MAKES THIS HAPPEN. AND THIS. IT'S ELECTRICITY. WHOA! ♪ BILL NYE, THE SCIENCE GUY ♪ ♪ BILL NYE, THE SCIENCE GUY ♪ ♪ BILL, BILL, BILL, BILL,
BILL, BILL ♪ ♪ BILL NYE, THE SCIENCE GUY ♪ Woman:
<i> SCIENCE RULES.</i> ♪ BILL NYE, THE SCIENCE GUY ♪ <i>INERTIA IS A PROPERTY OF MATTER.</i> ♪ BILL, BILL, BILL, BILL ♪ ♪ BILL NYE, THE SCIENCE GUY ♪ ♪ BILL, BILL, BILL, BILL ♪ <i> "T" MINUS SEVEN SECONDS.</i> ♪ BILL NYE, THE SCIENCE GUY. ♪ Man:
<i> BROUGHT TO YOU BY ELECTRONS--</i> <i> MAKING YOUR WORLD</i>
<i> A BRIGHTER PLACE.</i> HEY, IS YOUR TV ON? IF IT IS, THAT'S GREAT. YOU'RE USING ELECTRICITY. BUT IF YOU'RE WATCHING THIS SHOW
AND YOUR TV'S<i> NOT</i> ON... ANYWAY, WHAT IS ELECTRICITY? I MEAN, WHERE DOES IT COME FROM? IS IT JUST SITTING IN THE WALL
WAITING FOR US TO USE IT? OR IS CONSTANTLY
SPILLING OUT OF SOCKETS AND WE DON'T NOTICE IT? AND HOW CAN SOMETHING
SO POWERFUL BE INVISIBLE? WELL, ELECTRICITY IS THE FLOW OF TINY PARTICLES
CALLED "ELECTRONS." AND THEY'RE NOT JUST
SMALLER THAN ATOMS. THEY'RE ACTUALLY PART OF ATOMS. TAKE A LOOK AT THIS. IT'S OUR BATTERY-POWERED,
ELECTRICAL CIRCUIT OF SCIENCE. WE'RE GOING TO RUN
THIS BIG LIGHT WITH THIS BIG BATTERY. WATCH. SEE? RIGHT NOW,
ELECTRONS CAN FLOW FROM THIS SIDE OF THE BATTERY,
THROUGH THIS WIRE THROUGH THE SWITCH,
INTO THE LIGHT AND BACK TO THIS SIDE
OF THE BATTERY. THEY'RE FLOWING
IN A CLOSED PATH-- WHAT SCIENTISTS CALL
"AN ELECTRICAL CIRCUIT." NOW, "CIRCUIT"? THAT'S FROM AN OLD WORD
FOR "GO AROUND." SO ELECTRONS, RIGHT NOW, "GO
AROUND" AN ELECTRICAL CIRCUIT. THE FLOW OF ELECTRONS IS
A LOT LIKE THE FLOW OF WATER. NO KIDDING. WATCH. WHEN I OPERATE THIS GREAT
BIG WATER PUMP OF SCIENCE WATER GOES THROUGH THIS HOSE INTO THIS BOX AND MAKES THIS WATER WHEEL
GO AROUND. IT GOES OUT THE OTHER SIDE THROUGH THIS HOSE,
BACK TO THE PUMP. IT'S A CLOSED PATH
FOR THE FLOW OF WATER. IT'S A WATER CIRCUIT. IT'S JUST LIKE THE FLOW OF ELECTRONS THROUGH AN ELECTRICAL CIRCUIT. ELECTRICITY IS A VERY
VERSATILE FORM OF ENERGY. THE SAME ELECTRONS THAT ARE
MAKING THE LIGHT LIGHT UP ARE MAKING A MOTOR GO AROUND. SEE, ELECTRICITY CAN DO
ALL KINDS OF DIFFERENT JOBS AND THEY'RE ALL DONE
WITH ELECTRONS. ELECTRONS FLOWING THROUGH A WIRE ARE A LOT LIKE WATER
FLOWING THROUGH A HOSE. WHILE WE'VE GOT THE FLOW GOING,
WE CAN DO WORK. BUMPER CARS HAVE
ELECTRIC MOTORS. ELECTRICITY RUNS FROM THE ROD
THAT TOUCHES THE CEILING THROUGH THE ELECTRIC MOTOR
IN THE CAR AND THEN TO THE FLOOR. SO YOU DON'T GET A SHOCK
FROM THE FLOOR UNLESS YOU COULD TOUCH
THE CEILING AT THE SAME TIME. OTHERWISE, IT'S NOT
