1 00:00:17,917 --> 00:00:18,551 >>> SOUNDS FILL OUR EARS. 2 00:00:18,551 --> 00:00:21,187 TALKING, MUSIC, EVEN SOME SCIENTIFIC EXPERIMENTS. 3 00:00:21,187 --> 00:00:22,555 THEY ALL START WITH SOUND. 4 00:00:22,555 --> 00:00:23,923 BUT WHAT IS SOUND? 5 00:00:23,923 --> 00:00:24,824 WANT TO FIND OUT? 6 00:00:24,824 --> 00:00:27,027 WE'RE HERE TO ANSWER YOUR QUESTIONS. 7 00:00:27,027 --> 00:00:27,927 STAY TUNED. 8 00:00:27,927 --> 00:00:31,097 "D4K" IS NEXT. 9 00:00:44,277 --> 00:00:45,478 >> HI, I'M JOAN CARTAN-HANSEN. 10 00:00:45,478 --> 00:00:47,681 WELCOME TO "D4K," THE PLACE FOR SCIENCE. 11 00:00:47,681 --> 00:00:52,318 BEFORE WE GO TO YOUR QUESTIONS, LET'S LEARN A BIT MORE ABOUT 12 00:00:52,318 --> 00:00:55,055 SOUND. 13 00:00:55,055 --> 00:00:58,324 SOUND IS A FORM OF ENERGY, LIKE LIGHT OR ELECTRICITY. 14 00:00:58,324 --> 00:01:02,328 SOUNDS ARE MADE BY SMALL VIBRATIONS CALLED SOUND WAVES. 15 00:01:02,328 --> 00:01:06,499 SOUND WAVES MOVE BY THE SQUEEZING AND STRETCHING OF AIR. 16 00:01:06,499 --> 00:01:11,604 WHEN A SOUND OCCURS, MOLECULES ARE SQUEEZED TOGETHER. 17 00:01:11,604 --> 00:01:16,109 ONE MOLECULE SQUEEZES INTO THE NEXT WYNN, AND PULLED BACK IN 18 00:01:16,109 --> 00:01:19,546 PLACE BY THE ONE ON THE OTHER SIDE. 19 00:01:19,546 --> 00:01:23,016 THE MOLECULES MOVE THE SOUND ALONG IN A WAVE. 20 00:01:23,016 --> 00:01:26,252 SCIENTISTS STUDY SOUND WAVES ON A MACHINE CALLED AN 21 00:01:26,252 --> 00:01:26,619 OSCILLOSCOPE. 22 00:01:26,619 --> 00:01:27,654 LOUD SOUNDS HAVE MORE ENERGY. 23 00:01:27,654 --> 00:01:30,457 SO THEIR WAVES ARE BIGGER AND HAVE A GREATER HEIGHT. 24 00:01:30,457 --> 00:01:33,293 SOFT SOUNDS CREATE SMALLER WAVES. 25 00:01:33,293 --> 00:01:36,730 THE HEIGHT OF A WAVE IS CALLED ITS AMPLITUDE. 26 00:01:36,730 --> 00:01:39,532 THE FREQUENCY OR NUMBER MUCH VIBRATIONS PER SECOND, 27 00:01:39,532 --> 00:01:41,735 DETERMINES A SOUND'S PITCH. 28 00:01:41,735 --> 00:01:44,104 SOUND FREQUENCY IS MEASURED IN HERTZ. 29 00:01:44,104 --> 00:01:47,640 THE HIGHER THE FREQUENCY, THE HIGHER THE PITCH, AND THE 30 00:01:47,640 --> 00:01:50,110 GREATER THE HERTZ. 31 00:01:50,110 --> 00:01:52,012 >> I ONLY HAVE ONE PAGE OF MATH. 32 00:01:52,012 --> 00:01:55,482 >> HUMANS CAN HEAR SOUNDS BETWEEN 20 AND 20,000 HERTZ. 33 00:01:55,482 --> 00:01:58,151 BUT OTHER ANIMALS CAN HEAR EVEN MORE. 34 00:01:58,151 --> 00:02:01,688 ELEPHANTS CAN HEAR SOUNDS MUCH LOWER THAN HUMANS CAN. 35 00:02:01,688 --> 00:02:06,526 AND BATS HEAR FREQUENCIES MUCH TOO HIGH FOR HUMANS. 36 00:02:06,526 --> 00:02:11,164 BATS USE HIGH-PITCHED SOUND WAVES LIKE RADAR TO LOCATE THEIR 37 00:02:11,164 --> 00:02:11,431 FOOD. 38 00:02:11,431 --> 00:02:14,901 AND JUST BECAUSE WE CAN'T HEAR VERY HIGH AND VERY LOW FREQUENCY 39 00:02:14,901 --> 00:02:17,971 SOUNDS, DOESN'T MEAN WE CAN'T USE THEM. 40 00:02:17,971 --> 00:02:23,176 SCIENTISTS TRY TO DETECT VERY LOW INFRASONIC SOUNDS TO STUDY 41 00:02:23,176 --> 00:02:26,279 POTENTIAL EARTHQUAKE AND TO PREDICT VOLCANO ERUPTIONS. 42 00:02:26,279 --> 00:02:29,549 DOCTORS USE VERY HIGH FREQUENCY SOUNDS TO TAKE PICTURES INSIDE 43 00:02:29,549 --> 00:02:34,921 THE HUMAN BODY, LIKE THESE OF A BABY INSIDE A WOMAN'S WOMB. 44 00:02:34,921 --> 00:02:36,256 SOUND WAVES EXERT PRESSURE. 45 00:02:36,256 --> 00:02:41,027 THE AMOUNT OF A SOUND'S PRESSURE OR LOUDNESS IS MEASURED IN 46 00:02:41,027 --> 00:02:41,461 DECIBELS. 47 00:02:41,461 --> 00:02:44,030 DECIBELS IS ALSO A MEASURE OF INTENSITY. 48 00:02:44,030 --> 00:02:55,675 THE CLOSER YOU ARE, THE STRONGER THE FORCE. 49 00:02:55,675 --> 00:03:00,080 SO SAY WERE YOU STANDING NEXT TO LEAVES IN A LIGHT WIND. 50 00:03:00,080 --> 00:03:03,883 THAT SOUND WOULD MEASURE ABOUT 10 DECIBELS. 51 00:03:03,883 --> 00:03:07,787 A TOILET FLUSH IS ABOUT 67 DECIBELS. 52 00:03:07,787 --> 00:03:11,057 YOUR HAIR DRYER IS ABOUT 80 DECIBELS. 53 00:03:11,057 --> 00:03:16,062 AND THE SPACE SHUTTLE TAKING OFF IS ABOUT 200 DECIBELS. 54 00:03:16,062 --> 00:03:19,366 PROLONGED EXPOSURE TO SOUNDS ABOVE 85 DECIBELS CAN DAMAGE 55 00:03:19,366 --> 00:03:22,736 YOUR HEARING, SO BE SURE TO WEAR EAR PLUGS IF YOU'RE DOING 56 00:03:22,736 --> 00:03:24,437 SOMETHING AROUND LOUD SOUNDS. 57 00:03:24,437 --> 00:03:29,709 AND BE SURE THE VOLUME IN YOUR HEADPHONES IS SET AT A SAFE 58 00:03:29,709 --> 00:03:30,377 LEVEL. 59 00:03:30,377 --> 00:03:32,445 SOUND SURROUNDS AND DEFINES OUR WORLD. 60 00:03:32,445 --> 00:03:38,551 SO LISTEN UP, AND APPRECIATE SOUND. 61 00:03:38,551 --> 00:03:40,920 [APPLAUSE] >> JOINING ME NOW TO ANSWER YOUR 62 00:03:40,920 --> 00:03:42,989 QUESTIONS ABOUT SOUND ARE TWO SCIENTISTS. 63 00:03:42,989 --> 00:03:46,726 IN OUR POCATELLO STUDIO IS STEVE SHROPSHIRE, PROFESSOR OF PHYSICS 64 00:03:46,726 --> 00:03:47,560 AT IDAHO STATE UNIVERSITY. 65 00:03:47,560 --> 00:03:49,029 THANK YOU FOR JOINING US. 66 00:03:49,029 --> 00:03:51,765 >> THANK YOU FOR HAVING ME. 67 00:03:51,765 --> 00:03:56,569 >> AND JOINING ME HERE IN BOISE IS KATHRYN DEVINE, ASSISTANT 68 00:03:56,569 --> 00:03:58,405 PROFESSOR OF PHYSICS AT THE COLLEGE OF IDAHO. 69 00:03:58,405 --> 00:04:04,077 LET'S GO TO YOUR QUESTIONS. 