Transcript for NASASciFiles - The Case of the Barking Dogs

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HEY, YOU.

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HEY, ME?

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YEAH, YOU.

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COME SEE OUR CLUBHOUSE IN A TREE.

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WE ARE KIDS ON A MISSION TO EDUCATE
OURSELVES BY THE NASA VISION.

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COME EXPLORE MATH AND SCIENCE
'CAUSE THAT'S WHAT MAKES

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OUR ALLIANCE.

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WE ARE THE WHY?

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FILES CLUB.

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WE YEARN TO LEARN AND WANT TO
SEE EVERYTHING THAT WE CAN BE.

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SO COME JOIN US ON OUR JOURNEY.

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DON'T YOU TOUCH THAT DIAL.

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AND WELCOME TO THE NASA WHY?

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FILES.

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WAIT, WHAT ARE YOU DOING?

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LOOK, YOU JUST POURED
ORANGE JUICE IN YOUR CEREAL.

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I CAN'T BELIEVE I JUST DID
THIS, BUT I'M SO TIRED.

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HI, JACOB.

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HI.

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OH WOW, THIS IS SO COOL.

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OH, THIS IS MY FRIEND, P.J.
HE'S A FRIEND FROM SCHOOL.

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I TOLD HIM ABOUT OUR TREE HOUSE.

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HI.

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WHAT DO YOU GUYS DO IN THIS PLACE?

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YOU'LL FIND OUT SOON ENOUGH.

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I ASKED MY TWO FRIENDS TO JOIN US.

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THIS IS KALI AND CATHERINE.

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PRETTY NEAT.

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I LIKE THE SWING.

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YOU ALL WON'T BELIEVE
WHAT I JUST DID.

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WHAT DID YOU DO?

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I WAS SO TIRED THAT I ACCIDENTALLY
POURED ORANGE JUICE IN MY CEREAL.

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MY DOG ROCKY WOKE ME UP DURING
THE NIGHT, SOME TIME AROUND 10:30.

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SO DID MY DOG, ARF.

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HE JUST STARTED BARKING
FOR SOME REASON.

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YOU HAVE A DOG NAMED ARF?

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WELL, YEAH, IT MAKES SENSE.

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YOU KNOW, "ARF, ARF."

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HOW LONG HAS THIS BEEN GOING ON?

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FOR THE LAST SEVERAL NIGHTS.

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HEY, KSNN IS COMING ON.

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AND NOW, KSNN AFTERNOON NEWS.

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BROUGHT TO YOU BY THE GUM SONIC
TURBO ELECTRIC TOOTHBRUSH:

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BRUSH YOUR TEETH AT SUPERSONIC
SPEED WITH A GUM SONIC TURBO.

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GOOD AFTERNOON.

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I'M TED TUNE.

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TODAY'S TOP STORY: BARKING DOGS ARE
KEEPING OUR CITY'S RESIDENTS AWAKE.

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REPORTS BEGAN TO COME IN BETWEEN
10:00 P.M. AND MIDNIGHT LAST NIGHT.

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OUR ON-THE-SCENE REPORTER, I.M.
LISSNING, IS LIVE WITH THIS REPORT.

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THANKS, TED.

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AS YOU WELL KNOW, DOGS WILL
BARK AT JUST ABOUT ANYTHING,

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AND THEY WERE CERTAINLY
BARKING LAST NIGHT.

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BUT NO ONE HERE SEEMS
TO KNOW EXACTLY WHY:

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SOME RESIDENTS SPECULATED
THAT A CAT

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OR A PROWLER MAY HAVE
CAUSED THE DOGS TO BARK,

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OR IT COULD HAVE BEEN
SOMETHING AS SIMPLE AS THE WIND.

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WE MAY NEVER KNOW.

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I.M. LISSNING: KSNN
NEWS ON-THE-SCENE.

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THANKS, I.M., FOR THAT LIVE REPORT.

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AUTHORITIES ARE PLEADING WITH
LOCAL RESIDENTS TO BRING THEIR DOGS

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IN TONIGHT, SO THAT
EVERYONE CAN GET SOME SLEEP.

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I'M TED TUNE, AND
THAT'S ALL THE NEWS.

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WOW, IT'S NOT JUST ROCKY AND ARF.

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DOGS ARE BARKING IN OTHER
AREAS OF OUR NEIGHBORHOOD.

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BUT WHAT COULD BE SETTING THEM OFF?

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IT COULD BE A SNEAKY CAT
JUST TRYING TO TEASE THEM.

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MAYBE THE DOGS ARE JUST
TALKING TO EACH OTHER.

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RIGHT, AT THAT HOUR?

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I KNOW WE NEED TO
SOLVE THIS PROBLEM.

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REMEMBER, WE HAVE THAT BIG
TEST COMING UP NEXT WEEK.

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I NEED MY SLEEP, I CAN'T
AFFORD ANOTHER BAD GRADE.

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TODAY'S MONDAY, HOPEFULLY, WE CAN
FIGURE THIS ONE OUT BY TEST TIME.

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MAYBE I CAN HELP YOU, I'M
PRETTY GOOD ON THE COMPUTER.

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WE COULD DO A LITTLE
RESEARCH ON THE INTERNET.

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GOOD IDEA.

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I THINK WE CAN HELP TOO.

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YOU KNOW, SIX HEADS
ARE BETTER THAN ONE.

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I CAN'T BELIEVE I DIDN'T
MAKE THE CONNECTION.

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YOU THREE ARE ON KSNN, THEY CALL
YOU THE TREE HOUSE DETECTIVES.

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THAT'S US.

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MAYBE WE COULD BECOME
TREE HOUSE DETECTIVES TOO.

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HMM, MAYBE IF WE HAD A TEAM OF TREE
HOUSE DETECTIVES, WE COULD FIGURE

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OUT THE PROBLEM OF THE
BARKING DOG A LOT FASTER.

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MY MOM WORKS ON A TEAM AT
NASA LANGLEY RESEARCH CENTER;

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SHE SAYS THAT THEY HAVE A LOT
OF SUCCESS SOLVING PROBLEMS.

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MAYBE A TEAM APPROACH
IS THE WAY TO GO.

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LET'S GO FOR IT.

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OKAY.

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LET'S GET STARTED.

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WE DON'T KNOW MUCH.

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SO FAR, ALL WE KNOW IS
THAT THE DOGS ARE BARKING

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AND KEEPING EVERYONE UP.

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WE NEED HELP.

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LET'S GO ASK OUR NEIGHBOR,
DR. D. HE HELPED US

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THROUGH THE STINK PROBLEM.

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I HAVE AN IDEA, ANYTIME
WE TAKE A FIELD TRIP,

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LET'S PUT IT ON THE BOARD.

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THAT WAY, ALL OF US WILL
KNOW WHAT'S GOING ON.

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AND ANY INFORMATION YOU RECEIVE,
JUST ENTER IT INTO YOUR COMPUTER.

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GOOD IDEA.

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MAYBE JUST THE THREE OF US
SHOULD GO OVER BEFORE SCHOOL.

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I'LL GO TO SCHOOL EARLY.

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WE WILL TOO.

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LET'S GO SEE DR. D. OK,
I'M SURE HE'S WORKING

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ON ONE OF HIS PROJECTS.

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HEY, DR. D. I THINK
HE CAN HEAR YOU.

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YOU'RE SO LOUD.

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HI GUYS, WHAT BRINGS YOU OVER?

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YOU LOOK A LITTLE TIRED.

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SOME OF US ARE VERY TIRED.

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WE DIDN'T GET ANY SLEEP.

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BOTH OF OUR DOGS WERE
BARKING LAST NIGHT.

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DR. D, DID BERNIE BARK LAST NIGHT?

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NAH, YOU KNOW BERNIE.

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HE'S A LITTLE OLD-- SOMETIMES
HE'S REALLY OUT OF IT.

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DID BERNIE EVER BARK?

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OH YEAH, SURE, ESPECIALLY
WHEN HE WOULD SMELL

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OR HEAR SOMETHING HE
WASN'T FAMILIAR WITH,

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HE'D START BARKING TO SCARE IT OFF.

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SO COULD THERE BE A STRANGE SMELL
IN THE AIR THAT'S MAKING ALL

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OF THE DOGS IN THE
NEIGHBORHOOD START BARKING?

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COULD BE.

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I THOUGHT THE TREE HOUSE
DETECTIVES WOULD BE BACK,

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SO I MADE UP THIS BOARD.

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OH, THE SCIENTIFIC METHOD-- I'LL
LET YOU IN ON A LITTLE SOMETHING:

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THE SCIENTIFIC METHOD REALLY
HELPS YOU SOLVE PROBLEMS.

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WELL, IT HELPED US
WITH THE STINK PROBLEM.

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REMEMBER, THE SCIENTIFIC
METHOD IS A STEP-BY-STEP WAY

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TO SOLVE PROBLEMS.

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YOU CAN USE IT EVERYDAY.

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OH, IT'S ALL COMING BACK TO ME NOW.

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I HAVE SOMETHING FUN TO SHOW YOU

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THAT WILL HELP US REVIEW
THE SCIENTIFIC METHOD.

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LET'S GO TO MY LAB AND TRY IT OUT.

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OKAY.

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DOES ANYONE KNOW WHAT
THIS DEVICE IS CALLED?

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I'VE SEEN ONE BEFORE, BUT I
DON'T KNOW WHAT IT'S CALLED.

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IT'S CALLED A NEWTON'S CRADLE.

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IF YOU WANTED TO FIND OUT HOW
IT WORKED, WHAT WOULD YOU DO?

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I GUESS I'D PLAY AROUND WITH IT.

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IF WE WERE FOLLOWING THE SCIENTIFIC
METHOD, THE FIRST THING WE'D DO IS

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TO IDENTIFY THE PROBLEM.

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AND OF COURSE WE'D
HAVE TO OBSERVE IT.

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WELL, YOU'RE OBSERVING IT
ALREADY BY PLAYING WITH IT.

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WHAT DO YOU THINK IS THE PROBLEM?

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WELL, I NOTICE THAT WHEN
I PULL THIS BALL BACK,

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AND THEN RELEASE IT,
ANOTHER BALL POPS OUT.

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DOES THAT HAPPEN EVERY TIME?

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AND WHAT ABOUT TWO BALLS?

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THAT'S THE PROBLEM.

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REMEMBER, A PROBLEM HAS TO BE
STATED IN THE FORM OF A QUESTION.

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SO OUR PROBLEM IS, WHAT HAPPENS
TO THE BALLS ON THE OTHER SIDE

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WHEN I PULL BACK A
CERTAIN NUMBER OF BALLS?

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ISN'T THE NEXT PART OF THE
SCIENTIFIC METHOD RESEARCH?

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THAT'S CORRECT.

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OH, I LIKE THIS KIND OF RESEARCH.

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LET'S SEE WHAT HAPPENS
WHEN I PULL BACK TWO BALLS.

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I'LL COLLECT DATA.

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WHOAH, WAIT A MINUTE, DON'T FORGET;
WE HAVE TO CONTROL THE VARIABLES.

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ALL THE VARIABLES ARE
THE SAME EXCEPT FOR ONE.

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SO PULL BACK YOUR TWO
BALLS THE SAME DISTANCE

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THAT JACOB PULLED BACK HIS ONE.

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THAT'S RIGHT.

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I FORGOT ABOUT THOSE VARIABLES.

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WAIT, WHAT HAPPENS --
WHAT IF I DO THREE BALLS?

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ARE WE READY FOR OUR
HYPOTHESIS YET?

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I KNOW THE HYPOTHESIS:
WHEN YOU LET GO

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OF TWO BALLS, TWO BALLS COME OUT.

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AND IF YOU LET GO OF THREE
BALLS, THREE BALLS COME OUT.

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THAT'S RIGHT.

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REMEMBER, THE HYPOTHESIS HAS TO
BE WRITTEN SO IT CAN BE TESTED.

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FOR EXAMPLE, THE SAME NUMBER
OF BALLS I PULL BACK WILL COME

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OUT ON THE OTHER SIDE.

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OK, ARE WE READY TO EXPERIMENT YET?

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THAT'S MY FAVORITE PART.

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OK.

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LET'S TEST THE HYPOTHESIS.

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LET'S SEE WHAT HAPPENS IF
I PULL BACK FOUR BALLS,

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THEN FOUR BALLS SHOULD
COME OUT ON THE OTHER SIDE.

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WOW, OUR HYPOTHESIS WAS CORRECT.

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CONGRATULATIONS, BUT REMEMBER,

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IF THE DATA DOES NOT
SUPPORT THE HYPOTHESIS,

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YOU WOULD HAVE TO TRY AGAIN.

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BUT HOW DO WE OBSERVE OUR
PROBLEM OF THE BARKING DOGS?

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WE CAN'T STAY UP ALL NIGHT WAITING
FOR THE DOGS TO START BARKING.

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WELL, WE COULD.

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NOT ME, REMEMBER, I HAVE
THAT BIG TEST NEXT WEEK.

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I THINK WE NEED TO GO BACK
TO THE TREE HOUSE TO TALK

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ABOUT THIS PROBLEM,
AND THEN WE NEED

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TO DECIDE WHAT WE WANT TO RESEARCH.

