"Annenberg Media" "¶" "SOMEWHERE AROUND 1800," "THERE WAS AN EXTRAORDINARY FRENCHMAN" "WHOSE NAME WAS LAZARE CARNOT." "HE WAS A STATESMAN AND MINISTER" "IN VARIOUS FRENCH GOVERNMENTS." "HE WAS KNOWN AS THE ORGANIZER OF VICTORY" "OF THE FRENCH WARS OF REVOLUTION." "HE WAS ALSO A SCIENTIST AND ENGINEER" "WHOSE WORK IS REMEMBERED EVEN TODAY." "THIS GLORIOUS FAMILY TRADITION WAS CARRIED ON" "ALMOST A CENTURY LATER BY SADI CARNOT," "ANOTHER ENGINEER WHO BECAME PRESIDENT" "OF THE REPUBLIC OF FRANCE IN 1887," "A POSITION HE HELD UNTIL 1894" "WHEN HE WAS ASSASSINATED." "BUT THE MOST IMPORTANT CARNOT WAS NEITHER OF THESE." "HE WAS ONE WHO CAME BETWEEN THEM." "HIS NAME WAS NICOLAS LEONARD SADI CARNOT," "CALLED BY EVERYONE SADI," "AND THAT CARNOT WAS INTERESTED IN STEAM ENGINES." "[TRAIN WHISTLE]" "FROM ENGLAND'S FITS AND STARTS IN THE EARLY 1700's" "TO THE NONSTOP PROMISE OF THE AMERICAN FRONTIER," "NOTHING EXPANDED THE VISTA OF WESTERN CIVILIZATION" "WIDER AND FARTHER" "THAN THE INVENTION OF THE STEAM ENGINE." "[WHISTLE]" "MANY SAW THE COMING MACHINES AS A THREAT," "COUGHING, SPUTTERING, DISTURBING THE PEACE," "AND UPSETTING THE STATUS QUO." "THE MACHINE WAS VIEWED" "AS A NASTY LITTLE NUISANCE OF AN IDEA," "BUT ONCE GIVEN BIRTH, IT WAS HERE TO STAY." "STEAM ROSE IN THE INDUSTRIAL AGE" "AND GREW UP INTO THE POWER BEHIND THE REVOLUTION." "WITH GROWING ACCEPTANCE ON BOTH SIDES OF THE ATLANTIC," "AND IN AS MANY CLEVER CONFIGURATIONS" "AS ENGINEERS COULD DEVISE," "STEAM ENGINES BEGAN TO TURN DREAMS INTO REALITIES." "STEAM ENGINES TURNED THE LOOMS OF THE COTTON BELT" "AND WOVE THE FABRIC OF A NATION." "THE STEAM ENGINE CUT AND SHAPED THE WOOD," "DROVE THE PISTONS," "AND PULLED THE LEVERS." "THE STEAM ENGINE CHURNED THE BUTTER" "AND GROUND THE CORN" "AND TURNED THE SMALL FAMILY BUSINESS" "INTO AN INTERNATIONAL CONCERN." "WITH STEAM, THE GROUNDWORK WAS LAID," "AND THE SLEEVES OF AN INDUSTRIAL GIANT" "WERE ROLLED UP TO STAY." "THE POWER OF THE STEAM ENGINE" "WAS ENERGY AND MOVEMENT AND CHANGE." "IT BECAME A SYMBOL OF OPPORTUNITY" "WHETHER THAT MEANT ESCAPING FROM THE POTATO FAMINE," "FROM THE WAGES OF SLAVERY," "OR FROM THE RUSSIAN CZAR." "THE STEAM ENGINE SAVED TIME AND LABOR," "AND INDEED, FOR ALL ITS UPHEAVAL AND INEQUITY," "THE STEAM ENGINE OFFERED THE PROMISE" "OF A STEADY WAGE." "EVERY QUOTA WAS TO BRING