70 00:04:04,077 --> 00:04:08,515 >> MY NAME IS JACK, AND I GO TO SHADOW HILLS ELEMENTARY, AND MY 71 00:04:08,515 --> 00:04:11,618 QUESTION IS, HOW ARE SOUNDS MADE? 72 00:04:11,618 --> 00:04:14,421 >> WHEN YOU MAKE A SOUND YOU'RE ACTUALLY GETTING A LITTLE BIT OF 73 00:04:14,421 --> 00:04:16,589 ENERGY TO THE AIR AROUND YOU. 74 00:04:16,589 --> 00:04:20,326 AND SO SOUND IS A WAVE, A COMPRESSION WAVE OF ALL THE MALL 75 00:04:20,326 --> 00:04:23,329 CIEWLS IN THE AIR, CARRYING THAT ENERGY FROM WHATEVER MADE THE 76 00:04:23,329 --> 00:04:25,331 SOUND, MY VOICE, ALL THE WAY TO YOUR EAR. 77 00:04:25,331 --> 00:04:29,336 SO IT'S A WAVE TRAVELING THROUGH THE AIR. 78 00:04:29,336 --> 00:04:31,504 >> MY NAME IS SHELBY. 79 00:04:31,504 --> 00:04:37,243 MY QUESTION IS, HOW FAST AND HOW FAR DOES SOUND TRAVEL? 80 00:04:37,243 --> 00:04:41,247 >> WELL, AT ROOM TEMPERATURE SOUND TRAVELS AT ABOUT 330 81 00:04:41,247 --> 00:04:42,449 METERS PER SECOND. 82 00:04:42,449 --> 00:04:47,654 THAT'S OVER 300 YARDS EVERY SECOND, SO IT'S QUITE FAST. 83 00:04:47,654 --> 00:04:52,025 AND SOUNDS CAN TRAVEL A GREAT DEAL OF DISTANCES. 84 00:04:52,025 --> 00:04:57,197 WHEN A VOLCANO NEAR INDONESIA EXPLODED BACK IN THE 1800s, 85 00:04:57,197 --> 00:05:01,034 THE SOUND WAS HEARD FOR HUNDREDS AND HUNDREDS OF MILES. 86 00:05:01,034 --> 00:05:02,502 AND THAT'S THROUGH THE AIR. 87 00:05:02,502 --> 00:05:06,239 SOUND ACTUALLY TRAVELS A LITTLE BIT BETTER THROUGH WATER. 88 00:05:06,239 --> 00:05:09,943 WE KNOW WHALES CAN COMMUNICATE WITH EACH OTHER OVER HUNDREDS OF 89 00:05:09,943 --> 00:05:12,779 MILES OF OCEAN. 90 00:05:12,779 --> 00:05:15,949 >> NOAH FROM DALTON ELEMENTARY WOULD LIKE TO KNOW, WHY DOES 91 00:05:15,949 --> 00:05:18,852 SOUND TRAVEL IN WAVES? 92 00:05:18,852 --> 00:05:23,423 >> WELL, A WAVE IS A DISTURBANCE IN SOMETHING. 93 00:05:23,423 --> 00:05:30,263 AND IF YOU PUSH ON SOMETHING, LIKE A TABLE, YOU EXPECT THE 94 00:05:30,263 --> 00:05:31,264 WHOLE TABLE TO MOVE. 95 00:05:31,264 --> 00:05:35,602 BUT WITH AIR OR WATER, WHEN YOU PUSH ON ONE PART OF IT, IT TAKES 96 00:05:35,602 --> 00:05:39,706 A WHILE FOR THAT DISTURBANCE TO MOVE, TO GET A BUNCH OF OTHER 97 00:05:39,706 --> 00:05:39,906 STUFF. 98 00:05:39,906 --> 00:05:42,709 IT'S LIKE WHEN YOU SPLASH SOMETHING IN WATER, THROW A ROCK 99 00:05:42,709 --> 00:05:46,279 IN WATER, ALL THE WATER DOESN'T MOVE AT ONCE. 100 00:05:46,279 --> 00:05:48,281 BECAUSE IT'S KIND OF FLUID. 101 00:05:48,281 --> 00:05:51,251 YOU'LL HAVE A DISTURBANCE TRAVELING OUTWARDS IN A WAVE. 102 00:05:51,251 --> 00:05:55,121 WE SEE THAT IN WATER QUITE OFTEN, AND THAT'S REALLY WHAT 103 00:05:55,121 --> 00:05:57,557 HAPPENED -- WHAT IS HAPPENING IN AIR TOO, WITH THE SOUND WE HEAR, 104 00:05:57,557 --> 00:06:00,593 WE JUST DON'T SEE THE AIR MOVING IN THE SAME WAY. 105 00:06:00,593 --> 00:06:03,196 BUT IT DOES. 106 00:06:03,196 --> 00:06:08,601 >> HI, MY NAME IS ALYSSA, AND I GO TO WHITMAN ELEMENTARY SCHOOL 107 00:06:08,601 --> 00:06:08,868 LEWISTON. 108 00:06:08,868 --> 00:06:14,040 MY QUESTION IS, HOW DOES SOUND TRAVEL THROUGH SPACE? 109 00:06:14,040 --> 00:06:17,844 >> SOUND JUST LIKE YOU'VE JUST SAID, WHERE YOU HAVE ONE KIND OF 110 00:06:17,844 --> 00:06:22,048 PERSON PART OF THE AIR, ONE MOLECULE COMMUNICATING THAT WAVE 111 00:06:22,048 --> 00:06:25,318 TO THE NEXT ONE, THAT SAME THING HAPPENS IN SPACE. 112 00:06:25,318 --> 00:06:28,855 THE THING THAT'S DIFFERENT IS THAT OUT IN SPACE, THE DENSITY 113 00:06:28,855 --> 00:06:34,094 OF THE AIR IS A LOT LOWER, SO THE MOLECULES ARE FARTHER APART. 114 00:06:34,094 --> 00:06:38,431 AND SO SOUND CAN STILL TRAVEL IN SPACE AS LONG AS THERE IS ANY 115 00:06:38,431 --> 00:06:41,534 GAS OR MOLECULES OR ANYTHING THERE TO COMMUNICATE F THERE 116 00:06:41,534 --> 00:06:44,337 WASN'T ANYTHING THERE, SOUND WOULDN'T BE ABLE TO TRAVEL. 117 00:06:44,337 --> 00:06:49,275 SO THERE DOES HAVE TO BE A GAS CLOUD OR SOME MOL YOU'LL OUT 118 00:06:49,275 --> 00:06:53,279 THERE THAT CAN COMMUNICATE THE ENERGY TO THE NEXT ONE. 119 00:06:53,279 --> 00:06:58,385 >> MY NAME IS BRADEN, AND I GO TO LENA IN MOSCO, IDAHO. 120 00:06:58,385 --> 00:07:02,655 MY QUESTION IS, WHY DO A TRUMPET AND A SAXOPHONE SOUND DIFFERENT, 121 00:07:02,655 --> 00:07:07,027 EVEN WHEN THEY ARE PLAYING THE SAME NOTE AT THE SAME VOLUME? 122 00:07:07,027 --> 00:07:10,597 >> YOU'VE PROBABLY NOTICED LONGER AND BIGGER INSTRUMENTS 123 00:07:10,597 --> 00:07:14,601 MAKE LOWER PITCHED SOUNDS, LOWER NOTES, AND SHORTER AND SMALLER 124 00:07:14,601 --> 00:07:16,503 INSTRUMENTS MAKE HIGHER PITCHED SOUNDS. 125 00:07:16,503 --> 00:07:20,607 THAT HAS TO DO WITH HOW THE SOUND RESONATES IN THESE 126 00:07:20,607 --> 00:07:21,675 DIFFERENT INSTRUMENTS. 127 00:07:21,675 --> 00:07:25,078 TO ILLUSTRATE I HAVE SOME LITTLE PIPES HERE. 128 00:07:25,078 --> 00:07:27,881 AND THIS ONE IS CUT A LITTLE LONGER THAN THE OTHERS, AND WHEN 129 00:07:27,881 --> 00:07:31,718 I WHACK IT ON MY PALM, I GET A C NOTE. 130 00:07:31,718 --> 00:07:40,093 AND WITH THE BLACK ONE, THAT'S A D, ORANGE ONE, E, F, G, AND AN 131 00:07:40,093 --> 00:07:40,493 A. 132 00:07:40,493 --> 00:07:44,964 YOU CAN SEE THE SHORTER THE PIPE THE HIGHER THE PITCH. 133 00:07:44,964 --> 00:07:49,803 I'VE GOT SOMETHING YOU CAN DO AT HOME WITH A LITTLE PLASTIC 134 00:07:49,803 --> 00:07:50,070 STRAW. 