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THANKS FOR ALL YOUR HELP, DR.
D. SEE YA DR. D. BYE-BYE, GUYS.

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LET'S SEE: REMEMBER
OUR NEED TO KNOW BOARD?

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HOW COULD I FORGET THAT ONE?

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HEY, IT DID HELP US
SOLVE THE STINK PROBLEM.

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OK, WHAT DO WE KNOW?

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WE KNOW THAT DOGS ARE BARKING
AT ALL HOURS OF THE NIGHT.

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AND WE KNOW THAT'S
HAPPENING IN OUR NEIGHBORHOOD.

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WE NEED TO KNOW WHAT'S
MAKING THEM BARK.

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HMM, WHAT WOULD MAKE A DOG BARK?

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IT COULD BE A PROWLER OR A
ROBBER STAKING OUT THE AREA.

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OR IT COULD BE JUST A
MAD CAT GETTING EVEN.

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YEAH, BUT IF IT WAS A PROWLER,
WOULDN'T KSNN REPORT ABOUT IT?

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HMM, THAT'S TRUE, AND I
HAVEN'T HEARD ANYTHING

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ABOUT PROWLERS OR ROBBERS ON KSNN.

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CATS AREN'T A NEW PROBLEM,

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BUT WHATEVER IS SETTING OFF
THE BARKING DEFINITELY IS.

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OR REMEMBER WHAT DR. D
TOLD US ABOUT BERNIE?

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BERNIE BARKS AT STRANGE
SMELLS OR SOUNDS.

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KSNN DIDN'T REPORT ANY
ENVIRONMENTAL PROBLEMS

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WITH A SMELL.

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SINCE DR. D SAID IT
COULD ALSO BE SOUND,

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THEN LET'S INVESTIGATE SOUND.

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BUT REMEMBER THE STINK;
IT COULD BE ANYTHING.

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YES, WE NEED TO FIND OUT
A LITTLE MORE ABOUT SOUND.

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WE NEED TO START OUR
SOUND RESEARCH.

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WE SHOULD ALSO CHECK OUT
THE NASA WHY FILES WEBSITE.

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I SAW SOMETHING ON IT ABOUT SOUND.

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YOU WILL LOVE THE NASA
WHY FILES WEBSITE.

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MY MOM'S FRIEND, MRS. LESLIE BOWIE,

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WORKS OVER AT THE
CHILDREN'S MUSEUM.

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MAYBE SHE CAN HELP US
WITH THE SOUND PROBLEM.

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I CAN'T GO OVER THERE RIGHT NOW.

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I CAN'T GO EITHER.

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OK, I'LL PUT IT IN THE COMPUTER.

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MAYBE ONE OF THE OTHER
DETECTIVES WILL SHOW UP.

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THIS PLACE IS REALLY NEAT.

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YEAH, BUT I THINK WE NEED
TO FIND MS. LESLIE BOWIE.

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HI.

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I'M LESLIE BOWIE.

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I'M CURATOR HERE AT THE
CHILDREN'S MUSEUM OF VIRGINIA.

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HOW CAN I HELP YOU?

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HI, SOME OF OUR DOGS ARE BARKING
AND ARE WAKING US UP AT NIGHT.

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AND WE THINK THAT A REALLY STRANGE
SOUND MAY BE MAKING THEM BARK.

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CAN YOU TELL US WHAT SOUND IS?

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I THINK I CAN HELP YOU
UNDERSTAND, COME OVER THIS WAY.

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SOUND IS CREATED BY VIBRATION.

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A VIBRATION IS A BACK-AND-FORTH
MOTION A LOT LIKE THIS SLINKY.

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AN OBJECT VIBRATES AND
PUSHES AIR MOLECULES AROUND.

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THEN THESE SET OTHER AIR
MOLECULES INTO MOTION.

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BUT WE CAN'T ACTUALLY
SEE THE SOUND WAVES.

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BUT I CAN HELP YOU
SEE THE VIBRATIONS.

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THIS IS A TUNING FORK.

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LISTEN.

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I CAN HEAR A SOUND.

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ME TOO.

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AND I CAN HELP YOU
SEE THE VIBRATIONS.

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WHAT IS FREQUENCY?

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FREQUENCY IS THE RATE OF VIBRATION.

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THE HIGHER THE FREQUENCY,
THE HIGHER THE PITCH.

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HERE, LET ME SHOW YOU.

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I'VE FLATTENED A STRAW
AND CUT POINTS.

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NOW, BLOW HARD.

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I'LL CUT THE STRAW --
WHAT DO YOU NOTICE?

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IT'S HIGHER.

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I'LL CUT IT AGAIN.

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WHAT CHANGES?

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IT'S EVEN HIGHER.

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IT'S KIND OF LIKE THESE TUBES.

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THE LONGER THE TUBE,
THE LOWER THE SOUND.

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THAT'S RIGHT, THE SHORTER THE
TUBE, THE HIGHER THE SOUND.

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IT'S A LOT LIKE THE STRAWS.

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BIANCA, CAN YOU HEAR ME?

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YES, KALI.

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WE'RE HAVING SO MUCH FUN.

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BUT NOW IT'S TIME TO GO.

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I DON'T WANT TO GO, BUT I'LL
GO TELL MRS. BOWIE THANKS

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FOR THE INFORMATION.

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OKAY.

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SEE YOU.

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BYE.

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BYE-BYE.

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LET'S GET BACK TO WORK.

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WHEN MY DOG STARTS
BARKING, I'M USUALLY ASLEEP.

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MAYBE WE CAN ASK OTHER PEOPLE
TO OBSERVE THEIR DOGS AT NIGHT.

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I'LL CALL KSNN AND ASK THEM
TO ANNOUNCE IT ON THE NEWS.

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A BIG PART OF THE SCIENTIFIC
METHOD IS OBSERVATION.

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REMEMBER WHAT DR. D SAID, YOU HAVE

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TO DEFINE THE PROBLEM
THROUGH OBSERVATION.

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OBSERVATION IS MY FAVORITE
PART OF THE SCIENTIFIC METHOD.

[00:11:43.549]
IF YOU WANT TO LEARN MORE ABOUT THE
SCIENTIFIC METHOD, YOU SHOULD GO

[00:11:45.999]
TO THE NASA WHY FILES WEBSITE.

[00:11:49.799]
KSNN IS GREAT.

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LOOK, WE'RE ALREADY
GETTING RESPONSES

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FROM DIFFERENT NEIGHBORHOODS.

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LET'S SEE, THIS PERSON FROM COCHLEA
CASCADE SAYS HER DOG STARTS BARKING

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EARLY IN THE MORNING,
AND LATE AT NIGHT.

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BUT AT MIDNIGHT GROWL, THEY SAY

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THAT THEY HAVE BARKING
MAINLY IN THE MORNING.

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LET'S E-MAIL THEM BACK, AND SEE
IF THEY NOTICED ANY FUNNY SMELLS,

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SOUNDS, OR CREATURES AROUND THE
HOUSE WHEN THE DOGS WERE BARKING.

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HOW ARE WE GOING TO
SORT ALL THIS DATA?

[00:12:11.879]
DATA COLLECTION IS ALSO A BIG
PART OF THE SCIENTIFIC METHOD.

[00:12:15.839]
WITH THIS DATA, WE MIGHT BE ABLE
TO GET TO THE BOTTOM OF THIS.

[00:12:18.549]
MY MOM TOLD ME ABOUT SOMEONE AT
NASA LANGLEY WHO SPENDS A LOT

[00:12:21.539]
OF TIME COLLECTING
AND ANALYZING DATA.

[00:12:23.769]
MAYBE WE SHOULD TALK
TO THE EXPERTS AT NASA.

[00:12:26.439]
COMPUTER, GET ME AN EXPERT AT NASA
ON ANALYZING AND COLLECTING DATA.

[00:12:33.149]
HI, I'M DR. KARA LATORELLA AT
THE NASA LANGLEY RESEARCH CENTER.

[00:12:36.519]
HI, WE'RE TRYING TO SOLVE THE
PROBLEM OF THE BARKING DOGS.

[00:12:39.599]
I MIGHT BE ABLE TO HELP YOU,
WE COLLECT A LOT OF DATA HERE.

[00:12:42.209]
THAT'S HOW WE UNDERSTAND
PROBLEMS SO WE CAN SOLVE THEM.

[00:12:45.579]
RIGHT NOW, WE'RE DEVELOPING A
FLIGHT SIMULATION EXPERIMENT

[00:12:48.249]
SO WE CAN TEST A NEW DISPLAY IDEA.

[00:12:50.149]
WE'LL COLLECT DATA FROM PILOTS
TO SEE IF THEY CAN FLY YOU

[00:12:52.899]
AND YOUR FAMILY AROUND MORE
SAFELY WITH OUR NEW DISPLAY,

[00:12:55.539]
AS OPPOSED TO THE OLD ONE.

[00:12:57.239]
WE'VE RECEIVED A LOT OF
E-MAILS FROM NEIGHBORHOODS.

[00:12:59.579]
WE REALLY NEED TO KNOW THE BEST
WAY TO KEEP TRACK OF ALL THIS DATA.

[00:13:01.989]
HOW DO YOU SORT AND
COLLECT YOUR DATA?

[00:13:04.459]
WELL, FIRST, WE START WITH
A QUESTION OR A STATEMENT

[00:13:07.019]
OF WHAT WE THINK IS HAPPENING.

[00:13:08.569]
WE CALL THAT STATEMENT
A HYPOTHESIS.

[00:13:10.689]
SO FOR EXAMPLE, IN MY
CASE, I HYPOTHESIZED

[00:13:13.289]
THAT THE NEW DISPLAY WOULD BE
BETTER THAN THE OLD DISPLAY,

[00:13:15.379]
AND THAT THAT WOULD BE TRUE FOR
BOTH YOUNGER AND OLDER PILOTS.

[00:13:18.439]
THE DATA WE COLLECT WILL
FILL IN THE TEST MATRIX.

[00:13:21.019]
EACH DATA POINT CAN BE
CONSIDERED AN OBSERVATION.

[00:13:23.859]
IN MY EXPERIMENT, I'M USING
THE COMPUTER AND SENSORS

[00:13:26.819]
IN THE COMPUTER TO TAKE
THESE OBSERVATIONS.

[00:13:29.699]
YOU CAN ALSO TAKE DIRECT
OBSERVATIONS BY LOOKING

[00:13:31.999]
AT THINGS YOURSELF, OR INDIRECT
OBSERVATIONS BY ASKING OTHER PEOPLE

[00:13:35.119]
TO REPORT THINGS TO YOU.

[00:13:36.879]
HOW DO WE KNOW IF DATA'S
IMPORTANT TO OUR PROBLEM?

[00:13:39.099]
WELL, HOPEFULLY, YOUR DATA
SUPPORTS YOUR HYPOTHESIS.

[00:13:41.779]
THAT MEANS THE CONDITIONS YOU
THOUGHT WERE IMPORTANT ACTUALLY DID

[00:13:44.249]
INFLUENCE YOUR MEASURES.

[00:13:45.809]
IF IT DOESN'T, THEN YOU MIGHT
WANT TO COLLECT SOME MORE DATA,

[00:13:48.259]
OR DIFFERENT DATA, OR
RETHINK YOUR HYPOTHESIS.

[00:13:50.529]
THIS IS GREAT.

[00:13:51.029]
REMEMBER THE MATRIX DR. D
SHOWED US IN THE STINK PROBLEM?

[00:13:55.039]
WE CAN USE THAT TO
HELP US RULE OUT SOME

[00:13:57.179]
OF THE POSSIBLE SOURCES
OF THE PROBLEM.

[00:13:58.929]
BUT HOW DO WE SET UP A MATRIX?

[00:14:00.679]
YOU REALLY SHOULD SET UP YOUR
TEST MATRIX AHEAD OF TIME,

[00:14:03.149]
BEFORE YOU COLLECT DATA.

[00:14:04.969]
IN MY EXPERIMENT,
IT'S PRETTY SIMPLE

[00:14:06.349]
SINCE I ONLY HAVE TWO FACTORS
OF INTEREST: THE DISPLAY TYPE

[00:14:09.569]
AND AGE OF THE PILOTS.

[00:14:10.819]
AND I HAVE TWO LEVELS FOR
EACH OF THESE FACTORS.

[00:14:13.269]
FOR THE DISPLAY TYPE, I HAVE A
NEW DISPLAY AND AN OLD DISPLAY;

[00:14:15.819]
AND FOR THE AGE OF THE PILOTS,
I HAVE YOUNGER AND OLDER PILOTS.

[00:14:19.089]
YOUR MATRIX HELPS YOU ORGANIZE
YOUR DATA, SO YOU CAN LOOK AT IT,

[00:14:22.569]
ANALYZE IT, AND UNDERSTAND WHAT'S
IMPORTANT ABOUT YOUR PROBLEM.

[00:14:25.599]
WE CAN LOOK AT THE DATA AND
GET AN IDEA ABOUT THE SOURCE.

[00:14:28.509]
THANKS A LOT FOR ALL YOUR
HELP, NOW WE MIGHT BE ABLE

[00:14:30.979]
TO ACTUALLY MAKE SOME
SENSE OF ALL THIS.

[00:14:33.219]
THANKS FOR STOPPING BY.

[00:14:34.359]
GOOD LUCK.