A COMPLETE CIRCUIT. SCIENCE! AH! WE GOT ENERGY! I GOT THE POWER! ELECTRICITY IS FOREVER! MORE POWER! THIS IS WHERE THE SCIENCE RULES! Both:
SCIENCE IS COOL! Bill:
NOW YOU KNOW! THERE'S ENOUGH ELECTRICITY
COMING OUT OF THE WALL TO STOP YOUR HEART. SO DON'T STICK ANYTHING
BUT A PLUG IN A SOCKET. BE CAREFUL. UH, THIS IS GODZILLA'S
HAIR DRYER, I THINK. CHECK THIS OUT. IT'S AN ELECTRIC TRAIN. IT HAS TWO RAILS. ELECTRICITY GOES IN ONE SIDE
THROUGH THE MOTOR AND ENGINE THEN BACK OUT THE OTHER SIDE. IT'S A CIRCUIT. (<i> mooing and bleating</i> ) SO WHERE DOES ELECTRICITY
COME FROM, ANYWAY? WELL, IN 1831 TWO SCIENTISTS FIGURED OUT
HOW TO MAKE ELECTRICITY. IT WAS MICHAEL FARADAY
IN BRITAIN AND JOSEPH HENRY
IN THE UNITED STATES. AT ABOUT THE SAME TIME THEY BOTH DID AN EXPERIMENT
SOMETHING LIKE THIS: MICHAEL FARADAY TOOK
A COIL OF WIRE AND HE MOVED IT OVER A MAGNET,
AND WHEN HE DID ELECTRICITY STARTED
TO FLOW IN THIS COIL. THE ELECTRICITY WENT
DOWN OVER HERE TO ANOTHER COIL AND MADE A COMPASS NEEDLE MOVE. MICHAEL FARADAY WAS DOING
THIS EXPERIMENT FOR AN AUDIENCE AND A WOMAN CAME UP
TO HIM AFTERWARDS AND SAID, "MR. FARADAY OF WHAT USE IS IT?" AND HE SAID,
"MADAM, WILL YOU TELL ME THE USE OF A NEWBORN<i> CHILD?"</i> AND WHAT HE MEANT WAS,
WOULD YOU TAKE A LOOK? I'M MOVING THE NEEDLE
WITHOUT TOUCHING IT. YOU UNDERSTAND?
I HAVE A COIL WIRE OVER HERE MOVING A COMPASS NEEDLE
OVER THERE WITH NO APPARENT FORCE. SOME FORCE IS GOING
THROUGH THE AIR AND WIGGLING THAT NEEDLE. SOME SPECTACULAR EFFECT
IS HAPPENING HERE. YOU MAY NOT UNDERSTAND IT NOW. WITH NO APPARENT FORCE. IT'S GOING TO BE A BIG DEAL. THANK YOU FOR JOINING ME ON... CONSIDER THE FOLLOWING. MY NAME'S VENKATESH IYER AND I'M A SCIENTIST WORKING
ON ELECTRIC CARS AT WESTERN WASHINGTON UNIVERSITY'S
VEHICLE RESEARCH INSTITUTE. THIS IS VIKING 21,
AN ELECTRIC HYBRID CAR. IT IS THE FORERUNNER
OF ELECTRIC CARS AS STEAM ENGINES WERE
TO GASOLINE CARS. THIS CAR IS
SOLAR-ELECTRIC HYBRID WHICH MEANS IT RUNS
ON SOLAR POWER ELECTRICITY
AND ON COMPRESSED NATURAL GAS. THERE ARE
1,400 SOLAR CELLS ON IT. SOLAR CELLS CONVERT
LIGHT INTO ELECTRICITY AND THIS IS STORED
IN THE BATTERIES. THIS ELECTRICITY IS USED TO DRIVE THE ELECTRIC MOTOR
IN THE FRONT AND MOTOR IN THE BACK. IT IS ALL CHARGED UP SO IF YOU WANT
TO GO FOR A SPIN... LET'S ROLL. LET'S BURN RUBBER. ELECTRICITY IS
THE FLOW OF ELECTRONS. ELECTRONS ARE THE TINY PARTICLES THAT BUZZ AROUND
THE OUTSIDE OF ATOMS. NOW, WHEN ELECTRONS ARE ABLE
TO JUMP FROM ONE ATOM TO ANOTHER WELL, THAT'S
THE FLOW OF ELECTRICITY. NOW, IN SOME MATERIALS,
LIKE METALS ELECTRONS CAN JUMP
