Chapter 1 Flashcards
(7 cards)
1
Q
Astronomical Unit
A
- 150 million km or 93 miles
- average distance from the earth to the sun
- useful for measurements
2
Q
light year (ly)
A
10 trillion km or 6 trillion miles
-used for distances to stars and galaxies
3
Q
sizes of objects
A
- Earth: 10^4 km
- solar system 10^10
4
Q
Information is not instantaneous
A
- a letter is always to a future person
- sounds is always from the past (thunder & lighting)
- light is always from the past
- light travels at finite speed
5
Q
speed of light
A
186,000 mph 0r 3x10^8
-it takes light 1 year to travel 1 ly
6
Q
Distance of the moon from earth
A
moon is 1.3 light seconds away
7
Q
Time: When and where are we?
A
Big Bang
- Radiation only
- -matter forms (H/HE)
- –Stars & Galaxies form
- —First Stars Start to die
- —-New stars form from dead stars
- —–planets form with sun
- ——earth fully formed
- ——-life arises