[00:14:35.629]
WOW, WE HAVE MORE E-MAILS.

[00:14:37.319]
MAYBE WE WILL SEE A PATTERN IN
THE INCREASE OF STRANGE SMELLS,

[00:14:39.849]
SOUNDS, OR EVEN PROWLERS.

[00:14:41.999]
LOOK, THIS PERSON FROM COCHLEA
CASCADE SAID SHE DIDN'T NOTICE ANY

[00:14:45.309]
STRANGE SMELLS WHEN HER
DOG STARTED BARKING.

[00:14:47.449]
SMELL SEEMS LIKE SUCH A STRETCH.

[00:14:48.759]
I DON'T THINK WE'RE GOING TO
SOLVE THIS PROBLEM ANYTIME TODAY.

[00:14:52.199]
I AGREE.

[00:14:52.939]
TONIGHT, TRY TO SEE WHAT'S GOING
ON WHEN YOUR DOG STARTS BARKING.

[00:14:55.659]
I'LL TRY.

[00:14:56.449]
LET'S ALL TRY; WE NEED TO
FIGURE THIS ONE OUT QUICK.

[00:15:00.159]
SO WHAT'S UP?

[00:15:01.279]
WILL THE DOGS CONTINUE TO BARK?

[00:15:03.219]
ARE THE TREE HOUSE DETECTIVES
ASKING THE RIGHT QUESTIONS?

[00:15:05.609]
WILL THE SCIENTIFIC METHOD
WORK TO SOLVE THE PROBLEM?

[00:15:08.989]
TUNE IN NEXT TIME FOR THE
CASE OF THE BARKING DOGS.

[00:15:13.929]
WE CAN USE OUR INFORMATION TO PLOT
EXACTLY WHERE THE DOGS ARE BARKING

[00:15:21.099]
AND THE POSSIBLE CAUSES.

[00:15:23.229]
LET'S USE BLACK PUSH PINS FOR
DOGS BARKING IN THE NIGHT,

[00:15:26.879]
BLUE ONES FOR DOGS BARKING IN
THE DAY, GREEN FOR PROWLERS,

[00:15:31.179]
YELLOW FOR LOUD SOUNDS, AND
RED ONES FOR STRANGE SMELLS.

[00:15:34.619]
WE HAVE TOO MANY E-MAILS,
BUT NOT ENOUGH PUSH PINS.

[00:15:37.069]
REMEMBER IN SCHOOL,
WE USED PICTOGRAPHS

[00:15:39.249]
TO REPRESENT LARGE NUMBERS.

[00:15:40.949]
YEAH, EACH PUSH PIN CAN
EQUAL FIVE BARKING DOGS.

[00:15:44.589]
IN MIDNIGHT GROWL, WE HAVE
TEN DOGS BARKING IN THE DAY.

[00:15:47.049]
SO I'LL PUT TWO BLUE PUSH PINS.

[00:15:50.699]
IN COCHLEA CASCADE, WE HAVE
20 DOGS BARKING IN THE DAY

[00:15:55.399]
AND 10 DOGS BARKING AT NIGHT.

[00:15:57.629]
THAT MEANS WE HAVE FOUR BLUE
PUSH PINS AND TWO BLACK ONES.

[00:16:01.429]
LET'S JUST PUT IN A GREEN
PUSH PIN FOR EACH NEIGHBORHOOD

[00:16:04.019]
THAT REPORTED PROWLERS.

[00:16:05.679]
THAT WOULD BE MIDNIGHT GROWL
AND SLEEPLESS SUBDIVISION.

[00:16:10.059]
HMM, IF PROWLERS WERE THE
SOURCE OF THE PROBLEM,

[00:16:12.239]
THEN WOULDN'T EACH NEIGHBORHOOD

[00:16:13.329]
THAT REPORTED BARKING
DOGS HAVE PROWLERS?

[00:16:15.189]
AND THOSE WITH PROWLERS
WOULD HAVE BARKING.

[00:16:17.289]
BUT BY LOOKING AT THE MAP, WE
CAN SEE THAT THIS ISN'T TRUE.

[00:16:19.689]
SO I GUESS PROWLERS
AREN'T CAUSING THE PROBLEM.

[00:16:21.799]
WHAT ABOUT SMELLS?

[00:16:23.119]
SO FAR, NO ONE HAS
REPORTED ANY BAD SMELLS.

[00:16:25.729]
AND IF IT WAS A BAD SMELL, WOULDN'T
KSNN SAY SOMETHING ABOUT IT?

[00:16:29.589]
GOOD POINT.

[00:16:30.349]
WHAT ABOUT SOUND?

[00:16:31.899]
IN MIDNIGHT GROWL,
WE HAVE DOGS BARKING,

[00:16:33.869]
AND SOME RESIDENTS ARE
NOTICING LOUD NOISES.

[00:16:36.179]
I'LL PUT A YELLOW PUSH
PIN IN MIDNIGHT GROWL.

[00:16:40.019]
IN COCHLEA CASCADE,
THERE ARE DOGS BARKING,

[00:16:42.529]
AND THEY NOTICE LOUD SOUNDS.

[00:16:44.579]
ANOTHER PUSH PIN FOR
THAT NEIGHBORHOOD.

[00:16:46.929]
THIS LOOKS PROMISING.

[00:16:48.419]
IN THE EMAIL FROM SOUND SEASIDE,
THEY'VE NOTICED LOUD SOUNDS.

[00:16:52.329]
LET ME GET THIS ONE.

[00:16:54.069]
WELL, THERE ARE NO DOGS BARKING.

[00:16:55.519]
DOES THIS MEAN THAT THERE'S
NO CONNECTION TO SOUND?

[00:16:57.939]
MY GUESS IS NO.

[00:16:59.689]
WE MIGHT WANT TO RESEARCH
SOUND A LOT MORE,

[00:17:02.059]
BECAUSE BOTH MIDNIGHT GROWL

[00:17:03.809]
AND COCHLEA CASCADE HAVE
BARKING DOGS AND SOUND.

[00:17:07.009]
THERE MAY BE A CONNECTION.

[00:17:08.129]
YOU WOULD THINK THAT ALL DOGS WOULD
START BARKING AT ALL LOUD SOUNDS.

[00:17:12.819]
I THINK, SO FAR, IT'S SOUND.

[00:17:14.669]
THE MAP REALLY HELPS US SEE IT.

[00:17:16.489]
IT SURE HAS HELPED US
TO SOLVE THE PROBLEM.

[00:17:18.559]
YOU KNOW, AT THE NASA WHY FILES
WEBSITE THERE ARE SOME GREAT

[00:17:21.159]
ACTIVITIES USING A
MAP AND A MATRIX.

[00:17:23.049]
YOU SHOULD CHECK IT OUT.

[00:17:24.389]
I THINK WE NEED TO CONCENTRATE
ON SOUND A LITTLE MORE.

[00:17:26.449]
LET'S GO BACK TO OUR
NEED TO KNOW BOARD.

[00:17:28.049]
WE KNOW DOGS ARE BARKING.

[00:17:33.839]
AND WE KNOW THAT VIBRATIONS
PRODUCE SOUND,

[00:17:37.509]
AND THAT SOUND TRAVELS IN WAVES.

[00:17:39.719]
WE NEED TO KNOW MORE ABOUT HOW
SOUND TRAVELS, AND HOW WE HEAR IT.

[00:17:44.359]
LET'S THINK ABOUT SOUNDS
THAT MAKE DOGS BARK.

[00:17:47.169]
GARBAGE TRUCKS.

[00:17:48.519]
SIRENS.

[00:17:49.139]
DEFINITELY -- AND WORK TRUCKS.

[00:17:51.089]
I WONDER IF THERE'S A REASON WHY
THE DOGS AREN'T HEARING SOUNDS

[00:17:53.759]
IN SOUND SEASIDE?

[00:17:54.749]
MAYBE THEY HAVE WAX IN THEIR EARS.

[00:17:56.979]
YEAH, RIGHT.

[00:17:58.019]
MAYBE SOMETHING'S BLOCKING
THE SOUND, YOU KNOW,

[00:18:00.119]
KEEPING IT FROM GOING
TO OTHER PARTS OF TOWN.

[00:18:02.449]
THAT'S A GOOD IDEA, LIKE WHAT?

[00:18:04.789]
MAYBE A WALL; MAYBE MORE DOGS ARE
KEPT INSIDE IN THAT NEIGHBORHOOD.

[00:18:07.789]
THAT COULD BE IT.

[00:18:09.779]
I THINK THERE'S MORE CONNECTIONS
BETWEEN BARKING DOGS AND SOUND

[00:18:12.929]
THAN THERE IS WITH
PROWLERS OR EVEN SMELLS.

[00:18:16.229]
I SAY WE CONCENTRATE ON SOUNDS.

[00:18:18.459]
MY MOM'S FRIEND KNOWS
A LOT ABOUT EARS.

[00:18:20.419]
I THINK SHE'S CALLED
AN AUDIOLOGIST.

[00:18:22.119]
CAN YOU GO VISIT HER?

[00:18:23.339]
I CAN'T, I HAVE TO DO MY HOMEWORK.

[00:18:25.329]
JACOB AND I WILL GO.

[00:18:26.599]
HER NAME IS MS. HELEN DENNIE.

[00:18:29.029]
SHE WORKS AT SENTARA
HAMPTON GENERAL HOSPITAL.

[00:18:31.579]
SHE SAYS WE CAN COME OVER ANYTIME.

[00:18:34.049]
I'LL E-MAIL OUR PARENTS TO
TELL THEM WHERE WE'RE GOING.

[00:18:37.839]
GREAT, LET'S GET UP AND GO.

[00:18:40.139]
WE'RE KNOWN AS THE
TREE HOUSE DETECTIVES.

[00:18:45.469]
OH.

[00:18:45.729]
WE'RE TRYING TO GET SOME SLEEP,

[00:18:47.109]
BUT THE NEIGHBORHOOD
DOGS ARE KEEPING US UP.

[00:18:48.619]
OH NO.

[00:18:48.819]
WE WANTED TO KNOW
HOW OUR EARS WORK.

[00:18:51.129]
THAT WAY WE CAN FIGURE OUT
WHY THE DOGS KEEP BARKING.

[00:18:53.299]
AND HOW SOUNDS TRAVELS.

[00:18:54.719]
IF WE KNOW HOW SOUND TRAVELS, THAT
MIGHT HELP US SOLVE THE PROBLEM.

[00:18:57.839]
I THINK I CAN HELP YOU OUT;
LET'S MOVE INTO THE OTHER ROOM.

[00:19:02.269]
WHAT IS ALL THIS STUFF?

[00:19:03.269]
THIS IS EQUIPMENT WE USE
TO TEST PEOPLE'S HEARING.

[00:19:05.699]
COULD YOU TELL US HOW EARS WORK?

[00:19:07.219]
SURE, THE OUTER EAR COLLECTS AND
CONCENTRATES THE SOUND ENERGY.

[00:19:10.859]
THEN THIS IS CHANNELED
DOWN THE EAR CANAL.

[00:19:13.199]
THE EARDRUM VIBRATES, AND SO DO
THE SMALL BONES WITHIN THE EAR.

[00:19:17.049]
THEN THE SOUNDS GO THROUGH THE
COCHLEA, THE HAIR CELLS BEND,

[00:19:19.949]
AND THEN THE IMPULSES ARE SENT UP
THE AUDITORY NERVE INTO THE BRAIN,

[00:19:23.379]
WHERE THEY'RE DECODED.

[00:19:24.889]
ARE THERE SOUNDS PEOPLE CAN'T HEAR?

[00:19:26.609]
SURE, IF THEY'RE ABOVE
A CERTAIN FREQUENCY.

[00:19:28.539]
THE HUMAN EAR CAN HEAR
FREQUENCIES BETWEEN 20

[00:19:31.029]
AND 20,000 VIBRATIONS A SECOND.

[00:19:33.629]
FREQUENCIES -- HMM,
THAT MIGHT BE A CLUE.

[00:19:36.409]
THANKS FOR ALL YOUR HELP.

[00:19:37.379]
SURE.

[00:19:38.119]
BYE.

[00:19:38.619]
BYE, AND GOOD LUCK.

[00:19:39.929]
THANKS.

[00:19:42.589]
I BET NASA LANGLEY RESEARCH
CENTER COULD HELP US.

[00:19:44.599]
MY NEIGHBOR RESEARCHES NOISE
POLLUTION AND HOW IT AFFECTS US.

[00:19:47.409]
I'VE HEARD OF AIR POLLUTION,
BUT NOISE POLLUTION?

[00:19:49.889]
YES.

[00:19:50.789]
HER NAME IS MISS BRENDA SULLIVAN.

[00:19:52.839]
LET'S GO OVER AND TALK TO HER.

[00:19:54.459]
OK, I'LL CALL MY MOM FOR A RIDE.

[00:19:55.739]
I'M SURE GLAD IT'S A HALF DAY SO
WE CAN GET ALL THIS RESEARCH DONE.

[00:19:58.849]
YEAH.

[00:20:00.849]
TOO BAD P.J. COULDN'T MAKE IT.

[00:20:03.479]
LOOK.

[00:20:03.909]
WHAT OR WHO IS THAT?

[00:20:05.769]
OH, THAT'S FRED.

