"Annenberg Media" "¶" "CAPTIONING IS MADE POSSIBLE BY THE ANNENBERG/CPB PROJECT" "EVERYBODY HAS HEARD THAT THERE'S AN ENERGY CRISIS." "PEOPLE ARE ALWAYS TELLING US" "THAT WE MUST HELP CONSERVE ENERGY." "IT'S IMPOSSIBLE." "I DON'T MEAN IT'S IMPOSSIBLE TO CONSERVE ENERGY." "I MEAN IT'S IMPOSSIBLE NOT TO." "ENERGY IS ALWAYS CONSERVED, NO MATTER WHAT YOU DO." "THAT'S ONE OF THE MOST FUNDAMENTAL LAWS OF PHYSICS." "WE'LL SOON FIND OUT" "THAT THERE ARE THREE CONSERVATION LAWS" "THE CONSERVATION OF ENERGY..." "MOMENTUM..." "AND ANGULAR MOMENTUM." "THESE THREE GREAT CONSERVATION LAWS" "ARE THE CROWN JEWELS OF PHYSICS," "THREE QUANTITIES THAT ARE NEVER CREATED OR DESTROYED." "THE AMOUNT OF THEM IS THE SAME NOW" "AS IT'S ALWAYS BEEN AND ALWAYS WILL BE." "WHAT IS THIS CRISIS WE HEAR ABOUT?" "A BREAKDOWN IN THE LAWS OF PHYSICS?" "IMAGINE THIS SCENE" "THE PRESIDENT IN THE OVAL OFFICE." "ALL NATIONAL NETWORKS ARE THERE." "HE LOOKS STRAIGHT INTO THE TELEVISION SCREEN," "AND HE SAYS," ""IN THIS HOUR OF CRISIS, WE MUST ALL WORK TOGETHER" "TO HELP CONSERVE ANGULAR MOMENTUM."" "NOW, WAIT A MINUTE." "OBVIOUSLY THERE'S SOMETHING WRONG." "SOMETHING IS SPECIAL ABOUT ENERGY," "BUT TO UNDERSTAND WHAT," "WE MUST FIRST UNDERSTAND WHAT ENERGY IS." "ENERGY." "IN EVERY SHAPE AND FORM" "AROUND THE EARTH" "AND THROUGHOUT THE UNIVERSE," "ENERGY IS PROVIDED BY NATURE," "EVEN IF SOME OF IT," "IN A DEADLY GAME OF FOLLOW-THE-LEADER," "IS UNLEASHED BY MAN." "ENERGY..." "AND MORE ENERGY." "NO MATTER HOW OR HOW OFTEN IT'S USED," "REGULAR OR UNLEADED," "ENERGY IS ALWAYS CONSERVED." "BUT IF THAT'S A FACT" "AND THE LAW OF THE CONSERVATION OF ENERGY SAYS IT IS" "WHY ISN'T THERE ALWAYS ENOUGH ENERGY AT HAND?" "MOTION IS A FORM OF ENERGY" "BECAUSE ENERGY TAKES THAT FORM WHEN ANYTHING MOVES." "BUT IF ENERGY'S ALWAYS CONSERVED," "HOW DO MOVING OBJECTS EVER GET STARTED?" "COME ON, TONY!" "WAY TO GO, PETE!" "AND ONCE RUNNING," "WHATEVER DIRECTION THEY'RE MOVING IN," "IF ENERGY IS ALWAYS CONSERVED," "HOW CAN THEY EVER STOP?" "SOME PEOPLE WORK WITH MORE AND MORE WEIGHT." "OTHERS WORK OFF" "SOME OF THE WEIGHT THEY WALKED IN WITH." "YET EVEN HERE," "THE VITAL QUESTION IS, IF ENERGY IS ALWAYS CONSERVED," "WHY DO MUSCLES GET TIRED, AND WHY DO WEIGHTS FALL?" "THE ANSWER, LIKE EXERCISE IN GENERAL," "HAS TO DO WITH WORK." "IN FACT, PART OF THE ANSWER IS WORK." "IN EXERCISING THE CONSERVATION OF ENERGY," "WORK HAS A PRECISE DEFINITION." "THE GREATER THE WEIGHT," "THE MORE STRENGTH REQUIRED TO LIFT IT." "OF COURSE." "THE GREATER THE HEIGHT, THE MORE WORK." "WORK = FORCE TIMES HEIGHT." "WHEN THE