LISTEN, THERE'S TONS OF WAVES.
NO, , I'M NOT KIDDING.
THERE ARE AWESOME WAVES.
YOU GOT TO GET DOWN HERE
I'TELLING YOU.
HEY, ROCHELLE.
>> WHERE'S THE WAVES AT?
>>HAT ARE YOU TALKING ABOUT?
>> I DON'T SEE ANY WAVES.
>> OH, COME ON.
I MEAN, THERE'S SOUND WAVES,
THERE'S LIGHT WAVES,
THERE'S--THERE'S RADIO WAVES,
AND THERE'S SOME
X-RAYS, GAMMA RAYS.
I MEAN, RIT NOW, ROCHELLE,
WE ARE SURROUNDED BY BILLIONS
AND BILLIONS OF WAVES.
>> YOU CAN'T RIDE ANY OF THEM.
>> WELL, NO, NO.
BUT--BUT THEY'RE WAVES.
>> SPORTSFIGURES:
PUT YOUR BRAIN IN THE GAME.
[CAPTIONING MADE POSSIBLE BY
ESPN, INC.]
>> IF I WERE TO THROW A BALL
AT THESE CANS...
NO BIG DEAL, RIGHT?
I GAVE THE BALL SOME ENERGY,
THE ENERGY TRAVELED ACROSS
THE SAND TO THE CANS,
AND THEYELL DOWN.
BUT WHAT IF I WERE TO DO THIS?
OH, YEAH!
PRETTYOOL, HUH?
WELL, THAT'S HOW WAVES WORK.
WAVES TRANSFER ENERGY FROM
ONE PLACE TO ANOTHER WITHOUT
MOVING MATTER.
YOU SEE, OCEAN WAVES AND
SOUND WAVES ARE VING ENERGY.
THAT'S WHY WHEN YOU'RE
AT THE BEACH,
YOU'RE NOT REALLY SURFING WATER.
YOU'RE SURFING ENERGY.
YOU SHOULD CALL THIS THING
AN ENERGY BOARD.
UH, LISTEN, CAN I CALL YOU BACK?
OK, ALL RIGH BYE.
YOU KNOW, WAVES ARE AROUND US
ALL THE TI.
THERE'S SOUND WAVES,
THERE'S ELECTROMAGNETIC WAVES
LIKE RADIO WAVES,
THERE'S MICROWAVES,
THERE'S LIT WAVES.
YOU KNOW, EVEN YOUR CELL PHONE
WORKS BECAUSE OF WAVES.
NOW, LUCKILY FOR US, MOST WAVES
ARE INVISIBLE TO THE NAKED EYE.
THAT'S WHY LOOKING AT
OCEAN WAVES CAN HELP US
UNRSTAND WAVES.
'S ONE OF THE FES
YOU CAN ACTUALLY SEE WAVES
IN ACTION.
AND, OF COURSE, OCEAN WAVES
ARE GREAT FOR SURFING.
NOW, TO HELPS OUT TODAY,
WE'VE GOT ROCHELLE BALLARD.
NOW, ROCHELLE HAS BEENN
THE WORLD AMPIONSHIP TOUR
FOR 11 YEARS.
SHE ALSO HOLDS THE RECORD
FOR SCORING 2 PERFECT 10s
IN A SINGLE HEAT
AND HAS BEENOTED THE MOST
POPULAR SURFER FOR THE LAST
3 YEARS.
SHE ALSO HOSTS HER OWN CAMP,
THE ROCHELLE BALLARD SURF CAMP
IN HAWAII AND THIS YEAR,
IS DOING IT ONOTH COASTS.
AND SHE WAS FEATURED IN
THE MOVIE BL CRUSH.
SO I'D SAY SHE KNOWS A THING OR
2 ABOUT BIG WAVES.
SO, ROCHELLE, YOU'RE INTO
OCEAN WAVES, RIGHT?