[00:20:07.459]
YOU MUST BE THE TREE
HOUSE DETECTIVES?

[00:20:09.239]
I'M BIANCA, AND THIS IS JACOB.

[00:20:11.419]
WE'RE TRYING TO SOLVE A REALLY
BIG PROBLEM: DOGS ARE BARKING,

[00:20:14.439]
AND KEEPING US UP AT NIGHT
AND IN THE EARLY MORNING.

[00:20:16.489]
I HEARD ABOUT THAT IN THE NEWS.

[00:20:18.329]
WE THINK THAT A REALLY LOUD
SOUND MIGHT BE MAKING THEM BARK.

[00:20:21.899]
WE'RE RESEARCHING SOUND.

[00:20:23.279]
WE'D LIKE TO LEARN HOW YOU
DEAL WITH SOUND PROBLEMS.

[00:20:26.119]
WELL, I'M A PSYCHOACOUSTICIAN HERE
AT NASA LANGLEY RESEARCH CENTER.

[00:20:29.939]
THAT'S A REALLY BIG WORD; I
DON'T THINK I CAN EVEN SAY THAT.

[00:20:33.689]
SO WHAT DO YOU DO HERE?

[00:20:35.109]
WELL, AS A PSYCHOACOUSTICIAN, I
DESIGN, CONDUCT, AND ANALYZE TESTS

[00:20:39.519]
THAT INVESTIGATE THE PSYCHOLOGICAL
EFFECTS OF NOISE ON PEOPLE.

[00:20:43.059]
LET ME SHOW YOU ONE OF MY LABS.

[00:20:45.959]
IS THIS A REAL PLANE?

[00:20:47.499]
AH, NO, THIS IS A FAKE.

[00:20:48.869]
BUT WE GO UP IN REAL PLANES, WE
MAKE RECORDINGS, WE BRING THEM

[00:20:51.879]
DOWN TO THE LAB, AND
WE MODIFY THEM.

[00:20:53.839]
THEN WE CAN PLAY THEM BACK
TO PEOPLE IN HERE AND FIND

[00:20:56.279]
OUT WHICH KIND OF
SOUNDS THEY PREFER.

[00:20:57.919]
WHAT KINDS OF SOUNDS
DO PEOPLE PREFER?

[00:20:59.969]
WELL, QUIET ONES, REALLY.

[00:21:01.889]
WE HEAR FROM 20 VIBRATIONS
PER SECOND

[00:21:04.839]
TO 20,000 VIBRATIONS PER SECOND,

[00:21:07.179]
AND THE LOW FREQUENCY ONES BOTHER
US LESS THAN THE HIGH FREQUENCIES.

[00:21:11.459]
FOR INSTANCE, HAVE
YOU HEARD A PIECE

[00:21:13.239]
OF CHALK SCRATCHING
ON A CHALKBOARD?

[00:21:14.999]
YUCK.

[00:21:15.549]
WELL, THAT'S A HIGH
FREQUENCY SOUND.

[00:21:17.449]
WHAT ABOUT DOGS?

[00:21:18.479]
DO THEY HEAR DIFFERENTLY FROM US?

[00:21:20.309]
WELL, I'M NOT AN EXPERT ON DOGS,

[00:21:22.029]
BUT I KNOW DOGS CAN HEAR
HIGHER FREQUENCIES THAN WE DO.

[00:21:24.449]
THEY CAN HEAR VERY
HIGH FREQUENCIES.

[00:21:26.409]
COME ON.

[00:21:26.709]
LET'S GO.

[00:21:28.099]
SO, WE NEED TO FIND OUT WHAT KIND

[00:21:33.069]
OF THINGS MAKE VERY
HIGH-FREQUENCY NOISES.

[00:21:35.479]
WHAT ABOUT MACHINERY?

[00:21:36.969]
OR A FACTORY?

[00:21:37.839]
THEY BOTH MIGHT BE POSSIBILITIES.

[00:21:39.529]
THAT COULD BE IT, IT COULD BE
A NOISE FROM A NEARBY FACTORY.

[00:21:42.459]
WE MIGHT HAVE THE ANSWER.

[00:21:44.059]
YOU MEAN THE HYPOTHESIS.

[00:21:46.049]
YOU NEED TO GO AND TALK
TO MY FRIEND VETERINARIAN.

[00:21:48.439]
HIS NAME'S DR. GOODING.

[00:21:50.029]
OH, HERE HE IS, HE'S
RIGHT AROUND THE CORNER.

[00:21:52.429]
GREAT, I LOVE GOING
TO PET HOSPITALS.

[00:21:54.879]
I'LL CALL MY PARENTS
AND SEE IF IT'S OKAY.

[00:21:58.479]
I WONDER WHAT KIND OF
NEAT PETS WE'LL SEE TODAY.

[00:22:00.729]
HI, WE'RE THE TREE
HOUSE DETECTIVES.

[00:22:02.169]
WE'RE HERE TO SEE DR. GOODING.

[00:22:03.649]
PLEASE COME THIS WAY,
HOW CAN I HELP YOU?

[00:22:06.499]
[00:22:11.349]
THANKS FOR HELPING US.

[00:22:12.079]
I'M JACOB, AND THIS IS BIANCA.

[00:22:13.629]
HAVE YOU HEARD ABOUT THE
DOG-BARKING PROBLEM ON KSNN?

[00:22:17.189]
YES, I HAVE.

[00:22:18.329]
I KNOW IT'S KEEPING A LOT
OF PEOPLE UP AT NIGHT.

[00:22:20.829]
TELL ME ABOUT IT.

[00:22:22.019]
WE NEED TO KNOW IF DOGS HEAR
SOUND DIFFERENTLY FROM US.

[00:22:25.809]
WHOAH, LOOK AT THAT BIG DOG.

[00:22:27.839]
I KNOW HE CAN HEAR US.

[00:22:31.029]
YES, DOGS TEND TO HEAR AT A MUCH
HIGHER FREQUENCY THAN HUMAN BEINGS.

[00:22:35.539]
THIS MEANS THEY CAN HEAR SOUNDS
THAT THE HUMAN EAR CANNOT HEAR.

[00:22:39.399]
DOGS CAN HEAR SOUNDS BETWEEN
67 HERTZ AND 45 KILOHERTZ.

[00:22:43.749]
NOW, PEOPLE CAN ONLY HEAR
BETWEEN 20 HERTZ AND 20 KILOHERTZ.

[00:22:47.619]
DO THE INSIDES OF DOGS'
EARS LOOK LIKE OURS?

[00:22:51.079]
WHAT?

[00:22:51.829]
THAT'S ACTUALLY A GOOD QUESTION.

[00:22:53.669]
I HAVE SOMETHING TO SHOW YOU.

[00:22:55.249]
LET'S GO, GUYS.

[00:22:56.509]
LET'S TAKE A LOOK IN MILLIE'S EARS.

[00:23:02.379]
ACTUALLY, THE ANATOMY OF THE HUMAN
EAR IS SIMILAR TO THAT OF THE DOG.

[00:23:06.299]
THOSE ARE ACTUAL PICTURES
OF MILLIE'S EARS.

[00:23:10.109]
HOWEVER, DOGS HAVE
SOME EQUIPMENT OR PARTS

[00:23:13.219]
THAT MIGHT HAVE BETTER HEARING.

[00:23:14.999]
FOR EXAMPLE, DOGS TEND TO
HAVE A LONGER EAR CANAL

[00:23:18.209]
THAT MIGHT ALLOW SOUND TO
BE FUNNELED OR DIRECTED

[00:23:21.279]
INTO THE HEARING APARATUS.

[00:23:23.239]
IT'S A LOT LIKE THIS FUNNEL,
SOMETHING THAT IS USED

[00:23:26.529]
TO DIRECT WATER INTO THIS BOTTLE
SO THAT YOU DON'T SPILL IT.

[00:23:31.349]
[00:23:36.699]
SO THAT'S WHY DOGS CAN HEAR
NOISES AT HIGHER FREQUENCIES.

[00:23:41.829]
THEY CAN HEAR THINGS THAT WE CAN'T.

[00:23:44.779]
THAT'S TRUE.

[00:23:45.889]
DOGS USED TO BE WILD BEFORE
THEY WERE DOMESTICATED.

[00:23:49.139]
THEY HAD TO SURVIVE BY FINDING
FOOD AND ESCAPING PREDATORS.

[00:23:53.279]
THEREFOR, THEY MIGHT HAVE HAD TO
DEPEND ON THEIR EARS TO SURVIVE.

[00:23:57.319]
THAT'S COOL.

[00:23:58.249]
DR. GOODING, DO YOU KNOW ANY
EXAMPLES OF HIGH-FREQUENCY SOUNDS?

[00:24:01.849]
HMM, LET'S SEE.

[00:24:03.079]
ARE YOU FAMILIAR WITH DOG
WHISTLES OR PEST ZAPPERS?

[00:24:07.319]
THESE ARE GOOD EXAMPLES
OF HIGH-FREQUENCY SOUNDS.

[00:24:10.599]
THANKS, DOCTOR, FOR
ALL YOUR INFORMATION.

[00:24:14.759]
WE'LL SEE YOU LATER.

[00:24:16.849]
GOOD-BYE.

[00:24:17.209]
BYE.

[00:24:17.359]
I WONDER IF MORE PEOPLE HAVE
BOUGHT DOG WHISTLES LATELY.

[00:24:19.519]
WE SHOULD CHECK THAT OUT.

[00:24:21.169]
HEY GUYS, THERE'S A COOL ACTIVITY
AT THE NASA WHY FILES WEBSITE

[00:24:24.449]
WHERE IT LETS YOU
BUILD A SOUND CONE

[00:24:25.649]
AND GIVES YOU SUPER HUMAN HEARING.

[00:24:27.549]
YOU SHOULD CHECK IT OUT.

[00:24:28.559]
WE INTERRUPT THIS BROADCAST

[00:24:33.669]
FOR A SPECIAL KID SCIENCE
NEWS NETWORK BULLETIN.

[00:24:36.799]
WE GO NOW LIVE TO
REPORTER I.M. LISSNING.

[00:24:39.569]
THANKS, TED.

[00:24:40.769]
THERE'S NOTHING NEW TO
REPORT ON THE DOG DILEMMA.

[00:24:43.949]
THE MYSTERY HAS NOT BEEN SOLVED.

[00:24:46.949]
I REPEAT: THE MYSTERY
HAS NOT BEEN SOLVED.

[00:24:50.949]
MANY PEOPLE CONTINUE TO SUFFER FROM
LACK OF SLEEP, AS THE DOGS CONTINUE

[00:24:55.509]
TO BARK BETWEEN 10:00 P.M.
AND MIDNIGHT EVERY NIGHT.

[00:25:00.279]
I'M I.M. LISSNING, KSNN NEWS.

[00:25:03.339]
BACK TO YOU, TED.

[00:25:04.939]
THANKS FOR THAT INFORMATIVE REPORT,
I.M. THIS JUST IN: GUM SONIC,

[00:25:10.999]
MANUFACTURER OF THE MOST
POPULAR ELECTRIC TOOTHBRUSHES

[00:25:13.719]
ON THE MARKET, ANNOUNCED TODAY
THAT THERE MAY BE PROBLEMS

[00:25:16.679]
WITH THEIR NEWEST MODEL,
THE GUM SONIC TURBO.

[00:25:19.229]
GUM SONIC STRESSED THAT THERE IS NO
THREAT TO THE GENERAL POPULATION,

[00:25:23.569]
AND MORE STUDIES ARE
BEING CONDUCTED.

[00:25:25.279]
MORE AFTER THIS.

[00:25:26.609]
WE NEED TO LEARN MORE ABOUT
VERY HIGH FREQUENCY SOUNDS,

[00:25:30.149]
BECAUSE THAT IS WHAT THE
VETERINARIAN SAID DOGS CAN HEAR,

[00:25:32.499]
AND WE CAN'T.

[00:25:33.879]
SO WE NEED TO FIND OUT WHAT KINDS

[00:25:35.339]
OF THINGS MAKE HIGH-FREQUENCY
NOISES.

[00:25:37.689]
MISS SULLIVAN SAYS IT
COULD BE THE FACTORY

[00:25:40.349]
AND DR. GOODING SAYS IT COULD
BE PEST ZAPPERS OR DOG WHISTLES.

[00:25:44.249]
I THINK THEY'RE ALL POSSIBILITIES.

[00:25:45.829]
I THINK THE FACTORY IS IT;
YES, WE MIGHT HAVE THE ANSWER.

[00:25:49.729]
YOU MEAN A HYPOTHESIS.

[00:25:51.189]
BEFORE WE JUMP TO ANY
CONCLUSIONS, WE NEED TO LEARN

[00:25:53.839]
ABOUT HOW SOUND TRAVELS,
BECAUSE I DON'T KNOW

[00:25:56.589]
IF SOUND CAN TRAVEL THAT FAR.

[00:25:57.929]
LOOK, WE HAVE AN E-MAIL FROM DR.
D. HE WANTS TO TAKE US TO NASA,

[00:26:01.719]
HE'S GOING TO MEET US OUTSIDE.

[00:26:03.809]
I TALKED TO BRENDA SULLIVAN.

[00:26:04.839]
SHE'S ALLOWING US TO USE
THE ANECHOIC CHAMBER.