MORE OF EVERYTHING" "EVERYTHING FASTER AND BETTER AND EASIER" "AND CHEAPER BY THE DOZEN." "OUT AS FAR AS MEN COULD LAY TRACK," "WHEREVER ONE LOOKED," "IT SEEMED THE NATION'S MOST IMPORTANT PRODUCT" "WAS PROGRESS." "AS FAR AS THE STEAM ENGINE CARRIED BODY AND SOUL," "IT CARRIED MAN'S INTELLECT EVEN FURTHER." ""FULL SOON," LORD BYRON WROTE," ""STEAM ENGINES WILL CONDUCT HIM TO THE MOON."" "THE INSIGHT OF THE POET BYRON WAS ON THE RIGHT TRACK," "BUT THE STEAM ENGINE GOES ABOVE AND BEYOND THE MOON." "AS AN IDEA, IT GOES SO FAR AS TO RAISE QUESTIONS" "ABOUT THE MEANING OF TIME," "AND ABOUT THE ULTIMATE FATE OF THE UNIVERSE." "THAT WAS THE JOURNEY" "THAT BEGAN IN THE MIND OF SADI CARNOT." "BORN IN 1796," "CARNOT MAY HAVE INHERITED HIS APTITUDE" "FOR MATHEMATICS AND MILITARY ENGINEERING" "FROM HIS FATHER LAZARE," "WHO IN REWARD FOR HIS SKILLS IN ORGANIZATION AND TACTICS," "HAD BECOME A HERO OF THE FRENCH REVOLUTIONARY WARS." "WITH HIS FATHER'S INFLUENCE," "CARNOT ENTERED THE ECOLE POLYTECHNIQUE." "YOUNG CARNOT DISCOVERED BOTH THE STEAM ENGINE" "AND THE FACT THAT HIS COUNTRY LAGGED BEHIND" "IN ITS DEVELOPMENT." "FOR A MILITARY ENTITY LIKE FRANCE," "THIS WAS A PROBLEM." "FOR A MILITARY ENGINEER, IT WAS A CHALLENGE." "RATHER THAN BUILDING A BETTER STEAM ENGINE," "CARNOT CAME UP WITH A BETTER THEORY." "OF COURSE, STEAM POWER WAS, BY NO MEANS, A NEW IDEA." "STARTING WITH THOMAS SAVERY'S STEAM-DRIVEN WATER PUMP" "IN 1698," "INVENTORS AND ENGINEERS SUCH AS THOMAS NEWCOMEN," "RICHARD TREVITHICK, 9" "AND, OF COURSE, JAMES WATT," "HAD BEEN REFINING THE STEAM ENGINE" "MAKING IT BETTER, MORE POWERFUL," "AND, MOST IMPORTANT, MORE EFFICIENT." "ONE AFTER ANOTHER, INGENIOUS DEVICES" "FOR SQUEEZING A LITTLE MORE WORK" "OUT OF A TON OF COAL" "CAME FORTH FROM INVENTORS." "BUT IT WAS JAMES WATT'S DISCOVERY" "OF A WAY TO COOL THE STEAM OUTSIDE THE MAIN CYLINDER," "USING A CONDENSER," "THAT GOT THE ERA OF THE STEAM ENGINE UNDER WAY." "WHEN IT COMES RIGHT DOWN TO THE STEAM ENGINE," "WHAT'S REALLY ESSENTIAL?" "OF ALL THE VALVES" "AND GEARS," "OF ALL THE BEAMS AND PIPES," "OF ALL THE GADGETS AND GAUGES," "OF ALL THE ENGINES" "WITH ALL THEIR BELLS AND WHISTLES" "AND WHATEVER WORKS TO CATCH THE BUYER'S FANCY" "WHAT IS THE VERY ESSENCE OF THE ENGINE?" "IT'S THE CYLINDER," "A CYLINDER WITH A MOVABLE END" "PUSHED BY PRESSURIZED