WORK IS BEING DONE NEAR THE SURFACE OF THE EARTH," "THE FORCE IN THIS EQUATION" "IS THE CONSTANT FORCE OF GRAVITY," "WHICH EQUALS MASS TIMES THE ACCELERATION OF GRAVITY." "SO WORK = MASS TIMES g TIMES HEIGHT." "SOMETIMES FORCE MAKES MASS ACCELERATE," "BUT HERE, FORCE IS USED TO OVERCOME GRAVITY" "TO LIFT THE WEIGHT TO A CERTAIN HEIGHT." "IN THE CONSERVATION OF ENERGY," "THE ROLE OF WORK IS TO TRANSFER ENERGY" "FROM ONE PLACE TO ANOTHER," "FROM MUSCLE INTO STEEL, FOR EXAMPLE." "THE BARBELL HAS ENERGY BECAUSE OF ITS HEIGHT." "THAT'S POTENTIAL ENERGY, WHICH IS GIVEN THE SYMBOL U." "IN A CONSTANT GRAVITY FIELD," "THE POTENTIAL ENERGY OF ANY OBJECT" "IS WRITTEN AS mgh." "IN OTHER WORDS," "ITS POTENTIAL ENERGY IS EXACTLY EQUAL" "TO THE WORK THAT WAS PUT INTO IT." "IT'S CALLED POTENTIAL ENERGY" "BECAUSE AT ANY GIVEN HEIGHT, IT'S READY TO GO INTO ACTION." "THE GREATER THE HEIGHT," "THE MORE POTENTIAL ENERGY STORED IN THE WEIGHT," "POTENTIAL ENERGY THAT CAN CHANGE INTO MOTION." "FOR ALL ITS UPS AND DOWNS," "POTENTIAL ENERGY DEPENDS ONLY ON VERTICAL DISTANCE..." "BUT THERE MUST BE AN EASIER WAY TO MAKE THE POINT." "THESE MACHINES, THE MECHANICAL ONES," "COMBINE PULLIES," "CAMS, LEVERS," "AND INCLINED PLANES THAT GALILEO MIGHT HAVE ADMIRED." "A LOT OF EXPENSIVE TECHNOLOGY IS AT PLAY HERE" "TO INCREASE OR DECREASE OR JUST CHANGE THE DIRECTION" "OF THE FORCE NEEDED TO LIFT A WEIGHT." "NO MATTER IN WHAT DIRECTION THE FORCE IS APPLIED," "POTENTIAL ENERGY RELATES ONLY TO HEIGHT." "THE POTENTIAL ENERGY KEEPS CHANGING." "EVERY TIME ANYTHING MOVES UP OR DOWN," "POTENTIAL ENERGY BY ITSELF ISN'T CONSERVED." "IN THE LAW OF THE CONSERVATION OF ENERGY," "WHAT IS ACTUALLY CONSERVED?" "TOWARD THE END OF THE 16th CENTURY," "GALILEO GALILEI ASKED HIMSELF A SIMILAR QUESTION." "IT WAS ONE QUESTION" "FOR WHICH GALILEO FAILED TO FIND AN ANSWER." "NONETHELESS, WHILE USING INCLINED PLANES" "TO SLOW DOWN THE ACCELERATION OF FALLING BODIES," "HE DID FIND SOMETHING FASCINATING." "NO MATTER WHAT PATH IT FOLLOWED," "THE BALL WOULD RETURN TO ITS ORIGINAL HEIGHT," "ALMOST AS IF IT REMEMBERED ITS ORIGINAL POSITION." "GALILEO KNEW AN INANIMATE OBJECT" "COULDN'T REMEMBER WHERE IT HAD BEEN," "BUT HE REALIZED" "THE BALL RETAINED SOMETHING VERY POWERFUL." "IF NOT MEMORY, WHAT DID THE BALL CONSERVE?" "THE ANSWER DIDN'T COME SPEEDILY," "BUT SPEED IS THE KEY." "STARTING FROM THE SAME HEIGHT," "NO MATTER WHAT THE SLOPE OF THE INCLINE," "WHEN THE BALL GETS TO THE BOTTOM," "IT'S ALWAYS GOING AT THE SAME SPEED." "THE ENERGY OF THE BALL'S ORIGINAL HEIGHT" "IS STILL ROLLING ALONG, TRANSFORMED