FROM ATOM TO ATOM VERY EASILY. ATOMS IN METALS
ARE LIKE BEEHIVES. THE ELECTRONS ARE LIKE THE BEES
BUZZING AROUND THE HIVES. WHEN ELECTRICITY FLOWS IT'S LIKE THE BEES
JUMPING FROM HIVE TO HIVE. THAT'S ELECTRICITY. YOU CAN MAKE
AN ELECTRICAL CIRCUIT AND FIGURE OUT WHAT THINGS LET
ELECTRONS GO THROUGH THEM. HOOK UP A CIRCUIT LIKE THIS. THE TRICKY PART OF
A CIRCUIT LIKE THIS IS GETTING THE BATTERIES
TO STAY PUT. WE'VE GOT IT ALL WORKED OUT. TEST THINGS AND SEE
IF ELECTRICITY GOES THROUGH THEM AND WHAT
THINGS DON'T. (<i> squeaking</i> ) (<i> squeaking</i> ) METAL THINGS SEEM
TO CARRY ELECTRICITY WELL. RUBBER AND
PLASTIC THINGS DON'T. TRY THIS: A PENCIL. (<i> squeaking</i> ) NOW, A PENCIL
SLIT IN HALF. CHECK IT OUT--
IT CHANGES! THE CIRCUIT'S COMPLETE BUT THE PENCIL LEAD HOLDS
SOME ELECTRICITY BACK. THINGS THAT LET
ELECTRICITY THROUGH THEM ARE CALLED CONDUCTORS. THINGS THAT DON'T
ARE CALLED INSULATORS. THIS CAN BE CALLED A RESISTOR. IT'S IN BETWEEN A CONDUCTOR
AND AN INSULATOR. IT LETS SOME ELECTRONS THROUGH,
BUT NOT ALL. (<i> dog barking</i> ) Both:
WILD! WILD! W-W-W-W-WILD! ELECTRICAL CIRCUITS
AND WATER CIRCUITS BOTH HAVE PRESSURE AND FLOW. SOMETIMES WHEN YOU GO UP
TO A DRINKING FOUNTAIN THE WATER COMES OUT JUST FINE. BUT OTHER TIMES,
IT HARDLY COMES OUT AT ALL. THAT'S BECAUSE IT DOESN'T
HAVE ENOUGH PRESSURE. IN ELECTRICAL CIRCUITS,
THERE'S PRESSURE, TOO. IT'S CALLED "VOLTAGE." THE HIGHER THE VOLTAGE,
THE MORE ELECTRONS WANT TO JUMP. NOW, THE NUMBER OF ELECTRONS
THAT'S FLOWING THROUGH A WIRE WE CALL AMPERAGE OR JUST AMPS. AMPS ARE LIKE
THE AMOUNT OF WATER COMING OUT OF A FOUNTAIN. THE MORE AMPS,
THE MORE ELECTRONS. SO IN ELECTRICITY
WE END UP WITH TWO THINGS: VOLTAGE OR VOLTS,
AND AMPERAGE OR AMPS. VOLTS AND AMPS. VOLTS AND AMPS. VOLTS AND AMPS. THE SAME WAY WITH WATER WE END UP
WITH PRESSURE AND FLOW. PRESSURE AND FLOW. PRESSURE AND FLOW. NOW, THE COMBINATION OF VOLTS
AND AMPS, WE CALL WATTS. WATTS. Man:
WHAT? NOW, YOU KNOW ABOUT WATTS. A 100-WATT BULB NEEDS MORE WATTS
THAN A 40-WATT BULB. IT'S A BIGGER NUMBER. MORE WATTS. Man:
WHAT? NO, WATTS! THAT'S A LOT OF WATTS. OKAY, WE'RE GOING TO DO
SOME POWER EXERCISING. READY, AND... THE GENERATOR IS CONNECTED
TO THE EXERCISE BICYCLE WHEEL. WE'RE RUNNING A GENERATOR THAT'S COMPLETING A CIRCUIT AND WE'RE TURNING
THAT LIGHT BULB ON. IT TAKES A LOT OF POWER TO RUN AN ELECTRIC LIGHT BULB. IT TAKES A LOT OF WATTS. WHAT? WATTS! ELECTRICAL POWER! A 100-WATT LIGHT BULB
TAKES A HUNDRED WATTS OF POWER. THAT'S A LOT OF POWER. THAT'S A LOT OF WATTS. MAKE IT BURN! Man:
OKAY, IT'S BURNING.