STEAM." "OPENING A VALVE TO THE BOILER" "ADMITS HIGH-PRESSURE STEAM THAT PUSHES THE PISTON OUT," "DOING WORK ON THE FLYWHEEL." "THE FLYWHEEL PUSHES THE PISTON IN AGAIN," "EXPELLING SPENT STEAM THROUGH ANOTHER VALVE." "THE ENGINE IS READY FOR THE NEXT CYCLE." "AND SO IT GOES." "IN AND OUT, IN AND OUT." "NO MATTER THE PURPOSE OR DESIGN," "THE CYLINDER IS THE KEY." "EVERYTHING ELSE IS BELLS AND WHISTLES." "WITH THE BASIC STEAM ENGINE IN MIND," "SADI CABNOT ASKED NOT HOW TO MAKE IT BETTER," "BUT WHAT IS THE MOST EFFICIENT STEAM ENGINE" "THAT NATURE WILL ALLOW?" "LOOKING FOR THE ANSWER," "SADI CARNOT FOUND HIS INSPIRATION" "IN THE WATER WHEEL." "THE STEAM ENGINE WASN'T THE FIRST INVENTION" "TO EASE PHYSICAL LABOR'S BURDENS." "SINCE ANCIENT TIMES, BEASTS DID THEIR SHARE" "OF PLOWING AND MILLING," "OF PUMPING IRRIGATION WATER," "AND CARRYING CROPS TO MARKET." "AS A STEP AWAY FROM AGRARIAN CULTURE" "AND TOWARD THE INDUSTRIAL REVOLUTION" "AND ITS OWN BEASTLY MACHINES," "THE WATER WHEEL, NOT THE STEAM ENGINE," "CAME FIRST." "AND AS WATER POWERED THE LOOMS" "OF THE BRITISH TEXTILE INDUSTRY," "OTHER FLUIDS BEGAN MAKING THE ROUNDS" "IN THE MOST SCHOLARLY CIRCLES OF THE DAY." "THE SCIENTIFIC WORLD," "REGROUPING IN THE WAKE OF SIR ISAAC NEWTON," "BEGAN REALIZING THAT NOT ALL NATURAL PHENOMENON" "WERE EXPLAINED IN THE PRINCIPIA." "FOR A WHILE, A VARIETY OF MYSTERIOUS FLUIDS" "BECAME A POPULAR SOLUTION" "FOR ANY NUMBER OF PHYSICAL PUZZLES." "FOR EXAMPLE, THE SOLUTION TO THE PROBLEM" "OF ELECTRICITY" "WAS A FLUID FLOWING FROM THE MIND" "OF BENJAMIN FRANKLIN." "MEANWHILE, BACK ON THE CONTINENT," "JOSEPH PRIESTLY TRIED TO SOLVE THE PROBLEM OF COMBUSTION," "FIRE ITSELF," "AND THE RELATED PROBLEM OF METALS RUSTING." "PRIESTLY WAS A CHEMIST," "AND HIS SOLUTION WAS A FLUID, PHLOGISTON," "A SUBTLE WEIGHTLESS FLUID THAT, LIKE ELECTRICITY," "COMBINED WITH ORDINARY MATTER TO MAKE METALS" "AND ESCAPED WHEN METALS RUSTED." "ANOTHER PROBLEM WAS HEAT," "WHICH, FOR ALL PRACTICAL PURPOSES," "FLOWED LIKE A LIQUID FROM ONE BODY TO ANOTHER." "TO A CENTURY ALREADY AWASH IN FLUIDS," "A HEAT FLUID CALLED CALORIC" "BUT THERE WAS ONE FLUID THAT NEEDED NO INVENTING." "EVEN AS CARNOT STRUGGLED" "TO UNDERSTAND THE POWER OF STEAM," "THE COUNTRYSIDE ABOUNDED WITH EXAMPLES OF WATERPOWER." "JUST AS WATER WHEELS ARE RUN BY WATER" "FLOWING FROM