>> RIGHT.
>> SO WHAT CAN THE OCEAN
TELL US ABOUT OTHER KINDS
OF WAVES?
>> WELL, OCEAN WAVES ACTUALLY
HAVE THE SAME BASIC PROPERTIES
AS ALL T OTHER WAVES
OUT THERE, IT'S JUST THAT
YOU CAN SEE OCEAN WAVES.
>> OK, COOL.
LET'S START WITH THEASICS.
WHERE DO WAVES COME FROM?
>> IT STARTS OFF BY A STORM
OUT ATEA, AND THE WIND
ACTUALLY KICKS UP AND CREATES
A WAVE.
>> SO IF WE'RE TALKING ABOUT
WAVES AS TRANSFERRG ENERGY,
LET'S SAY,
IT'S THE ENERGY FROM THE WIND
THAT'S TRANSFERRED INTO
THE WAVE, RIGHT?
>> RIGHT.
SO WHEN THERE'S A BIG STORM
OUT AT SEA, IT'S CREATING A LOT
OF ENERGY, SO I'M HEADING
TO THE BEACH.
>> UNLIKE OCEAN WAVES,
SOUND WAVES ARE CAUSED BY
VIBRATIONS.
VIBRATIONS SET UP A DISTURBANCE
IN THE MEDIUM,
LIKE WHEN I GIVE ENERGY TO THIS
TUNING FORK, IT VIBRATES AND
DISTURBS THE AIR AROUND IT.
THAT DISTURBANCE TRAVELS OUT
THROUGH THE MEDIUM, THE AIR,
AS WAVES.
TO UNDERSTAND HOW WAVES WORK,
WE START HERE WITH A PENDULUM.
A PENDULUM SWINGS BACK
AND FORTH, RIGHT,
LIKE A GRANDFATHER CLOCK--
BACK AND FORTH, BA AND FORTH.
THE TIME IT TAKES FOR
THE PENDULUM TO COLETE
ONE BACK AND FORTH...
IS CALLED A PERIOD.
NOW, HERE'S SOMETHING
REALLY COOL.
WHAT HAPPENS IF  LENGTHEN
THE ARM OF THE PENDULUM?
>> IT LENGTHENS THE TIME
OF THE PERIOD. IT SLOWS DOWN.
>> RIGHT.
GALILEO FIGURED THAT ONEUT.
NOW, LET'S SAY I PULL OUT
THE PLUG, START TO LET THE SAND
FUNNEL OUT, WHAT HAPPENS?
>> IT GOES BACK AND FORTH
IN THE SAME SPOT,
AND WE GET A LINE.
>> YES, BUT WHAT IF I START TO
MOVE THE SAND?
>> WE GET A WAVY LINE.
>> AH, WHAT'S THAT CALLED?
>> IT'S CALLED A SINE CURVE
OR A SINE WAVE.
>> SORT OF LOOKS LIKE WAVES
IN THE WATER.
SEE, THE SINE CURVE IS THE SPE
OF THE WAVE.
NOW, THERE'S 2 ELEMENTS THAT
MAKE UP A WAVE.
THE CREST IS THE TOP OF
THE WAVE, AND THE TROUGH
IS THE LOW VALLEY PART.
YOU NEED BOTH TO MAKE UP
A WAVE: THE CREST AND
THE TROUGH.
SO HOW HIGH WAS THAT WAVE?
>> THAT WAVEAD AN AMPLITUDE
OF ABOUT 3 METERS.
AMPLITUDE IS THE HEIGHT
OF THE WAVE.
 NO, WAIT, 3 METERS?
IT SEEMED MUCH HIGHER
THAN THAT, THOUGH.
>> YOU'RE LOOKING AT 3 METERS
OF THE CRESTF THE WAVE,
AND YOU'RE LOOKING AT 3 METERS
OF THE TROUGH OF THE WAVE
WHEN ACTUAY YOU'RE TAKING
YOUR READING FROM WHERE
THE FLAT WATER WOULD BE.