135 00:07:50,070 --> 00:07:54,274 IF YOU TAKE A STRAW AND YOU CUT LITTLE GROOVES IN IT, SHAPED 136 00:07:54,274 --> 00:07:58,578 LIKE TRIANGLES, LIKE I HAVE HERE, AND YOU BITE IT DOWN WITH 137 00:07:58,578 --> 00:08:02,649 YOUR TEETH, YOU CAN MAKE A LITTLE REED. 138 00:08:02,649 --> 00:08:04,751 A LOT OF INSTRUMENTS WORK ON REEDS. 139 00:08:04,751 --> 00:08:09,289 WHEN YOU BLOW AIR BETWEEN THE REEDS, THEY VIBRATE. 140 00:08:09,289 --> 00:08:12,759 AND THE LONGER THE INSTRUMENT, THE LOWER THE PITCH OF SOUND 141 00:08:12,759 --> 00:08:14,661 WILL RESONATE IN THAT. 142 00:08:14,661 --> 00:08:23,236 AND SO IF I JUST BLOW ON THIS STRAW, WE GET A NOTE, AND IF I 143 00:08:23,236 --> 00:08:26,573 TAKE TWO STRAW AND STICK THEM TOGETHER, I'LL GET A LOWER 144 00:08:26,573 --> 00:08:34,347 PITCH. 145 00:08:34,347 --> 00:08:39,953 AND I CAN EVEN CHANGE THE LENGTH OF THE PIPE AND GET DIFFERENT 146 00:08:39,953 --> 00:08:54,334 PITCHES FROM THE SAME STRAW. 147 00:08:54,334 --> 00:08:57,570 * >> THAT'S GREAT. 148 00:08:57,570 --> 00:08:58,271 [LAUGHTER] OK. 149 00:08:58,271 --> 00:09:04,844 LET'S GO BACK TO THE QUESTIONS. 150 00:09:04,844 --> 00:09:10,650 >> HI, MY NAME IS SARAH, I GO TO ST. MARY'S ELEMENTARY, AND MY 151 00:09:10,650 --> 00:09:16,389 QUESTION IS, WHY -- HOW DOES SOUND TRAVEL BETTER THROUGH 152 00:09:16,389 --> 00:09:16,923 WATER? 153 00:09:16,923 --> 00:09:18,124 >> WELL, WATER IS DENSER. 154 00:09:18,124 --> 00:09:21,761 THERE'S MORE STUFF THERE IN A SMALLER SPACE, AND THE MOLECULES 155 00:09:21,761 --> 00:09:25,865 ARE CLOSER TOGETHER, AND SO WHEN SOME MOLECULES GET THE ENERGY 156 00:09:25,865 --> 00:09:30,036 FROM THE SOUND, FROM THE DISTURBANCE, THEY WILL COLLIDE 157 00:09:30,036 --> 00:09:34,140 WITH OTHER MOLECULES SOONER, AND MORE RAPIDLY. 158 00:09:34,140 --> 00:09:38,778 AND ALSO WATER IS A LITTLE MORE ELASTIC THAN AIR, AND YOU CAN 159 00:09:38,778 --> 00:09:41,581 THINK OF IT AS BEING STIFFER IN A WAY. 160 00:09:41,581 --> 00:09:46,052 AND ALL THAT CONTRIBUTES TO MAKING THE SOUND TRAVEL BETTER 161 00:09:46,052 --> 00:09:47,787 AND FARTHER. 162 00:09:47,787 --> 00:09:50,623 >> ONE OF THE THINGS I'VE ALWAYS FOUND INTERESTING, I DON'T KNOW 163 00:09:50,623 --> 00:09:55,161 ABOUT THE AUDIENCE OUT THERE, BUT I ALWAYS TRIED TO TALK TO MY 164 00:09:55,161 --> 00:09:56,796 BROTHER UNDER WATER WHEN WE WERE KIDS. 165 00:09:56,796 --> 00:09:58,631 IT WOULD ALWAYS SOUND WEIRD. 166 00:09:58,631 --> 00:10:01,067 THAT'S BECAUSE WATER TRANSMITS DIFFERENT FREQUENCIES AT 167 00:10:01,067 --> 00:10:06,106 DIFFERENT SPEEDS, SO OUR EARS ARE USED TO HEARING SOUNDS IN 168 00:10:06,106 --> 00:10:06,373 AIR. 169 00:10:06,373 --> 00:10:09,542 BUT EVEN THOUGH WATER CAN TRANSMIT SOUNDS FASTER BETTER, 170 00:10:09,542 --> 00:10:14,381 IT DOESN'T TRANSMIT IT IN A WAY OUR EARS ARE USED TO HEARING, 171 00:10:14,381 --> 00:10:17,817 WHICH IS WHY IT SOUNDS GAR ABOUTED. 172 00:10:17,817 --> 00:10:22,255 >> IS THERE AN OBJECT SO THICK OR SO STRONG THAT SOUND CAN'T 173 00:10:22,255 --> 00:10:25,091 PASS THROUGH IT? 174 00:10:25,091 --> 00:10:29,396 >> IT KIND OF DEPENDS, I GUESS, ON HOW YOU THINK ABOUT IT. 175 00:10:29,396 --> 00:10:33,633 SOUND IS ENERGY TRAVELING, IT'S AN ENERGY WAVE, SO THE LOUDER 176 00:10:33,633 --> 00:10:36,102 THE SOUND, THE MORE ENERGY YOU'RE PUTTING IN, THE THICKER 177 00:10:36,102 --> 00:10:38,938 SOMETHING WOULD HAVE TO BE TO STOP THE ENERGY FROM TRAVELING 178 00:10:38,938 --> 00:10:41,141 THROUGH IT. 179 00:10:41,141 --> 00:10:44,110 AND SO, FOR EXAMPLE, IF I WAS WHISPERING AND YOU HAD JUST A 180 00:10:44,110 --> 00:10:46,046 WALL, THAT WOULD BE ENOUGH TO STOP THE SOUND FROM TRAVELING 181 00:10:46,046 --> 00:10:46,546 THROUGH IT. 182 00:10:46,546 --> 00:10:49,649 BUT IF I WAS SHOUTING, MAYBE A WALL WOULDN'T BE ENOUGH AND IT 183 00:10:49,649 --> 00:10:51,117 WOULD HAVE TO BE THICKER. 184 00:10:51,117 --> 00:10:54,387 IT DEPENDS ON HOW LOUD THE SOUND IS OR HOW THICK SOMETHING WOULD 185 00:10:54,387 --> 00:10:56,056 HAVE TO BE TO BLOCK THE SOUND. 186 00:10:56,056 --> 00:10:58,725 >> HI, MY NAME IS SEAN, AND I'M FROM ILLINOIS. 187 00:10:58,725 --> 00:11:04,264 MY QUESTION IS, HOW FAR CAN THE FIRE ALARM SOUND POSSIBLY 188 00:11:04,264 --> 00:11:04,798 TRAVEL? 189 00:11:04,798 --> 00:11:07,334 >> DEPENDS ON THE FIRE ALARM AND IT DEPENDS ON WHAT'S IN THE WAY 190 00:11:07,334 --> 00:11:08,535 OF THE FIRE ALARM. 191 00:11:08,535 --> 00:11:12,505 AGAIN, THE THINGS THAT CAN MAKE SOUND TRAVEL FARTHER IS THE 192 00:11:12,505 --> 00:11:15,375 AMOUNT OF ENERGY THAT IS BEING PRODUCED OR THAT THE SOUND IS 193 00:11:15,375 --> 00:11:16,076 GIVING OUT. 194 00:11:16,076 --> 00:11:19,079 AND SO IF YOU -- IT DEPENDS ON THE VOLUME OF YOUR FIRE ALARM 195 00:11:19,079 --> 00:11:20,747 AND THE FIRE ALARM. 196 00:11:20,747 --> 00:11:23,650 SOMETIMES BIG APARTMENT BUILDINGS HAVE VERY HIGH ENERGY 197 00:11:23,650 --> 00:11:26,519 LOUD FIRE ALARMS, LIKE IN A SCHOOL BUILDING BECAUSE THEY 198 00:11:26,519 --> 00:11:29,456 HAVE TO BE ABLE TO HEARD TROUT THE WHOLE BUILDING, VERSUS THE 199 00:11:29,456 --> 00:11:33,126 FIRE ALARM IN MY BEDROOM ISN'T AS LOUD, IT PRODUCES LESS 200 00:11:33,126 --> 00:11:33,460 ENERGY. 201 00:11:33,460 --> 00:11:36,363 SO YOU WOULDN'T BE ABLE TO HEAR IT PROBABLY AS FAR AS MY 202 00:11:36,363 --> 00:11:37,263 NEIGHBOR'S HOUSE. 