CAN WE STOP NOW? NEXT. ELECTRONS ARE PUSHED
BY CHEMICAL REACTIONS LIKE IN BATTERIES OR THEY GET PUSHED
BY GENERATORS. NOW I NEED TO FIND
SOMEONE TO PUSH ME. (<i> screams</i> ) Bill:
BATTERIES AND HOT DOGS
ARE A LOT ALIKE. NO KIDDING. A HOT DOG HAS A PIECE OF MEAT
WITH A ROLL AROUND IT. WELL, INSIDE A BATTERY, THERE'S
A LONG ROD WITH A CAN AROUND IT. NOW, BETWEEN THE ROD AND THE CAN ARE SOME GOOPY CHEMICALS
CALLED ELECTROLYTE. NOW, THAT'S WHAT MAKES
ELECTRICITY FLOW. BETWEEN A HOT DOG AND THE ROLL ARE SOME GOOPY CHEMICALS
CALLED MUSTARD AND RELISH. SO INSTEAD OF POLES,
IT HAS ROLLS. HA-HA! NOW, IF YOU PUT A HOT DOG
IN A FLASHLIGHT... NOTHING HAPPENS... DUH! THAT'S BECAUSE A HOT DOG
DOESN'T HAVE THE RIGHT CHEMICALS TO MAKE ELECTRICITY FLOW,
BUT A BATTERY DOES AND THOSE CHEMICALS
ARE WHAT MAKES ELECTRICITY FLOW FROM ONE END OF THE BATTERY
TO THE OTHER. NOW, WHEN THE CHEMICALS
ARE USED UP THE ELECTRICITY STOPS
AND THE BATTERY'S DEAD. BUT BATTERIES ARE
A GOOD COMPACT SOURCE OF ENERGY. SO ARE HOT DOGS. (<i> dog barking</i> ) MMM. ELECTRICITY CAN BE DANGEROUS. THERE'S ENOUGH POWER
IN A WALL SOCKET LIKE THIS TO BURN YOUR SKIN. JUST BE CAREFUL. HEY! SO NOW IT'S TIME TO FEED
OUR FAMOUS ELECTRIC EEL. THIS IS A SOUTH AMERICAN
ELECTRIC EEL FOUND ONLY IN SOUTH AMERICA. IT CAN PRODUCE UP TO 800 VOLTS
AT ONE AND A HALF AMPS. (<i> crackling</i> ) IF YOU PUT YOUR HAND INTO THIS TANK WITH THE FISH,
JUST ONE HAND YOUR HAND WOULD PROBABLY FLY OUT
WHEN HE DISCHARGED HIS CHARGE. (<i> crackling</i> ) IF YOU PUT TWO HANDS IN THERE YOU WOULD PROBABLY
BE ELECTROCUTED. (<i> crackling</i> ) Bill:
IMAGINE... IF YOU HAD ALL THIS WATER
FALLING FROM HERE DOWN... (<i> tires screeching</i> ) ...TO THERE--
OVER 100 METERS-- YOU COULD GENERATE 6½ MILLION KILOWATTS
OF ELECTRICITY. THAT'S A LOT OF WATTS. Man:
<i> WHAT?</i> (<i> electrical buzzing</i> ) THAT'S GRAND COULEE DAM IN
WASHINGTON STATE IN THE U.S.A. IF YOU'VE LIFTED
A BUCKET OF WATER YOU KNOW IT'S PRETTY HEAVY. WELL, IMAGINE HOW HEAVY
THE WATER IS BEHIND THAT DAM. IT'S OVER 100 METERS HIGH. IT'S ALMOST TWO KILOMETERS LONG. THAT'S A LOT OF WATER. SO AS THE WATER FLOWS