>> TO MEASURE THE HEHT OF
A WAVE, ITS AMPLITUDE,
WE HAVE TO DRAW A LINE DOWN
THE CENTER OF THE WAVE.
>> THE DISTANCE FROM THE CENTER
NE TO THE CREST IS THE WAVE'S
AMPLITUDE, HOW HIGH IT IS.
>> AND THE TROUGH IS ALSO
THE SAME DISTAE FROM
THE CENTER LINE.
>> SO, ROCHELLE, WHAT'S
THE OTHER WAY THAT WAVES
ARE MEASURED?
>> WELL, BESIDES THE AMPLITUDE,
THE WAVE HEIGHT, YOU ACTUALLY
HAVE THE WAVELENGTH.
>> WAVELENGTH--OK, HOW DO WE
MEASURE THAT?
>> WAVELENGTH IS MEASURED FROM
CREST TOREST.
IT'S THE DISTANCE BETWEEN THOSE.
>> IF YOU MEASURE THESE WAVES
FROM CREST TO CREST,
I'D SAY THEY WERE ABOUT A GOOD
10 METERS APART.
F. RADIO WAVES LOOK LIKE THIS,
AND THEIR WAVELENGTHS
ARE MEASURED IN METERS.
FROM CREST TO CREST,
IT MIGHT BE ABOUT 3 METERS.
A.M. RADIO WAVES HAVE
WAVELENGTH OF ABOUT
200 METERS, THAT'S LONGER THAN
2 FOOTBALL FIELDS.
>> BESIDES AMPLITUDE
AND WAVELENGTH, THERE'S ANOTHER
WAWE MEASURE WAVES IN TIME.
>> RIGHT, HOW FREQUENTLY
THE WAVE COMES IN, WE CALL THAT
THE WAVE'S FREENCY.
>> RIGHT.
>> WHEN YOU TUNE IN
A RADIO STATION,
YOU'RE TUNING TO THE FREQUENCY
OF THAT STATION'S RADIO WAVES.
NOW, IF YOU EVER LOOK CLOSELY
AT A TUNER, YOU'LL SEE IT'S
LABELED TH "kHz" ON THE A.M.
SIDE AND "MHz" FOR THE F.M.
THAT STANDS FOR "KILOHERTZ"
AND "MEGAHERTZ."
HERTZ IS THE UNIOF MEASUREMENT
WE USE FOR FREQUENCY.
ONE VIBRATIOPER SECOND
IS ONE HERTZ, 2 VIBRATIONS
PER SECOND IS 2 HERTZ.
BUT RADIO WAVES HAVE A MUCH
HIGHER FREQUENCY THAN THAT,
SO WE MEASURE THEM
IN KILO AND MEGA.
KILO IS TIMES A THOUSAND,
MEGA IS TIMES A MILLION.
940 ON THE A.M. DIAL MEANS
THE VES ARE ARRIVING
940,000 TIMES PER SECOND.
 ON THE F.M. DIAL MEANS
THE WAVES ARE ARRIVING
95 MILLI TIMES PER SECOND.
IT'S A LOT OF WAVES.
THE FREQUENCY OF THESE WAVES
HERE ARE OBVIOUSLY MUCH SLOWER
THAN THAT.
ONE CREST EVERY 5 SECONDS
IS 1/5 HERTZ.
HERE'S HOW FREQUENCY
AND A RADIO WORK.
THIS TUNING FORK HERE IS
THE NOTE MIDDLE "C."
IT HAS A FREQUENCY OF 262 HERTZ.
THIS TUNING FORK IS
THE NOTE "A" AND HAS A FREQUENCY
OF 440 HERTZ.
IF I RING THE "A" TUNING FORK
AND HOLD IT UP AGAINST THE ""
NADA, NOTHING HAPPENS.