[00:26:06.839]
THE WHAT?

[00:26:07.689]
JUST FOLLOW ME.

[00:26:09.149]
WHAT DO YOU THINK OF THIS?

[00:26:11.669]
WOW, THIS IS PRETTY AMAZING.

[00:26:15.689]
AN ANECHOIC CHAMBER IS A SPECIAL
CHAMBER THAT ABSORBS SOUNDS.

[00:26:18.779]
SOUNDS CAN'T BOUNCE OFF THE
WALLS, CEILINGS, OR THE FLOOR.

[00:26:21.959]
THIS IS WEIRD, WHAT ARE ALL
THOSE THINGS ON THE WALL?

[00:26:24.909]
THOSE ARE WEB-SHAPED SPONGES,
THAT'S WHAT ABSORBS THE SOUND.

[00:26:27.669]
LET'S TRY AN EXPERIMENT.

[00:26:30.099]
BIANCA, STAND OVER HERE.

[00:26:31.829]
MATTHEW, GO ACROSS
THE ROOM FROM HER.

[00:26:33.649]
OK.

[00:26:34.379]
NOW, FACE INTO THE WALL, BIANCA,
AND YELL AS LOUD AS YOU CAN.

[00:26:37.689]
WOW!

[00:26:38.069]
WHAT'D YOU HEAR?

[00:26:40.469]
I COULD HEAR HER, BUT
SHE WASN'T THAT LOUD.

[00:26:42.759]
I YELLED AS LOUD AS I COULD,
AND YOU STILL COULDN'T HEAR ME?

[00:26:46.539]
NOT REALLY, AND THAT'S
UNUSUAL, FOR ONCE.

[00:26:50.299]
LET ME SHOW YOU ANOTHER
PROPERTY OF SOUND.

[00:26:53.829]
NOW, MATTHEW, STAND ABOUT 1/2
METER AWAY FROM THE SPEAKER.

[00:26:57.919]
AFTER I TURN UP THE SOUND REALLY
LOUD, I WANT YOU TO WALK BACKWARDS

[00:27:01.549]
UNTIL THE SOUND APPEARS
TO BE ABOUT HALF AS LOUD.

[00:27:04.249]
OKAY.

[00:27:04.559]
YOU READY?

[00:27:04.849]
IT SOUNDS ABOUT HALF AS LOUD HERE.

[00:27:06.959]
IT'S NOT SURPRISING TO FIND
OUT THAT SOUND GETS SOFTER

[00:27:15.079]
AS YOU MOVE FURTHER
AWAY FROM THE SOURCE.

[00:27:16.799]
THIS IS CALLED INVERSE RELATION.

[00:27:18.939]
MATHEMATICS WILL HELP US
UNDERSTAND HOW IT WORKS.

[00:27:21.899]
EVERY TIME YOU MOVE A LITTLE MORE
THAN THREE TIMES FURTHER AWAY,

[00:27:25.229]
IT WILL SOUND HALF AS LOUD.

[00:27:27.089]
I HAVE SO MUCH INFORMATION
IN MY HEAD, IT HURTS.

[00:27:30.999]
WE NEED TO GO BACK TO THE
TREE HOUSE AND SORT IT ALL

[00:27:34.189]
OUT ON THE NEED TO KNOW BOARD.

[00:27:35.839]
LET'S GO.

[00:27:36.089]
DR. D SAYS THAT WE NEED
TO LOOK FOR LOUD SOUNDS

[00:27:39.509]
THAT COULD BE CAUSING
THE DOGS TO BARK.

[00:27:41.969]
I KNOW ONE SOUND THAT'S REALLY
LOUD -- IT'S A GARBAGE TRUCK,

[00:27:44.839]
AND I KNOW THEY MAKE DOGS BARK.

[00:27:46.729]
WHAT ABOUT SIRENS?

[00:27:47.999]
MY DOG ALWAYS BARKS
WHEN HE HEARS A SIREN.

[00:27:50.539]
YEAH, AND THERE'S A NEW
FACTORY NEAR HOLLOW SOUND.

[00:27:52.769]
I BET THAT'S IT, YOU KNOW, IN THE
STINK, IT WAS THE CANDY FACTORY.

[00:27:56.409]
MAYBE NOISES FROM THE FACTORY
ARE MAKING THE DOGS BARK.

[00:27:59.579]
THAT SHOULD BE OUR HYPOTHESIS.

[00:28:00.859]
LET'S LOOK AT THESE E-MAILS.

[00:28:03.179]
WOW, LOTS OF DOGS ARE
BARKING IN HOLLOW SOUND.

[00:28:05.729]
THAT'S RIGHT NEAR THE FACTORY.

[00:28:07.659]
SO THAT'S GOT TO BE IT.

[00:28:09.399]
OH, THIS IS TOO EASY.

[00:28:10.849]
WE ARE SO GOOD.

[00:28:13.049]
SO WHAT'S UP?

[00:28:14.109]
WILL THE TREE HOUSE
DETECTIVES SOLVE THIS PROBLEM?

[00:28:16.219]
DO YOU THINK THEIR
HYPOTHESIS IS RIGHT OR WRONG?

[00:28:18.939]
ARE HIGH AND LOW FREQUENCIES
AN IMPORTANT PART

[00:28:21.159]
OF SOLVING THIS PROBLEM?

[00:28:22.709]
WE'LL SEE YOU NEXT TIME FOR
THE NEXT NASA WHY FILES:

[00:28:24.999]
THE CASE OF THE BARKING DOGS.

[00:28:30.339]
DID YOU WATCH YOUR DOG LAST NIGHT?

[00:28:33.449]
I TRIED TO, BUT I'VE BEEN SO
TIRED, I FELL RIGHT ASLEEP.

[00:28:36.339]
DID YOU EVER DO THAT
SOUND CONE ACTIVITY?

[00:28:39.989]
I DID.

[00:28:40.349]
IT WAS A LOT OF FUN, BUT I
COULDN'T HEAR THE FREQUENCY LIKE

[00:28:43.149]
THAT OF A DOG WHISTLE.

[00:28:44.139]
I DON'T THINK IT'S GOING TO
HELP US SOLVE THE PROBLEM.

[00:28:46.639]
OH WELL, AT LEAST WE TRIED.

[00:28:48.239]
BUT I THINK WE'RE GETTING
SOMEWHERE; LET'S GET ORGANIZED.

[00:28:51.069]
WHY DO WE NEED TO DO THAT?

[00:28:52.399]
WE ALREADY KNOW WHAT'S CAUSING
THE PROBLEM; IT'S THE FACTORY.

[00:28:55.509]
DR. D TOLD US NOT TO
JUMP TO ANY CONCLUSIONS.

[00:28:58.679]
SO LET'S FIGURE THIS THING
OUT: BACK TO THE MATRIX BOARD.

[00:29:02.569]
ACROSS THE TOP ARE THE NAMES OF
THE NEIGHBORHOODS: MIDNIGHT GROWL,

[00:29:09.559]
COCHLEA CASCADE, SOUND SEASIDE,
AND SOUTHERN SLEEPLESS SUBDIVISION.

[00:29:14.399]
DOWN THE LEFT SIDE, WE HAVE ONE
CAUSE, WHICH IS GARBAGE PICK-UP,

[00:29:18.229]
AND WE HAVE THE EFFECT
OF DOGS BARKING.

[00:29:20.229]
THE TRUCKS WERE IN
MIDNIGHT GROWL ON MONDAY,

[00:29:23.089]
AND THERE WERE DOGS BARKING.

[00:29:25.109]
THEN IN SLEEPLESS SUBDIVISION,
THEY WERE THERE ON TUESDAY,

[00:29:28.369]
BUT NO DOGS WERE BARKING.

[00:29:30.539]
OKAY, IN SOUND SEASIDE, THEY
HAVE NOT YET HAD GARBAGE PICK-UP.

[00:29:34.009]
IN COCHLEA CASCADE, THERE WAS
GARBAGE PICK-UP ON WEDNESDAY,

[00:29:37.049]
AND THE DOGS WERE STILL BARKING.

[00:29:38.679]
THIS IS CONFUSING.

[00:29:40.529]
THE MATRIX SHOWS US THAT THERE
IS A RELATIONSHIP BETWEEN GARBAGE

[00:29:43.809]
AND DOGS BARKING,
BUT ONLY ON TWO DAYS.

[00:29:46.859]
COCHLEA CASCADE HAD
BARKING ON MONDAY,

[00:29:48.969]
BUT THERE WAS NO GARBAGE
PICK-UP ON THAT DAY.

[00:29:51.249]
YEAH, AND LET'S REMEMBER, DOGS
HAVE BEEN BARKING AT NIGHT,

[00:29:53.749]
AND THERE'S NO GARBAGE
PICK-UP AT NIGHT.

[00:29:55.939]
MAYBE WE NEED TO RULE
OUT GARBAGE TRUCKS.

[00:29:57.479]
WHAT ABOUT SIRENS?

[00:29:58.799]
FORGET IT, SIRENS
GO OFF ALL THE TIME,

[00:30:01.079]
SO WHY WOULD THERE BE MORE
BARKING NOW THAN BEFORE?

[00:30:03.519]
I THINK WE NEED TO
FIND A NEW HYPOTHESIS.

[00:30:09.639]
GOOD MORNING -- I'M TED TUNE WITH
THE KID SCIENCE NEWS NETWORK NEWS.

[00:30:16.959]
THE MYSTERY OF THE BARKING DOGS
CONTINUES TO CONFUSE AUTHORITIES.

[00:30:20.889]
MORE DOGS WERE HEARD
BARKING LAST NIGHT

[00:30:22.549]
AND EVEN MORE PEOPLE WERE KEPT
AWAKE BETWEEN 10 P.M. AND MIDNIGHT.

[00:30:26.479]
WE URGE YOU TO PLEASE BRING IN
THOSE DOGS, SO THAT THOSE OF US

[00:30:30.059]
WHO HAVE TO GET UP IN THE
MORNING CAN GET SOME SLEEP.

[00:30:33.199]
AND IN CONSUMER NEWS,
THE GUM SONIC COMPANY,

[00:30:39.619]
MAKERS OF THE GUM SONIC TURBO,

[00:30:41.559]
ISSUED AN OFFICIAL
PRODUCT RECALL TODAY.

[00:30:44.049]
ANYONE WHO BOUGHT THE GUM SONIC
TURBO MODEL ELECTRIC TOOTHBRUSH IS

[00:30:47.849]
URGED TO RETURN IT TO THE GUM
SONIC COMPANY FOR A FULL REFUND.

[00:30:53.999]
AND THAT'S ALL THE NEWS.

[00:30:57.959]
[00:31:00.109]
I REALLY THINK WE'RE ON TO
SOMETHING, BUT WE NEED TO FIGURE

[00:31:02.359]
OUT WHERE THE SOUND
COULD BE COMING FROM.

[00:31:04.059]
THAT'S A GOOD IDEA, BECAUSE
RIGHT NOW, WE DON'T KNOW

[00:31:06.329]
IF THE SOUND IS COMING FROM
OUTSIDE, INSIDE OUR HOUSES,

[00:31:09.129]
OR EVEN FROM ACROSS TOWN.

[00:31:10.739]
MAYBE WE NEED TO KNOW MORE
ABOUT HOW FAST SOUND CAN TRAVEL.

[00:31:13.569]
LET'S EXPERIMENT.

[00:31:14.389]
THAT'S PART OF THE
SCIENTIFIC METHOD.

[00:31:15.559]
YEAH, AND MAYBE OUR TEACHER
AND FRIENDS AT SCHOOL CAN HELP.

[00:31:18.029]
I'LL E-MAIL MY TEACHER AND ASK
HER IF SHE HAS AN EXPERIMENT

[00:31:21.519]
TO HELP US SEE HOW
FAST SOUND TRAVELS.

[00:31:26.469]
OKAY.

[00:31:27.709]
GOOD MORNING, MRS. RICLES.

[00:31:29.439]
WELL, GOOD MORNING.

[00:31:30.369]
I GOT YOUR E-MAIL THIS MORNING, AND
I HAVE JUST THE EXPERIMENT FOR YOU.

[00:31:33.369]
I HAVE IT ALL WRITTEN DOWN HERE.

[00:31:34.919]
THANKS, MRS. RICLES,
FOR HELPING US.

[00:31:37.439]
YOU'RE WELCOME.

[00:31:38.099]
IT LOOKS LIKE WE NEED TO GO
OUTSIDE AND CREATE ECHOES.

[00:31:40.369]
AND MEASURE HOW LONG IT TAKES
US TO HEAR THOSE ECHOES.

[00:31:43.619]
LET'S GET STARTED.

[00:31:45.209]
OKAY.

[00:31:46.859]
OKAY, EVERYBODY LINE UP IN THREES.

[00:31:49.029]
ONE PERSON WILL DO THE CLAPPING,

[00:31:50.519]
THE OTHER PERSON WILL
TIME THE NUMBER OF CLAPS,

[00:31:53.209]
AND THE OTHER WILL TAKE THE DATA.

[00:31:56.179]
WE NEED A SET OF PIPES, A METER
STICK, A STOPWATCH, A PENCIL

[00:31:59.619]
AND A PAPER, AND GOGGLES.

