"Annenberg Media" "¶" "CAPTIONING IS MADE POSSIBLE BY THE ANNENBERG/CPB PROJECT" "INA WORLD OFCONSTANTSHORTAGES," "ONEQUANTITYREMAINS INABUNDANTSUPPLY." "IT'SCALLEDENTROPY." "THE SCIENCE OF THERMODYNAMICS IS BASED" "ON FOUR FUNDAMENTAL POSTULATES OR AXIOMS" "WHICH ARE CALLED" "THE FOUR LAWS OF THERMODYNAMICS." "OF THESE FOUR LAWS," "THE SECOND LAW WAS DISCOVERED FIRST." "THE FIRST LAW WAS DISCOVERED SECOND." "THE THIRD TO BE DISCOVERED WAS CALLED THE zeroth LAW." "THE FOURTH LAW IS CALLED THE THIRD LAW." "ALL OF THAT MAKES PERFECT SENSE." "LET ME TELL YOU BRIEFLY WHAT THOSE FOUR LAWS ARE." "THE zeroth LAW JUST SAYS" "THAT THE IDEA OF TEMPERATURE MAKES SENSE." "THE FIRST LAW IS THE CONSERVATION OF ENERGY." "THE SECOND LAW IS THE ENTROPY PRINCIPLE." "THE THIRD LAW SAYS" "THAT THERE IS A TEMPERATURE SO LOW" "THAT IT CAN NEVER BE REACHED." "FROM THESE FOUR LAWS," "PEOPLE HAVE DEDUCED NOT ONLY THE PROPERTIES OF MATTER," "BUT THE ULTIMATE FATE OF THE UNIVERSE ITSELF." "IF WE'RE GOING TO GET ANYWHERE, WE BETTER START." "CHALKIE'S BILLIARD ACADEMY, AN INNER SANCTUM OF SORTS," "WHERE BEYOND THE HARSH GLARE OF THE LIMELIGHT," "CELEBRITIES OF SPORT, DANDIES OF HIGH SOCIETY," "AND CAPTAINS OF INDUSTRY" "GATHER TO PURSUE A COMMON INTEREST." "ONE MAY WONDER HOW THESE GENTLEMEN" "KEEP THEIR NAMES OUT OF THE NEWSPAPERS," "TO SAY NOTHING OF THE LEARNED JOURNALS." "THE OBSERVER MAY ASK," ""WHAT ARE NICE GUYS LIKE THESE DOING IN A PLACE LIKE THIS?"" "BUT TO THOSE IN THE KNOW, THEIR PURPOSE IS OBVIOUS" "TO INVESTIGATE THE LAWS OF THERMODYNAMICS." "BUT WHY CHALKIE'S?" "PARTLY, OF COURSE, IT'S THE AMBIANCE," "WHICH IS THE LAST WORD IN UNDERSTATED ELEGANCE." "THAT GOES WITHOUT SAYING." "MOSTLY IT'S THE EQUIPMENT," "SPECIAL APPARATUS THAT IN THE INTERESTS OF SCIENCE" "CHALKIE'S ALWAYS SEEMS TO HAVE ON HAND." "EVEN NOW, TWO DISTINGUISHED SCIENTISTS HOLD BEAKERS." "HELD WITH THE GREATEST CARE," "EACH BEAKER CONTAINS A LITTLE EXPERIMENTAL FLUID," "WHICH, UNFORTUNATELY, IS AN ACQUIRED TASTE." "HOWEVER, BEFORE THINGS BEGAN TO GET OUT OF HAND," "THE FLUID WAS POURED INTO THE BEAKERS" "AT A TEMPERATURE OF 295 KELVINS." "AND WITH SCIENTIFIC PRECISION," "SEVERAL GEOMETRICAL CUBES OF CRYSTALLINE H20" "WERE ADDED." "INITIAL TEMPERATURE OF THE CRYSTALS-- 273 KELVINS." "AS TIME PASSES," "HEAT FROM THE WARM FLUID FLOWS INTO THE CUBES," "BUT THE ICE FAILS TO WARM UP IN RESPONSE." "THE CUBES DON'T MELT AT ONCE," "WHICH STIRS UP A SCIENTIFIC CONTROVERSY." "THIS CALLS FOR MORE TESTS." "DURING 126 EXPERIMENTS-- BUT WHO'S COUNTING" "NONE