203 00:11:37,263 --> 00:11:40,567 BUT IF A FIRE ALARM IN A BIG BUILDING GOES OFF YOU CAN HEAR 204 00:11:40,567 --> 00:11:41,768 IT FARTHER AWAY. 205 00:11:41,768 --> 00:11:45,905 IT COMES DOWN TO HOW MUCH ENERGY THE SOUND IS GIVING OFF, HOW 206 00:11:45,905 --> 00:11:51,411 MUCH ENERGY IS GOING ON AT THE SOURCE. 207 00:11:51,411 --> 00:11:54,748 >> DID YOU KNOW THAT DOLPHINS ON COULD HEAR SOUNDS UNDER WATER 208 00:11:54,748 --> 00:11:56,282 FROM 15 MILES AWAY? 209 00:11:56,282 --> 00:11:58,718 SNAKES ON THE OTHER HAND HAVE NO EARS. 210 00:11:58,718 --> 00:12:06,326 THEY SENSE SOUND WITH THEIR TONGUES. 211 00:12:06,326 --> 00:12:10,263 CAMERON AT DOLL TON ELEMENTARY WOULD LIKE TO KNOW, HOW MANY 212 00:12:10,263 --> 00:12:13,333 ANIMALS USE SOUND TO NAVIGATE THEIR WAY AROUND THE WORLD? 213 00:12:13,333 --> 00:12:14,501 >> LOTS OF THEM. 214 00:12:14,501 --> 00:12:20,273 WE KNOW THAT BATS USE SOUND TO NAVIGATE, AND TO HUNT. 215 00:12:20,273 --> 00:12:24,010 THEY ACTUALLY LISTEN VERY CLOSELY TO THE SOUND, THE ECHOS 216 00:12:24,010 --> 00:12:28,882 OF THE SOUND THAT BOUNCE OFF OF THE INSECTS AND OBJECTS AROUND 217 00:12:28,882 --> 00:12:29,115 THEM. 218 00:12:29,115 --> 00:12:32,185 ALSO A LOT OF THINGS THAT LIVE IN WATER. 219 00:12:32,185 --> 00:12:36,089 SINCE SOUND TRAVELS SO WELL THROUGH WATER, A LOT OF FISH AND 220 00:12:36,089 --> 00:12:40,360 OCEAN CREATURES USE SOUND TO NAVIGATE, AND ALSO TO HUNT. 221 00:12:40,360 --> 00:12:43,663 AND THERE'S EVEN SOME BIRDS THAT DO THAT TOO. 222 00:12:43,663 --> 00:12:47,667 >> MA TILDA, ALSO FROM DALTON GARDENS ELEMENTARY WOULD LIKE TO 223 00:12:47,667 --> 00:12:50,103 KNOW, WHY CAN'T YOU SEE SOUND WAVES? 224 00:12:50,103 --> 00:12:55,475 >> SO A SOUND WAVE IS A LITTLE TINY MOLECULE THAT YOU CAN'T 225 00:12:55,475 --> 00:12:55,742 SEE. 226 00:12:55,742 --> 00:12:58,978 SO I GUESS IT GOES DOWN TO THE FACT YOU CAN'T SEE THE AIR, EVEN 227 00:12:58,978 --> 00:13:01,781 THOUGH THERE IS STUFF IN THE AIR BETWEEN US, YOU CAN'T SEE IT. 228 00:13:01,781 --> 00:13:03,983 THERE'S NOTHING THAT I CAN SEE HERE. 229 00:13:03,983 --> 00:13:08,254 BUT THAT'S THIS AIR IN FRONT OF ME IS WHAT IS MAKING THE SOUND 230 00:13:08,254 --> 00:13:09,155 WAVE PROPAGATE THROUGH. 231 00:13:09,155 --> 00:13:12,225 I SUPPOSE IF YOU HAD AMAZING EYES AND COULD SEE THE MOLECULES 232 00:13:12,225 --> 00:13:14,894 MOVING, YOU WOULD BE ABLE TO SEE THE SOUND WAVE, BUT WE CAN'T 233 00:13:14,894 --> 00:13:17,630 ACTUALLY SEE THE SMALL, SMALL THINGS IN THE AIR THAT ARE 234 00:13:17,630 --> 00:13:20,333 TRANSMITTING THE SOUND WAVE ALONG THE AIR. 235 00:13:20,333 --> 00:13:25,905 >> IF I COULD JUMP IN, THERE IS -- IF YOU EVER WATCHED 236 00:13:25,905 --> 00:13:31,277 EXPLOSIONS, OR VERY, VERY LOUD NOISES, YOU SEE IT A LOT WITH 237 00:13:31,277 --> 00:13:32,812 ARTILLERY, SAY WITH THE ARMY. 238 00:13:32,812 --> 00:13:37,017 YOU CAN ACTUALLY SEE WHAT LOOKS LIKE A SOUND WAVE, BUT WHAT 239 00:13:37,017 --> 00:13:40,653 YOU'RE SEEING IS YOU HAVE SO MUCH ENERGY BEING DEPOSITED IN 240 00:13:40,653 --> 00:13:44,290 THE AIR, THE WATER IN THE AIR CONDENSES OUT INTO LITTLE WATER 241 00:13:44,290 --> 00:13:47,827 DROP LET'S, AND YOU'LL ACTUALLY SEE WHAT LOOKS LIKE A WAVE 242 00:13:47,827 --> 00:13:51,031 TRAVELING THROUGH THE AIR, BUT IT'S REALLY THE WATER CONDENSING 243 00:13:51,031 --> 00:13:54,000 OUT BRIEFLY AS THE SOUND WAVE GOES THROUGH IT. 244 00:13:54,000 --> 00:13:56,936 SO YOU'RE NOT ACTUALLY SEEING THE AIR, BUT YOU'RE SEEING WATER 245 00:13:56,936 --> 00:14:00,940 THAT'S BEING IN A WAY DRIVEN OUT OF THE AIR BRIEFLY BY THE 246 00:14:00,940 --> 00:14:02,308 INTENSE SOUND. 247 00:14:02,308 --> 00:14:07,047 >> HI, MY NAME IS ANNE. 248 00:14:07,047 --> 00:14:10,984 MY QUESTION IS, HOW FAST DO YOU HAVE TO GO TO BREAK THE SOUND 249 00:14:10,984 --> 00:14:11,317 BARRIER? 250 00:14:11,317 --> 00:14:15,889 >> THE SPEED OF SOUND IS 330 METERS PER SECOND. 251 00:14:15,889 --> 00:14:18,324 HERE AT ROOM TEMPERATURE. 252 00:14:18,324 --> 00:14:21,361 SO THAT'S ABOUT HOW FAST YOU'D HAVE TO GO. 253 00:14:21,361 --> 00:14:26,066 ABOUT 330 YARDS EVERY SECOND. 254 00:14:26,066 --> 00:14:26,433 >> HI. 255 00:14:26,433 --> 00:14:30,437 MY NAME IS McKENNA, I GO TO RUSSELL SCHOOL IN MOSCO. 256 00:14:30,437 --> 00:14:34,908 MY QUESTION IS, WHY IS THE SPEED OF LIGHT FASTER THAN THE SPEED 257 00:14:34,908 --> 00:14:36,009 OF SOUND? 258 00:14:36,009 --> 00:14:38,511 >> THAT'S ACTUALLY A REALLY INTERESTING QUESTION. 259 00:14:38,511 --> 00:14:42,182 LIGHT WAVES AND SOUND WAVES ARE A PRETTY DIFFERENT AND VERY 260 00:14:42,182 --> 00:14:42,916 FUNDAMENTAL WAY. 261 00:14:42,916 --> 00:14:47,253 SO SOUND WAVES REQUIRE THAT YOU HAVE AIR OR GAS OR SOMETHING 262 00:14:47,253 --> 00:14:50,557 THAT WILL TRANSMIT, SOME MOLECULE THAT WILL TRANSMIT THE 263 00:14:50,557 --> 00:14:53,927 WAVE, BECAUSE THEY HAVE TO PASS THE SIGNAL TO THE NEXT MOLECULE 264 00:14:53,927 --> 00:14:55,662 TO PASS THE WAVE ALONG. 265 00:14:55,662 --> 00:14:59,232 LIGHT, ON THE OTHER HAND, IF YOU HAD A VACUUM WHICH IS A TOTAL 266 00:14:59,232 --> 00:15:02,235 ABSENCE OF ANYTHING, TOTALLY EMPTY SPACE, YOU CAN STILL HAVE 267 00:15:02,235 --> 00:15:07,040 A LIGHT WAVE TRAVEL THROUGH IT BECAUSE LIGHTS -- LIGHT TRAVELS 268 00:15:07,040 --> 00:15:10,410 THROUGH A FIELD, IT DOESN'T REQUIRE HAVING MOLECULES. 