[00:32:01.109]
WE WILL USE THE SIDE
OF THE BUILDING

[00:32:03.119]
TO BOUNCE SOUND OFF,
TO CREATE AN ECHO.

[00:32:04.979]
MEASURE 57 METERS FROM THAT WALL.

[00:32:07.219]
I CAN DO THAT, BUT I NEED HELP.

[00:32:10.799]
[00:32:14.869]
I CAN HELP.

[00:32:17.919]
[00:32:19.299]
OKAY, YOU NEED TO STAND RIGHT HERE.

[00:32:21.469]
THIS IS WHERE WE'LL
START THE EXPERIMENT.

[00:32:23.549]
WE NEED TO START CLAPPING THESE
TWO ITEMS TOGETHER LIKE THIS.

[00:32:26.539]
AND LISTEN FOR THE ECHO.

[00:32:29.309]
YOU REALLY NEED TO
GET A RHYTHM GOING,

[00:32:30.749]
SO THAT YOU CAN HEAR THE ECHO
IN BETWEEN CLAPS, LIKE THIS.

[00:32:35.099]
LET'S TRY IT.

[00:32:38.389]
THAT'S GOOD.

[00:32:39.739]
OK, I'M HEARING THE ECHO.

[00:32:40.879]
LET'S TIME THE NUMBER OF CLAPS IN
20 SECONDS, AND RECORD OUR DATA

[00:32:44.409]
SO WE CAN ANALYZE IT
WHEN WE GET BACK INSIDE.

[00:32:50.079]
I HAVE 30 CLAPS.

[00:32:51.049]
THAT'S GREAT.

[00:32:52.299]
LET'S DO THE EXPERIMENT AGAIN,
SO WE CAN TAKE AN AVERAGE

[00:32:55.099]
OF THE NUMBER OF CLAPS.

[00:32:56.249]
REMEMBER, WHEN YOU ARE
EXPERIMENTING YOU MUST

[00:32:59.189]
HAVE REPEATED TRIALS.

[00:33:00.109]
IN THE STINK PROBLEM,
WE LEARNED THAT WE NEED

[00:33:02.469]
TO PERFORM THE EXPERIMENT
AT LEAST THREE TIMES.

[00:33:05.229]
OK, WE NEED ANOTHER
GROUP TO LINE UP.

[00:33:09.529]
LET'S COUNT DOWN -- 3, 2, 1, GO.

[00:33:14.499]
[00:33:27.179]
DO YOU KNOW WHY IT'S
IMPORTANT TO TAKE AN AVERAGE?

[00:33:29.159]
TAKING AN AVERAGE HELPS US
TO ELIMINATE THE POSSIBILITY

[00:33:32.839]
THAT SOMEONE COUNTED WRONG,
READ THE STOPWATCH WRONG,

[00:33:35.559]
OR DIDN'T UNDERSTAND
THE INSTRUCTIONS.

[00:33:37.999]
DO YOU KNOW HOW TO
CALCULATE AN AVERAGE?

[00:33:40.709]
IT'S EASY.

[00:33:41.929]
FOR EXAMPLE, YOU CAN TAKE
THE NUMBERS, 20, 22, AND 19.

[00:33:46.249]
YOU ADD THEM UP, AND DIVIDE THEM
BY THREE, AND THAT'S YOUR AVERAGE.

[00:33:49.899]
NOW, TO CALCULATE THE SPEED OF
SOUND, WE NEED TO TAKE THE NUMBER

[00:33:53.159]
OF SECONDS, AND WE DIVIDE
IT BY THE NUMBER OF CLAPS.

[00:33:56.709]
THIS IS GOING TO TELL US THE
AMOUNT OF TIME BETWEEN CLAPS.

[00:34:00.429]
WHAT DO WE GET?

[00:34:02.649]
THAT'S 0.66.

[00:34:05.839]
LET'S SEE -- I CALCULATE
THAT TO BE TWO THIRDS

[00:34:07.619]
OF A SECOND BETWEEN CLAPS.

[00:34:10.089]
OKAY, WE HAVE TWO THIRDS
OF A SECOND BETWEEN CLAPS,

[00:34:13.959]
AND THE ECHO COMES
HALFWAY BETWEEN CLAPS.

[00:34:16.719]
THEN IT ONLY TAKES ONE THIRD OF
A SECOND FOR THE SOUND TO TRAVEL

[00:34:20.709]
TO THE WALL AND BACK TO US.

[00:34:22.049]
I GUESS THAT SOUNDS CORRECT.

[00:34:23.729]
AND TO FIGURE OUT HOW FAR IT
TRAVELS FROM US TO THE WALL

[00:34:27.589]
AND BACK, WOULDN'T WE JUST
TAKE 57 METERS AND DOUBLE IT?

[00:34:30.679]
WHAT?

[00:34:31.249]
114 METERS?

[00:34:34.219]
CORRECT.

[00:34:34.579]
NOW, TO FIGURE OUT THE SPEED,

[00:34:36.699]
DIVIDE DISTANCE TRAVELED
BY THE TIME.

[00:34:39.619]
OKAY, THAT WOULD BE 114 METERS
DIVIDED BY ONE THIRD OF A SECOND.

[00:34:44.419]
THAT COMES TO 342
METERS PER SECOND.

[00:34:47.839]
THAT'S BEYOND FAST.

[00:34:49.759]
A METER IS JUST A LITTLE
LONGER THAN A YARD.

[00:34:52.599]
THIS MEANS THAT SOUND TRAVELS MORE

[00:34:54.239]
THAN THREE FOOTBALL
FIELDS IN A SECOND.

[00:34:57.119]
WOW, THAT'S REALLY FAST.

[00:34:58.529]
NOW WE ACTUALLY SAW
HOW FAST SOUND TRAVELS.

[00:35:02.359]
LET'S GO TELL DR. D.
HEY, DR. D. OH, HI, KIDS.

[00:35:08.369]
DR. D, I DID THIS REALLY COOL
EXPERIMENT AT SCHOOL, AND IT SHOWED

[00:35:11.529]
THAT SOUND TRAVELED SO FAST.

[00:35:13.689]
WHAT DO YOU THINK AFFECTS
HOW FAST SOUND TRAVELS?

[00:35:17.029]
OH, YOU MEAN, WHAT
ARE THE VARIABLES?

[00:35:18.969]
AH, VERY GOOD.

[00:35:19.929]
COULD IT HAVE ANYTHING
TO DO WITH TEMPERATURE?

[00:35:22.319]
THAT'S A GREAT QUESTION.

[00:35:23.519]
SPEED OF SOUND INCREASES
WITH TEMPERATURE.

[00:35:25.689]
THAT'S ONE VARIABLE.

[00:35:26.599]
ANOTHER VARIABLE IS MOISTURE.

[00:35:27.789]
I GUESS THIS MEANS THAT
ON HOT, HUMID DAYS,

[00:35:30.889]
WHEN IT'S REALLY STICKY OUTSIDE,
SOUND TRAVELS REALLY FAST.

[00:35:34.229]
NO, NOT THAT MUCH FASTER.

[00:35:35.549]
THE MATERIAL THAT SOUND TRAVELS
THORUGH, WHICH WE CALL THE MEDIUM,

[00:35:38.669]
MAKES A BIG DIFFERENCE.

[00:35:40.099]
GENERALLY SOUNDS TRAVEL
FASTER THROUGH LIQUIDS

[00:35:42.209]
THAN THEY DO THROUGH AIR.

[00:35:43.449]
THEY TRAVEL FASTER THROUGH
SOLIDS THAN THROUGH LIQUIDS.

[00:35:45.669]
WHY DOES THAT HAPPEN?

[00:35:47.269]
IT'S CALLED ELASTICITY.

[00:35:48.549]
I'LL SHOW YOU HOW IT WORKS.

[00:35:49.959]
I'M DOING AN EXPERIMENT.

[00:35:50.999]
MATTHEW, WHY DON'T YOU
FINISH LINING UP THE DOMINOS

[00:35:52.789]
ON THE TABLE, IF YOU WOULD PLEASE?

[00:35:54.259]
SURE.

[00:35:55.569]
[00:35:57.039]
BIANCA, GRAB A HOLD OF THIS
SPRING AND HOLD ON REALLY TIGHT.

[00:36:00.459]
I'M GOING TO SEND A WAVE
PULSE DOWN THE SPRING.

[00:36:04.069]
PAY CAREFUL ATTENTION
TO HOW FAST IT'S GOING.

[00:36:06.929]
[00:36:08.519]
ALRIGHT, NOW SOLIDS AND LIQUIDS
ARE MORE ELASTIC THAN GASES.

[00:36:12.199]
TO SEE HOW MUCH OF A
DIFFERENCE THIS MAKES,

[00:36:14.819]
I'M GOING TO INCREASE THE
ELASTICITY OF THIS SPRING

[00:36:17.739]
BY INCREASING ITS TENSION.

[00:36:19.369]
ELASTICITY TELLS ME HOW FAST
THINGS ARE BROUGHT BACK TO PLACE

[00:36:23.049]
WHEN THEY'RE DISTURBED.

[00:36:23.779]
ARE YOU READY?

[00:36:24.839]
WATCH CAREFULLY.

[00:36:27.649]
WOW, IT'S REALLY MOVING.

[00:36:30.759]
NOTICE HOW THE WAVE OR ENERGY
TRAVELS THROUGH THE SPRING,

[00:36:33.869]
BUT THE SPRING DOESN'T GO ANYWHERE;

[00:36:35.119]
IT JUST VIBRATES IN PLACE.

[00:36:37.089]
IT'S LIKE THE DOMINOS THAT
MATTHEW JUST SET UP; WHEN HE KNOCKS

[00:36:39.749]
OVER THE FIRST ONE, THE
ENERGY WILL TRAVEL THROUGH,

[00:36:42.739]
BUT THE INDIVIDUAL DOMINOS
JUST MOVE A LITTLE BIT.

[00:36:46.329]
TRY IT, MATTHEW.

[00:36:47.269]
OKAY.

[00:36:48.559]
[00:36:53.789]
COOL, NOW WE KNOW THAT SOUND GETS
SOFTER AS IT TRAVELS FROM A SOURCE.

[00:36:57.359]
WHEN SOUND TRAVELS THROUGH A
MEDIUM, THE MOLECULES VIBRATE

[00:36:59.859]
IN PLACE, BUT DON'T
REALLY GO ANYWHERE.

[00:37:02.019]
WHAT ELSE DO WE KNOW ABOUT SOUND?

[00:37:04.249]
WELL, WE KNOW THE MEDIUM
AFFECTS HOW FAST SOUND TRAVELS;

[00:37:07.109]
WE ALSO KNOW IT INFLUENCES
HOW FAR SOUND GOES.

[00:37:10.169]
BUT I THOUGHT WE ALREADY
TALKED ABOUT HOW SOUND DIED OFF

[00:37:12.409]
IN THE DISTANCE, WHEN WE WERE IN
THAT ROOM WITH ALL THE SPONGES.

[00:37:15.409]
THAT'S RIGHT; WE DISCUSSED HOW
SOUND GETS SOFTER WITH DISTANCE,

[00:37:18.449]
BECAUSE THE WAVES SPREAD OUT.

[00:37:20.089]
IS THAT LIKE WHEN YOU THROW
A ROCK INTO A POND OF WATER,

[00:37:22.609]
AND THE CIRCLES GET BIGGER AS
THEY MOVE AWAY FROM THE SPLASH?

[00:37:25.599]
EXACTLY, BUT IN ADDITION TO THAT,

[00:37:27.779]
THE MEDIUM AFFECTS
HOW FAR SOUND TRAVELS

[00:37:30.149]
BY ABSORBING THE SOUND ENERGY.

[00:37:32.169]
I HAVE A FRIEND OVER AT NASA
WHO SPECIALIZES IN ACOUSTICS.

[00:37:34.849]
HER NAME IS DR. CHRISTINE DARDEN.

[00:37:36.679]
GO TALK WITH HER, SHE CAN HELP YOU
UNDERSTAND HOW THE MEDIUM AFFECTS

[00:37:40.529]
HOW FAR SOUND TRAVELS.

[00:37:41.999]
MAYBE WE CAN DIAL HER UP WHEN
WE GET BACK TO THE TREE HOUSE.

[00:37:44.679]
THANKS FOR ALL YOUR
HELP, DR. D. SEE YOU.

[00:37:47.569]
BYE.

[00:37:48.179]
BYE, GUYS.

[00:37:51.179]
COMPUTER, GET US DR.
CHRISTINE DARDEN

[00:37:53.869]
AT NASA LANGLEY RESEARCH CENTER.

[00:37:58.259]
OH, HI, KIDS, I'M DR.
DARDEN, AN ENGINEER HERE

[00:38:02.029]
AT NASA LANGLEY RESEARCH CENTER.

[00:38:04.119]
I'VE DONE SONIC BOOM RESEARCH
HERE FOR MANY, MANY YEARS.

[00:38:07.459]
WHAT'S A SONIC BOOM?

[00:38:08.839]
DOESN'T IT HAVE TO DO WITH
THE SPEED OF AIRPLANES?

[00:38:12.009]
YES, IT DOES.

[00:38:13.059]
A SONIC BOOM OCCURS WHEN
AN AIRPLANE TRAVELS FASTER

[00:38:16.059]
THAN THE SPEED OF SOUND.

