Imaging
Partnership
STEM PRACTITIONER RESOURCES
The science of the sun
LESSON ONE
What you will learn:
• A introduction to how optics feature in science and the environment
• What is the sun, how old it is and what it does?
• What a “Goldilocks Planet” is and why Earth is a perfect environment
for life?
• The main energy sources we use on Earth
• What kind of scientists study the sun?
• What is meant by “optics”?
• How light and shade is used in photography
What you should be able to do:
• Demonstrate and understanding of how optics feature in science
and the environment
• Demonstrate and understanding of is the sun, how old it is and of
why the suns energy is important to life on Earth
• Demonstrate and understanding of what a goldilocks planet is and
why Earth is a perfect environment for life
• Demonstrate an understanding of the main energy sources we use
on Earth
• Demonstrate an understanding of the use light and shade in
photography
• Take photographs using correct techniques as required
The Sun
• The sun is a huge burning ball of plasma
at the centre of our Solar System
• Everything in our Solar System orbits the
sun.
• Our solar system is made up of 8 planets,
many dwarf planets and smaller objects
such as minor planets, asteroids and
satellites.
• The sun is so big it could contain over
1 million Earths inside it
• From pole to pole it has a diameter of
864,938 compared to the Earths 7,900
miles.
• You could line up 109 Earths across
the face of the sun
• The face of the sun is known as the
“photosphere” and it is the heat from
here that reaches the Earth as
sunlight
The history of the sun
• Scientists have worked out the age of the
sun as 4.5 billion years old
• This can be determined by studying
meteorites which contain the element
Rubidium
• By studying the decay of Rubidium the
age of the meteorite can be determined.
• As scientists know that the Earth, planets,
comets and moons formed at the same
time as the sun that is how they
determined how old it is
The history of the sun
• Although it looks empty, space is filled with
gas and dust
• Our solar system originates from a diffuse
(spread out) cloud of hydrogen called a
“solar nebular” and also helium and
remnants from the death of stars
• As waves of energy travelled through space
these were all pressed closer together to
form clouds of particles and gas
• Gravity then caused these clouds to
collapse and to spin
• Spinning caused the cloud to flatten into a disk
and in the centre a mass of hydrogen and
helium clumped together which would become
the sun
• Leftover material became the planets
• Over the course of 50 million years the
temperature and pressure of the centre material
increased causing a fusion of hydrogen which
fuels the sun today
• The sun has enough nuclear fuel to stay as it is for
another 5 billion years after which it will cool
down and become a red giant.
The Solar System
• The planets in our
solar system are at
varying distances
from the sun.
• Mercury is the
closest and is
between 28.5 and
43.5 million miles
depending on
where it is in its
orbit.
• Neptune is furthest
away at 2.8 billion
miles!
Earths as a “Goldilocks Planet”
• Taking into account that planets too
close to the sun are too hot and planets
too far from the sun are too cold the
location of Earth is very important.
• Earth is the only planet in our solar system
to support life.
• Earth is known as a “Goldilocks Planet” as
the temperature is “just right”!
• Scientists look for Goldilocks planets in
other solar systems as they are the ones
that would likely support life
The suns energy
• The photosphere has a temperature of
about 5500 ºc and the core more than
15 million ºc
• The sunlight travels at the speed of light
and takes just 8.4 minutes to reach
Earth
Energy
• Earth receives just a tiny percentage (less than a billionth
of a percentage) of the suns energy
• 34% is reflected back into space by clouds and snow
• 42% warms the land and water
• 23% supports the water cycle (evaporation and
precipitation)
• 1% controls the wind and water currents
• 0.23% controls photosynthesis
How Earth uses the suns energy
• The suns energy warms the planet,
powers the weather and the water cycle
which make it possible for plants to grow
• The solar energy that powers the plants
then turns into fuel that allows animals to
live
• These animals then do their part to keep
the planet alive as well, eg. as food for
other animals, as pollinators for plants and
as predators that maintain a balance in
the eco system
Energy usage
• We can capture the energy and use it in a
number of ways such as:
• Solar heating
• Solar photovoltaic (solar panels)
• Solar thermal electricity
• Solar architecture
• We will come back to these over the next
10 weeks
Alternatives to current fuel
• Both fossil fuels and nuclear power require money and
resources to run and have a long list of environmental
problems linked to them
• The energy from the sun is vast and inexhaustible
• Once there is a system in place to convert it into energy
the fuel will be free
• It is also a clean alternative to fossil fuels which contribute
to global warming
People who study the sun
• As you are well aware there are different
scientists for different areas of science and
the same can be said about astronomy,
which is the study of space
• There are also astronomers who study the
sun
People who study the sun
• There are lots of different things to study about
the sun such as:
• How the sun controls our climate
• The study of solar wind, space weather and solar
flares
• How the study of our sun (a star) can reveal a
lot of information about other stars in the
universe
• The suns age and lifespan
• How the sun produces energy by nuclear fusion
How photographers use light and shade
• So that’s a simple version of the history of the sun and how
its energy is created and how it can be used as an energy
source
• But how does that affect you?
• If we go back to the beginning of this lesson we were
looking at how “optics” are used in science and the
environment
• Optics is a branch of physics which involves the behavior
and properties of light, its interactions with matter and the
construction of instruments that use or detect it
• It is these instruments that we are concerned with
How do photographers use light and shade
to take photographs?
• Photography is the art or practice of taking and
processing photographs using a camera
• Cameras contain a light sensitive surface in the form of
photographic film, or more commonly in digital
cameras, a sensor
• Light and shade are really important in photography
and cause the camera to create different results
• A photograph of a brightly lit scene creates highlights
in an image
• Photographing the dark creates shadows
• Both are important to create contrast in an image and
to keep your image from looking flat as contrast adds
dimension to your image
Group activity
• Take a photo of a scene that is brightly lit and contains
little or no shadows
• Take a photograph of a dark scene. Do you notice the
camera performing differently, blurring perhaps?
• Now take a photograph of something that has both
highlights and shadows.
• Do the first 2 images appear flat?
• Does the 3rd image contain more definition?
So what have we learned?
• A introduction to how optics feature in science and the environment
• What is the sun, how old it is and what it does?
• What a “Goldilocks Planet” is and why Earth is a perfect environment
for life?
• The main energy sources we use on Earth
• What kind of scientists study the sun?
• What is meant by “optics”?
• How light and shade is used in photography