Hello and welcome to our first lecture
introduction of Earth Science. In this
lecture I will summarize most of what is
covered in more detail in chapter 1 of
your textbook.
Your main learning objectives are:
to get a sense of what our science is.
Specifically list and describe each of
the four branches of our science to get
a sense of the scientific method
able to demonstrate each of the steps
involved in the scientific method. And
there are other parts of this lecture
that you need to know as well, but the
two SLO s listed are the big picture
ideas.
Earth science.  Earth science includes the
study of four natural components that
make up and surround planet Earth geology, meteorology, oceanography, and astronomy.
Geology is the study of the solid earth
and the materials and processes that
make and shaped its surface meteorology
is the study of the gas component of
Earth, our atmosphere and the and the
composition and processes that operate
within the atmosphere. Oceanography is
the study of the composition and
processes of the oceans as well as the
topography of the seafloor
and the interaction of the ocean with
the shorelines. Astronomy is the study of
the universe. In this course we're going
to narrow that study down to just our
solar system.
Here we have a geologic process in
action - lava flowing into the ocean and
solidifying into rock.
An earthquake is another example of a
geologic process this photograph shows
the aftermath of a strong earthquake
that recently happened in Central
America.
 
Here we have a landslide.  Landslides and
earthquakes both can happen suddenly and
without warning and can be considered
natural disasters, when they negatively
impact people. It's for this reason that
earth scientists study these natural
phenomena. We want to better understand them so we can make predictions and save lives.
Earth is made of rock, so earth scientists study the rock of
Earth's crust like the cliffs we see
here at the Grand Canyon. Oceanography
of oceans. One area that is of particular
interest for our scientists are where
the ocean and the land interact, along
the coasts. Here we have waves crashing
on the shore. The landscape being changed by the process of the ocean interacting
with the land is one that could
potentially affect people, so again it is
of interest to earth scientists. Smog
negatively affects humans so this
atmospheric condition is studied by
atmospheric scientists like
meteorologists. Tornadoes are studied by
meteorologists as well they occur in the
atmosphere and this atmospheric based
natural disaster is one that of course
can negatively affect humans. By studying tornadoes hurricanes and other such atmospheric processes,
we can make
better predictions about when and where
it will happen and in doing so save
lives. By studying objects outside of our
planet we can better understand Earth,
because the material that makes up our
solar system, galaxy and universe are
ultimately made of the same things that
earth, that earth is, such as atoms and
elements. So in this illustration here we
have the
Milky Way galaxy in which our solar system is
contained. Earth is contained within our
solar system. Earth's continents are
comprised of landforms such as mountains
which are made of rock. Rock is made of
minerals, minerals are made of the atoms
of the elements that we find not only
here on earth but in the universe beyond.
Our solar system formed
about 4.6 billion years ago. This is a
huge amount of time and as human beings
that live only a hundred years, if we are
lucky, billions of years is very
challenging for us to conceptualize. To
help put 4.6 billion years into
perspective let's compress this history
of Earth and our solar system into a
calendar year, with January first just
after midnight being the origin of Earth
and December 31st,m at midnight being this
moment. Looking at the calendar here,
here's our our origin of Earth and go to
early mid-february we have the oldest
known rocks that exist on our surface
those are about four billion years old.
The earliest evidence of any life
doesn't show up until near the end of
March. This would be simple single-cell
microscopic organisms. We continue
through our calendar April, May, June, July,
August, September, October and we don't
get until mid-november until we have
animals with hard part's becoming
abundant.  So this is important because
this is when organisms begin to resemble
something like they look today.  In
particular these organisms had shells... in
the sea. It's not until the very end of
November that plants and animals
actually exist on land. So if you can
consider that all of November, October,
September August, all the way back to the
beginning of the year so for 11 months
of our history, out of 12, there was nothing
on land, just rock. Completely barren. No
greenery no animals until the end of
November and we get into December, we
break this down into some more detail.
We see the days of December, from December 15th through the 26th dinosaurs dominate
to land. So the dinosaurs were a very
successful species, existing for close to
200 million years.
Move down to December 31st, the last
thing on the calendar year. We have some
different times outlined here. Let's look
at this, December 31st,
11:49 p.m. humans, homo sapiens appear. So
we're not around until the very last 11
minutes of the entire year. Our ice age
our most recent Ice Age, glaciers recede
from the Great Lakes at 11:58 and 45
seconds, so 15 seconds before midnight.
December 31st 11:59 and 45 seconds to
11:59 and 50 seconds Rome rules the
Western world. So the Roman Empire the
longest existing Empire is around for
five seconds on this timescale. Columbus
arrives
the new world at three seconds to
midnight.
And as I mentioned before, this very
moment is right at midnight so on this
calendar our life, 100 years if we're
lucky, is less than a second.
So earth science,
the science is contained within this
subject, geology, meteorology, astronomy
and oceanography are studied by
scientists and the study in science is
done through a orderly but natural
process that we call a scientific
inquiry this is also known as the
scientific method
this refers to the stats that people use
to construct predictive predictable and
repeatable explanations about the
workings of the world around us. This
process can start with an observation
and/or question about a particular
phenomenon, perhaps there's something out
of the ordinary that we observe, maybe in
our everyday lives or maybe in a more
scientific setting.  This is naturally
followed by the desire to explain what
is happening, this reasonable explanation
is called a hypothesis. Hypothesis is
sometimes called an educated guess.
In order to determine if the hypothesis
is correct or valid it must be tested
and this is done through collecting data
The data is then analyzed to determine
if it supports the hypothesis. If so then
it would advance to the greater
scientific community for further
scrutiny. This may take years, even
decades of time in order for enough
testing, enough people to analyze the
testing, enough people to discuss the
testing, before the hypothesis is fully
accepted by the global scientific
community. If it gets to that point and
all the testing supports the hypothesis
then we can go to step five, which is a
theory. A theory is a very certain
explanation for the phenomenon something
that's been tested retested and is not
debated by it by anyone. We leave the
possibility
that in the future, with different
testing methods, with different
technology, with different discoveries, we
may modify the theory,
but the word theory in science refers to
something that is very, very certain and
is agreed upon by all scientists. If
instead the results of our testing and
analysis did not support the hypothesis
then that hypothesis needs to be
reevaluated or perhaps scrapped
altogether.
so here we have a series of photographs
representing some examples of how
scientists collect data using technology,
hands-on using magic manual tools, this
person's in a lab, studying using the
microscope.
Scientific method practice: so in order
to test your own understanding of the
scientific method, I'd like you to
imagine this scenario and work your way
through it,
using the steps of the scientific method
that we have just discussed. After
entering a dark room you turn on the
light switch, the light does not come on.
Consider how these five steps in the
scientific method would apply into this
situation.
Write down your answer and submit these
answers to the discussion assignment,
"scientific method" which you can find on
canvas; so there are the steps outline
once again. I look forward to reading
your discussion comments and see how you
went about handling this scenario.
That's the end of this lecture