269 00:15:10,410 --> 00:15:14,314 SO KIND OF OFF TOPIC, BUT THEY'RE VERY DIFFERENT AND VERY 270 00:15:14,314 --> 00:15:14,781 INTERESTING. 271 00:15:14,781 --> 00:15:18,518 THE SPEED THEN SINCE LIGHT DOESN'T DEPEND ON MOLECULES 272 00:15:18,518 --> 00:15:21,988 COMPRESSING INTO EACH OTHER TO TRANSMIT THE WAVE ALONG, THEY 273 00:15:21,988 --> 00:15:28,061 CAN TRAVEL FASTER, SO IT HAS TO DO WITH HOW THE 274 00:15:28,061 --> 00:15:28,895 WAVE -- PROPAGATES THROUGH SPACE. 275 00:15:28,895 --> 00:15:32,098 SO IT JUST A VERY DIFFERENT WAY OF HAVING THE ENERGY TRAVEL 276 00:15:32,098 --> 00:15:36,169 THROUGH SPACE THAT MAKES IT SO LIGHT CAN GO FASTER. 277 00:15:36,169 --> 00:15:38,805 >> JACK FROM DALTON ELEMENTARY WOULD LIKE TO KNOW, HOW DOES 278 00:15:38,805 --> 00:15:41,641 YOUR VOICE ECHO? 279 00:15:41,641 --> 00:15:44,711 >> YOUR VOICE ECHOS WHEN THE SOUND BOUNCES OFF OF SOMETHING 280 00:15:44,711 --> 00:15:45,011 ELSE. 281 00:15:45,011 --> 00:15:48,715 IT'S BASICALLY A REFLECTION OF THE SOUND. 282 00:15:48,715 --> 00:15:52,452 AGAIN, USING THE ANALOGY OF THROWING A ROCK INTO WATER, IF 283 00:15:52,452 --> 00:15:57,957 YOU'VE GOT LIKE A STIFF BANK, A CONCRETE POND, YOU'LL SEAT WATER 284 00:15:57,957 --> 00:16:00,493 RIPPLES HITTING THE EDGE OF THE POUND EVER POND AND BREAKING 285 00:16:00,493 --> 00:16:00,860 BACK. 286 00:16:00,860 --> 00:16:04,197 THE SAME THINGS HAPPEN WITH YOUR ECHO, AND YOU CAN HEAR THE SOUND 287 00:16:04,197 --> 00:16:06,199 BOUNCING OFF OF SOMETHING. 288 00:16:06,199 --> 00:16:08,702 SO IT'S LIKE THE SOUND WAVE IS MOVING AND HITS SOMETHING AND 289 00:16:08,702 --> 00:16:09,869 BOUNCES RIGHT BACK TOWARDS YOU. 290 00:16:09,869 --> 00:16:12,572 SO YOU CAN HEAR YOUR OWN VOICE AGAIN. 291 00:16:12,572 --> 00:16:14,074 OR OTHER SOUNDS, TOO. 292 00:16:14,074 --> 00:16:17,243 SO IT'S BASICALLY A BOUNCING OFF THE SOUND OFF SOMETHING ELSE. 293 00:16:17,243 --> 00:16:26,252 >> MY NAME IS ALYSSA, HOW DOES SOUND TRAVEL TO iPOD TO 294 00:16:26,252 --> 00:16:26,619 HEADPHONES? 295 00:16:26,619 --> 00:16:29,155 >> IT'S NOT SOUND TRAVELING THROUGH THE CORD, IT'S BASICALLY 296 00:16:29,155 --> 00:16:30,323 AN ELECTRICAL SIGNAL. 297 00:16:30,323 --> 00:16:34,594 AND THE ELECTRICAL SIGNAL GOES TO A SPEAKER, AND THE ENERGY OF 298 00:16:34,594 --> 00:16:39,599 THE ELECTRICITY MAKES A LITTLE MEMBRANE THERE VIBRATE. 299 00:16:39,599 --> 00:16:42,335 AND SOMETHING VIBRATES, IT WILL MOVE THE AIR AROUND IT. 300 00:16:42,335 --> 00:16:48,541 SO THE SOUND IS ONLY EXISTS THERE AT THE SPEAKER INSIDE YOUR 301 00:16:48,541 --> 00:16:48,808 EAR. 302 00:16:48,808 --> 00:16:51,644 IT DOESN'T EXIST INSIDE THE CORD. 303 00:16:51,644 --> 00:16:52,445 THAT'S ELECTRICITY. 304 00:16:52,445 --> 00:16:57,050 IT CARRIES THAT INFORMATION THAT BASICALLY MAKES THE SPEAKER 305 00:16:57,050 --> 00:16:57,384 MOVE. 306 00:16:57,384 --> 00:17:00,387 >> A LOT OF YOU HAD QUESTIONS ABOUT SOUND AND HEARING. 307 00:17:00,387 --> 00:17:04,391 SO LET'S LEARN A LITTLE BIT MORE ABOUT HOW OUR EARS AND BRAINS 308 00:17:04,391 --> 00:17:06,026 HEAR SOUND. 309 00:17:06,026 --> 00:17:09,396 >> WHEN YOU MAKE A SOUND, YOU CREATE ENERGY IN THE FORM OF 310 00:17:09,396 --> 00:17:10,964 SOUND WAVES. 311 00:17:10,964 --> 00:17:15,969 A LOUD SOUND HAS TALLER WAVES THAN A SOFT ONE. 312 00:17:15,969 --> 00:17:18,872 THESE WAVES EVENTUALLY ENTER YOUR EARS. 313 00:17:18,872 --> 00:17:21,041 THE SOUND WAVES TRAVEL DOWN THE EAR CANAL. 314 00:17:21,041 --> 00:17:24,978 THE EAR CAN AM IS ABOUT AN INCH LONG, AND AT ITS END IS A THIN 315 00:17:24,978 --> 00:17:27,047 PIECE OF SKIN CALLED THE EARDRUM. 316 00:17:27,047 --> 00:17:30,884 THE EARDRUM IS STRETCHED TIGHT, JUST LIKE THE TOP OF A DRUM. 317 00:17:30,884 --> 00:17:35,055 WHEN THE SOUND WAVES HIT THE EARDRUM, IT BEGINS TO VIBRATE. 318 00:17:35,055 --> 00:17:38,625 THAT VIBRATION MAKES THREE TINY BONES IN YOUR MIDDLE EAR BEGIN 319 00:17:38,625 --> 00:17:40,060 TO MOVE. 320 00:17:40,060 --> 00:17:43,797 THESE THREE LITTLE BONES ARE KNOWN AS THE HAMMER, ANVIL, AND 321 00:17:43,797 --> 00:17:47,434 STIR UP, BECAUSE THAT'S WHAT THEY KIND OF LOOK LIKE. 322 00:17:47,434 --> 00:17:50,704 THEY FEEL THE BONES TRANSMIT OR MOVE THE SOUND WAVES ALONG TO 323 00:17:50,704 --> 00:17:51,638 THE INBOUNDER EAR. 324 00:17:51,638 --> 00:17:55,275 THEY ALSO INCREASE THE FORCE OF SOUND WAVES. 325 00:17:55,275 --> 00:18:01,214 THEY MOVE INTO A SNAIL SHAPED STRUCTURE CALLED THE COKE LEE A. 326 00:18:01,214 --> 00:18:05,952 THEY'RE FILLED WITH FLUID AND 17,000 HAIRLIKE TISSUES. 327 00:18:05,952 --> 00:18:09,189 SOUND WAVES MOVE THROUGH THE FLUID AND THE HAIR BENDS. 328 00:18:09,189 --> 00:18:12,225 SOMEHOW THE MOVEMENT OF THOSE HAIRS STIMULATES THE 30,000 329 00:18:12,225 --> 00:18:15,061 NERVE FIBERS. 330 00:18:15,061 --> 00:18:17,764 THAT NERVE CARRIES THE SIGNAL TO THE BRAIN AND THE BRAIN FIGURES 331 00:18:17,764 --> 00:18:19,332 OUT WHAT THE SOUND IS. 332 00:18:19,332 --> 00:18:22,235 YOU NEED TWO EARS TO FIGURE OUT WHERE A SOUND COMES FROM. 333 00:18:22,235 --> 00:18:25,572 YOUR BRAIN FIGURES THE TERRENCE BETWEEN THE TWO SOUND LEVELS, 334 00:18:25,572 --> 00:18:28,508 AND CALCULATES THE DIRECTION OF THE SOUND. 335 00:18:28,508 --> 00:18:32,145 IT'S IMPORTANT TO PROTECT YOUR HEARING FROM LOUD SOUNDS. 