A HIGH PLANE TO A LOWER PLANE," "A STEAM ENGINE, HE THOUGHT, RUNS BY CALORIC" "FLOWING FROM HIGH TEMPERATURE TO LOW TEMPERATURE." "WITH THIS SIMPLE PICTURE IN MIND," "SADI CARNOT HAD FOUND THE KEY TO NATURE'S LIMIT" "ON HOW EFFICIENT A STEAM ENGINE COULD BE." "THAT IDEA WAS THE STARTING POINT" "OF CARNOT'S THEORY." "IT STILL REMAINS ONE OF THE BASIC FOUNDATIONS" "OF PHYSICS." "OF COURSE, NOW IT'S CALLED" "CARNOT REALIZED THAT A WATER WHEEL," "RUNNING BACKWARDS," "COULD BE USED TO LIFT WATER UPHILL." "HE COULD EVEN IMAGINE" "ONE WATER WHEEL DRIVING ANOTHER IN REVERSE" "FALLING WATER ON ONE SIDE" "BEING USED TO RAISE WATER ON THE OTHER SIDE." "HE KNEW THE MACHINE COULD NEVER RAISE MORE WATER UPHILL" "THAN WAS FLOWING DOWNHILL." "APPLIED TO THE FLOW OF HEAT INSTEAD OF WATER," "THAT PRINCIPLE BECAME" "WITH THIS INSIGHT," "CARNOT KNEW THAT THE BEST ENGINE NATURE WOULD ALLOW" "COULD RUN EQUALLY WELL BACKWARDS AND FORWARDS," "AN ENGINE THAT COULD TAKE HEAT" "AT LOW TEMPERATURE" "AND RAISE IT TO HIGH TEMPERATURE." "IN AN ORDINARY ENGINE," "HIGHER TEMPERATURE HEAT" "FLOWS IN," "WORK IS DONE," "AND HEAT FLOWS BACK OUT" "AT LOW TEMPERATURE." "CARNOT IMAGINED AN ENGINE" "THAT COULD WORK IN REVERSE." "HEAT WOULD FLOW IN" "AT LOW TEMPERATURE," "WITH THE HELP OF WORK" "SUPPLIED FROM OUTSIDE," "AND HEAT WOULD BE DEPOSITED" "AT HIGH TEMPERATURE." "THERE'S A NAME FOR A MACHINE" "THAT WORKS THAT WAY." "IT'S CALLED A REFRIGERATOR." "A REFRIGERATOR, WITH THE HELP OF A MOTOR," "REMOVES HEAT WHERE IT'S ALREADY COLD" "AND DEPOSITS HEAT AT HIGHER TEMPERATURE" "OUTSIDE OF ITSELF." "THE IDEA IS NOT UNCOMMON TODAY," "BUT IN THE 1820's, CARNOT HAD A CHALLENGE" "HOW TO DESIGN A STEAM ENGINE" "THAT COULD WORK EQUALLY WELL AS A REFRIGERATOR." "CARNOT STARTED BY REDUCING THE ENGINE" "TO ITS ESSENTIALS" "NO BOILER," "NO FLYWHEEL," "NO VALVES." "HE DID NEED A CYLINDER AND A MOVABLE PISTON," "BUT HE COULD EVEN DO WITHOUT STEAM" "BECAUSE THE CYLINDER COULD BE FILLED WITH AIR." "HEAT IT, AND THE AIR EXPANDS," "DRIVING THE PISTON OUTWARD." "COOL IT, AND THE AIR CONTRACTS," "MAKING IT EASY TO PUSH THE PISTON BACK IN." "HEAT FLOWS IN AT HIGH TEMPERATURE" "AND THE PISTON DOES WORK." "AS THE CYLINDER COOLS," "IT TAKES WORK TO PUSH THE PISTON IN." "BUT SINCE IT'S COOLER," "THE AIR INSIDE EXERTS LESS PRESSURE," "SO IT TAKES LESS