OF THE CHALKIE SCIENTISTS CAN FIND" "A SINGLE INSTANCE OF A WARM ICE CUBE." "BUT THEY HAVE FOUND" "A DILUTION OF THE PROPERTIES" "OF THE EXPERIMENTAL FLUID." "THE ICE, STAYING AT A CONSTANT TEMPERATURE OF 273 KELVINS," "MELTS INTO LIQUID WATER AS HEAT FLOWS INTO IT." "WHAT ACCOUNTS FOR THIS STRANGE BEHAVIOR IN CHALKIE'S," "OR FOR THAT MATTER, EVERYWHERE IN THE WORLD?" "EVENTUALLY, OF COURSE, ICE MELTS." "BUT ALONG THE WAY, IN ITS SOLID STATE," "WHY WON'T IT WARM UP?" "IN ANY CASE, IN THE END, THE ICE, THE EXPERIMENTAL FLUID," "AND EVERYTHING ELSE" "REACHES A STATE OF EQUILIBRIUM." "SOMEWHERE, AT LEAST IN THEORY," "THERE'S A HEAVENLY STATE CALLED EQUILIBRIUM." "BUT IN THE REAL WORLD, EQUILIBRIUM IS HARD TO FIND." "ON A POLYNESIAN ISLE, THE PLANET CRANKS UP" "AND LIQUID FIRE BUBBLES FROM DOWN BELOW." "IN THE POLAR CENTER OF THE ARCTIC OCEAN," "THE WORLD'S ORIGINAL ICE MACHINE" "WORKS AROUND THE CLOCK." "IN THE DEEP AND DARKEST HEART OF EQUATORIA," "THE SUN SEARS A SAVANNA WITH A RELENTLESS REGULARITY." "A SHOUT AWAY," "LIQUID THUNDERS TO THE ROCKS BELOW." "FROM THE BEGINNING TO THE ENDS OF THE EARTH," "THE EARTH ITSELF IS A GREAT MACHINE," "A FACTORY THAT NEVER RUNS DOWN," "NEVER TAKES A BREAK OR GOES ON STRIKE" "THE ENGINE OF NATURE, A POWERHOUSE DRIVEN NONSTOP" "BY THE LIMITLESS ENERGY OF THE SUN." "WHETHER IT'S TRADE WINDS OF THE OCEANS" "OR THE DIESEL ENGINES OF SHIPS THAT PLY THEM," "ALL ENGINES WORK BECAUSE HEAT IN MOTION" "CAN SET MATTER INTO MOTION." "FOR SEVERAL HUNDRED YEARS," "THE HEAT ENGINE HAS GONE FAR AND WIDE." "BUT PAST OR PRESENT," "THE HEAT ITSELF GOES ONLY ONE WAY," "FROM HIGH TO LOW TEMPERATURE." "THE EXISTENCE OF ANY ENGINE ON EARTH," "INCLUDING THE EARTH ITSELF," "DEPENDS ON ONE OF ITS PARTS" "WORKING AT A HIGHER TEMPERATURE THAN ANOTHER." "IN NATURE'S ENGINE, FOR EXAMPLE," "POWERFUL CURRENTS ARE DRIVEN THROUGH THE EARTH'S ATMOSPHERE" "BY THE DIFFERENCE BETWEEN THE EQUATOR'S TEMPERATURE" "AND THE TEMPERATURE AT THE POLES." "FROM POLE TO POLE AND ENGINE TO ENGINE," "THE PRINCIPLE IS THE SAME." "IN THIS VEHICLE, IT'S THE DIFFERENCE" "BETWEEN THE TEMPERATURE OF THE EXPLODING GASOLINE AND AIR" "AND THE CIRCULATING WATER OF ITS COOLING SYSTEM." "STEAM ENGINES OPERATE BETWEEN" "THE FIREBOX'S HIGH TEMPERATURE" "AND THE ATMOSPHERE'S LOW TEMPERATURE." "THE BIGGER THE TEMPERATURE DIFFERENCE" "THE HOTTER IN ONE PART, THE COOLER IN ANOTHER" "THE BETTER THE ENGINE WORKS." "BUT IF THE FUEL STOPS FLOWING" "AND THE HOTTER PART COOLS DOWN," "THE ENGINE STOPS." "OBVIOUSLY, THAT