While Mona Lisas and Mad Hatters, Sons of Doctors, Sons of Lawyers Turn around and say Good Morning to the Night For Unless they See the Sky, But they can’t and that is why They know not if it’s dark outside or light They know not if it’s dark outside or light. Bernie Taupin wri,ng and Elton John singing about New York City. 

ANNOUNCEMENTS •  LAB CLASSES BEGIN FOR ALL SECTIONS NEXT WEEK

•  TEXTBOOK: EXCELLENT ON BASIC INFORMATION. READING ASSIGNMENTS ARE MANDATORY

•  OFFICE HOURS WILL BE POSTED NEXT WEEK. IF PROBLEMS NEXT WEEK, TALK TO LAB TA OR SEND ME EMAIL: STOCKE@CASA.COLORADO.EDU

•  BACK IN DUANE NEXT TUESDAY

•  QUESTIONS ?

Much too early for a question..question

What constella,ons would be visible in the sky aEer Sunset this day ? 

What constella,ons would be visible in the sky before Sunrise this day ? 

DAILY MOTION OF THE SKY. GREEN LINE IS THE CELESTIAL EQUATOR WHEREON STARS RISE DUE EAST AND SET DUE WEST

THE RISING AND SETTING POINTS OF ALL STARS IS SYMMETRICAL AROUND THE MERIDIAN (NOT 180O OPPOSITE). THIS IS ALSO TRUE FOR THE SUN, MOON AND PLANETS ON ANY GIVEN SINGLE DAY THESE RISING AND SETTING AZIMUTHS ARE FIXED AT ANY SPECIFIC LATITUDE

FOR ANCIENT HUMANS THE MOTIONS VISIBLE IN THE SKY DEFINED THE VERY NATURE OF TIME AND INCREMENTS OF TIME

 DURING THE DAY: THE MOTION OF THE SUN AND ITS SHADOW DEFINED THE “HOURS OF THE DAY”. NOON IS THE TIME THAT THE SUN CROSSES THE MERIDIAN

  THE DAY IS THE TIME BETWEEN SUCCESSIVE NOONS

  AT NIGHT THERE WERE THE DECANS. STAR GROUPS THAT DEFINE THE NIGHTTIME HOURS BY THEIR SUCCESSIVE RISINGS, ONE AFTER ANOTHER.

 . THE TRADITION OF THE 24 HOUR DAY PROBABLY CAME FROM ANCIENT EGYPT BUT NO ONE KNOWS FOR SURE.

One decan “constellation” is marked in a green box and “marches” across the 70 day calendar diagonally as it rises earlier and earlier each 10 days. NOTE: Big Dipper (Bull’s Thigh” constellation at top !

OF THE 30 REMAINING EGYPTIAN OBELISKS: 7 ARE IN EGYPT AND ELEVEN ARE IN ROME !!!

UNTIL THE INVENTION OF MECHANICAL, PENDULUM AND GEARED CLOCKS IN EUROPE AT THE END OF THE MIDDLE AGES, THE MOST ACCURATE CLOCKS IN THE WORLD WERE WATER CLOCKS FIRST IN EGYPT, THEN GREECE THEN CHINA

HORIZON TO ZENITH = 90 O (CALLED ALTITUDE) FULL CIRCUMFERENCE OF HORIZON = 360O

(CALLED AZIMUTH) BASE 60 COMES FROM BABYLONIANS

The major difference between the Ancient and the Modern Sky is that the Modern sky has an…extra added dimension: Depth. Until the Greeks ancient peoples made no attempt to determien how far away anything was in the sky. In fact, since the Heavens were “another realm”, there was no ancient belief that the heavens could be measured like distances on the Earth. And due to the finite speed of light, the further away something is in the sky, the further back into time that we are viewing it at. Distances in Space = “Look Back Time” (in light-years) (in years)

DISTANCES IN SPACE: FIRST STEPS TAKEN BY GREEKS, BUT VASTNESS WAS NOT APPRECIATED….EVEN NEW IDEAS OF MEASUREMENT REQUIRED: THE LIGHT-YEAR: THE DISTANCE LIGHT TRAVELS IN ONE YEAR @ 186,000 MILES PER SECOND. MOON IS 1.5 LIGHT-SECONDS AWAY SUN IS 8.5 LIGHT-MINUTES AWAY SATURN: 30 LIGHT-MINUTES AWAY PLUTO: 2 LIGHT-HOURS ALPHA CENTAURUS (NEAREST STAR BEYOND OUR SOLAR SYSTEM): 4.3 LIGHT-YEARS

FINITE OR INFINITE UNIVERSE STILL DEBATED TODAY.

TELESCOPES ARE “TIME MACHINES”

the further we look out into space the further we look back into time.

LIGHT-YEARS ARE A MEASUREMENT OF DISTANCE….THE DISTANCE LIGHT TRAVELS IN ONE YEAR ≈ 6 TRILLION = 6 X 1012 MILES THIS ALSO MEANS THAT LIGHT CREATED BY AN OBJECT ONE LIGHT-YEAR AWAY IS ALSO ONE YEAR OLD WHEN WE SEE IT. MOONLIGHT IS 1.5 SECONDS OLD SUNLIGHT IS 8.5 MINUTES OLD SATURN’S LIGHT THROUGH A TELESCOPE IS 30 MINUTES OLD SIGNAL FROM THE NEW HORIZONS PROBE WHEN IT ARRIVES AT PLUTO IS 2 HOURS OLD LIGHT FROM NEAREST STAR (ALPHA CENTAURI) IS 4.3 YEARS OLD LIGHT FROM SIRIUS IS 9 YEARS OLD LIGHT FROM THE PLEIADES IS 400 YEARS OLD LIGHT FROM THE GALACTIC CENTER OF THE MILKY WAY IS 24,000 YEARS OLD LIGHT FROM THE ANDROMEDA GALAXY IS 2 MILLION YEARS OLD LKIGHT FROM THE MOST DISTANT GALAXY KNOWN TODAY IS 13 BILLION YEARS OLD LIGHT FROM THE BEGINNING OF OUR UNIVERSE IS 13.5 BILLION YEARS OLD = THE “AGE” OF OUR UNIVERSE.

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Farthest galaxies: light was emitted nearly 13 billion years ago …. But we are staying within the solar system. Take ASTR 1020 next semester for the truly cosmic stuff!