INTO SPEED." "HUMAN MOVEMENT BEAUTIFULLY DEMONSTRATES" "HOW ENERGY CAN CHANGE FORMS." "PUSHING A SWING MAY NOT SEEM LIKE WORK," "BUT IT IS." "IT INCREASES THE SWINGING GIRL'S SPEED" "AT THE BOTTOM OF THE ARC" "AND HER POTENTIAL ENERGY AT THE TOP." "WHILE THE FLOW OF ENERGY FROM ONE FORM TO ANOTHER" "MAY BE CHILD'S PLAY," "IT ALL BEGINS WITH A LITTLE WORK." "A LITTLE WORK IS FORCE THROUGH A LITTLE DISTANCE," "BUT IT ALL ADDS UP," "OR, IN THE LANGUAGE OF CALCULUS, IT INTEGRATES." "IFWORKIS DONEAGAINST ACONSTANT,OPPOSINGFORCE," "ASINLIFTINGABLOCK" "FROM ONE HEIGHT TO ANOTHER," "THE WORK IS THE DIFFERENCE" "BETWEEN THE POTENTIAL ENERGY" "ATTHETWOHEIGHTS," "THATIS," "THE CHANGE IN POTENTIAL ENERGY." "IFWORKIS DONE" "WITHNOOPPOSINGFORCE," "THEWORKIS STILLFORCE" "INTEGRATEDOVERDISTANCE," "BUTTHERESULTOFTHEWORK" "ISTOACCELERATETHE BLOCK." "ITGAINSSPEED." "WHATHAPPENS" "IF WE CONSIDER THE INTERVAL" "INTERMSOF SPEED?" "IN TERMS OF SPEED, THE WORK" "IS THE CHANGE IN THE QUANTITY 1/2mv-SQUARED." "THIS IS AN ENERGY OF MOTION." "IT'S CALLED KINETIC ENERGY." "IT TAKES MORE" "THAN THE SPEEDY WORK OF CALCULUS" "TO CREATE THE KINETIC ENERGY OF A BODY IN MOTION." "THESE ATHLETES WORK THEIR BODIES" "UP TO MAXIMUM SPEED" "AND THEN USE THAT KINETIC ENERGY" "TO LAUNCH THEMSELVES ACROSS AMAZING DISTANCES." "OF COURSE, WHEN THEY DO THAT," "THEY LOSE THE KINETIC ENERGY THEY'VE WORKED HARD TO BUILD UP." "BUT IF THERE ARE ONLY TWO FORMS OF ENERGY" "POTENTIAL AND KINETIC" "AND NEITHER IS CONSERVED," "HOW CAN ANY FORM OF ENERGY BE CONSERVED?" "THERE'S A SIMPLE YET POWERFUL EXPLANATION," "BUT IT TAKES A LITTLE LEAP OF IMAGINATION." "OH, YEAH!" "POTENTIAL ENERGY CHANGES CONSTANTLY..." "AND KINETIC ENERGY IS IN A CONSTANT STATE OF FLUX." "BUT WHEN THE SUM OF KINETIC AND POTENTIAL ENERGY" "IS CONSIDERED TOGETHER," "THE TOTALITY OF ENERGY IS A CONSTANT." "IN OTHER WORDS, ENERGY, E, = POTENTIAL, U, + KINETIC, K," "AND THAT'S A CONSTANT." "POTENTIAL ENERGY OF HEIGHT" "CHANGES INTO KINETIC ENERGY OF MOTION" "AND BACK AGAIN." "THE BALL DOESN'T REMEMBER ITS HEIGHT." "IT CONSERVES ITS ENERGY UNTIL" "WHEN ITS ENERGY IS AGAIN ALL POTENTIAL" "IT MUST BE AT ITS ORIGINAL HEIGHT." "TURNING SPEED INTO HEIGHT" "CAN BE BOTH A SPECTACULAR FEAT OF COORDINATION" "AND AN IMPRESSIVE DEMONSTRATION OF THE RELATIONSHIP" "BETWEEN KINETIC AND POTENTIAL ENERGY." "IN THIS CASE," "THE FASTER THE RUN, THE HIGHER THE VAULT." "MUSCLES INCREASE KINETIC ENERGY MORE AND MORE," "EVENTUALLY TO THE LIMIT OF THE ATHLETE'S ABILITY." "THE POLE CHANGES ALL THAT KINETIC ENERGY" "INTO GREAT