[00:38:17.939]
WE DO LOTS OF SONIC BOOM
TESTING IN THIS WIND TUNNEL.

[00:38:21.639]
IN FACT, THE FIRST MODELS
THAT WE USED WERE NO LARGER

[00:38:25.169]
THAN MY FINGERNAIL.

[00:38:25.999]
WHEN AN AIRPLANE TRAVELS
THROUGH THE AIR,

[00:38:29.229]
IT GENERATES PRESSURE WAVES
THAT TRAVEL AT THE SPEED

[00:38:31.679]
OF SOUND IN ALL DIRECTIONS.

[00:38:33.519]
A PLANE FLYING AT THE SPEED OF
SOUND MOVES AT THE SAME SPEED

[00:38:37.299]
AS THE DISTURBANCES,
CAUSING A SHOCK WAVE TO FORM.

[00:38:41.319]
WHEN THE PLANE FLIES FASTER
THAN THE SPEED OF SOUND,

[00:38:44.359]
THE SHOCK WAVE FORMS
A CONE SHAPE ATTACHED

[00:38:47.269]
TO THE NOSE OF THE AIRPLANE.

[00:38:49.439]
AIR PRESSURE JUST INSIDE THE CONE
IS HIGH, AND AIR PRESSURE AHEAD

[00:38:53.609]
OF THE CONE IS NORMAL.

[00:38:55.359]
THIS SHOCK WAVE, OR CONE,
EXTENDS TO THE GROUND,

[00:38:58.619]
PERHAPS 10 TO 15 MILES.

[00:39:01.289]
THE SONIC BOOM IS HEARD
WHEN THE SUDDEN CHANGE

[00:39:03.549]
IN PRESSURE CROSSES YOUR EAR.

[00:39:06.199]
LET ME DEMONSTRATE FOR
YOU WITH THIS BALLOON.

[00:39:09.099]
THE AIR PRESSURE INSIDE
THIS BALLOON IS HIGHER

[00:39:11.489]
THAN THE AIR PRESSURE
OUTSIDE THE BALLOON.

[00:39:13.979]
IF I POP THE BALLOON, A SHOCK
WAVE IS GENERATED MUCH LIKE A

[00:39:17.529]
SONIC BOOM.

[00:39:18.599]
COULD THERE BE A VERY
HIGH FREQUENCY SOUND

[00:39:20.469]
THAT PEOPLE CAN'T
HEAR, BUT DOGS CAN?

[00:39:22.989]
ABSOLUTELY.

[00:39:23.949]
BUT REMEMBER: THAT VERY HIGH
FREQUENCY SOUND CAN'T COME

[00:39:26.959]
FROM FAR AWAY.

[00:39:28.229]
BECAUSE HIGH-FREQUENCY
SOUNDS DON'T TRAVEL VERY FAR.

[00:39:30.789]
THAT'S RIGHT.

[00:39:31.869]
THANKS, DR. DARDEN.

[00:39:33.699]
YOU'RE WELCOME.

[00:39:34.919]
GOOD-BYE AND GOOD LUCK.

[00:39:38.839]
WELL, WE HAVE ALREADY ELIMINATED
GARBAGE TRUCKS AND SIRENS,

[00:39:41.479]
AND MOST OTHER LOUD NOISES.

[00:39:43.449]
THE FACTORY IS STILL A POSSIBILITY.

[00:39:45.129]
BUT PEOPLE HAVEN'T COMPLAINED YET.

[00:39:47.169]
SO IT MUST BE A VERY
HIGH-FREQUENCY SOUND.

[00:39:49.049]
AND BESIDES, HIGH-FREQUENCY
SOUNDS CAN'T TRAVEL VERY FAR,

[00:39:53.609]
SO IT CAN'T BE THE FACTORY.

[00:39:55.079]
SO I GUESS OUR HYPOTHESIS
OF THE FACTORY IS WRONG;

[00:39:57.489]
IT'S BACK TO THE DRAWING BOARD.

[00:39:59.279]
MAYBE WE NEED TO FIND
SOMETHING CLOSE TO OUR HOUSES

[00:40:01.259]
OR EVEN INSIDE OUR HOUSES THAT
MAKES A HIGH FREQUENCY NOISE.

[00:40:04.009]
WELL, HOW ARE WE SUPPOSED
TO DO THAT?

[00:40:05.409]
WE CAN'T EVEN HEAR
HIGH-FREQUENCY NOISES.

[00:40:07.739]
REMEMBER THOSE DOG WHISTLES?

[00:40:09.209]
THEY'RE HIGH FREQUENCY.

[00:40:10.079]
YES, LET'S CHECK THAT OUT.

[00:40:11.499]
LET'S CHECK THAT OUT TOMORROW.

[00:40:13.979]
SOUNDS GOOD TO ME.

[00:40:15.639]
SO WHAT'S UP?

[00:40:16.569]
DO YOU THINK DOG WHISTLES ARE
THE SOURCE OF THE PROBLEM?

[00:40:18.659]
ARE THE DOGS HEARING A SOUND
FROM INSIDE THEIR HOUSE?

[00:40:21.399]
OR COULD THERE BE AN OUTSIDE
SOURCE FOR THIS PROBLEM?

[00:40:24.509]
DON'T MISS THE FINAL EPISODE
OF THE NASA WHY FILES:

[00:40:27.149]
THE CASE OF THE BARKING DOGS.

[00:40:28.569]
OK, THANK YOU.

[00:40:29.069]
BYE-BYE.

[00:40:31.679]
WELL, THAT'S IT.

[00:40:34.839]
I CALLED THE LAST PET STORE.

[00:40:39.749]
MOST OF THEM SAID THEY HAVEN'T
SOLD ANY DOG WHISTLES RECENTLY,

[00:40:43.429]
AND SOME SAID THEY NEVER
EVEN CARRIED DOG WHISTLES.

[00:40:45.789]
GREAT, THIS MEANS WE CAN
CROSS OFF HIGH-FREQUENCY SOUND

[00:40:48.659]
AS A HYPOTHESIS.

[00:40:49.929]
NO, IT MEANS WE CAN
CROSS OFF DOG WHISTLES.

[00:40:52.659]
HAVE YOU FIGURED OUT
THE ANSWER YET?

[00:40:54.289]
WE COULD USE YOUR HELP.

[00:40:55.859]
THIS IS REALLY HARD.

[00:40:57.359]
WE'RE NEVER GOING TO FIGURE
OUT WHY THE DOGS ARE BARKING,

[00:40:59.319]
AND I'M NEVER GOING
TO GET ANY SLEEP.

[00:41:01.639]
OK, LET'S THINK.

[00:41:03.049]
WE'VE LEARNED A LOT, BUT WE STILL
DON'T KNOW WHAT THE ANSWER IS.

[00:41:06.079]
IT COULD BE AN INSIDE
NOISE OR -- LET ME THINK --

[00:41:09.049]
A COFFEE GRINDER OR BLENDER?

[00:41:10.969]
YEAH, EVEN MY MOM'S BLENDER
MAKES A LOT OF NOISE.

[00:41:14.559]
NO, I DON'T THINK IT COULD BE
A COFFEE GRINDER OR BLENDER,

[00:41:17.279]
BECAUSE THEY'VE BEEN
AROUND FOR A LONG TIME.

[00:41:19.429]
THIS IS SO HARD.

[00:41:20.959]
REMEMBER WHAT DR. D
SAYS: NEVER GIVE UP,

[00:41:23.779]
BECAUSE THE ANSWER COULD
BE RIGHT IN FRONT OF US.

[00:41:26.279]
REALLY?

[00:41:26.589]
ALL I SEE IN FRONT OF ME IS JACOB.

[00:41:29.259]
OKAY, YOU GUYS, KNOCK IT OFF.

[00:41:31.059]
WE NEED TO GET BACK TO
OUR NEED TO KNOW BOARD.

[00:41:34.919]
WE NOW KNOW IT'S NOT DOG WHISTLES.

[00:41:37.129]
BUT IT'S STRANGE BECAUSE BOTH DOGS
INSIDE AND OUTSIDE ARE BARKING.

[00:41:41.199]
IT STILL COULD BE A
HIGH-FREQUENCY SOUND.

[00:41:43.969]
BUT HIGH-FREQUENCY SOUNDS
DON'T TRAVEL VERY FAR.

[00:41:46.929]
WE ALSO KNOW THAT SOUNDS TRAVEL

[00:41:48.269]
THROUGH A SOLID, A
LIQUID, AND A GAS.

[00:41:50.609]
SO WE NEED TO KNOW WHICH THINGS
MAKE HIGH-FREQUENCY NOISES.

[00:41:53.679]
WHO SHOULD WE ASK?

[00:41:54.919]
LET'S DO AN INTERNET SEARCH.

[00:41:56.369]
MORE RESEARCH.

[00:41:57.809]
YES, BUT THIS RESEARCH IS FUN.

[00:41:59.719]
LOOK AT THESE ANIMALS
THAT USE HIGH FREQUENCY --

[00:42:04.349]
BATS, DOLPHINS --
THAT'S INTERESTING.

[00:42:07.419]
HEY, WE'RE LEARNING
ABOUT BATS IN SCHOOL.

[00:42:09.199]
MAYBE WE COULD GO TO A MUSEUM.

[00:42:12.789]
I THINK I'LL STAY HERE
AND LOOK AT THIS RESEARCH.

[00:42:15.049]
I'LL STAY WITH YOU.

[00:42:15.889]
OK, I'LL GET ONE OF THE OTHER TREE
HOUSE DETECTIVES TO COME WITH ME.

[00:42:24.889]
[00:42:24.989]
YOU TWO LOOK LIKE YOU'RE
LOOKING FOR SOMETHING.

[00:42:27.149]
MY NAME IS MRS. CHRIS
LEWIS; CAN I HELP YOU?

[00:42:29.599]
HI, I'M MATTHEW, ANDTHIS
IS CATHERINE,

[00:42:32.259]
AND WE'RE WORKING ON A PROBLEM.

[00:42:38.309]
IT'S A SOUND PROBLEM, AND
WE REALLY NEED TO LEARN MORE

[00:42:39.869]
ABOUT HOW HIGH FREQUENCY TRAVELS.

[00:42:40.739]
I MAY BE ABLE TO HELP.

[00:42:41.369]
LET ME SHOW YOU SOMETHING THAT
USES HIGH FREQUENCY SOUND.

[00:42:43.119]
LET ME INTRODUCE YOU
TO A BIG BROWN BAT.

[00:42:45.749]
WOW.

[00:42:46.639]
DOES HE BITE?

[00:42:47.579]
NO -- YOU CAN TOUCH HIM
GENTLY IF YOU'D LIKE.

[00:42:50.349]
DO BATS USE HIGH-FREQUENCY SOUNDS?

[00:42:52.799]
SURE, BATS HUNT IN THE DARK;
THEY USE HIGH-FREQUENCY SOUNDS

[00:42:56.259]
AND LISTEN FOR THE ECHOES IN
ORDER TO NAVIGATE AND FIND FOOD.

[00:42:59.789]
THAT'S GREAT.

[00:43:00.459]
WE HEARD THAT HIGH-FREQUENCY
SOUNDS DON'T TRAVEL VERY FAR.

[00:43:04.429]
IS THAT TRUE FOR BATS?

[00:43:05.549]
YES, THAT'S TRUE.

[00:43:06.559]
AIR ABSORBS SOUND, ESPECIALLY
HIGH FREQUENCY SOUND.

[00:43:09.549]
SOME BATS CAN HEAR
THINGS 60 FEET AWAY,

[00:43:12.289]
BUT THE AVERAGE IS ONLY
ABOUT 15 FEET AWAY.

[00:43:14.399]
IN SCHOOL, WE JUST
DID AN EXPERIMENT

[00:43:18.019]
ON HOW FAST SOUND TRAVELS.

[00:43:18.969]
THIS SOUNDS AMAZING, BUT
DOES IT REALLY HELP THE BATS?

[00:43:22.369]
OH, YES, IT DOES.

[00:43:23.549]
A BAT CAN TELL THE SPEED AND
DIRECTION OF A MOVING OBJECT,

[00:43:26.109]
WHETHER IT'S ALIVE OR NOT,
EVEN IF IT'S HARD OR SOFT.

[00:43:29.299]
IN FACT, IN A PERFECTLY DARK ROOM,
VERY MUCH LIKE THIS, A BAT CAN FLY

[00:43:33.699]
THROUGH WITHOUT RUNNING
INTO A MOVING WIRE THAT'S

[00:43:36.279]
AS THIN AS A HUMAN HAIR.

[00:43:38.249]
IN FACT, A BIG BROWN BAT CAN CATCH
UP TO 600 MOSQUITOES IN ONE HOUR.

[00:43:43.109]
600 MOSQUITOES AN HOUR?

[00:43:44.919]
DOESN'T THAT SEEM INCREDIBLE?

[00:43:46.249]
YEAH.

[00:43:47.439]
THANKS, MRS. LEWIS.

[00:43:48.329]
THAT WAS SO FUN.

[00:43:50.119]
BYE.

[00:43:50.709]
GOOD LUCK.

[00:43:51.779]
BYE.