BUT IF I WERE TO HAPPEN TO HAVE
ANOTHER "C" TUNING FORK,
262 HERTZ, AND I RING IT.
[HUMMING]
THE WAVES FROM ONE TUNING FORK
ARE RINGING THE OTHER BECAUSE
THEY'RE ON THE SAME FREQUENCY.
YOUR RADIO ANTENNA,
IT WORKS THE SAME WAY.
PRETTY COOL, H?
HA HA HA HA HA!
WHAT ABOUT STAYING IN SHAPE
FOR SURFING?
I AN, DO YOU DO SPECIFIC
EXERCISES, IS IT CARDIOVASCULAR,
IS IT WEIGHTLIFTING?
>> RIGHT NOW, I'M RUNNING AND
SWIMMING AND, YOU KNOW,
TRYING TO KEEP LOOSE A SO ON.
I'M DOING MY YOGA.
AT DIFFERENT TIMES WHEN I'M
TRYING TO ACTUALLY STRENGTHEN,
I'LL LIFT WEIGHTS ON MY LEGS.
AND WHEN I'M TRYING TO IMPROVE
MY SURFING TECHNIQUES,
I'LL GET ON THE BIG SWISS BALLS
AND STAND ON THEM AND HAVE
MEDICINE BALLS THROWN AT ME
AND DO BALANCING THINGS.
YOU OW, IT'S NICE TO HAVE
VARIETY, AND IT'S GREAT TO HAVE,
LIKE, PURPOSE IN WHERE YOU'RE
TRYING TO GO WITH VANCEMENT.
[MUSIC PLAYING]
>> YOU CAN ACTUALLY SEE WAVES
USING A TELEPHONE CORD
LIKE THIS.
NOW, IF MARA SENDS ONE PULSE
DOWN THIS WAY, IT REFLECTS
AND COMES BACK
IF SHE SENDS 2 PULSES,
THEY REFLECT, THEN RETURN
TO THE SAME PLACE.
AND IF SHE CONTINUES TO SEND
PULSES, IT'LL FO A PATTERN
THAT LOOKS LIKE THIS.
BUT WHAT'S THE DIFFERENCE
BETWEEN THIS WAVAND WAVES
IN THE OCEAN?
>> THE WAVES AT THE BEACH ARE
MOVING WHEN ALL OF ITS
WATER MOVE.
THIS ONE HAS PLACES WHERE IT
STAYS STATIONARY.
THE WAVE MOVES BACK AND FORTH.
>> RIGHT, WE CALL THAT
A STANDING WAVE.
BUHOW COME IT DOESN'T MOVE?
>> THE ENERGY SHE'S PUTTING
THROUGH THE CORD GOES THROUGH
THE CORD BUT HASOWHERE TO GO,
SO IT REFLECTS BACK.
>> OK, SO A STANDING WAVE
ACTUALLY RESULTS FROM 2 WAVE
TRAVELING IN OPPOSITE
DIRECTIONS, RIGHT?
>> RIGHT, THAT'S WHAT MAS
A STANDING WAVE.
>> WAVES AT THE BEACH
ARE MORE TYPICAL.
MOST WAVES ARE TRAVELING WAVES,
AND THEY MOVE FROM ONE PLACE
TO ANOTHER.
>> RIGHT, SO THE WATER IS MOVING
TOWARDS THE SHORE?
>>HE WATER IS MOVING
UP AND DOWN, AND THE WAVES
ARE MOVING THROUGH IT, BUT NOT
ACTUALLY TOWARDS THE BEACH.
THE WATER STAYS IN
THE SAME PLACE.
>> NO WAY.
>> WAY.
>> YOU MEAN TOELL ME
THE WATES NOT MOVING TOWARDS
THE BEACH?
>> ONLY AFTER THE WAVE BREAKS,
THEN THE WATER MOVES
UP THE BEACH.
>> SO WHAT'S UP WITH THAT?
