Sundials & Starfinders

Slides:



Advertisements
Similar presentations
Design an Analemmatic Sundial For Your Latitude
Advertisements

Locating Positions on Earth
Chapter S1 Celestial Timekeeping and Navigation
Latitude The equator is the reference line..
REVIEW: Time and Diurnal Motion Review Questions Jan 12, 2011.
Engage: Use the Big Dipper to find the North Star, Arcturus, Cassiopeia. Find Summer Triangle, Milky Way. Explore: Students make a sample observation of.
Solving problems with the astrolabe. The astrolabe can be used to solve many types of astronomical problem The times of sunrise and sunset The time of.
The Memphis Astronomical Society Presents A SHORT COURSE in ASTRONOMY
Key Ideas Describe two lines of evidence for Earth’s rotation.
Unit III: The Earth in Space
H OW TO TELL T IME Rebecca Smith MSTI 131 Lesson Plan.
A100 Oct. 13 Keeping Time READ Essay 2 – Keeping Time in the text, pp
The Day. Shadow Clock When positioned correctly, the value on a sundial in DeKalb tells A. universal time. B. local sidereal time. C. local mean solar.
any object in space outside of Earth's atmosphere
Roger A. Freedman • William J. Kaufmann III
11/15/99Norm Herr (sample file) Making a Star Clock (Astrolabe)
1 General Astronomy Physics 103 Dr. Tyler E. Nordgren Dr. Julie A. Rathbun.
Locating Positions on Earth
Time. Learning Outcomes To distinguish between a solar day and a sidereal day. To explain and interpret data provided by shadow sticks. To describe how.
Star Finders: The Big Dipper Science 6 Mrs. DeForge.
The Strange Time of the Sundial “O Lord God! You have made the heavens and earth by your great power; nothing is too hard for you!” Jeremiah 32:17.
MAKE AN EQUATORIAL SUNDIAL For Your Latitude and Longitude North American Sundial Society Created by: R.L. Kellogg May,
Motion in the Sky. Discussion How do we estimate how far away things are from us in everyday life?
Chapter 1 Cycles of the Sky
Motions of the Earth Stuff everyone should know Chapters 2, 3.
Lesson 3: How Do Earth and Its Moon Move? By: Mr. Leslie’s Class.
Orienteering ALERT Cadet Alpha 3 rd California Jason Kim September 2006.
Seasonal Motion. Reminder: iSkylab 1 due in two weeks, Sep 23 Observe! Ask questions! Already demonstrated Option 1 measurement (shadow of a stick  altitude.
SEASONS TEST.
Design a Gnomonic Sundial For Your Latitude North American Sundial Society Created by: R.L. Kellogg Sept
Space, Earth and Celestial Objects © Lisa Michalek.
Chapter 6: Earth’s Motions in Space Ms. Johnson Foundations.
1. During different seasons, different constellations appear in the night sky because we see the stars from a different position in Earth’s orbit. 2.
O North Pole The time is mid-day. The observer O at the equator looks straight up and sees the sun overhead. Sun Serpens Pisces Orion Leo.
Earth’s Rotation K. Williams, PRES. We live on Earth.
Seasonal Motion & Ecliptic. “Motion” Debriefing Stars circle NCP counterclockwise –For circumpolar stars: E  W if above Polaris, but W  E if below Polaris.
1 “First day, I’d tell the class all I knew,” he told The Saturday Evening Post, “and there was nothin’ left to say for the rest o’ the semester.” - Andy.
A collection of working models to cut-out and glue together Gerald Jenkins Magdalen Bear.
Stars - Circumpolar.  These constellations can be seen all year long, for they never set below the horizon.  Examples include Ursa Major, Ursa Minor,
Unit 1 (Unit 4 in textbook)
1 Lecture 29 Measuring Time on Earth Ozgur Unal. 2  What time is it in your hometown at the moment?  What time is it in NYC?
Today! From Earth’s Perspective: Celestial Motion: Stellar Motion Solar Motion Planetary Motion.
Sun Dials What time is it ? Sun was only way to tell time until ~1000AD in the West (Chinese had water clocks) Garden Sun Dials - old fashion - frumpy.
Design an Analemmatic Sundial For Your Latitude North American Sundial Society Created by: R.L. Kellogg Sept
The Solar System. The Earth Moves The Earth rotates. The side of the Earth that is facing the sun has day. The Earth revolves around the sun. One revolution.
Studying Space Section 2 Section 2: Movements of the Earth.
2/25/2016The Seasons1 The Reasons for Seasons. 2/25/2016The Seasons2 Day Night Cycle.
Knowing the Heavens Chapter Two. Naked-eye astronomy had an important place in ancient civilizations Positional astronomy –the study of the positions.
Motion in the Sky. Discussion What is a year? Discussion What is a day?
Chapter S1 Celestial Timekeeping and Navigation
EARTH'S ROTATION AND REVOLUTION
Did you get the Key Ideas from the Seasonal Stars Lecture Tutorial?
Sun’s annual motion and the Seasons
Locating Positions on Earth
Sundials & Starfinders
Traveling Through Earth
Chapter 17 Earth’s Cycles.
Sundials.
Precession and The Celestial Poles
Today! From Earth’s Perspective: Celestial Motion: Stellar Motion
Chapter 1 Cycles of the Sky
Chapter 1 Cycles of the Sky
REVIEW: Time and Diurnal Motion
Planisphere Practice Planisphere Practice Planisphere Practice.
The Reasons for Seasons
ASTRO UNIT 1 REVIEW.
REVIEW: Time and Diurnal Motion
The Reasons for Seasons
Charlie Haffey Norwood Public Schools
Presentation transcript:

