earth science3
Welcome to PSC 1210
Earth and Space Science for
K-8 Teachers
The mostly (but not entirely!) on-line version
Goals of PSC 1210
Understand important concepts in Earth and Space Science
Develop science process skills
Appreciate and apply the scientific method
Learn using techniques you will apply as a teacher (harder with on-line version)
On line version will differ from previous versions- less hands on, more individual research/problem solving
Goals of Today’s Lecture
Terminology, vocabulary, intro to writing techniques
Quick review of math concepts used in our class
Mapping- beginning the use of Google Earth (or google maps)
Some Science Terminology, 1
scientific fact – specific, verifiable information
*Sulfur is a yellow mineral.
*Granite is an igneous rock.
hypothesis – possible action and/or explanation for a behavior or an observation; must be tested through experimentation
*The continents can move around
Science starts with hypotheses and sets up tests for failure.
Some Science Terminology, 2
law - generalized statement of a relationship between variables in a system based on repeated experimentation; can be used to predict behavior of a system. Laws are always true.
*Less dense fluids float above more dense fluids.
theory - generalized explanation for observations based on repeated experimentation or observations
*Plate tectonics is the theory which explains that continents move because of convection currents in the mantle.
Laws describe things, but theories also explain them
How to recognize?
Hypothesis: If …… then……. or “I think that”
Fact: This is true
Law: This is always true. Formulas.
Theory: This is always true because.
or
This explains why this happens.
Scientific Method
Make an observation that raises a question State a question
Determine a possible reason for the observation Pose a hypothesis
Design and carry out an investigation to support or disprove the hypothesis Do an experiment
Or make an observation or do a simulation on a computer
Evaluate hypothesis- is your hypothesis strengthened or disproven?
What additional work needs to be done to test the hypothesis? Or…. Turn it into a law or theory?
Scientific Method
Understand variables:
Independent variable = one changed by the experimenter
Dependent variable = one that changes as a result of a change in the independent variable
Controlled variable = any property that is not being investigated and must remain the same during the experiment
Scientific Method
Make an observation that raises a question. Birds always eat at my red feeder and
ignore my blue one. Why?
Determine a possible reason for the observation. Pose a hypothesis.
Birds prefer red feeders.
Design and carry out an investigation to prove or disprove the hypothesis
Determine the variables:
Independent = color of the feeder
Dependent = # of birds at the feeder
Scientific Method
Determine the variables:
Controlled = type of feeder, type of food, time of day recorded, height of feeder, location of feeder…
Set up 3 blue and three red identical bird feeders. At a set time each day for 10 days, record how many birds are at each feeder. Record data in a suitable table.
Scientific Method
Compile information from the experiment.
Analyze the data. Make a bar graph of the number of birds at each color feeder for each day.
Decide if the hypothesis was correct. Make a conclusion
I was wrong. The number of birds were almost the same. Perhaps it was because I put different food in the red feeder than the blue feeder. I had not controlled for food type!
But this is still legitimate science testing a hypothesis
For weather observation
Hypothesis: If its 50 degrees when I wake up, then it will be 70 degrees in the
afternoon
How does the afternoon temperature depend upon the morning
temperature?
Collect data: Turns out that need to control for different conditions
Is it sunny or cloudy? Raining?
Is it windy? Which way is the wind blowing?
Classify for the different conditions:
Under what circumstances does the data support the hypothesis?
Theory: If its sunny, the afternoon temperature will be warmer than if
its cloudy because the sun’s rays can more readily warm the surface.
What is a Misconception?
Incorrect understanding of term or process: “Theoretical misunderstanding”
Not merely a misfact
Can be taught to you or you can come to it based on your personal experience
Highly resistant to change
Some Misconceptions in Earth/Space Science
The seasons are caused by the Earth’s distance from the Sun.
Continents do not move.
Most rivers flow “down” from north to south.
Some Misconceptions in Earth/Space Science
The soil we see today has always existed.