>>F WE PUT A MARK ON THE CORD,
YOU CAN SEE WHAT HAPPENS.
>> OK.
>> WATCH WHEN WE MAKE THE WAVE,
THE TAPE MOVES UP AND DOWN,
BUT IT DOESN'T MOVE ALONG
WITH THE WAVE.
>> WELL, MAYBE THAT'S BEUSE
IT'S A STANDING WAVE, RIGHT?
I MEAN, THE WAVES OUT IN
THE OCEAN ARE TRAVELING,
SO THE WATER MUST TRAVEL.
>> NO, IT'S THE SAME FORAVES
IN THE WATER.
WE'RE PROVING IT RIGHT NOW.
AS THE WAVES PASS, WE JUST GO
UP AND DOWN, BUT WE'RE NOT
MOVING TOWARDS THE BEACH.
>> SO THE WATER TRANSMITS
THE ENERGY WITHOUT
TRANSMITTING MATTER?
>> RIGHT, AND IT TRANSMITS IT
THROUGH THE MEDIUM OF WATER.
>> MEDIUM? WHAT'A MEDIUM?
YOU SEE, THE THING WITH
SOUND WAVES OR WATER WAVES IS
THAT THEY MOVE THROUGH A MEDIUM,
BUT THEY DON'T MOVE THE MEDIUM.
WHEN YOU HEAR A SOUND LIKE, UH,
RADIO FROM A SPEAKER,
THE SOUND WAVES ARE AVELING
OUT THROUGH THE MEDIUM OF AIR.
NOW, IF THE AIR MOVED EVERY TIME
U HEARD A SOUND, YOU'D FEEL
A WIND, BUT YOU DON'T.
IF I EAT A PIECE OF THIS GARLIC,
START TALKING TO MY
FRIENDS HERE--
HEY, GUYS, HOW'S IT GOING?
IT'S NOT A PROBLEM WHEN THEY
HEAR MY VOICE, BUT WHEN THE AIR
FROM MY UTH REACHES THEM...
[BLOWS]
>> ONE THING YOU HAVEN'T SAID
IS THAT SOUND TRAVELS IN
DIFFERENT TYPES OF WAVES
THAN WATER.
>> WHAT DO YOU MEAN?
>> WELL, WAVES ON THE BEACH ARE
WHAT'S CALLED TRANSVERSE WAVES,
AND SOUND TRAVELS THROUGH
LONGITUDINAL WAVES.
>> SO WHAT KIND OF WAVE IS THIS?
>> THIS IS CALLED
A TRANSVERSE WAVE BECAUS
THE WAVE MOTION IS AT
A RIGHT ANGLE TO THE DIRECTION
OF THE WAVE SPEED.
>> SO THE WAVE DECTION
MOVES THIS WAY, BUT THE CREST
AND THE TROUGH MOVE IN
THIS DIRECTION?
>> RIGHT.
MOST WAVES ARE TRANSVERSE--
THE WAVES ON THEATER,
THE WAVES ON THE STRINGS
OF MUSICAL INSTRUMENTS,
EVEN LIGHT WAV AND RADIO WAVES
ARE TRANSVERSE.
>> SOME WAVES, LIKE SOUND,
TRAVEL DFERENTLY.
>> SOUND TRAVELS IN
A LONGITUDINAL WAVE ALSO CALLED
A COMPRESSION WAVE.
THE AIR PARTICLES MOVE IN
THE SAME DIRECTION AS THE WAVE.
IT WORKS LIKE THIS.
>> BUT WHERE ARE THE CRESTS?
>> INSTEAD OF CRESTS,
WE HAVE COMPRESSIONS.
SEE THE COMPRESSED AREAS.
>> AND INSTEAD OF TROUGHS,
THERE'S E AREA BETWEEN
COMPRESSIONS CALLED RAREFACTION.
