHT" "IN ALL COLORS, SHAPES, AND SIZES." "BUT BEHIND THE GLITTERING FACADE," "CHARGE AND FIELD, ENERGY, VOLTAGE, AND FORCE" "ARE THE STUFF OF ELECTRICITY," "AND THAT'S THE STUFF THAT HOLDS THE UNIVERSE TOGETHER." "AT THE BEGINNING OF THE 1800s," "A BRITISH CHEMIST NAMED JOHN DALTON" "PROPOSED THE LAW OF SIMPLE AND MULTIPLE PROPORTIONS," "AND THAT LAW, FOR THE FIRST TIME," "GAVE A SOLID, SCIENTIFIC FOUNDATION" "TO THE ANCIENT IDEA OF THE ATOMIC THEORY OF MATTER." "BUT NOT ALL SCIENTISTS ACCEPTED DALTON'S THEORY." "THROUGHOUT THE CENTURY," "THERE WAS A GROUP OF CONSERVATIVE CHEMISTS" "WHO ESSENTIALLY THOUGHT THAT IT WAS BAD SCIENCE" "TO BELIEVE IN ANYTHING YOU COULDN'T SEE." "OF THE ATOMIC THEORY THEY SAID," ""WE DON'T NEED THAT HYPOTHESIS."" "THEY WEREN'T THE ONLY ONES" "WHO DIDN'T BELIEVE IN DALTON'S THEORY." "DALTON HAD A RIVAL FOR THE TITLE" "OF GREATEST CHEMIST IN ENGLAND." "HIS NAME WAS HUMPHREY DAVY." "DAVY DIDN'T BELIEVE IN DALTON'S THEORY EITHER," "BUT HIS REASON WAS THE EXACT OPPOSITE." "HE THOUGHT THAT DALTON HADN'T GONE FAR ENOUGH." "HIS ARGUMENT WENT SOMETHING LIKE THIS." "HE SAID, "THERE ARE 40 CHEMICAL ELEMENTS" ""THAT WE KNOW OF." ""THAT MEANS THAT ACCORDING TO DALTON'S THEORY," ""THERE MUST BE 40 DIFFERENT KINDS" ""OF INDIVISIBLE ATOMS" "TO EXPLAIN THE PROPERTIES OF THOSE ELEMENTS."" ""BUT," HE SAID, "OF THOSE 40 ELEMENTS," ""26 ARE METALS." ""THEY ALL SHARE THE SAME PROPERTIES" ""OF SHINY SURFACES," ""GOOD ELECTRICAL AND THERMAL CONDUCTIVITY," ""MECHANICAL DUCTILITY, AND OTHER PROPERTIES." ""THOSE CAN'T BE ACCIDENTS" ""THAT JUST HAPPENED 26 SEPARATE TIMES." "THERE MUST BE SOME UNDERLYING PRINCIPLE OF METALIZATION."" "THAT IS TO SAY," "DALTON'S ATOMS MUST HAVE SOME INNER STRUCTURE." "IT TOOK 100 YEARS," "BUT IT TURNED OUT IN THE END" "THAT BOTH DALTON AND DAVY WERE RIGHT." "MATTER IS MADE OF ATOMS," "AND ATOMS DO HAVE AN INNER STRUCTURE," "WHICH EXPLAIN WHY METALS EXIST." "BUT LONG BEFORE THAT WAS UNDERSTOOD," "IN FACT, EVEN BEFORE THE TIME OF DAVY AND DALTON," "ALL OF IT WAS MADE USE OF" "BY A WILY ITALIAN NAMED ALESSANDRO VOLTA," "WHO INVENTED THE ELECTRIC BATTERY." "AND THAT'S OUR STORY FOR NEXT TIME." "CAPTIONING IS MADE POSSIBLE BY THE ANNENBERG/CPB PROJECT" "CAPTIONING PERFORMED BY THE NATIONAL CAPTIONING INSTITUTE, INC." "CAPTIONS COPYRIGHT 1986 CALIFORNIA INSTITUTE OF TECHNOLOGY," "THE CORPORATION FOR COMMUNITY COLLEGE TELEVISION, AND THE ANNENBERG/CPB PROJECT" "PUBLIC PERFORMANCE OF CAPTIONS PROHIBITED WITHOUT PERMISSION OF NATIONAL CAPTIONING INSTITUTE" "Annenberg Media" "¶" "For information about this and other Annenberg Media programs call 1-800-LEARNER and visit us at"