1.1 Scale and Organization Flashcards
What are atoms expressed in?
Nanometers; one billionth of a meter
How big is a micrometer?
One-millionth of a meter
(size of cells, bacteria, and other small structures)
What is an AU
- Astronomical Unit
- One AU is the average distance between the earth and sun’s centres: 149.6 million kilometers
How much is a light year?
What is it typically used for?
- A unit of astronomical distance equal to the distance light travels in ONE YEAR in a vaccum
- The light year is used to express distances to stars and other celestial objects
What is a parsec?
- Unit of distance larger than light years
- Equivalent to 3.26156 light years
What is the Andromeda galaxy? How far away is it?
The Andromeda galaxy is the closest neighboring galaxy?
What is the Proxima Centauri?
- Closest star to our sun: 1.301 pc
What can we use for truly vast distances?
- Megaparsecs (MPS)
- equivalent to 1 million PC or 3.26 million ly
How old is the universe?
- 13.77 billion years
- Based on microwave background radiation and the movement of galaxies following the big bang
How old is the universe? - What is this estimate based on?
Microwave radiation and the movement of galaxies following the big bang
What is “deep time”?
- “Deep” as in the time the Earth has existed, over 4.54 billion years
How many units are there in the Geological Time Scale?
SEVERAL
Which are the largest subdivisions of the GTS?
- Eon
- Era
- Period
- Epoch
- Age
How much does the precambrian represent?
- 87% of geological time
- NOTE: an informal division, not a main subdivision
What is the Hadean Eon?
- A unit of time meant to represent the very earliest part of the Archean Eon
- NOTE: an informal division, not a main subdivision
What is the upper part of the precambrian?
- The Proterozoic Eon
- Starts at 2.5Ga
Which Eon is the most finely divided?
- The Phanerozoic
- 538.8Ma
- Because it’s younger than other Eons and more rock available for study
How was each period in the Phanerozoic defined?
- When it was recognized that life became sufficiently different to warrant the erection of a new subdivision
What do the differences between the eras in the Phanerozoic Eon represent?
- Sudden catastrophes in the biosphere called MASS EXTINCTION EVENTS
FIGURE 9
What is a system?
- A system is a set of interacting or interdependent components or elements that form a unified whole and exhibit properties and behaviours that emerge from the interactions among the components
Earth’s 4 major systems:
- The biosphere
- The hydrosphere
- The geosphere
- The atmosphere