>> OK, SO WHENOU'RE MEASURING
A LONGITUDINAL WAVE, YOU HAVE TO
MEASURE FROM COMPRESSION
TO COMPRESSION INSTEAD OF
FROM CREST TO CREST?
>> RIGHT.
>> IF WE USE ARROWS TO SHOW
HOW MUCH A WHICH WAY
EACH PARTICLE'S DISPLACED
AS THE COMPRESSION WAVE
PASSES THROUGH THEM,
WE GET A GRAPH THAT LOOKS
LIKE THIS.
IF YOU WERE TO TAKE ALL THOSE
ARROWS AND TURN THEM VERTICALLY,
THE SHAPE NOW MAS
A SINE CURVE.
THAT'S WHAT OSCILLOSCOPES DO.
THEYONVERT THE COMPRESSIONS
IN RAREFACTIONS SO WE SEE THEM
AS SINE WAVES.
OK, SO WE'VE SEEN THAT WAVES
ARE MEASURED IN AMPLITUDE,
WAVENGTH, AND FREQUENCY.
AND IF WE USE WAVELENGTH
AND FREQUENCY, WE CAN FIGURE OUT
SOMETHING ELSE ABOUT A WAVE:
ITS SPEED.
>>T'S ACTUALLY PRETTY EASY TO
FIGURE OUT A WAVE'S SPEED
IF YOU KNOW THE FREQUENCY
AND THE WAVELENGTH.
SO WE CAN USE THE EQUATION:
SPEED = WAVELENGTH X FREQUENCY.
>> OK, WELL, WE FIGURED OUT
THAT THESE WAVES HERE HAVE
A WAVELENGTH OF ABOUT 5 METERS,
AND A CREST PASSES EVERY
5 SECONDS, RIG?
SO OUR FREQUENCY IS 1/5 HERTZ.
SO WE JUST PLUG IN OUR NUMBERS:
WAVELENGTH IS 5 METERS,
FREQUENCY IS 1/5.
5 X 1/5 IS...
>> ONE METER PER SECON
>> OH, WAIT A SECOND,
THAT'S ONLY 2 MILES PER HOUR.
>> WELL, THESE ARE JUST
BABY WAVES.
BIG WAVES N TRAVEL AS FAST
AS HUNDREDS OF MILES PER HOUR.
SOUND WAVES TRAVEL AT ABOUT
350 METERS PER SECOND
AT SEA LEVEL.
AND LIGHT TRAVELS MOST
A MILLION TIMES AS FAST AT
300 MILLION METERS PER SECOND.
>> WOW.
IMAGINE IF WE COULD SURF
A LIGHT WAVE
>> THAT WOULD BE PRETTY COOL.
>> OK, GUYS, SO WHAT DID
WE LEARN?
>> WAVES ARE ENERGY MOVING
THUGH A MEDIUM LIKE
SOUND WAVES THROUGH AIR.
>> ENERGY IS TRANSFERRED WITHOUT
MATTER BEING TRANSFERRED.
THE WATER MOVES UP AND DOWN
BUT DOEST GET CLOSER
TO THE BEACH.
>> WAVES ARE MEASURED IN
AMPLUDE, WAVELENGTH,
AND FREQUENCY.
>> THERE ARERANSVERSE WAVES
LIKE LIGHT AND LONGITUDINAL
WAVES LIKE SOUND.
AND TO FIND THE SPEED OF A WAVE,
JUST MULTIPLY THE FREQUENCY
TIMES THE WAVELENGTH.
>> OK, COOL.
AH! WELL, THAT'S IT.
I'D LIKE TO THANK
ROCHELLE BALLARD...
>> RIGHT.
>> AND OUR STUDENTS
MARA, MELISSA, RYAN, AND RYAN
FOR HELPING US OUT TODAY
ON ESPN SPORTSFIGURES:
MAKING WAVES.
I GOT TO GO.
I'M GONNA CATCH SOME ENERGY.
