WEBVTT 00:19.986 --> 00:23.690 align:left position:42.5%,start line:83% size:47.5% DEAN: HEY THERE STAR GAZERS. 00:23.790 --> 00:26.526 align:left position:72.5%,start line:83% size:17.5% I'M DEAN REGAS, ASTRONOMER FOR THE CINCINNATI OBSERVATORY. 00:26.626 --> 00:28.695 align:left position:42.5%,start line:83% size:47.5% JAMES: AND I'M JAMES ALBURY, DIRECTOR OF THE KIKA 00:28.795 --> 00:31.197 align:left position:82.5%,start line:83% size:7.5% SILVA PLA PLANETARIUM IN GAINESVILLE, FLORIDA. 00:31.297 --> 00:33.767 align:left position:75%,start line:83% size:15% WE'RE HERE TO HELP YOU FIND YOUR WAY AROUND THE SKY TONIGHT. 00:33.867 --> 00:36.970 align:left position:42.5%,start line:83% size:47.5% DEAN: THE WINTER SOLSTICE IS THURSDAY DECEMBER 21ST 00:37.070 --> 00:40.006 align:left position:80%,start line:89% size:10% AND SUN WORSHIPPERS CAN FINALLY REJOICE! 00:40.106 --> 00:44.444 align:left position:72.5%,start line:83% size:17.5% THIS IS THE TIME WHEN THE NORTHERN HEMISPHERE EXPERIENCES THE SHORTEST DAYS AND LONGEST 00:44.544 --> 00:45.445 align:left position:40%,start line:89% size:50% NIGHTS. 00:45.545 --> 00:46.846 align:left position:42.5%,start line:83% size:47.5% JAMES: WAIT A SECOND, REJOICE? 00:46.946 --> 00:48.114 align:left position:25%,start line:89% size:65% ON THE SHORTEST DAY? 00:48.214 --> 00:49.616 align:left position:25%,start line:89% size:65% WHAT'S TO CELEBRATE? 00:49.716 --> 00:50.850 align:left position:15%,start line:89% size:75% SOUND LIKE LOTS OF DARKNESS. 00:50.950 --> 00:53.753 align:left position:42.5%,start line:83% size:47.5% DEAN: WELL, EVERY DAY AFTER DECEMBER 21ST, THE SUN 00:53.853 --> 00:57.223 align:left position:72.5%,start line:83% size:17.5% WILL GET HIGHER IN THE SKY AND STAY UP LONGER ABOVE THE HORIZON. 00:57.323 --> 01:00.827 align:left position:77.5%,start line:83% size:12.5% THE SUN WILL STOP ITS SOUTHWARD MIGRATION AND START HEADING NORTH AGAIN. 01:00.927 --> 01:03.229 align:left position:42.5%,start line:83% size:47.5% JAMES: I WISH IT WOULD HURRY UP ALREADY, IT'S FREEZING 01:03.329 --> 01:04.431 align:left position:37.5%,start line:89% size:52.5% OUT HERE! 01:04.531 --> 01:06.499 align:left position:42.5%,start line:83% size:47.5% DEAN: LET'S SHOW YOU THE REASON FOR THE SEASONS 01:06.599 --> 01:09.269 align:left position:42.5%,start line:83% size:47.5% JAMES: THE CHANGING SEASONS ARE CAUSED BY ONE THING 01:09.369 --> 01:12.439 align:left position:87.5%,start line:83% size:2.5% - THE 23 AND A HALF DEGREE TILT OF THE EARTH. 01:12.539 --> 01:16.443 align:left position:75%,start line:83% size:15% AS OUR PLANET ROTATES DAILY ON ITS AXIS, WE ALSO REVOLVE AROUND THE SUN. 01:16.543 --> 01:21.581 align:left position:77.5%,start line:83% size:12.5% BUT OUR ROTATIONAL AXIS IS TILTED COMPARED TO OUR ORBIT AROUND THE SUN, AND WE ALWAYS 01:21.681 --> 01:22.949 align:left position:20%,start line:89% size:70% KEEP THIS SLANTED VIEW. 01:23.049 --> 01:25.452 align:left position:42.5%,start line:83% size:47.5% DEAN: WHEN WE, IN THE NORTHERN HEMISPHERE, ARE TILTED 01:25.552 --> 01:29.823 align:left position:72.5%,start line:83% size:17.5% MOST DIRECTLY TOWARD THE SUN WE SOAK UP SOLAR ENERGY TO THE MAX. 01:29.923 --> 01:33.793 align:left position:77.5%,start line:83% size:12.5% THAT DAY IS CALLED THE SUMMER SOLSTICE AND IT OCCURRED ON JUNE 21ST THIS YEAR. 01:33.893 --> 01:38.798 align:left position:70%,start line:83% size:20% AT THIS POINT THE SUN'S RAYS SHINE MOST DIRECTLY ON THE NORTHERN HEMISPHERE. 01:38.898 --> 01:42.168 align:left position:75%,start line:83% size:15% WE GET MORE ENERGY PER SQUARE INCH, AND THUS IT'S HOTTER. 