WORK." "THERE'S SOME NET WORK GAIN BY THE MACHINE." "THERE IT IS-- THE ESSENTIAL ENGINE." "HEAT ENERGY GOES IN" "AND LESS HEAT ENERGY COMES OUT." "AND THE DIFFERENCE COMES OUT AS USEFUL WORK." "THE ESSENTIAL ENGINE SHARES THE MOST IMPORTANT FEATURES" "OF ALL REAL ENGINES" "HEAT GOES IN, WORK GETS DONE," "AND HEAT MUST ALWAYS BE EXPELLED" "AT LOWER TEMPERATURE" "TO MAKE THE ENGINE READY FOR THE NEXT STROKE." "BUT THERE IS A PROBLEM." "HEAT FLOWS EASILY FROM A HOT SOURCE" "INTO A COLD CYLINDER," "OR FROM A HOT CYLINDER INTO A COLD SOURCE," "BUT THOSE STEPS CANNOT RUN IN REVERSE." "THEY WOULD REQUIRE HEAT TO RUN THE WRONG WAY." "CARNOT'S IDEAL ENGINE," "THAT WORKS EQUALLY WELL BACKWARDS AS FORWARDS," "COULD NOT USE THOSE TWO STROKES." "TO MAKE A REVERSIBLE STROKE," "THE CYLINDER WOULD HAVE TO BE HOT" "BEFORE THE HEAT RUNS IN." "ALLOW THE HOT GAS TO EXPAND," "AND MORE HEAT FLOWS IN DOING WORK." "PUSH THE PISTON BACK IN" "AND HEAT FLOWS THE OTHER WAY." "THAT'S A REVERSIBLE STROKE." "IT TAKES PLACE AT CONSTANT TEMPERATURE," "SO IT'S CALLED ISOTHERMAL." "HEAT GOES IN, THE GAS EXPANDS," "AND WORK IS DONE." "NEXT, A BRILLIANT STROKE" "ISOLATED FROM THE HEAT SOURCE," "GAS IS ALLOWED TO EXPAND, DOING MORE WORK." "SINCE THERE IS NO EXTERNAL SOURCE OF HEAT," "IT COMES FROM THE INTERNAL ENERGY OF THE GAS," "CAUSING IT TO COOL." "THIS STEP IS ALSO REVERSIBLE," "AND IT'S CALLED ADIABATIC." "NOW THE CYLINDER IS READY FOR ANOTHER ISOTHERMAL STEP," "THIS TIME USING UP SOME WORK" "TO EXPEL HEAT AT LOW TEMPERATURE." "FINALLY, A ADIABATIC SQUEEZE WARMS THE GAS," "GETTING IT BACK TO THE STARTING POINT," "READY FOR ANOTHER CYCLE." "ON EACH CYCLE," "SOME NET WORK IS DONE," "AS IN A REAL ENGINE." "EACH STEP WORKS EQUALLY WELL" "RUNNING BACKWARDS." "SO, THE CARNOT ENGINE" "IS BOTH AN ENGINE" "AND A REFRIGERATOR," "WORKING EQUALLY WELL" "IN BOTH DIRECTIONS" "A PERFECTLY REVERSIBLE MACHINE." "CARNOT'S ENGINE WORKS PERFECTLY ONLY IN THE IMAGINATION," "BUT IT HAS A LOT IN COMMON WITH A REAL ENGINE." "LIKE A REAL STEAM ENGINE," "THE CARNOT ENGINE USES A HEAT SOURCE" "AT HIGH TEMPERATURE." "IT ALSO NEEDS A PLACE TO RELEASE HEAT" "AT A LOWER TEMPERATURE" "AND A CYLINDER" "WHERE GASES CAN EXPAND AND CONTRACT." "JUST ABOUT THERE, THE SIMILARITIES END," "AND THE REAL CHALLENGE BEGINS." "HOW COULD CARNOT PROVE" "THAT HIS WAS THE MOST