[00:43:52.209]
NOW WE NEED TO FIGURE
OUT HOW TO TELL

[00:43:54.199]
WHICH THINGS ARE MAKING
HIGH-FREQUENCY NOISES.

[00:43:56.339]
YEAH, YOU'RE RIGHT.

[00:44:00.089]
HOW DO WE FIGURE OUT WHAT'S MAKING
THESE HIGH-FREQUENCY SOUNDS?

[00:44:03.049]
LET'S DO AN INTERNET SEARCH AND
TRY TO FIND A LIST OF THINGS

[00:44:06.009]
THAT MAKE HIGH-FREQUENCY SOUNDS.

[00:44:07.809]
LOOK UP HIGH FREQUENCY.

[00:44:09.129]
HOW DO I DO THAT?

[00:44:10.229]
JUST TYPE IN HIGH-FREQUENCY SOUND.

[00:44:12.419]
THAT'S PRETTY COOL.

[00:44:14.519]
HAVE YOU EVER SURFED THE NET?

[00:44:16.389]
OH, LOOK.

[00:44:16.899]
HERE IT IS.

[00:44:17.849]
WOW, WHAT'S AN ELECTRONIC
DOG REPELLER?

[00:44:20.549]
AN ELECTRONIC DOG FIGHT STOPPER?

[00:44:22.869]
THAT SOUNDS WEIRD.

[00:44:24.479]
AND A PEST ZAPPER?

[00:44:26.039]
A TOOTHBRUSH?

[00:44:27.709]
I DIDN'T KNOW TOOTHBRUSHES
HAD HIGH-FREQUENCY SOUNDS.

[00:44:30.009]
THOSE ELECTRIC ONES.

[00:44:31.559]
OH.

[00:44:31.609]
I WOULDN'T KNOW MUCH ABOUT THAT;
I HAVE TO BRUSH MY TEETH BY HAND.

[00:44:36.569]
WHAT SHOULD WE DO WITH THIS?

[00:44:37.749]
LET'S E-MAIL ALL THE PEOPLE WHO
RESPONDED TO OUR FIRST EMAIL.

[00:44:40.529]
LET'S ASK THEM IF THEY HAVE ANY
OF THESE WEIRD ELECTRONIC DEVICES.

[00:44:44.399]
THAT'S A GREAT IDEA.

[00:44:48.179]
LET'S GET BUSY.

[00:44:51.479]
HEY, GUYS.

[00:44:54.269]
WHAT ARE YOU DOING TODAY?

[00:44:55.259]
OH WE WERE JUST PLAYING AROUND
IN YOUR LAB -- JUST KIDDING.

[00:44:58.709]
WE HAVE A LIST OF THINGS THAT
MAKE HIGH-FREQUENCY NOISES.

[00:45:00.989]
BUT WE'RE NOT SURE IF
WE'RE ON THE RIGHT TRACK.

[00:45:02.129]
WE WERE HOPING YOU COULD HELP US.

[00:45:02.939]
LET'S REVIEW WHAT WE KNOW.

[00:45:03.619]
WE KNOW THAT DOGS CAN HEAR
AT VERY HIGH FREQUENCIES,

[00:45:05.949]
MUCH HIGHER THAN HUMAN
BEINGS CAN HEAR.

[00:45:07.819]
AT THE MUSEUM, THE BAT CURATOR
TOLD US HIGH-FREQUENCY SOUNDS DON'T

[00:45:11.209]
TRAVEL VERY FAR.

[00:45:12.549]
HIGH AND LOW FREQUENCY SOUND
TRAVEL IS AN EASY CONCEPT.

[00:45:15.799]
DO YOU HAVE AN EXPERIMENT FOR US?

[00:45:17.819]
I CERTAINLY DO.

[00:45:18.889]
IN FACT, I COULD DO A
LITTLE SHOW-AND-TELL.

[00:45:21.379]
WOULD YOU LIKE ME TO
COME TO YOUR CLASS?

[00:45:24.479]
YES, YOU CAN COME TO OUR CLASS.

[00:45:28.779]
OH, THAT WOULD BE GREAT.

[00:45:30.759]
BOYS AND GIRLS, THIS IS DR. D. HE'S
BROUGHT SOMETHING REALLY SPECIAL

[00:45:34.179]
TO SHARE WITH US TODAY.

[00:45:35.449]
GOOD MORNING.

[00:45:36.379]
GOOD MORNING.

[00:45:38.139]
I ALREADY HAVE AN
EXPERIMENT SET UP.

[00:45:40.309]
IT'S GOING TO SHOW YOU THE
DIFFERENCE BETWEEN HIGH

[00:45:42.229]
AND LOW FREQUENCY SOUNDS.

[00:45:43.869]
WILL WE BE ABLE TO SEE ANYTHING?

[00:45:45.589]
NO, BUT YOU'LL BE ABLE TO HEAR IT.

[00:45:46.869]
THIS MACHINE IS GOING TO PRODUCE
SOUNDS AT DIFFERENT FREQUENCIES.

[00:45:50.179]
I WANT YOU TO RAISE YOUR HAND WHEN
YOU CAN'T HEAR THE SOUND ANYMORE.

[00:45:53.599]
THIS IS GOING TO GIVE
YOU AN IDEA ABOUT HIGH

[00:45:55.239]
AND LOW FREQUENCY SOUNDS.

[00:45:57.649]
HERE WE GO.

[00:45:59.949]
[00:46:15.049]
OH, SO WE LOST YOUR TEACHER
FIRST; I CAN'T HEAR IT EITHER.

[00:46:19.449]
WHEN YOU GET OLDER, YOU CAN'T HEAR
HIGH-FREQUENCY SOUNDS AS WELL.

[00:46:22.439]
LET'S KEEP GOING.

[00:46:29.819]
AH, NO ONE CAN HEAR IT NOW, BUT I
BET YOUR DOGS CAN STILL HEAR IT.

[00:46:34.339]
NOW WE'LL NEED SOME VOLUNTEERS.

[00:46:36.499]
HMM, I'LL TAKE YOU AND
YOU AND YOU AND YOU.

[00:46:40.489]
I'M GOING TO TRANSMIT A
LOW-FREQUENCY SOUND TO YOU.

[00:46:46.219]
P.J.'S GOING TO PUT THE PHONE
BOOK BETWEEN THE SPEAKER

[00:46:48.419]
AND YOUR EAR A COUPLE OF TIMES.

[00:46:50.369]
LET'S DO IT.

[00:46:50.929]
WHAT HAPPENED?

[00:46:58.069]
THE SOUND WASN'T AS LOUD.

[00:47:02.459]
NOW I'M GOING TO TRANSMIT
A HIGHER FREQUENCY SOUND.

[00:47:11.459]
[00:47:13.129]
WHAT HAPPENED THIS TIME?

[00:47:18.169]
IT SEEMED LIKE THE SOUND
WAS BLOCKED OFF A LOT MORE.

[00:47:22.449]
LET'S TRY AGAIN.

[00:47:28.439]
WHY DON'T YOU TWO SWITCH PLACES?

[00:47:37.439]
[00:47:38.879]
NOW, P.J., DID BOTH
SOUNDS GET SOFTER

[00:47:40.929]
WHEN JACOB PUT THE PHONE BOOK
BETWEEN THE SPEAKER AND YOUR EAR?

[00:47:43.639]
YES, BUT THE HIGH-FREQUENCY
SOUND SEEMED TO DIE OFF MORE.

[00:47:46.719]
WHY DO YOU THINK SO?

[00:47:47.579]
I DON'T KNOW -- MAYBE YOU PUT
THE BOOK CLOSER TO MY EAR.

[00:47:50.789]
THE BOOK WAS THE SAME
DISTANCE BOTH TIMES.

[00:47:53.949]
REMEMBER, WITH THE
SCIENTIFIC METHOD,

[00:47:56.609]
WE CAN ONLY CHANGE ONE
VARIABLE AT A TIME.

[00:47:59.499]
I CHANGED THE FREQUENCY, SO
I'M GLAD JACOB WAS CAREFUL

[00:48:02.299]
TO KEEP THE BOOK DISTANCE
THE SAME BOTH TIMES.

[00:48:04.389]
I THINK THAT LOW-FREQUENCY
SOUNDS TRAVEL BETTER

[00:48:07.079]
THAN HIGH-FREQUENCY SOUNDS.

[00:48:08.709]
WELL, LOW-FREQUENCY SOUNDS DO
BEND AROUND CORNERS A LOT EASIER

[00:48:11.689]
THAN HIGH-FREQUENCY SOUNDS.

[00:48:13.379]
THAT'S WHY THE LOWER FREQUENCY
SOUND WAS A LITTLE CLEARER;

[00:48:15.999]
BECAUSE IT BENT AROUND
THE PHONE BOOK.

[00:48:18.409]
THIS IS SO COOL.

[00:48:20.249]
THIS EXPERIMENT TAUGHT US THAT
HIGH-FREQUENCY SOUNDS DON'T BEND

[00:48:23.369]
AROUND CORNERS VERY EASILY.

[00:48:24.499]
DON'T FORGET WHAT WE
LEARNED ABOUT THE BATS.

[00:48:26.959]
HOW COULD WE FORGET?

[00:48:28.889]
HIGH-FREQUENCY BAT CALLS
DON'T TRAVEL VERY FAR.

[00:48:31.669]
WHAT DOES ALL THIS MEAN?

[00:48:33.529]
LET'S GO BACK TO OUR TREE HOUSE
AFTER SCHOOL, AND THINK ABOUT IT.

[00:48:36.149]
IT'S TOO BAD P.J. COULDN'T
MAKE IT TO THE TREE HOUSE.

[00:48:41.139]
THAT SURE WAS A GREAT
SHOW-AND-TELL WE HAD AT SCHOOL.

[00:48:42.979]
IT REALLY MADE IT CLEAR TO ME THAT
HIGH-FREQUENCY SOUNDS DON'T BEND

[00:48:46.409]
AROUND CORNERS EASILY;
THEY ONLY GO STRAIGHT.

[00:48:48.169]
LET'S GET BACK TO OUR
NEED TO KNOW BOARD.

[00:48:50.979]
WE KNOW THAT HIGH-FREQUENCY
SOUNDS DON'T TRAVEL VERY FAR.

[00:48:53.499]
WE KNOW THAT IT'S NOT
A LOW-FREQUENCY SOUND

[00:48:55.499]
BECAUSE HUMANS AREN'T
COMPLAINING ABOUT IT.

[00:48:57.249]
WE LEARNED THAT FROM
MS. SULLIVAN AT NASA.

[00:48:59.089]
WE ALSO KNOW THAT
HIGH-FREQUENCY SOUNDS CAN COME

[00:49:01.519]
FROM INSIDE THE HOUSE.

[00:49:02.869]
REMEMBER OUR LIST?

[00:49:04.509]
WE ALSO NEED TO KNOW WHICH
NEIGHBORHOODS ARE HEARING BARKING,

[00:49:07.519]
AND THE ITEM THAT IS MAKING
THE HIGH-FREQUENCY SOUND.

[00:49:11.419]
WOW, LOOK AT ALL THE
E-MAILS WE'VE RECEIVED.

[00:49:13.549]
WE BETTER START SEPARATING
THEM OUT.

[00:49:15.749]
I DIVIDED THEM INTO
PILES BY SUBDIVISION.

[00:49:18.169]
LET'S PUT THEM ON A MATRIX BOARD.

[00:49:19.659]
OH, GREAT, ANOTHER MATRIX.

[00:49:21.799]
HEY, A MATRIX BOARD CAN HELP
YOU SORT YOUR INFORMATION.

[00:49:24.819]
IT MAY LOOK HARD,
BUT DON'T SWEAT IT.

[00:49:26.329]
OKAY, OKAY, OKAY, OKAY,
LET'S GET STARTED.

[00:49:30.789]
ON THE MATRIX BOARD, ACROSS THE
TOP, WE HAVE THE SUBDIVISIONS:

[00:49:34.029]
MIDNIGHT GROWL, COCHLEA
CASCADE, SOUND SEASIDE,

[00:49:39.009]
AND THE SOUTHERN SLEEPLESS
DIVISION.

[00:49:41.519]
NOW DOWN THE SIDE, LET'S PUT THE
POSSIBLE CAUSES: DOG REPELLERS,

[00:49:45.409]
DOG FIGHT STOPPERS, PEST ZAPPERS,
AND ELECTRONIC TOOTHBRUSHES.

[00:49:49.839]
ALSO ON THE SIDE, LET'S PUT THE
EFFECTS: BARKING IN THE DAY,

[00:49:52.939]
AND BARKING IN THE NIGHT.

[00:49:54.919]
OKAY, IN MIDNIGHT GROWL,
THEY STILL HAVE DOGS BARKING,

[00:49:58.059]
AND THEY HAVE DOG
REPELLERS AND TOOTHBRUSHES.

[00:50:01.249]
AND IN THE SOUTHERN
SLEEPLESS DIVISION,

[00:50:03.719]
THEY HAVE DOGS BARKING
AND TOOTHBRUSHES.

[00:50:06.849]
BUT ON SOUND SEASIDE, THEY HAVE
TOOTHBRUSHES, BUT NO DOGS BARKING.

[00:50:11.029]
SO IT CAN'T BE A TOOTHBRUSH.

[00:50:12.489