CAN SPELL TROUBLE." "IF EVERY PART OF THE ENGINE HAS THE SAME TEMPERATURE," "IF ALL MOTION CEASES AND THERE'S NO VITALITY LEFT," "THE ENGINE REACHES ITS FINAL STATE" "THE STATE OF EQUILIBRIUM." "FROM A SCIENTIFIC PERSPECTIVE, THEN, WHAT'S THE PICTURE?" "IN THIS MOLECULAR DYNAMICS CALCULATION," "EACHPAIROF ATOMS ISPROGRAMMEDTO INTERACT" "WITHA REALISTIC INTERATOMICFORCE." "SO THEN WHAT REALLY HAPPENS" "WHEN A WARM BODY IS BROUGHT INTO CONTACT WITH A COLD ONE?" "THERMAL ENERGY SPREADS FROM WARM TO COLD" "UNTIL BOTH BODIES REACH THE SAME TEMPERATURE." "THIS IS THE STATE OF THERMAL EQUILIBRIUM." "AT FIRST GLANCE," "THERMAL EQUILIBRIUM SEEMS DIFFERENT" "FROM THE MECHANICAL IDEA OF STABLE EQUILIBRIUM," "WHICH KEEPS A BODY SAFE FROM FALLING." "WHEN A FALLING BODY HITS THE GROUND," "EACH BOUNCE IS SMALLER THAN THE LAST." "IT'S BECAUSE THE KINETIC ENERGY OF THE WHOLE BODY" "BECOMES TRANSFORMED INTO THE CHAOTIC MOTIONS" "OF THE ATOMS THAT COMPOSE IT." "THAT PROCESS IS SIMILAR" "TO HEAT FLOWING INTO A COLD BODY." "THE END RESULT IS THE SAME." "ALL OF THE AVAILABLE ENERGY EVENTUALLY BECOMES SHARED" "AS KINETIC AND POTENTIAL ENERGY" "OF RANDOM MOTIONS OF ALL THE ATOMS." "ALTHOUGH THE IDEA OF EQUILIBRIUM" "SEEMS THE ULTIMATE IN SERENITY," "THAT VIEW HIDES THE SEETHING MOTION OF THE ATOMS WITHIN." "SO UNDERSTANDING EQUILIBRIUM IS A MATTER OF PERSPECTIVE," "OF SEEING WITHIN, AND OF SEEING BEYOND." "BECAUSE EQUILIBRIUM IS A STATE" "IN WHICH ALL TEMPERATURES ARE EQUAL," "IT'S A PLACE WHERE NO MACHINES OPERATE," "NO GEYSERS SPRAY," "NO VOLCANOES ERUPT," "NO WATER FALLS." "NO BIG ENGINES WANT TO DO ANY WORK," "AND NO LITTLE ENGINES CAN." "EVERYWHERE, NATURE SEEMS IMPELLED" "TOWARD THE STATE OF EQUILIBRIUM" "HOT BODIES AND COLD ONES" "STRIVING TOWARD THE SAME TEMPERATURE," "AND FALLING BODIES TURNING PERFECTLY GOOD WORK" "INTO USELESS HEAT." "FROM THE PHYSICIST'S POINT OF VIEW," "WHEN NATURE BEHAVES IN SUCH A UNIVERSAL FASHION," "THERE MUST BE A SCIENTIFIC EXPLANATION." "AND THERE IS." "THE EXPLANATION BEGAN AS AN IDEA, OF COURSE," "AN IDEA FOR THE CONSTRUCTION OF A BETTER STEAM ENGINE." "AMANNAMEDCARNOT WASABLETO SHOW" "FOR A WORK SOURCE PROFICIENT, THERE'S NONE SO EFFICIENT" "ASANENGINE THATSIMPLYWON'TGO." "SADI CARNOT'S GREATEST IDEAS NEVER WORKED," "AND IN THE REAL WORLD PROBABLY NEVER WILL." "YET HE WANTED TO CREATE AN ENGINE" "AS PERFECT AS NATURE WOULD PERMIT," "AND THE LOGIC TO COME PRETTY CLOSE." "GIVENA DIFFERENCE INTEMPERATURE" "AHIGHTEMPERATURETi," "ANDA LOWTEMPERATURETo- " "CARNOTDESIGNED" "APERFECTABSTRACTION." "HIS