EFFICIENT ENGINE POSSIBLE?" "THE ANSWER MAY BE FOUND" "BY COMPARING A REAL ENGINE" "WITH THE CARNOT ENGINE." "BURNING FUEL PRODUCES AN AMOUNT OF HEAT, Qi," "AT HIGH TEMPERATURE, Ti." "PUT THAT HEAT" "INTO THE CARNOT ENGINE" "AND IT DOES WORK, W." "THE EFFICIENCY OF THE ENGINE" "IS THE WORK OUT" "DIVIDED BY THE HEAT IN." "COULD A REAL ENGINE BE MORE EFFICIENT" "THAN A CARNOT ENGINE," "REQUIRING LESS HEAT IN--Qir" "TO PRODUCE THE SAME AMOUNT OF WORK?" "IF SO, THAT WORK" "COULD MAKE THE CARNOT ENGINE" "RUN BACKWARDS." "IF THE REAL ENGINE WERE CONNECTED," "TO THE CARNOT ENGINE," "THE EFFECT WOULD BE SIMILAR" "TO CARNOT'S HYPOTHETICAL WATER WHEELS." "THE REAL MACHINE DOES WORK" "THE EXACT AMOUNT OF WORK" "THE CARNOT ENGINE NEEDS" "TO RUN BACKWARDS." "IF THE REAL ENGINE" "WERE MORE EFFICIENT," "Qir WOULD BE SMALLER THAN Qi." "WHEN THE TWO ENGINES" "ARE CONNECTED," "THEY MAKE HEAT RUN UPHILL." "BUT THAT VIOLATES" "IF THIS LAW IS CORRECT," "THE REAL ENGINE CAN'T BE" "MORE EFFICIENT THAN A CARNOT." "OPERATING BY HEAT" "FLOWING FROM HIGH TEMPERATURE" "TO LOW TEMPERATURE," "THE CARNOT ENGINE IS MORE EFFICIENT" "THAN A REAL ENGINE." "SINCE THE SECOND LAW IS CORRECT," "THE CARNOT ENGINE" "IS THE MOST EFFICIENT ENGINE MOTHER NATURE ALLOWS." "CARNOT BEGAN WITH A BRILLIANT ANALOGY" "THE WATER WHEEL" "AND CONCLUDED WITH THE ESSENCE" "OF THE MOST EFFICIENT ENGINE POSSIBLE" "BETWEEN TWO TEMPERATURES." "BUT CARNOT'S ANALOGY WASN'T ENTIRELY CORRECT." "UNLIKE WATER IN A WHEEL," "HEAT DOESN'T MERELY FLOW THROUGH AN ENGINE." "SOME HEAT GETS USED UP AND ACTUALLY TURNS INTO WORK." "IN CONSIDERING THE LAW OF THE CONSERVATION OF ENERGY," "IT'S VERY EASY TO ASK CARNOT'S QUESTION" "AND COME UP WITH THE WRONG ANSWER." "IF AN ENGINE USES HEAT" "TO PRODUCE WORK," "THE MOST EFFICIENT ENGINE" "WOULD SEEM TO BE ONE" "THAT TURNS ALL HEAT INTO WORK." "BUT THAT'S THE WRONG ANSWER." "EVEN BEFORE THE LAW OF THE CONSERVATION OF ENERGY," "CARNOT REALIZED SOME HEAT MUST FLOW OUT" "OF ANY ENGINE AT LOW TEMPERATURE." "THAT WAS THE POINT OF WATT'S CONDENSER" "AND THE REASON EVERY CAR NEEDS A EFFICIENT COOLING SYSTEM." "ACCORDING TO THE LAW OF THE CONSERVATION OF ENERGY," "THE WORK DONE IS THE DIFFERENCE" "BETWEEN THE HEAT IN AND THE HEAT OUT," "SO THE EFFICIENCY OF ANY ENGINE" "IS ALWAYS LESS THAN 1." "CARNOT'S ORIGINAL LOGIC WAS SO PRECISE" "THAT