POTENTIAL." "SUDDENLY, FALLING FASTER AND FASTER," "HIS ACCUMULATED POTENTIAL ENERGY" "CHANGES BACK INTO KINETIC ENERGY." "BUT SOMETHING'S WRONG HERE." "NOW HE HAS NEITHER POTENTIAL NOR KINETIC ENERGY," "AND IF ENERGY IS CONSERVED, WHERE DID IT GO?" "INDEED, WHAT HAPPENS" "TO ALL THE USED-UP ENERGY ON EARTH?" "IN THE END," "KINETIC ENERGY AND POTENTIAL ENERGY ALIKE" "HIT THE DUST." "NOTHING ON EARTH MOVES FOREVER." "THE CONSERVATION OF ENERGY," "THE LAW OF INERTIA," "GALILEO'S LAW OF FALLING BODIES" "THESE ARE NOTIONS OF SCIENCE, NOT SCIENCE FICTION." "BUT TO VISUALIZE THEM CLEARLY," "IT HELPS TO TRAVEL BEYOND EVERYDAY EXPERIENCE" "TO A WORLD ALMOST WITHOUT FRICTION..." "WHERE ASTRONAUTS FIND THAT THINGS WORK" "THE WAY GALILEO SAID THEY SHOULD." "I'LL DROP THE TWO OF THEM HERE," "ANDHOPEFULLY, THEY'LLHITTHEGROUND" "ATTHESAMETIME." "MR.GALILEOWASCORRECT." "IT TOOK 400 YEARS AND BILLIONS OF DOLLARS," "BUT EVEN HERE ON THE MOON," "A CERTAIN AMOUNT OF FRICTION STILL EXISTS." "BUT WITH OR WITHOUT FRICTION," "THESE COSMIC EXPLORERS" "AREN'T THE ONLY ONES WHO CAN SLIP UP." "OH,DADGUMIT!" "JACKSCHMITT'S HAVINGA FEWPROBLEMS." "CONSIDER THE CONTROVERSIAL DISCOVERY OF AMERICA." "SHE MIGHT HAVE BEEN CHANCED UPON" "BY SOUTH SEA DRIFTERS." "BUT SPECULATIVE THEORIES ASIDE," "HISTORIANS GENERALLY AGREE THAT AROUND 900 A.D.," "THE VIKINGS FOUND THESE FIELDS RIPE FOR DISCOVERY" "OR REDISCOVERY, AS THE CASE MUST HAVE BEEN." "BUT THAT'S ANOTHER STORY." "AND IN ANY CASE," "AMERICA WAS THE NAME THAT EUROPEANS SETTLED ON." "AMERICA WAS NAMED AFTER AMERIGO VESPUCCI," "AN ITALIAN WHO NAVIGATED FIRST FOR SPAIN," "THEN FOR PORTUGAL." "AMERIGO WASN'T THE FIRST TO SET FOOT" "ON THE SHORES OF THE AMERICAS." "NEITHER WAS ENGLAND'S EXPLORER CAPTAIN JAMES COOK," "AND, CONTRARY TO POPULAR OPINION," "NEITHER WAS CHRISTOPHER COLUMBUS." "NONETHELESS, COLUMBUS USUALLY GETS CREDIT" "FOR DISCOVERING THE AMERICAS," "NOT FOR WHEN, BUT FOR HOW HE GOT THE JOB DONE." "COLUMBUS DISCOVERED AMERICA SO VERY WELL" "THAT NOBODY HAD TO COME ALONG AND DO IT AIN." "NOT UNLIKE ANY NEW WORLD," "THE CONTINENT OF PHYSICS WAS AND STILL IS" "RIPE FOR DISCOVERY." "THE FRONTIERS ARE RIGOROUS..." "THE DISCOVERIES SOMETIMES SHOCKING..." "AND OFTEN VERY CONTROVERSIAL." "BUT THROUGHOUT THE LAND OF PHYSICS," "THE REWARDS CAN BE GREATER THAN THE HARDSHIPS." "JAMES PRESCOTT JOULE" "GETS CREDIT FOR DISCOVERING" "THE LAW OF THE CONSERVATION OF ENERGY." "HE WASN'T THE FIRST TO EXPLORE THE REGION," "BUT LIKE COLUMBUS, HE RETURNED WITH MAPS" "THAT THE REST OF THE WORLD COULD FOLLOW WITH CONFIDENCE." "THE SON OF A BRITISH