Sundials & Starfinders

Sundials Sundials come in variety of forms but all sundials measure “Solar Time”

Sundials Each hour on a sundial is 15° wide. But……. Basic Parts: Hours markers Gnomon – A device that cast a shadow on the hour markers. Basic Premise: If we divide the day into 24 hours and the Earth rotates about 360° each day then, Each hour on a sundial is 15° wide. But…….

Sundials The Gnomon must be aligned with the Earth’s rotation axis for the sundial to work properly.

Sundials There is an alternate version of a sundial called an “Analematic Sundial” This style of sundial uses a vertical gnomon. However, the gnomon must be movable and calendar positions must be determined for each day’s gnomon location.

Sundials Analemmatic Sundial

There’s still a problem Sundials There’s still a problem

Sundials The Solar Day is not always 24 hours long due to our changing orbital speed. The Solar Day can be 15 minutes longer or shorter than the clock day depending on the time of year.

Sundials

Sundials The Result: If we want the sundial to read the same time as the clock, we need to add or subtract a correction factor This factor may also include Daylight Savings Time.

Sundials To read the sundial: Orient sundial so that the gnomon points north. 2. Read the hour markers to determine solar time. 3. Add or subtract appropriate correction factor.

Sundials Try some examples On October 13th, what time is it if the sundial reads 2:30 pm? On January 25th, what time is it if the sundial reads 10:00 am? When is there no correction to the sundial? When is Daylight Saving Time the only correction?

Sundials Another use for the Sundial is finding directions. To find your directions: Use a clock to find the time. Perform a reverse correction to determine the correct sundial reading at that time. Turn sundial until it reads the corrected time. You are now facing north.

Starfinders In ancient times, starfinders were called astrolabes. They were typically made of brass or wood. Astrolabs rarely had constellation names, stars only.

Starfinders Identifying stars or constellations: 1. Line up the time of night with the current date. 2. Hold the direction your are facing at the bottom. 3. The constellations (or stars) will be directly in front of you .

Starfinders Rising or setting times: Place the star or constellation on the eastern or western horizon of the starfinder. Read the time for that date.

Starfinders Finding the time: Rotate starfinder until it matches the sky. Pay special attention to the Dippers and Cassiopeia (looks like a “W”). Read the time next to your current date.

Starfinders Which constellation is just above the eastern horizon at 10:00 pm on the 14th of October? Which constellation is just above the southern horizon at midnight on January 15th?

Starfinders

Starfinders What time does time does Sirrius rise tonight? What time does the backward questions mark of Leo rise tonight? What time does Aquila set tonight?