Unit 5 topic 1

Question 1

what is a frame of reference

Answer 1

is a set of axes of any kind that is used to describe the positions or motions of things

Question 2

what are the aces for the frame of references?

Answer 2

equator and the prime meridian

Question 3

what are the terms we use to locate the earth

Answer 3

latitude and longitude

Question 4

what are the celestial bodies

Answer 4

the sun, the moon, stars and planets

Question 5

what are the few things that the Egyptians learned about stars?

Answer 5

• the stars make unchanging patterns in the sky, the groupings are called constellations - each day a new set of starts are in the night sky from this observations people developed the ability to predict changing seasons helped create calendars - the sun rises and sets at a rate different from the stars as well as the moon - moon shows phases

Question 6

People wanted to measure the celestial bodies how did they do this?

Answer 6

they would give a celestial body two co-ordinates measured in degrees 1. the first angle is measured clockwise from north that is called azimuth 2. next they would measure the celestial body angle above the horizon in degrees. This is called altitude

Question 7

what are the the altitude- azimuth coordinates?

Answer 7

angles used to specify the coordinated of a celestial body

Question 8

is it true that the altitude azimuth coordinates for each celestial body change depending on the time of the reading

Answer 8

true

Question 9

what is a astrolabe

Answer 9

is a device used to measure the altitude of an object

Question 10

what is a compass

Answer 10

is used to measure an object’s azimuth

Question 11

how did the astrolabe work?

Answer 11

this was a device held vertically from a ring with a pointer on it. the pointer was used to sight a star and measure the angle to it. The ancient Romans used angles to survey practical things such as their aqueducts. With these tools, navigation was improved and the great sea explorations of the world began

Question 12

with the earth as the frame of reference what happens to the celestial bodies in the sky?

Answer 12

the move in the sky at the same rate

Question 13

How do you track the actual motion of each celestial body? and why?

Answer 13

you need to use the stars as the frame of reference instead of the earth. this is because we are looking for motions in the sky that are different from the big motion caused by earth rotation

Question 14

how do you use stars as a frame of reference?

Answer 14

you would have to look at the planet and see what stars you can find relatively close near it.

• you would mark down the position of the stars, if you made similar observations over several weeks you could see in which direction the planet is moving.

Question 15

what does earth-centered or geocentric mean

Answer 15

having the earth as the center of the Astro system

Question 16

who is Aristotle?

Answer 16

he created the earth-centered model and inner spheres. inside this sphere, he arranged more concentric spheres on which were attached teh sun, moon, and the five known planets.