The scale of things and the view from the earth

Question 1

Who measured the circumference of the earth in 200BC

Answer 1

Eratosthenes

Question 2

–1—- proposed a method to measure the distance to the Sun and the Moon in 280BC. Using how long it takes for the Moon to cross —2— shadow during —3–, he also tried to measure their sizes. He measured the —4— between the sun and the —5— or –6— quarter moon. Using these —7— and geometry, he calculated the —8– of the Earth-Sun distance and the —— - Moon distance.

Answer 2

1) Aristarchus
2)Earth’s
3)eclipses

Question 3

From slide 9 picture, what is cos(theta) ?

Answer 3

Dm/Ds
Dm = distance to moon from earth
Ds = distance to sun from earth

Question 4

The earth is –1– times bigger than the Moon

Answer 4

• 4 times

Question 5

the sun is 400 times bigger than the —–

Answer 5

Moon

Question 6

astronomical unit is

Answer 6

the average distance between Earth and Sun 1AU = 1.5*10^8

Question 7

one Light-year is —–( 1 a sentence)—– and is approx. —-2—

Answer 7

1) Distance travelled by light in one year
2) 9.46MM km (mega *mega)

Question 8

Parsec is a distance at which 1AU perpendicular to the —–1—- line of sight —–2—– an angle of 1 —-3—-

Answer 8

1)observers
2)subtends
3)arcsec

Question 9

a theory is

Answer 9

a set of tested ideas written using math to try explaining how things behave

Question 10

A hypothesis is

Answer 10

an idea or set of ideas

Question 11

A model is

Answer 11

an idea written in math language and that can be tested via experiments

Question 12

theory

Answer 12

Models that can explain
and predict behaviours

Question 13

Laws - theories that —1—- be proved –2—

Answer 13

1)cannot
2)proved

Question 14

if earth was flat, —– and —- will happen at the same for —— on Earth

Answer 14

1) daytime
2) nighttime
3)everyone

Question 15

earth curves —- m every —- km

Answer 15

5m
8km

Question 16

kilometers for :
astronomical unit :
light years:
parsecs:

Answer 16

1) nearby objects / planets
2)distances within solar system
3) distance between stars
4)distances between galaxies

Question 17

Constellations:

-How many altogether?
-What are they?
-How many stars can the human in the best conditions

Answer 17

• 88 constellations
  -groups of stars forming -images
  -6000

Question 18

angles can be used to measure the _____ size of an object. That is how ______ the object appears in the sky.

Answer 18

angular, wide

Question 19

angular distance: the distance in ____________ that seperates two objects in the sky

Answer 19

degrees

Question 20

diurnal motion is a consequence of …

Answer 20

Earth’s rotation around itself

Question 21

what is diurnal motion ….

Answer 21

how every day we see the sun, moon planets and stars rising in the east and setting in the west.

Question 22

How do we know that it’s earth rotating and the planets stars etc?

Answer 22

Foucaults pendulum

Question 23

yearly motion is a consequence of

Answer 23

consequence of Earth’s rotation around the sun

Question 24

celestial sphere is

Answer 24

an imaginary surface surrounding Earth that contains all objects in the sky

Question 25

Key points of the celestial sphere

Answer 25

Clestial equator
Zenith
North/South celestial poles
Horizon
Circumpolar stars

Question 26

MOTIONS OF THE CELESTIAL SPHERE
> The ____ axis of earth is slowly moving with time. This is called ————-

Answer 26

> rotation axis
Precession

Question 27

CELESTIAL CO-ORDINATES
Declination: measured in degrees, arcmin and arcsec. ——- distance —– or —– from the equator

Answer 27

1) angular distance
2)north
3)south

Question 28

Right ascension: ______ distance from the ___ _____ eastword along the celestial equator up to the circle used to measure its ________

Answer 28

1) angular distance
2) vernal equinox
3) declination