ENGINE TAKES IN HEAT, Qi," "ATTHEHIGHTEMPERATURE," "TURNSSOMEINTOWORK,W," "ANDEXPELSTHEREST,Qo," "ASHEAT" "ATTHELOWERTEMPERATURE." "BECAUSE THE CARNOT CYCLE COULD RUN" "JUST AS WELL IN REVERSE," "IT WAS THE PICTURE" "OF THE IDEAL ENGINE," "THE MOST EFFICIENT MACHINE NATURE'S LAWS COULD PERMIT." "BUT WITH CARNOT'S EARLY DEATH," "HIS IDEAS SEEMED DESTINED FOR OBLIVION." "THAT'S PROBABLY WHERE THEY WOULD HAVE ENDED" "HAD NOT TWO GREAT SCIENTISTS" "TAKEN AN INTEREST IN CARNOT'S THEORY." "RUDOLF CLAUSIUS, A GERMAN PHYSICIST," "AND WILLIAM THOMSON," "THE GLASGOW PROFESSOR OF NATURAL PHILOSOPHY" "WHO WOULD BECOME LORD KELVIN," "RESCUED CARNOT'S ORIGINAL WRITINGS" "AND FROM THESE VERY PAGES BROUGHT FORTH" "THE SCIENCE OF THERMODYNAMICS." "WITHIN CARNOT'S REASONING," "CLAUSIUS AND THOMSON SAW AN AMAZING FACT." "THEY SAW IT IN TERMS" "OF AN ASTONISHING MATHEMATICAL SIMPLICITY." "IN CARNOT'S IDEAL ENGINE," "THE RATIO OF THE HEAT TAKEN IN TO THE HEAT WASTED" "WAS THE SAME AS THE RATIO" "OF THE TWO ABSOLUTE TEMPERATURES" "NEEDED TO DRIVE THE ENGINE." "THIS WAS THE IDEAL" "THAT STEMMED FROM CARNOT'S IMAGINATION" "SOMETHING THAT GOES IN" "IS THE SAME WHEN IT COMES OUT." "IF IT'S NOT THE HEAT OR THE TEMPERATURE," "WHAT IS IT?" "THE HEAT DIVIDED BY THE TEMPERATURE" "AT WHICH IT FLOWS." "ACCORDING TO CLAUSIUS," "THAT'S ENTROPY." "IN A CARNOT ENGINE," "ENTROPY FLOWS IN AT HIGH TEMPERATURE," "DOES ITS JOB," "AND THE SAME AMOUNT OF ENTROPY" "FLOWS OUT AT LOW TEMPERATURE." "SO AN IDEAL ENGINE" "NOT ONLY CONSERVES ENERGY," "IT CONSERVES ENTROPY AS WELL." "THAT'S THE IDEAL." "BUT WHAT ABOUT THE REALITY?" "IN THE REAL WORLD," "WITH THE CLANKING, PUFFING ENGINE," "WHAT REALLY HAPPENS?" "FOR ONE THING, ALL ENGINES CONSERVE ENERGY." "THE WORK EQUALS THE DIFFERENCE BETWEEN THE HEAT IN" "AND THE HEAT LEFT OVER." "BUT USING THE SAME TEMPERATURES," "A REAL ENGINE DOES LESS WORK THAN CARNOT'S IDEAL." "IT DOES LESS WORK," "LEAVING MORE HEAT TO RELEASE." "EVEN THOUGH THE ENTROPY FLOWING IN" "MIGHT BE THE SAME AS CARNOT'S," "THE ENTROPY THAT FLOWS OUT" "IS BIGGER." "THAT'S AN AMAZING FACT." "THE ENTROPY THAT FLOWS OUT OF A REAL ENGINE" "IS BIGGER THAN THE ENTROPY THAT FLOWS IN." "DO REAL ENGINES CREATE ENTROPY OUT OF NOTHING?" "YES." "THAT'S BECAUSE IN REAL ENGINES HEAT FLOW ISN'T ISOTHERMAL." "POWER STROKES AREN'T ADIABATIC." "THERE'S ALWAYS FRICTION BETWEEN MOVING PARTS." "NO MATTER WHAT THE FINAL PRODUCT WILL BE," "ALL REAL ENGINES MANUFACTURE ENTROPY." "NO MATTER THE CONDITIONS IN THE WORK