BREWER," "JOULE STUDIED THE EFFICIENCY OF STEAM IN ELECTRIC ENGINES" "FOR THE FAMILY BUSINESS." "HE DEVISED AN INGENIOUS METHOD OF MEASURING" "HOW MUCH MECHANICAL ENERGY TURNS INTO HEAT." "A LARGE WEIGHT LIFTED TO A CERTAIN HEIGHT" "HAS A PRECISE POTENTIAL ENERGY, mgh." "JOULE ARRANGED" "TO HAVE FALLING WEIGHTS TURN PADDLE WHEELS" "INSIDE A CAREFULLY INSULATED CONTAINER OF WATER." "THEN HE MEASURED THE WATER'S TEMPERATURE." "IN THIS WAY, JOULE SHOWED" "THAT A GIVEN LOSS OF POTENTIAL ENERGY" "ALWAYS TURNS INTO PRECISELY THE SAME AMOUNT OF HEAT." "JOULE'S CONCEPT," "THIS IDEA OF LOSS AND GAIN" "IN RELATION TO THE CONSERVATION OF ENERGY," "IS VIRTUALLY UNKNOWN HERE." "FOR THE SAKE OF THIS GROUP'S MORALE," "IGNORANCE IS BLISS." "CONSIDER THE DIABOLICAL FACT THAT KIL0CALORIES," "COMMONLY KNOWN TO DIETERS AS FOOD CALORIES," "HAVE A TENDENCY TO GENERATE FAT." "FOR EXAMPLE," "TO BURN OFF THE 800 FOOD CALORIES" "FROM A SINGLE SLICE OF CHOCOLATE CAKE," "IT WOULD TAKE THIS FELLOW ABOUT 2,000 LIFTS." "WHEN YOU CONSIDER" "THAT THE PURPOSE OF THIS LIFTING," "PUSHING," "DANCING, AND BENDING" "IS TO GET RID OF POTENTIAL OR KINETIC ENERGY," "THE FACT THAT ALL ENERGY IN EVERY FORM" "IS ALWAYS CONSERVED" "WOULD BE VERY DEPRESSING NEWS FOR THESE PEOPLE." "CONSERVE IT?" "NOT AT ALL." "THEY WANT TO WASTE IT," "LOSE IT, USE IT UP, AND WORK UP A GOOD SWEAT." "THIS MACHINE, FOR EXAMPLE, IS DESIGNED TO WASTE ENERGY." "IN FACT, IT COULD BE SEEN AS AN EXTRAORDINARY HEATER." "THE KINETIC ENERGY OF ANY FALLING OBJECT" "IS TRANSFORMED INTO ANOTHER KIND OF KINETIC ENERGY." "THE VIBRATIONS OF ATOMS" "HAVE A NUMBER OF EFFECTS." "THEY JOSTLE THE NEARBY MOLECULES OF AIR," "WHICH CREATES SOUND WAVES," "AND THEY ALWAYS GENERATE HEAT." "THE HEAT SPREADS FROM MOLECULE TO MOLECULE," "DISSIPATING THE ENERGY, BUT NEVER DESTROYING IT," "NOT EVEN ONE ERG OF IT." "ENERGY THAT SEEMS TO VANISH INTO HEAT" "IS MERELY SPREADING INTO RANDOM VIBRATIONS," "INCREASING THE KINETIC AND POTENTIAL ENERGIES OF ATOMS" "BY EXACTLY THE AMOUNT THAT'S BEEN LOST." "THROUGHOUT THE SCIENTIFIC WORLD," "THIS ACTIVITY CAN BE MEASURED PRECISELY." "WORK, POTENTIAL ENERGY, AND KINETIC ENERGY," "EACH A FORM OF THE SAME BASIC QUANTITY," "ARE ALL EXPRESSED IN THE SAME UNIT," "WHICH IS EQUAL TO ONE NEWTON METER." "THAT UNIT, THE JOULE, IS SLIGHTLY LESS" "THAN THE ENERGY OF ONE POUND LIFTED ONE FOOT." "4.2 JOULES ARE EQUAL TO 1 CALORIE," "THE STANDARD MEASURE OF HEAT." "STARTING IN NUCLEAR FIRES WITHIN THE SUN," "ENERGY FLOWS THROUGHOUT THE SOLAR SYSTEM," "EVER CHANGING IN KIND, BUT ALWAYS IN THE SAME AMOUNT." "IT