Dinosaurs and humans existed at the same time.
The phases of the Moon are caused by a shadow from the Earth.
General theme to misconceptions: earth/space does not change
In this class we’ll learn about how the earth changes and evolves
Different cycles
Rock cycles
Earth’s crust and interior cycles
Water (hydrology) cycle
Atmospheric and climate cycles
Outer Space also changes
other planets have cycles, not always the same as the earth!
solar systems and stars are formed, destroyed and reform
Math in PSC 1210
1. Fractions better known as ratios in science
Consider fraction 1/2. Compares the number 1 (numerator)
to the number 2 (denominator)
In science, the numerator and denominator often describe different
things!
Example: Driving- mph. Miles per hour
Speed or velocity: A ratio of distance divided by time
60 mph = 60 miles/1 hour = 120 miles/2 hours = 30 miles/0.5 hours
Verbally, the word “per” is key in describing a ratio
What kind of ratios will we use?
(notice the word “per” in all three examples)
Density. Amount of mass per volume.
typically the mass is in grams (or maybe kilograms)
and the volume is in cubic centimeters (a cube a centimeter
long on all sides. A centimeter is about the size of your
thumbnail.
Density tells you how packed together the molecules and
atoms are.
2. Velocity- as discussed on the other page
3. Gradients- rate of change. Like a mountain slope- is it steep or flat?
feet per mile
A steep slope is walking one mile and going up (or down) a
thousand feet: 1000 ft/mile (same as 2000 ft/2 miles etc.)
Flat is walking one mile and only going up (or down) 20 feet or
less
Another gradient- change in temperature
You drive 100 miles and its 30 degrees warmer (this can
happen and we’ll discuss how)
30 degrees/100 miles = 0.3 degrees/mile
Calculations with ratios- basic algebra
You are given two things, find the third
Example: you have 4 hours and you drive 65 miles
per hour. How far do you go?
velocity x time = distance
65 miles/hour x 4 hours = 260 miles
Complication with using ratios- need to pay attention to units
Consider: you drive 60 mph- how many miles do you drive in 60 seconds?
60 miles 1 hour
------ x ------- x 60 seconds Need conversion!
hour 3600 seconds
Units appear on top and bottom cancel out. We’re left with
60 x 60
-------- = 1 mile so….. 60 mph is 1 mile per 60 seconds or 1 mile per minute
3600
60 miles 1 hour
----- x ------- x 60 seconds
hour 3600 seconds
(only thing left is “miles”)
Another example of conversions using density
How much does a gallon of water weigh??
We know density of water is 1 gram/cc (cc means cubic centimeter)
Need conversion factor: how many cc’s in a gallon?
(from google: 3785 cc’s per gallon)
1 gram 3785 cc’s
----- x ----- = 3785 grams
cc gallon
Last conversion: 454 grams/pound
3785 grams x 1 pound
------ = 8.3 pounds
454 grams
The key to these conversions is to put the unit you want to eliminate on both top and bottom
Math in PSC 1210- PART 2
Be comfortable with big numbers! Exponents
The Earth is 4.5 billions of years old.
The solar system (sun + planets) is 6 billion miles across.
Billions, millions, thousands, hundreds………….. etc
1,000,000,000 = 109 = 1 billion, i.e. 1 followed by 9 zeros
1,000,000 = 106 = 1 million
1,000 = 103 = 1 thousand
1 million x 1 thousand (6 zeros + 3 zeros = 9 zeros) = 1 billion
1 thousand x 1 thousand (3 zeros + 3 zeros = 6 zeros) = 1 million
In between we have 10,000 or 100,000 (4 zeros, 5 zeros) etc.
What we’re interested in about these numbers
Not so much exact values (very hard to know), but how many zeros-
what is the exponent?