FROM THE TOP TO THE BOTTOM IT RUNS HUGE GENERATORS. NO, NO, REALLY HUGE. I MEAN<i> BIG.</i> I MEAN<i> VERY BIG.</i> I MEAN BIGLY, HUGELY, BIGLY,
HUGELY BIG GENERATORS. THAT'S A LOT OF WATTS. Man:
WHAT? WATTS! ELECTRIC POWER. ELECTRIC POWER THAT RUNS
FROM HERE TO MILLIONS OF HOMES
SO THAT PEOPLE LIKE YOU CAN WATCH TELEVISION
AND PLAY VIDEO GAMES AND POP POPCORN
IN MICROWAVE OVENS AND HAVE TOASTED TARTS
FROM YOUR TOASTER IN THE MORNING AT BREAKFAST. MAN, THAT THING IS BIG. (<i> electrical buzzing</i> ) WE USE ELECTRICITY ALL DAY. MOST OF THE TIME, WE DON'T THINK
ABOUT WHERE IT COMES FROM. ELECTRICITY MAY TRAVEL
HUNDREDS OF KILOMETERS THROUGH POWER LINES
BEFORE IT GETS TO OUR HOMES. WHOA! WHEN WE MAKE ELECTRICITY
WITH A MAGNET AND A COIL OF WIRE EITHER THE MAGNET
OR THE COIL HAS TO BE MOVING. NOW, NOTICE THAT THE COIL IS EITHER RIGHT SIDE UP
OR UPSIDE DOWN. RIGHT SIDE UP. UPSIDE DOWN. AND THE ELECTRICITY
THAT GETS MADE GOES THIS WAY OR THAT WAY. THIS WAY, THAT WAY. WE SAY IT'S "ALTERNATING." WE CALL IT
ALTERNATING CURRENT OR "A.C." NOW, WHEN YOU MAKE ELECTRICITY
WITH BATTERIES THE ELECTRICITY ONLY GOES
IN ONE DIRECTION. WE SAY IT'S
DIRECT CURRENT OR "D.C." SO THIS IS D.C., A.C., AND... "P.C." P.C., THAT'S
WHAT I CALL POPCORN. (<i> bell dings</i> ) Woman:
WE'VE KNOWN FOR YEARS THAT THE SUN IS
A WONDERFUL SOURCE OF ENERGY. BUT WE NEED
TO LEARN ABOUT IT. WE ARE TRYING TO GATHER
SOME INFORMATION TO MAKE PHOTOVOLTAICS
MORE ECONOMICALLY VIABLE. A PHOTOVOLTAICS CELL IS
BASICALLY A LITTLE CELL THAT YOU SHINE SUNLIGHT ON
AND GET ELECTRICITY. IF YOU'VE EVER USED
A HANDHELD CALCULATORS THEY HAVE
A TINY PHOTOVOLTAIC CELL. BASICALLY THIS IS
WHAT THESE ARE. THEY'RE PHOTOVOLTAIC CELLS SO THIS COULD DRIVE
JUST ONE BIG CALCULATOR. SUN POWER! Bill:
BIRDS CAN SAFELY SIT ON ONE
OF THE WIRES ON POWER LINES BECAUSE THEN THEIR BODIES
DON'T COMPLETE A CIRCUIT. THE MONSTERS
IN SCIENCE FICTION MOVIES-- THEY COMPLETE CIRCUITS. OUCH! FOR ELECTRICITY TO DO WORK IT HAS TO FLOW
IN A COMPLETE LOOP. THAT'S CALLED A CIRCUIT. TURNING ON A SWITCH
COMPLETES A CIRCUIT. TURNING IT OFF BREAKS THE LOOP. Man:
HEY, TURN ON THE LIGHTS.