PLACE," "THE SUPPLY OF ENTROPY ALWAYS INCREASES." "NO MATTER THE WORK PLACE," "HUMANS DON'T OWN THE PATENT ON THE MANUFACTURE OF ENTROPY." "DAY IN AND DAY OUT," "MOTHER NATURE'S MACHINES CRANK OUT ENTROPY." "NOBODY ON EARTH CAN COMPETE WITH HER OUTPUT." "EVERY BODY OF MATTER IN THE UNIVERSE" "CONTAINS SOME ENTROPY." "ALTHOUGH IT ISN'T ALWAYS EASY TO TELL" "HOW MUCH ENTROPY A BODY HAS," "IT ISN'T HARD TO DETERMINE" "WHEN ENTROPY FLOWS FROM ONE BODY TO ANOTHER." "IF HEAT FLOWS OUT OF A BODY ATTEMPERATURE"T "," "THEENTROPYOF THEBODY DECREASESBYQ/ T." "IFHEATFLOWSIN," "THEBODY'SENTROPY INCREASESBYTHATAMOUNT." "THROUGHOUT THE COSMOS, WHEN AND WHERE HEAT FLOWS," "ENTROPY FLOWS WITH IT." "ALL ENGINES EXTRACT HEAT FROM SOMEWHERE" "THE SUN, PERHAPS, OR A SHIP'S BOILER" "USE SOME OF IT TO DO THEIR WORK, AND THEN RELEASE THE REST." "WHERE THE HEAT'S RELEASED DOESN'T MATTER TOO MUCH." "IT FLOWS INTO THE ATMOSPHERE, THE SEA," "ANYWHERE THAT'S COOL" "AND TOO LARGE TO BE AFFECTED BY THE FLOW OF HEAT." "ENGINES DESIGNED BY HUMANS OPERATE THE SAME WAY" "AS THE ONES MOTHER NATURE COOKS UP." "WHILE HEAT FLOWS FROM HIGH TO LOWER TEMPERATURES," "THINGS KEEP ROLLING." "AS LONG AS THERE'S FUEL" "COAL, OIL, WOOD, OR WHATEVER WORKS" "THEY'LL KEEP ROLLING." "BUT IF THE FUEL IS CUT OFF, THE HEAT CEASES FLOWING." "THE BODY COOLS." "ITS TEMPERATURE LOWERS LITTLE BY LITTLE." "WHEN IT'S THE SAME TEMPERATURE AS ITS SURROUNDINGS," "IT'S IN A STATE OF EQUILIBRIUM." "AS LONG AS HEAT FLOWS" "AND A WARM BODY IS WARMER THAN THE COOL ONE," "ENTROPY WILL INCREASE." "IT WILL CONTINUE TO INCREASE" "UNTIL NOTHING ELSE CAN POSSIBLY HAPPEN" "THE STATE OF EQUILIBRIUM." "SHOULD THAT HAPPEN, ENTROPY WOULD INCREASE NO MORE." "IN OTHER WORDS," "THE STATE OF EQUILIBRIUM IS THE STATE OF MAXIMUM ENTROPY." "ALL OF NATURE'S PROCESSES CAN BE SEEN" "AS A CONSTANT DRIVE TO INCREASE ENTROPY" "THROUGHOUT THE UNIVERSE." "THOUGH THESE FACTS HAVE BEEN ESTABLISHED" "IN MOST SCIENTIFIC CIRCLES," "SOME DEDICATED RESEARCHERS WON'T LEAVE WELL ENOUGH ALONE." "THAT'S BECAUSE ONE FACT STILL PUZZLES THE MOST CURIOUS." "THOUGH ICE MELTS AS HEAT FLOWS INTO IT" "FROM THE EXPERIMENTAL FLUID," "THE ICE DOESN'T WARM UP WHILE THERE'S ANY SOLID LEFT." "AFLOWOF HEAT" "CAUSESTHETRANSFORMATION OFICEINTOWATER" "ATA CONSTANTTEMPERATURE." "THEREFORE, INCHANGINGFROMICE ," "THEWATER'SENTROPY ISINCREASED." "SO WATER IS A STATE OF HIGHER ENTROPY THAN ICE." "ANY SOLID IS A STATE OF LOWER ENTROPY" "THAN THE SAME MATTER IN LIQUID FORM." "LIQUID IS A MORE DISORDERED STATE OF MATTER" "THAN