IT REMAINED VALID" "EVEN WITH THE DISCOVERY OF THE CONSERVATION OF ENERGY." "NO ENGINE, NOT EVEN A CARNOT ENGINE," "CAN REACH THE GOAL OF PERFECT EFFICIENCY." "BUT THEN HOW EFFICIENT CAN A CARNOT ENGINE BE?" "IT DEPENDS ON THE TEMPERATURE." "THE HOTTER THE HIGH TEMPERATURE" "AND THE COOLER THE LOW TEMPERATURE," "THE MORE EFFICIENT THE ENGINE." "IN FACT, LATER GENERATIONS WOULD DISCOVER" "THAT FOR A CARNOT ENGINE," "Qo OVER Qi" "IS EQUAL TO To OVER Ti." "AND THAT'S THE MOST EFFICIENT" "AN ENGINE CAN BE." "SADI CARNOT DIED IN 1832." "HE WAS ONLY 36 YEARS OLD." "HE DIED TRAGICALLY IN HIS YOUTH" "OF SCARLET FEVER." "DURING HIS LIFETIME, HE WASN'T REALLY FAMOUS." "HE WAS RESPECTED, BUT HE WAS AN ENGINEER." "ENGINEERS TRY TO BUILD BETTER MACHINES." "CARNOT'S IDEAS, CLEVER AS THEY WERE," "HELPED NO ONE BUILD A BETTER MACHINE." "ALTHOUGH HE WAS RESPECTED," "NOBODY GOT STEAMED UP ABOUT WHAT HE HAD DONE." "WHEN JOULE CAME ALONG" "AND DISCOVERED THE CONSERVATION OF ENERGY," "THE SITUATION FOR CARNOT GOT EVEN WORSE." "HIS REASONING WAS BASED ON A FAULTY FOUNDATION" "OF THE OLD CALORIC THEORY." "BUT A GERMAN PHYSICIST" "BY THE NAME OF RUDOLF CLAUSIUS" "CAME ALONG AT THAT POINT AND RESCUED CARNOT'S IDEAS." "WHAT CLAUSIUS HAD SHOWN WAS THAT IN AN IDEAL ENGINE" "THERE IS SOMETHING WHICH IS THE SAME GOING IN" "AS IT IS COMING OUT." "SOMETHING IS CONSERVED IN AN IDEAL ENGINE." "IT ISN'T ENERGY," "IT'S THE RATIO OF HEAT IN" "TO THE TEMPERATURE AT WHICH IT GOES IN." "CLAUSIUS NAMED THAT IDEALLY CONSERVED QUANTITY," "SOMETIMES CONSERVED QUANTITY" "HE CALLED IT ENTROPY." "IF I HAD TO SUMMARIZE THE HISTORY OF THE STEAM ENGINE," "I WOULD SAY THIS" "JAMES WATT, WHO WANTED TO MAKE MONEY," "INVENTED A MORE EFFICIENT STEAM ENGINE." "SADI CARNOT, WHO WANTED TO INVENT" "A MORE EFFICIENT STEAM ENGINE," "CHANGED OUR VIEW OF THE UNIVERSE" "BECAUSE OUR VIEW IS BASED ON THE PRINCIPLE" "THAT CAME OUT OF CLAUSIUS' ANALYSIS" "OF CARNOT'S WORK-- THE PRINCIPLE OF ENTROPY." "ENTROPY IS OUR NEXT SUBJECT." "CAPTIONING PERFORMED BY THE NATIONAL CAPTIONING INSTITUTE, INC." "CAPTIONS COPYRIGHT 1985 CALIFORNIA INSTITUTE OF TECHNOLOGY," "THE CORPORATION FOR COMMUNITY COLLEGE TELEVISION, AND THE ANNENBERG/CPB PROJECT" "Annenberg Media" "¶" "For information about this and other Annenberg Media programs call 1-800-LEARNER and visit us at"