336 00:18:32,145 --> 00:18:34,681 MUSCLES IN THE MIDDLE EAR PROTECT THE EAR BY STIFFENING 337 00:18:34,681 --> 00:18:38,485 THE EARDRUM, OR BY MOVING THE STIR UP BONE AWAY FROM THE INNER 338 00:18:38,485 --> 00:18:38,785 EAR. 339 00:18:38,785 --> 00:18:43,156 BUT SUDDEN LOUD SOUNDS CAN BREAK THE EARDRUM OR CAUSE OTHER 340 00:18:43,156 --> 00:18:49,095 DAMAGE AND CONTINUED LOUD SOUNDS CAN DAMAGE THE TINY HAIRS IN THE 341 00:18:49,095 --> 00:18:49,429 COCHLEA. 342 00:18:49,429 --> 00:18:52,632 BE SURE TO WEAR HEARING PROTECTION IF YOU'RE GOING TO BE 343 00:18:52,632 --> 00:18:55,435 AROUND LOUD NOISES, AND TURN THE VOLUME DOWN ON YOUR HEADPHONES. 344 00:18:55,435 --> 00:18:59,305 BECAUSE ONCE YOUR HEARING IS DAMAGE THE, IT CAN'T BE MADE ALL 345 00:18:59,305 --> 00:18:59,572 BETTER. 346 00:18:59,572 --> 00:19:01,841 ABOUT 200,000 AMERICANS ARE DEAF. 347 00:19:01,841 --> 00:19:04,210 THAT MEANS THEY CAN'T HEAR ANYTHING. 348 00:19:04,210 --> 00:19:07,547 ANOTHER 3 MILLION HAVE SEVERE HEARING PROBLEMS. 349 00:19:07,547 --> 00:19:10,950 SOME USE HEARING AIDS TO AMPLIFY OR INCREASE THE STRENGTH OF 350 00:19:10,950 --> 00:19:13,386 SOUND WAVES SO THEY CAN HEAR BETTER. 351 00:19:13,386 --> 00:19:15,021 OTHERS HAVE A COCHLEAR IMPLANT. 352 00:19:15,021 --> 00:19:18,758 THAT'S WHERE A SMALL MICROPHONE HELPS TRANSMIT SOUND TO THE 353 00:19:18,758 --> 00:19:19,292 INNER EAR. 354 00:19:19,292 --> 00:19:22,662 INDIVIDUALS WHO ARE DEAF OR HARD OF HEARING SOMETIMES USE SIGN 355 00:19:22,662 --> 00:19:24,030 LANGUAGE TO COMMUNICATE. 356 00:19:24,030 --> 00:19:26,232 OTHERS CAN READ LIPS. 357 00:19:26,232 --> 00:19:29,235 COMMUNICATING, WHETHER IT'S WITH YOUR EARS OR YOUR HANDS, IS 358 00:19:29,235 --> 00:19:30,570 ESSENTIAL TO LIFE. 359 00:19:30,570 --> 00:19:36,476 BY THE WAY, YOUR EAR DOES ONE OTHER THING -- REMEMBER THE 360 00:19:36,476 --> 00:19:36,710 COCHLEA? 361 00:19:36,710 --> 00:19:39,979 MOVEMENT OF THE FLUID INSIDE THAT TELLS THE BRAIN ABOUT YOUR 362 00:19:39,979 --> 00:19:40,880 BODY POSITION. 363 00:19:40,880 --> 00:19:43,950 THAT WAY YOU CAN TELL UP FROM DOWN, EVEN WITH YOUR EYES 364 00:19:43,950 --> 00:19:44,217 CLOSED. 365 00:19:44,217 --> 00:19:47,987 WHEN YOU SPIN AROUND, THE FLUID IN THE COCHLEA SPINS TOO, AND 366 00:19:47,987 --> 00:19:55,061 THAT EXPLAINS WHY YOU FEEL DIZZY. 367 00:19:55,061 --> 00:19:59,099 >> HI, MY NAME IS JOY, I GO TO WHITMAN ELEMENTARY SCHOOL. 368 00:19:59,099 --> 00:20:02,502 MY QUESTION IS, HOW DO YOU HEAR SOUNDS IN YOUR EARS? 369 00:20:02,502 --> 00:20:02,736 >> OK. 370 00:20:02,736 --> 00:20:06,339 SO YOUR EARS I THINK YOU HAVE PROBABLY NOTICED, YOUR EARS HAVE 371 00:20:06,339 --> 00:20:08,808 A LITTLE HOLE IN THEM, THERE'S A LITTLE ENTRANCE THERE. 372 00:20:08,808 --> 00:20:12,078 SO THE SOUND WAVES COME IN AND THEY HIT THAT ENTRANCE TO YOUR 373 00:20:12,078 --> 00:20:17,017 EAR, AND THEN WHAT -- YOU HAVE LITTLE HAIRS IN YOUR EAR THAT 374 00:20:17,017 --> 00:20:20,720 RESPOND TO THE WAVES, SO JUST KIND OF LIKE SEAWEED IN A POND 375 00:20:20,720 --> 00:20:23,890 THAT'S GETTING MOVED AROUND BY THE WAVES IN THE WATER, THE 376 00:20:23,890 --> 00:20:29,129 SOUND WAVE MOVES THESE LITTLE DETECTORS IN YOUR EAR AROUND, 377 00:20:29,129 --> 00:20:32,465 AND THOSE TRANSMIT A SIGNAL TO THE NERVOUS SYSTEM THAT 378 00:20:32,465 --> 00:20:34,467 EVENTUALLY COMMUNICATES THAT INFORMATION TO YOUR BRAIN AND 379 00:20:34,467 --> 00:20:37,037 TELLS YOU WHAT KIND OF SOUND YOU'RE HEARING. 380 00:20:37,037 --> 00:20:41,007 >> MY NAME IS KENDALL, I GO TO CAMELOT ELEMENTARY, AND MY 381 00:20:41,007 --> 00:20:45,679 QUESTION IS, WHY DO LOUD NOISES HURT OUR EARS? 382 00:20:45,679 --> 00:20:49,649 >> AGAIN, WITH THE LITTLE HAIRS IN YOUR EARS, A LOUD SOUND, THAT 383 00:20:49,649 --> 00:20:54,320 WOULD BE LIKE A WAVE THAT'S TOO BIG IN THE EXPOND SMASHES ALL 384 00:20:54,320 --> 00:20:55,488 THE SEAWEED DOWN. 385 00:20:55,488 --> 00:21:00,260 SO IF YOU HAVE A WAVE THAT'S TOO MUCH ENERGY COMING TO YOUR EAR, 386 00:21:00,260 --> 00:21:05,799 IT CAN HURT ALL THOSE LITTLE DETECTORS BECAUSE THEY'RE NOT 387 00:21:05,799 --> 00:21:08,868 CLIPPED, ARE -- THEY'RE NOT EQUIPPED OR THEY'RE NOT READY 388 00:21:08,868 --> 00:21:09,903 FOR ALL THAT ENERGY. 389 00:21:09,903 --> 00:21:13,173 IT CAN ACTUALLY HURT THE DETECTORS IN YOUR EAR, AND THEN 390 00:21:13,173 --> 00:21:16,910 IF YOU HAVE EVER HEARD A REALLY LOUD NOISE THAT CAUSES RINGING 391 00:21:16,910 --> 00:21:21,381 IN YOUR EAR, THE INABILITY TO HEAR AS WELL THAN BEFORE YOU 392 00:21:21,381 --> 00:21:24,351 HEARD THE LOUD NOISE, IT'S BECAUSE YOU DAMAGED THE 393 00:21:24,351 --> 00:21:25,919 DETECTORS IN YOUR EAR. 394 00:21:25,919 --> 00:21:28,288 >> HANNAH WOULD LIKE TO KNOW IF THERE'S A CLASSROOM FULL OF KIDS 395 00:21:28,288 --> 00:21:30,924 AND THE TEACHER WAS SPEAKING, WOULD THE KIDS ALL HEAR THE 396 00:21:30,924 --> 00:21:33,093 SOUND AT THE SAME TIME? 397 00:21:33,093 --> 00:21:33,360 >> NO. 398 00:21:33,360 --> 00:21:34,728 THEY WOULDN'T. 399 00:21:34,728 --> 00:21:39,132 BUT IN A CLASSROOM, IT'S ENOUGH SPACE SO THAT AGAIN, SOUND 400 00:21:39,132 --> 00:21:44,037 TRAVELS AT ABOUT 330 METERS PER SECOND, THE TYPICAL CLASSROOM IS 401 00:21:44,037 --> 00:21:48,208 ONLY MAYBE A DOZEN METERS, MAYBE AT MOST 15 METERS LONG. 402 00:21:48,208 --> 00:21:54,014 AND SO YOU'RE TALKING ABOUT TINY FRACTIONS OF A SECOND DIFFERENCE 403 00:21:54,014 --> 00:21:56,750 BETWEEN WHEN SOMEONE CLOSE TO THE TEACHER CAN HEAR AND SOMEONE 404 00:21:56,750 --> 00:21:57,150 FAR AWAY. 405 00:21:57,150 --> 00:22:00,487 IF YOU WANT TO BE VERY PICKY, YES, THEY'LL HEAR IT AT 406 00:22:00,487 --> 00:22:04,257 DIFFERENT TIMES, BUT IT WILL BE SO QUICK, NO ONE REALLY WILL 407 00:22:04,257 --> 00:22:04,724 NOTICE. 