01:42.268 --> 01:44.771 align:left position:42.5%,start line:83% size:47.5% JAMES: NOW THE OPPOSITE OCCURS WHEN THE EARTH SWINGS 01:44.871 --> 01:46.739 align:left position:80%,start line:89% size:10% AROUND TO THE OPPOSITE SIDE OF THE SUN. 01:46.840 --> 01:50.376 align:left position:77.5%,start line:83% size:12.5% HERE, WE, IN THE NORTHERN HEMISPHERE, ARE TILTED AWAY FROM THE SUN. 01:50.477 --> 01:54.781 align:left position:72.5%,start line:83% size:17.5% THE SUN'S RAYS FEEBLY STRIKE US AT A LOW ANGLE SPREADING OUT THE SAME ENERGY OVER 01:54.881 --> 01:56.216 align:left position:32.5%,start line:89% size:57.5% A LARGER AREA. 01:56.316 --> 01:58.852 align:left position:75%,start line:83% size:15% EACH SQUARE INCH GETS A LOT LESS ENERGY THAN IN SUMMER. 01:58.952 --> 02:02.689 align:left position:77.5%,start line:83% size:12.5% WE CALL THIS THE WINTER SOLSTICE AND THAT OCCURS ON DECEMBER 21ST THIS YEAR. 02:02.789 --> 02:06.059 align:left position:42.5%,start line:83% size:47.5% DEAN: THE SUN'S OUTPUT IS THE SAME ALL YEAR-ROUND. 02:06.159 --> 02:10.396 align:left position:72.5%,start line:83% size:17.5% BUT THE DIFFERENCE IN OUR SEASONS IS HOW MUCH OF THAT ENERGY WE SOAK UP. 02:10.497 --> 02:14.467 align:left position:77.5%,start line:83% size:12.5% IT HAS NOTHING TO DO WITH HOW CLOSE OR FAR WE ARE FROM THE SUN. 02:14.567 --> 02:19.405 align:left position:72.5%,start line:83% size:17.5% WE'RE CLOSEST TO THE SUN EVERY YEAR IN JANUARY AND FARTHEST FROM THE SUN IN JULY. 02:19.506 --> 02:22.075 align:left position:75%,start line:83% size:15% SO THE DISTANCE DOESN T CAUSE THE DIFFERENCE IN THE SEASONS 02:22.175 --> 02:24.544 align:left position:10%,start line:89% size:80% HEY JAMES, ARE YOU STAYING COOL? 02:24.644 --> 02:26.079 align:left position:42.5%,start line:83% size:47.5% JAMES: THE SUN 02:26.179 --> 02:27.180 align:left position:20%,start line:89% size:70% IS BLASTING OFF MY HAIR! 02:27.280 --> 02:29.082 align:left position:42.5%,start line:83% size:47.5% DEAN: OH YOU'RE DOING GREAT. 02:29.182 --> 02:33.019 align:left position:75%,start line:83% size:15% NOW LET'S SEE HOW OUR TILT AFFECTS THE VIEW FROM DOWN ON EARTH. 02:33.119 --> 02:34.988 align:left position:42.5%,start line:83% size:47.5% DEAN: SORRY ABOUT YOUR HAIR. 02:35.088 --> 02:36.222 align:left position:42.5%,start line:83% size:47.5% JAMES: IT'S OKAY. 02:36.322 --> 02:37.223 align:left position:30%,start line:89% size:60% IT'LL GROW BACK. 02:37.323 --> 02:38.424 align:left position:42.5%,start line:83% size:47.5% DEAN: HA! 02:38.525 --> 02:40.627 align:left position:42.5%,start line:83% size:47.5% JAMES: ANYWAY, WE HAVE OUR SKIES SET TO DECEMBER 02:40.727 --> 02:43.229 align:left position:17.5%,start line:89% size:72.5% 21ST JUST BEFORE SUNRISE. 02:43.329 --> 02:48.201 align:left position:72.5%,start line:83% size:17.5% LET'S TRACE THE PATH THAT THE SUN TAKES ACROSS THE SKY ON THIS, THE SHORTEST DAY OF THE YEAR. 02:48.301 --> 02:52.138 align:left position:77.5%,start line:83% size:12.5% THE SUN WILL RISE SOUTH OF EAST, AND REACH ITS HIGHEST POINT IN THE SOUTHERN SKY 02:52.238 --> 02:53.339 align:left position:35%,start line:89% size:55% AROUND NOON. 02:53.439 --> 02:55.241 align:left position:85%,start line:89% size:5% THEN THE SUN WILL SET SOUTH OF WEST. 02:55.341 --> 02:58.344 align:left position:42.5%,start line:83% size:47.5% DEAN: FOR MOST OF THE COUNTRY YOU'LL GET ABOUT 9-10 02:58.444 --> 03:00.180 align:left position:12.5%,start line:89% size:77.5% HOURS OF DAYLIGHT ON THIS DAY. 03:00.280 --> 03:03.683 align:left position:77.5%,start line:83% size:12.5% THAT ALSO MEANS YOU'LL GET 14-15 HOURS OF DARKNESS! 