SOLID IS." "IT HAS A HIGHER ENTROPY." "ON LAND AND SEA OR SEA ON LAND" "OR ANYWHERE IN THE UNIVERSE" "INCREASING ENTROPY MEANS INCREASING DISORDER." "THE ICE ITSELF, A CRYSTALLINE SOLID," "IS A STATE OF MATTER" "IN WHICH MOLECULES EXIST" "IN A NEAT, GEOMETRICALLY SYMMETRIC FRAMEWORK." "IN A SOLID," "WHEN THE ATOMS CLUSTER" "IN THE MOST FAVORABLE CONFIGURATION," "THE MOLECULES ARE ARRANGED" "TO REDUCE THEIR POTENTIAL ENERGY TO A MINIMUM." "WATER'S A DIFFERENT PICTURE." "REMEMBER" "LIQUID MOLECULES ARE CHAOTIC," "SCATTERED AND DISORGANIZED." "OBVIOUSLY, LIQUID MOLECULES DON'T MINIMIZE" "THEIR POTENTIAL ENERGY AS THE SOLIDS DO." "SO LIQUIDS NOT ONLY HAVE" "MORE ENTROPY THAN SOLIDS," "THEY ALSO HAVE HIGHER POTENTIAL ENERGY" "AND, THEREFORE, MORE TOTAL ENERGY." "TO MELT OR NOT TO MELT, THAT'S THE QUESTION." "IF THE DYNAMIC ISN'T CLEAR AS CRYSTAL" "IN THIS CASE, AN ICE CRYSTAL" "LOOK AT IT FROM THE ICE CUBE'S VIEWPOINT." "IF THE ICE MELTS, IT BECOMES WATER," "A STATE OF HIGHER ENTROPY." "NATURE LOVES TO INCREASE ENTROPY." "BEFORE MELTING," "THE ICE MUST ALSO INCREASE ITS ENERGY," "WHICH REQUIRES EXTRACTING ENERGY" "FROM THE REST OF THE UNIVERSE." "BUT IF HEAT ENERGY" "FLOWS OUT OF THE WORLD" "INTO THE ICE," "IT REDUCES THE ENTROPY" "OF THE UNIVERSE," "AND THAT'S NOT GOOD." "HOW BAD IS IT?" "THE ENTROPY OF" "THE REST OF THE WORLD" "DECREASES BY THE ENERGY FLOWING" "DIVIDED BY THE TEMPERATURE." "NATURE ALWAYS WANTS" "TO INCREASE ENTROPY," "IN THIS CASE" "THE ENTROPY OF THE ICE" "PLUS THE REST OF THE UNIVERSE." "IF THE TEMPERATURE'S VERY SMALL," "IT'S VERY BAD INDEED." "MELTING THE ICE WOULD CAUSE" "A BIG DECREASE IN ENTROPY" "OF THE ENTIRE UNIVERSE." "IF THE TEMPERATURE IS BIG," "IT'S NOT SO BAD." "THE COMBINED ENTROPY INCREASES" "WHEN ICE MELTS." "THAT'S WHY IN THE GRAND SCHEME OF THINGS," "ICE NEVER MELTS AT LOW TEMPERATURE," "AND ICE NEVER EXISTS AT HIGHER TEMPERATURE." "MEANWHILE, BACK IN CHALKIE'S," "TO SAY NOTHING OF THE UNIVERSE," "THERE'S A TEMPERATURE IN THE MIDDLE" "AT WHICH NEITHER ICE NOR WATER IS FAVORED." "IT'S THE ONLY TEMPERATURE" "AT WHICH BOTH ICE AND WATER CAN EXIST TOGETHER." "THAT'S WHY THESE SCIENTIFIC BEAKERS" "WILL NEVER WARM UP UNTIL ALL THE ICE HAS MELTED." "THE QUANTITY NATURE STRIVES TO MAXIMIZE" "IS NOT MERELY THE ENTROPY OF THE ICE." "AT A GIVEN TEMPERATURE," "IT IS ENTROPY MINUS THE ENERGY" "OVER THE TEMPERATURE OF THE ICE." "AS ENERGY MINUS TEMPERATURE TIMES ENTROPY OF ANY SAMPLE" "GETSSMALLER," "THEENTROPY OFTHEENTIREUNIVERSE" "GETSBIGGER." "E" " TSIS CALLED