408 00:22:04,724 --> 00:22:10,630 >> YOU COULD NOTICE IT IF YOU WERE IN A MUCH LARGER SPACE. 409 00:22:10,630 --> 00:22:13,733 SO YOU'VE PROBABLY SEEN THIS WHEN YOU'VE WATCHED FIREWORKS, 410 00:22:13,733 --> 00:22:16,369 WHERE FIREWORKS, IF YOU'RE VERY CLOSE TO WHERE THE FIREWORKS ARE 411 00:22:16,369 --> 00:22:19,906 GOING OFF YOU SEE THE EXPLOSION AT THE SAME TIME YOU HEAR THE 412 00:22:19,906 --> 00:22:20,106 BOOM. 413 00:22:20,106 --> 00:22:23,009 IF YOU'RE FARTHER AWAY, AGAIN, YOU THAN GET SEVERAL HUNDRED 414 00:22:23,009 --> 00:22:25,712 FEET AWAY FROM THE FIREWORKS AND STILL BE ABLE TO SEE THEM, THE 415 00:22:25,712 --> 00:22:28,014 PEOPLE CLOSER TO THE FIREWORKS ARE HEARING THEM SOONER THAN YOU 416 00:22:28,014 --> 00:22:28,281 ARE. 417 00:22:28,281 --> 00:22:30,717 THAT'S HOW YOU GET THAT LAG BETWEEN WHEN YOU SEE THEM AND 418 00:22:30,717 --> 00:22:32,552 WHEN YOU HEAR THE EXPLOSION. 419 00:22:32,552 --> 00:22:37,290 IT COULD BE OVER A LARGE DISTANCES TO NOTICE THAT EFFECT. 420 00:22:37,290 --> 00:22:41,394 >> GABE WOULD LIKE TO KNOW, WHAT IS ULTRASOUND? 421 00:22:41,394 --> 00:22:43,563 >> SO ULTRASOUND IS SOMETHING THAT I THINK A LOT OF PEOPLE 422 00:22:43,563 --> 00:22:47,000 HEAR ABOUT IN MEDICINE IN TERMS OF BEING ABLE TO GET AN 423 00:22:47,000 --> 00:22:47,567 ULTRASOUND IMAGE. 424 00:22:47,567 --> 00:22:51,204 THAT'S THE TECHNIQUE OF USING SOUND, SINCE SOUND WAVES TRAVEL 425 00:22:51,204 --> 00:22:54,941 THROUGH MEDIUM, TO USE SOUND TO BOUNCE OFF AN OBJECT LIKE INSIDE 426 00:22:54,941 --> 00:22:58,978 THE HUMAN BODY, SO YOU CAN PUT AN ULTRASOUND MACHINE ON SOME OF 427 00:22:58,978 --> 00:23:02,315 THESE ABDOMEN AND SEE THEM INSIDE THEM BECAUSE THE SOUND 428 00:23:02,315 --> 00:23:05,218 WAVES COMES THROUGH, INTERACT WITH SOMETHING DENSER THAN 429 00:23:05,218 --> 00:23:07,787 SOMETHING IN THE REST OF THE BODY AND REFLECTS BACK OUT AND 430 00:23:07,787 --> 00:23:12,625 SO THEN THE DETECTOR CAN USE THOSE IMAGES TO MAKE A PICTURE. 431 00:23:12,625 --> 00:23:16,096 >> ELLIE WOULD LIKE TO KNOW HOW FAR CAN SOUND TRAVEL? 432 00:23:16,096 --> 00:23:18,798 >> THIS DEPENDS ON HOW LOUD THE ORIGINAL SOUND WAS. 433 00:23:18,798 --> 00:23:21,701 SO THE MORE ENERGY THAT GOES INTO THE ORIGINAL SOUND, THE 434 00:23:21,701 --> 00:23:24,004 FARTHER IT CAN TRAVEL. 435 00:23:24,004 --> 00:23:27,073 AND SO IF YOU HAVE LIKE A WHISPER YOU MIGHT NOT BE ABLE TO 436 00:23:27,073 --> 00:23:30,443 HEAR THAT MORE THAN A FEW FEET AWAY, BUT IF YOU HAVE A LOUD 437 00:23:30,443 --> 00:23:32,645 VOLCANO EXPLODING WITH A LOT OF ENERGY YOU MIGHT BE ABLE TO HEAR 438 00:23:32,645 --> 00:23:34,447 THAT HUNDREDS OF MILES AWAY. 439 00:23:34,447 --> 00:23:34,814 >> HI. 440 00:23:34,814 --> 00:23:39,819 MY NAME IS CASSIDY, AND I GO TO WEST PARK ELEMENTARY SCHOOL IN 441 00:23:39,819 --> 00:23:40,086 MOSCOW. 442 00:23:40,086 --> 00:23:45,358 THIS IS MY QUESTION -- ARE THERE SOFT SOUNDS YOU CAN'T HEAR? 443 00:23:45,358 --> 00:23:46,760 >> OH, YES. 444 00:23:46,760 --> 00:23:50,930 AGAIN, WE HAVE TO HAVE A CERTAIN AMOUNT OF ENERGY COMING INTO OUR 445 00:23:50,930 --> 00:23:54,834 EARS TO MOVE OUR LITTLE CILIA AROUND ENOUGH FOR US TO DETECT 446 00:23:54,834 --> 00:23:56,836 THE SOUND. 447 00:23:56,836 --> 00:24:02,042 THERE ARE VERY, VERY FAINT SOUNDS WE CAN'T HEAR. 448 00:24:02,042 --> 00:24:05,512 IT'S LIKE INSECTS STRACHG THEMSELVES. 449 00:24:05,512 --> 00:24:08,581 WE'VE BEEN ABLE TO PICK UP THAT SOUND WITH SENSITIVE 450 00:24:08,581 --> 00:24:11,051 MICROPHONES, BUT NO MATTER HOW HARD YOU LISTEN I DON'T THINK 451 00:24:11,051 --> 00:24:13,787 YOU CAN HEAR A BUG SCRATCHING ITS BACK. 452 00:24:13,787 --> 00:24:15,622 >> LET ME ASK A COUPLE OTHER QUESTIONS. 453 00:24:15,622 --> 00:24:18,525 WHY DID YOU GUYS DECIDE TO STUDY PHYSICS AND THEREFORE STUDY 454 00:24:18,525 --> 00:24:20,160 ABOUT SOUND? 455 00:24:20,160 --> 00:24:22,629 >> SO WHEN I WAS IN COLLEGE, I REALLY LIKED MATH. 456 00:24:22,629 --> 00:24:26,066 I WAS GOOD AT MATH, AND I REALLY LIKED SCIENCE, BUT DIDN'T KNOW 457 00:24:26,066 --> 00:24:27,734 WHAT AREA I WANTED TO GO INTO. 458 00:24:27,734 --> 00:24:32,105 SO MY FIRST YEAR OF COLLEGE I STARTED WORKING, I TOOK A 459 00:24:32,105 --> 00:24:34,874 PHYSICS CLASS AND REALIZED THAT THAT WAS THE PERFECT COMBINATION 460 00:24:34,874 --> 00:24:39,879 OF BEING ABLE TO USE MY MATH SKILLS AND THEN SCIENCE, AND I 461 00:24:39,879 --> 00:24:42,716 STARTED WORKING FOR A PROFESSOR WHO DID ASTRONOMY, WHICH WAS THE 462 00:24:42,716 --> 00:24:46,353 COOLEST THING TO ME AT THE TIME. 463 00:24:46,353 --> 00:24:50,090 SO THEN I WAS ABLE TO COMBINE MATH, PHYSICS, AND ASTRONOMY 464 00:24:50,090 --> 00:24:52,826 INTO THE SAME LIFE TRAJECTORY. 465 00:24:52,826 --> 00:24:54,761 SO THAT'S BEEN GREAT. 466 00:24:54,761 --> 00:24:55,395 >> STEVE? 