I CAN'T SEE. (<i> crashing</i> ) I WISH THERE WERE
NO SUCH THINGS AS BATTERIES. Announcer:
<i> COMING THIS HOLIDAY SEASON</i> <i> A MOVIE THAT WILL BRIGHTEN</i>
<i> YOUR SPIRITS.</i> <i> SO HE WANTS TO KNOW</i> WHAT LIFE WOULD BE LIKE
WITHOUT BATTERIES? WELL, LET'S SHOW HIM. Announcer:
<i> IT'S ONE BOY'S JOURNEY</i> <i> INTO A LIFE</i>
<i> WITHOUT DIRECT CURRENT.</i> MOM, COME ON,
WE'RE GOING TO BE LATE. OKAY, OKAY. OH, DEAR, IT'S STOPPED. AH! WHAT DO YOU MEAN,
"IT'S STOPPED"? MOM, WHAT'S WRONG? OH, DEAR, IT'S DEAD. WHAT DO YOU MEAN,
"IT'S DEAD"? THE BATTERY'S DEAD. OH! HEY! Announcer:
<i> FROM THE DIRECTOR</i>
<i> OF</i> COMPASS MAN<i> COMES:</i> OH, THE BATTERY. Boy:
HEY, GRANDPA, HEY, GRANDPA! GRANDPA! GRANDPA! CAN YOU HEAR ME? GRANDPA! GRANDPA! HEY, GRANDPA,
HOW ARE YOU DOING? I CAN'T HEAR YOU. GRANDPA,
WHAT'S WRONG? YOUR BATTERY'S DEAD? Announcer:
<i> CAN ONE BOY SURVIVE IN A WORLD</i>
<i> WITHOUT BATTERIES?</i> THESE BATTERIES MUST BE DEAD. THIS PLUG FITS
IN THIS SOCKET PERFECTLY. BUT THIS PLUG IS FROM EUROPE AND IT DOESN'T FIT
IN OUR SOCKETS. HMM, NO WAY. DIFFERENT COUNTRIES USE
DIFFERENT-STYLE PLUGS FOR THEIR ELECTRICITY. BUT NOTICE THEY ALL
HAVE TWO PRONGS. THAT'S BECAUSE ELECTRICITY
HAS TO FLOW IN A LOOP. SO IT GOES IN ONE PRONG,
THROUGH THIS WIRE THROUGH AN APPLIANCE
LIKE THIS BLENDER THEN OUT THE OTHER SIDE
AND BACK INTO THE WALL. IT'S A CIRCUIT; THAT'S GOOD. MMM, THAT<i> IS</i> GOOD. (<i> to the tune</i>
<i> of "Achy, Breaky Heart"</i> ) ♪ WELL, EVERYBODY KNOWS
THAT WHEN ELECTRONS FLOW ♪ ♪ THAT FLOW IS
KNOWN AS ELECTRICITY ♪ ♪ AND ALTHOUGH
YOU MIGHT SAY SO ♪ ♪ WITHOUT IT, DON'T YOU KNOW ♪ ♪ WE'D BE UNPLUGGED,
BUT NOT ON MTV ♪ ♪ NOW, IN A BATTERY,
CURRENT'S CALLED "D.C." ♪ ♪ IT FLOWS STRAIGHT
FROM THE MINUS TO THE PLUS ♪ ♪ BUT THE CURRENT IN YOUR WALL
IS KNOWN AS "A.C.," Y'ALL ♪ ♪ AND IT CYCLES
BACK AND FORTH WITHOUT A FUSS ♪ ♪ SO DON'T LOSE THAT CHARGE,
THAT AC/DC CHARGE ♪ ♪ YOUR CURRENT
ALTERNATING OR DIRECT ♪ ♪ BECAUSE IF YOU LOSE
THAT CHARGE, THAT AC/DC CHARGE ♪ ♪ THERE'S NO REASON
FOR A CIRCUIT TO CONNECT ♪ ♪ OOH! ♪ THEY'RE BEAUTIFUL, AREN'T THEY? ALL THOSE ELECTRONS FLOWING THROUGH ALL THOSE CONDUCTORS
AND COMPLETE CIRCUITS. LOOK AT ALL THAT LIGHT! IT'S GREAT, IT'S ELECTRICITY! WELL, GUESS WATT? Man:
REAL FUNNY, BILL. THAT'S THE END OF OUR SHOW. SEE? THIS GENERATOR IS CONNECTED
TO THE EXERCISE BICYCLE WHEEL. IT COMPLETES A CIRCUIT
THAT POWERS THIS LIGHT BULB. JUST A FEW MORE MINUTES! THAT'S IT, BREATHE! SEE, IT TAKES 100 WATTS TO RUN
A 100-WATT LIGHT BULB. NOW, 100 WATTS,
THAT'S A LOT OF WATTS! THAT'S A LOT OF POWER! POWER? THAT'S
ENERGY PER UNIT TIME. YOU'RE BURNING CALORIES! DON'T SLOW DOWN...
MAKE IT BURN! KEEP PEDALING, SCIENCE GUY. THE LIGHT BULB WILL TURN ON
IF YOU PEDAL FASTER. <font color="#ffff00"> Captioning sponsored by</font>
<font color="#ffff00"> DISNEY EDUCATIONAL PRODUCTIONS</font> Captioned by
<font color="#00ffff"> Media Access Group at WGBH</font>
access.wgbh.org