03:03.783 --> 03:07.020 align:left position:42.5%,start line:83% size:47.5% JAMES: LET'S COMPARE THIS TO THE SPRING EQUINOX - NEXT 03:07.120 --> 03:09.088 align:left position:12.5%,start line:89% size:77.5% YEAR IT WILL BE ON MARCH 20TH. 03:09.189 --> 03:12.492 align:left position:72.5%,start line:83% size:17.5% NOW LET'S TRACE THE PATHWAY THAT THE SUN TAKES ON THIS DAY. 03:12.592 --> 03:14.494 align:left position:15%,start line:89% size:75% THE SUN WILL RISE DUE EAST 03:14.594 --> 03:16.329 align:left position:77.5%,start line:83% size:12.5% REACH ITS HIGHEST POINT ABOVE THE SOUTHERN HORIZON 03:16.429 --> 03:18.298 align:left position:22.5%,start line:89% size:67.5% AND THEN SET DUE WEST. 03:18.398 --> 03:20.800 align:left position:42.5%,start line:83% size:47.5% DEAN: NOTICE HOW THE SUN WENT HIGHER IN THE SKY 03:20.900 --> 03:22.035 align:left position:20%,start line:89% size:70% THAN IT DID IN DECEMBER. 03:22.135 --> 03:24.871 align:left position:25%,start line:83% size:65% THE HIGHER THE SUN, THE MORE DIRECT ENERGY WE GET. 03:24.971 --> 03:27.106 align:left position:42.5%,start line:83% size:47.5% JAMES: AND LOOK AT HOW MUCH LONGER THE SUN WAS IN 03:27.207 --> 03:28.208 align:left position:40%,start line:89% size:50% THE SKY! 03:28.308 --> 03:30.610 align:left position:70%,start line:89% size:20% 12 HOURS OF DAYLIGHT, AND 12 HOURS OF DARKNESS. 03:30.710 --> 03:31.611 align:left position:20%,start line:89% size:70% EQUAL DAY, EQUAL NIGHT. 03:31.711 --> 03:33.947 align:left position:85%,start line:89% size:5% THATS WHY THEY CALL IT THE EQUINOX. 03:34.047 --> 03:36.482 align:left position:42.5%,start line:83% size:47.5% DEAN: WHAT ABOUT THE SUMMER SOLSTICE? 03:36.583 --> 03:42.388 align:left position:75%,start line:83% size:15% NOW OUR SKY IS SET TO JUNE 21ST, AND WE CAN WATCH THE SUN RISE NORTH OF EAST 03:42.488 --> 03:44.090 align:left position:17.5%,start line:89% size:72.5% GO VERY HIGH IN THE SOUTH 03:44.190 --> 03:45.458 align:left position:22.5%,start line:89% size:67.5% AND SET NORTH OF WEST. 03:45.558 --> 03:48.027 align:left position:42.5%,start line:83% size:47.5% JAMES: THE SUN WENT HIGHER STILL IN THE SKY. 03:48.127 --> 03:53.700 align:left position:77.5%,start line:83% size:12.5% AND THE HOURS OF DAYLIGHT REACH A WHOPPING 14-15 HOURS FOR MOST OF THE U.S WITH ONLY 03:53.800 --> 03:55.201 align:left position:37.5%,start line:83% size:52.5% 9-10 HOURS OF DARKNESS. 03:55.301 --> 03:57.870 align:left position:42.5%,start line:83% size:47.5% DEAN: AND ALL OF THIS IS CAUSED BY THE 23 AND 03:57.971 --> 03:59.939 align:left position:10%,start line:89% size:80% A HALF DEGREE TILT OF THE EARTH. 04:00.039 --> 04:04.110 align:left position:42.5%,start line:83% size:47.5% DEAN: SO ON DECEMBER 21ST WATCH THIS EXTREME SOUTHERLY 04:04.210 --> 04:05.378 align:left position:40%,start line:89% size:50% SUNSET. 04:05.478 --> 04:06.946 align:left position:42.5%,start line:83% size:47.5% JAMES: AND IN SIX MORE MONTHS IT WILL REACH THE OTHER 04:07.046 --> 04:10.717 align:left position:77.5%,start line:83% size:12.5% EXTREME: NORTHERNMOST SUNSET ON THE SUMMER SOLSTICE ON JUNE 21ST. 04:10.817 --> 04:13.586 align:left position:42.5%,start line:83% size:47.5% DEAN: SOAK UP THE SOLSTICE SUN - BECAUSE THE LONGER 04:13.686 --> 04:16.656 align:left position:70%,start line:89% size:20% DAYS ARE RETURNING AND SUMMER IS COMING SLOWLY 04:16.756 --> 04:20.756 align:left position:42.5%,start line:83% size:47.5% BOTH: KEEP LOOKING UP!