467 00:24:55,395 --> 00:24:59,599 >> WELL, I HAD A VERY GOOD HIGH SCHOOL PHYSICS TEECHER, AND HE 468 00:24:59,599 --> 00:25:04,404 INSPIRED ME, AND HE STRONGLY INFLUENCED MY CHOICE OF CAREER 469 00:25:04,404 --> 00:25:09,309 AND STUDY, BUT PHYSICS AND SCIENCE IN GENERAL, I LIKE THE 470 00:25:09,309 --> 00:25:13,480 IDEA OF BEING ABLE TO FIGURE OUT HOW THINGS WORK. 471 00:25:13,480 --> 00:25:14,881 HOW THE UNIVERSE WORKS. 472 00:25:14,881 --> 00:25:22,255 WE LIVE IN A WONDEROUS PLACE, AND LEARNING MORE ABOUT IT IS 473 00:25:22,255 --> 00:25:23,490 JUST FASCINATING. 474 00:25:23,490 --> 00:25:27,627 AND SCIENCE SEEMED TO ME AND STILL DOES THE BEST WAY TO GO 475 00:25:27,627 --> 00:25:30,263 ABOUT LEARNING MORE ABOUT THE WORLD AROUND US. 476 00:25:30,263 --> 00:25:34,000 >> STEVE, IF A STUDENT WANTS TO BECOME A PHYSICIST AND STUDY 477 00:25:34,000 --> 00:25:37,337 SOUND, WHAT SHOULD THEY DO WHEN THEY GET TO SCHOOL, WHAT CLASSES 478 00:25:37,337 --> 00:25:40,073 SHOULD THEY TAKE? 479 00:25:40,073 --> 00:25:41,274 >> OH, SCIENCE. 480 00:25:41,274 --> 00:25:43,076 SCIENCE AND MATHEMATICS. 481 00:25:43,076 --> 00:25:46,346 MATHEMATICS IS THE LANGUAGE OF WHICH SCIENCE IS SPOKEN. 482 00:25:46,346 --> 00:25:50,550 SO YOU NEED TO BE FAIRLY FLUENT WITH MATH IN ORDER TO DO 483 00:25:50,550 --> 00:25:50,817 SCIENCE. 484 00:25:50,817 --> 00:25:57,457 BUT I WOULD SAY SAMPLE AS MANY SCIENCE CLASSES AS YOU CAN, AND 485 00:25:57,457 --> 00:25:59,392 GO WITH WHAT YOU FIND INTERESTING. 486 00:25:59,392 --> 00:26:01,961 WHAT FASCINATES YOU. 487 00:26:01,961 --> 00:26:03,563 >> WOULD I AGREE WITH THAT TOO. 488 00:26:03,563 --> 00:26:06,466 THE MATHEMATICS IS IMPORTANT BECAUSE IT HELPS YOU KIND OF, 489 00:26:06,466 --> 00:26:08,768 AGAIN, SPEAK THE LANGUAGE OF THE SCIENCES. 490 00:26:08,768 --> 00:26:12,972 WHEN I STARTED TAKING SCIENCE I TOOK BIOLOGY AND CHEMISTRY, AND 491 00:26:12,972 --> 00:26:16,609 GEOLOGY, PHYSICS, AND THEY'RE ALL -- THEY ALL GET USED 492 00:26:16,609 --> 00:26:19,579 TOGETHER, THERE'S NOT CLEARLY SEPARATED OUT FIELDS IN 493 00:26:19,579 --> 00:26:22,982 ASTRONOMY, THERE'S A LOT OF CHEMISTRY AND IN PHYSICS THERE'S 494 00:26:22,982 --> 00:26:23,249 BIOLOGY. 495 00:26:23,249 --> 00:26:26,252 SO I WOULD HAVE TO AGREE WITH STEVE, TAKE AS MUCH SCIENCE AS 496 00:26:26,252 --> 00:26:28,688 YOU CAN SO YOU CAN FIND THE THING YOU'RE REAL LIQUEURUS 497 00:26:28,688 --> 00:26:30,890 ABOUT AND WANT TO KEEP ASKING QUESTIONS ABOUT. 498 00:26:30,890 --> 00:26:34,594 >> I'M SORRY WE'VE RUN OUT OF TIME. 499 00:26:34,594 --> 00:26:36,730 I THANK STEVE SHROPSHIRE AND KATHRYN DEVINE FOR ANSWERING OUR 500 00:26:36,730 --> 00:26:37,263 QUESTIONS. 501 00:26:37,263 --> 00:26:37,797 THANKS, STEVE. 502 00:26:37,797 --> 00:26:39,632 >> THANK YOU. 503 00:26:39,632 --> 00:26:40,367 >> THANKS, KATHRYN. 504 00:26:40,367 --> 00:26:41,868 >> THANKS SO MUCH FOR HAVING US. 505 00:26:41,868 --> 00:26:45,705 >> YOU CAN LEARN LOTS MORE ABOUT SOUNDS AND OTHER TOPICS ON THE 506 00:26:45,705 --> 00:26:48,108 "D4K" WEBSITE AND WE'LL ANSWER MORE QUESTIONS ABOUT SOUND IN 507 00:26:48,108 --> 00:26:49,175 THE "D4K" WEB ONLY. 508 00:26:49,175 --> 00:26:53,646 YOU'LL FIND IT ALL AT IDAHOPTV.ORG/D4K. 509 00:26:53,646 --> 00:26:56,916 OUR LATEST WINNER IN OUR QUESTION CONTEST IS TAYLOR AT 510 00:26:56,916 --> 00:26:59,452 MRS. HUNT'S CLASS AT CYNTHIA MANN ELEMENTARY IN BOISE. 511 00:26:59,452 --> 00:27:01,454 REMEMBER, WHEN YOU SEND IN A QUESTION, YOU AND YOUR CLASS ARE 512 00:27:01,454 --> 00:27:02,856 ELIGIBLE FOR OUR CONTEST. 513 00:27:02,856 --> 00:27:06,659 CHECK OUT THE CONTACT US PART OF THE "D4K" WEBSITE FOR SHOW 514 00:27:06,659 --> 00:27:10,663 DEADLINES AND HOW TO SUBMIT YOUR I'M AND VIDEO QUESTIONS. 515 00:27:10,663 --> 00:27:14,668 AND CHECK OUT MY SCIENCE BLOG FOR THE LATEST SCIENCE NEWS FOR 516 00:27:14,668 --> 00:27:15,301 KIDS. 517 00:27:15,301 --> 00:27:15,669 IDAHOPTV.ORG. 518 00:27:15,669 --> 00:27:16,503 THANKS FOR JOINING US. 519 00:27:16,503 --> 00:27:19,706 WE'LL SEE YOU NEXT TIME ON "D4K." 520 00:27:21,341 --> 00:27:22,042 Captioning Performed By LNS Captioning www.LNScaptioning.com 521 00:27:23,977 --> 00:27:25,879 >> DO YOU HAVE A SCIENCEQUESTION? 522 00:27:25,879 --> 00:27:26,212 >> YEAH! 523 00:27:26,212 --> 00:27:28,415 >> DO YOU WANT TO WIN SOME PRIZES? 524 00:27:28,415 --> 00:27:28,715 >> YEAH! 525 00:27:28,715 --> 00:27:31,685 >> WHEN YOU SEND US A QUESTION TO USE ON "D4K," YOU AND YOUR 526 00:27:31,685 --> 00:27:34,487 CLASS ARE ELIGIBLE TO WIN DVDs AND OTHER PRIZES. 527 00:27:34,487 --> 00:27:37,490 CHECK OUT THE "D4K" WEBSITE FOR THIS SEASON'S TOPICS AND SEND IN 528 00:27:37,490 --> 00:27:38,425 YOUR QUESTIONS. 529 00:27:38,425 --> 00:27:41,628 YOU CAN SEND US AN EMAIL OR VIDEO QUESTION. 530 00:27:41,628 --> 00:27:43,697 RECORD OUT YOUR WEBCAM OR CELL PHONE. 531 00:27:43,697 --> 00:27:46,499 IF YOU'RE AN EDUCATOR WE'LL EVEN LEND ACAMERA. 532 00:27:46,499 --> 00:27:49,436 FIND OUT ALL THE DETAILS ON HOW TO ?END YOUR QUESTION AND WIN ON 533 00:27:49,436 --> 00:27:51,638 THE "D4K" WEBSITE. 534 00:27:51,638 --> 00:27:56,443 THAT'S "D4K" "D4K" THE PLACE FOR SCIENCE. 535 00:28:36,616 --> 00:28:39,352 >> IF YOU WANT TO LEARN MORE ABOUT THIS TOPIC OR WATCH OUR 536 00:28:39,352 --> 00:28:41,588 VIDEOS, CHECK OUT THE "D4K"