Age of earth: measured in billions years (OK, this we know is 4.5 billion)
Movement of continents: measured in tens and hundreds of millions (7 or 8 zeros)
Ice ages: measured in thousands of years (3 to 4 zeros)
Changes in stream flow, erosion etc: could be tens, hundreds or thousands
of years (1,2 or 3 zeros)
Damage from Earthquakes: less than 1 year (more likely a tiny fraction of a year)
Astronomy
Size of earth and smaller planets: thousands of miles across (3 zeros)
Size of Jupiter and bigger planets: tens of thousands of miles across (4 zeros)
Size of sun and stars: hundreds of thousands of miles or even millions of miles
across (5 or 6 zeros)
Goal for end of class
Be able to make some simple estimates of time, space and speed of
events in earth and space science.
Over a wide ranges of spatial and temporal scales
(from seconds to billions of years and from centimeters to billions of
miles (kilometers)
Google Maps vs. Google Earth
Similar but not the same
Google Maps (good for driving directions)
Street views, traffic, driving directions
2. Google Earth – like “Maps” but for earth as a planet
Go to https://www.google.com/earth/ and then launch it. (or perhaps download or get from app store depending upon device
..
Google Maps is for navigating around, Google Earth is for exploring our planet as a whole and is better for now, but
I think google maps can work. Google Earth works better on a computer/laptop than a ipad/phone.
Google Earth shows
land
sea
details of surface (and not only that!)
but not clouds
Satellite photo shows
land
sea
lots of clouds
but not details of surfaces
Using Google Earth vs. Satellite image
what are the differences?
Using Google Earth and Google Maps
4 skills to practice today
1. Learn to zoom in and out. The picture of the earth as a planet is very
zoomed “out”. You can zoom in all the way to see buildings.
2. Learn to see the place names in Google Earth
3. Learn to mark distances between two points in Google Earth. Try different
units.
4. Some simple analysis of geography
When we zoom out……….. What do we see?
(either +/- on computer, or with spreading fingers on
touch screen)
4 colors
Blue (Earth is a “blue marble”)- surface is mostly water
Green – biology (not really subject of this class, but we’ll mention
it on occasion)
brown- surface without biology, deserts
(we will discuss why they occur and why they are located
where they are)
white- ice
Interesting to compare to Mars and Moon (not sure
how to get this on my ipad, it’s a tab on top on the computer)
What colors do they show? How do they
agree or disagree with Earth’s colors
Google Moon and Google Mars for comparison
Which object is more similar to earth? And why?
Zoom in- look for places
On laptop:
Expand the layers tab on left. Check borders and labels,
places, roads
Countries- yellow labels on computer, white on Ipad
States- white
Places/natural features- green
(compare Blue Ridge Mountains with Appalachian Mountains-
Whats the difference? Unfortunately, not shown in Ipad)
On ipad:
go to triple line tab on left, and touch “map style” (the symbol
is called the “layers” symbol),
play with checking “clean” or “exploration” or everything
In general, the Ipad is more finicky when names show up- I have to
play with zooming in or out
Look at countries, cities, continents
How many continents and oceans?
What is the meaning of a continent or ocean. Not a good answer!
Continent:
large, continuous, discrete mass of land,
ideally separated by an expanse of water.
https://www.universetoday.com/72611/what-is-a-continent/
But when is it a continent and when is it an island? Somewhat arbitrary.
Comparing Greenland (island) vs. Australia (continent).
A combination of reasons, some of which we’ll discuss.
- Greenland animals and plants are similar to N. America; Australia is
more unique
- Australia is its own tectonic plate (whats that? Stay tuned!)
- Culturally, very different than the rest of Asia
None of these are great reasons, but they add up
Europe is considered a separate continent from Asia. Does that make sense?
Look at Google Earth and you decide!
Oceans- how many oceans do we have?
4 (Atlantic, Pacific, Indian, Arctic)
Or………………….
Just 1!
Look at google earth
Finally, where are there mountains? What do you see where its blue?
Google Earth shows the terrain under the water – hugely important for
earth science.