REACHES THE EARTH AS LIGHT RAYS" "THAT ENERGIZE THE PLANET AND EVERYTHING ON IT." "ONLY TWO FORMS OF ENERGY ARE MECHANICAL" "POTENTIAL AND KINETIC." "WORK-- FORCE TIMES DISTANCE" "TRANSFORMS ENERGY," "SUCH AS ENERGY HIDDEN IN THE BIOSPHERE," "INTO THE VISIBLE POTENTIAL ENERGY" "OF THE WEIGHT, POISED HIGH ABOVE THE FLOOR." "ENERGY CHANGES CONSTANTLY FROM POTENTIAL TO KINETIC," "FROM KINETIC TO POTENTIAL AND BACK AGAIN..." "AGAIN AND AGAIN, IN COUNTLESS WAYS." "IN WHATEVER FORM, HOWEVER, MECHANICAL ENERGY" "EVENTUALLY BEGINS TO VANISH ONCE AGAIN," "BEGINS TO DISAPPEAR FROM SIGHT AND SOUND," "NOT LOST OR DESTROYED, BUT TRANSFORMED BACK INTO HEAT." "ENERGY IS NEVER LOST AND ALWAYS CONSERVED." "BUT DISSIPATED INTO THE RANDOM MOTIONS" "OF COUNTLESS ATOMS AND MOLECULES," "ENERGY BECOMES HARDER AND HARDER TO RETRIEVE" "AND ALMOST IMPOSSIBLE TO MAKE USE OF AGAIN." "WHETHER OR NOT THESE MEN AND WOMEN" "ARE AWARE OF IT," "THAT IS, NONETHELESS, THE INEVITABLE END" "OF ALL THE ENERGY ON EARTH." "SO, THERE YOU HAVE IT." "ENERGY IS CONSERVED, BUT WE RENDER IT USELESS." "THE ENERGY STORED IN GASOLINE IS RELEASED" "WHEN IT EXPLOS IN THE PISTONS OF YOUR CAR." "SOME OF THAT ENERGY" "IS TEMPORARILY TURNED INTO THE KINETIC ENERGY" "OF THE MOTION OF THE CAR." "ALL OF IT WINDS UP AS USELESS HEAT" "AT THE TEMPERATURE OF THE ENVIRONMENT." "IT CAN'T BE TURNED INTO GASOLINE AGAIN." "THERE REALLY IS A CRISIS." "IN A FEW DECADES, WE'RE USING UP THAT FUEL" "IT TOOK THE EARTH MILLIONS OF YEARS TO CREATE." "IT CAN NEVER BE REPLACED." "ALL OF THAT STORED ENERGY HAS BECOME USELESS." "EVEN ASIDE FROM THE SOCIAL PROBLEM," "THERE'S A PHILOSOPHICAL POINT." "WE'VE LEARNED TODAY THAT THERE ARE CERTAIN THINGS" "WHICH, ONCE DONE, CAN NEVER BE UNDONE." "THAT'S MORE THAN JUST A WISE OBSERVATION" "ABOUT THE HUMAN CONDITION." "IT'S A BASIC LAW OF PHYSICS." "THAT NEW LAW HAS BEEN EXPRESSED WITH GREAT PRECISION MANY TIMES," "BUT MY FAVORITE EXPRESSION OF IT" "WAS MADE BY AN 11th-CENTURY PERSIAN MATHEMATICIAN" "NAMED OMAR KHAYYAM." "HE SAID, "THE MOVING FINGER WRITES," ""AND HAVING WRIT, MOVES ON." ""NOR ALL YOUR PIETY NOR WIT CAN CANCEL HALF A LINE," "NOR ALL YOUR TEARS WASH OUT A WORD OF IT."" "SEE YOU NEXT TIME." "ACCORDINGTOTHELAW  OFTHECONSERVATIONOFENERGY," "ALTHOUGHENERGYCHANGESFORMS," "THETOTALAMOUNTOFENERGY INTHEUNIVERSE" "ISALWAYSCONSTANT." "CAPTIONING PERFORMED BY THE NATIONAL CAPTIONING INSTITUTE, INC." "CAPTIONS COPYRIGHT 1985 CALIFORNIA INSTITUTE OF TECHNOLOGY" "THE CORPORATION FOR COMMUNITY COLLEGE TELEVISION 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"