THEFREEENERGY." "ALTHOUGH THERE IS NO FREE LUNCH," "THERE'S PLENTY OF FREE ENERGY." "EVERY BIT OF MATTER IN THE WORLD" "MAKES ITS OWN SHARE OF FREE ENERGY" "AS SMALL AS POSSIBLE." "THAT'S WHAT IT TAKES" "SO WITHIN THE CONFINESY OF A SCIENTIFIC BEAKER," "AS WELL AS THROUGHOUT THE UNIVERSE," "THE LAW OF INCREASE OF ENTROPY" "DRIVES MATTER FROM ORDER TO DISORDER." "FOR SOME TIME, SOME HAVE THOUGHT THAT THE INCREASING ENTROPY" "IS DRIVING THE UNIVERSE ITSELF" "TOWARD THE ULTIMATE STATE OF DISORDER." "THEY CALL IT THE HEAT DEATH OF THE UNIVERSE." "IT'S NOT A PRETTY SIGHT." "IT'S A PROVOCATIVE NOTION." "DANGEROUS, TO SAY THE LEAST." "WILL ALL THIS INCREASING ENTROPY" "PLUNGE THE UNIVERSE INTO TOTAL CHAOS?" "IF SO, IT WON'T BE THE FIRST TIME" "THAT THE UNIVERSE'S FATE" "HAS BEEN DISCOVERED IN SCOTCH ON THE ROCKS." "THE ENTROPY PRINCIPLE HELPS US TO UNDERSTAND" "NOT ONLY THE EFFICIENCY OF STEAM ENGINES," "BUT WHY LIQUIDS FREEZE AND SOLIDS MELT" "AT CERTAIN TEMPERATURES." "SOME PEOPLE BELIEVE IT HAS A MORE PROFOUND MEANING." "THEY BELIEVE THAT THE ENTROPY PRINCIPLE" "DEFINES THE DIRECTION OF THE FLOW OF TIME ITSELF." "LET ME EXPLAIN." "SUPPOSE YOU COULD SEE A COLLISION" "BETWEEN TWO ATOMS." "ONE ATOM MIGHT COME IN LIKE THIS," "AND GO OUT LIKE THAT." "THE OTHER ATOM COLLIDES WITH IT" "AND GOES OUT IN THAT DIRECTION." "IN A MOVIE OF F THAT EVENT," "YOU WOULDN'T KNOW IF IT WERE RUNNING FORWARDS OR BACKWARDS." "AT THE MICROSCOPIC LEVEL, THE ENTROPY LAW DOESN'T APPLY." "THE LAWS OF PHYSICS WORK FORWARDS AND BACKWARDS." "ACCORDING TO THE LAWS OF PHYSICS," "TIME DOESN'T HAVE A DEFINITE DIRECTION" "AT THIS LEVEL." "SUPPOSE YOU SAW SOMEBODY DROP A BALL FROM A TOWER." "WITH A MOVIE OF THAT," "YOU'D KNOW WHETHER IT WAS RUNNING FORWARDS OR BACKWARDS." "WHEN IT'S RUNNING FORWARDS," "THE BOUNCES GET SMALLER EACH TIME." "IF THE BOUNCES GOT BIGGER," "YOU WOULD KNOW THE FILM WAS RUNNING BACKWARDS." "NOW THE ENERGY OF THE BALL IS TURNING INTO HEAT." "THAT INCREASES THE ENTROPY OF THE UNIVERSE." "THE CORRECT WAY TO RUN THE FILM" "IS IN THE DIRECTION OF INCREASING ENTROPY." "THAT DEFINES THE DIRECTION OF THE FLOW OF TIME." "SOME THINK THE SECOND LAW OF THERMODYNAMICS" "DEFINES THE DIRECTION OF THE FLOW OF TIME." "OTHERS SAY IT'S A MERE TAUTOLOGY." "ENTROPY INCREASES WITH TIME, TIME INCREASES WITH ENTROPY." "I UNDERSTAND PERFECTLY WHICH WAY TIME FLOWS," "AND I THINK THAT OUR TIME IS UP." "I'LL SEE YOU NEXT TIME," "OR IF ENTROPY DECREASES, I'LL SEE YOU LAST TIME." "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"