words are in blue
It is a hot summer day. Child 1 and Child 2 are in a hurry to reach
the meeting place to exchange postage stamps. Everyone has a stamps
holder full of lovely, interesting stamps. They meet together in the
park and are now shaking hands like real businessmen ready to start
their important work.
Not far away, a bench is heated by the pitiless sun’s rays.
In an instant both of them decide to sit on the bench and start the
exchange of stamps. But… both of them are jumping-up immediately
because the bench is burning their skin. They seem scared looking
the bench, unable to understand what is happening.
In the same moment, Father stops nearby and cannot resist smiling
- looking at the children’s faces.
For sure you’ve encountered one of the
effects of solar radiation, haven’t you? Maybe it would be
better to find a place in the shade.
Child 2: Won’t the
bench be hot there?
Father: Why not find out for
Child1: Does this mean there
is no solar radiation occurring?
Father: No, solar radiation
is influencing the whole planet, however hot or cold the weather.
Without solar radiation life is impossible. Only the shadow produced
by trees or buildings or other obstacles situated in front of the
solar rays is protecting us against the overheating of our body and
offering a more pleasant place to sit. But here we are. What do you
say about that bench? Don’t be scared. So, what do you say?
Both children, together: Much
Child 1: You know, we wanted
to make some stamp exchanges, but why not tell us more about the power
of the Sun?
Father: Let’s start,
The Sun is a star with its own heat. The Sun
has a very high temperature, it is incandescent and it lights all
the planets around it. It is not only lighting them but it is heating
them more or less, depending on the distance between it and them.
A large part of the Sun’s heat is lost in space and just a
small part is heating our planet, the Earth. The Sun radiates 174,423,000,000,000
kilowatt hours of energy to the Earth per hour. In other words, the
Earth receives 1.74 x 1017 watts of energy.
Both children, together: Wow! No wonder the
bench was hot!
the air blanket that surrounds the Earth, also captures some
heat coming from the Sun, and the oceans as well as the glacial
situated at the N and S poles, are reflecting heat back into space
like mirrors. However, as you’ve felt on your skin, the heat
that touches the land and all the objects and beings existing on Earth-
is quite significant. That’s why your mothers gave you white
hats, to protect you against the excessive heat because black coloured
clothes capture heat rather than offering protection from it.
Child 2: If solar radiation
is so strong, it would be interesting to use it. For example, isn’t
it possible to use it instead of using gas for kitchen stoves? Wow,
I’m on the way to an epochal discovery! Cooking with the Sun!
Child 1: OK, I understand,
you are always hungry, that’s why you are speaking only about
cooking. But I can invent a system able to heat water with solar
Father: Excellent! Both
of you have brilliant ideas, but unfortunately or maybe fortunately
inventions were made many years ago. People have been using the Sun’s
power to heat water and to preserve food for thousands of years.
Child 1 and Child 2 are looking very sad.
Child 1: For a moment
thereI thought I’d be the youngest inventor in the world…
Father: Don’t worry.
In a way you are inventors because you didn’t know that all
those things have already been invented. But you can be also creators
of equipment that use solar energy.
C1 and C2 are happy
Both children, together: Great,
but how, what can we do?
Father: If you want, we
can go to my workshop and with some luck and skill, we will enjoy
food prepared with the Sun. That’s OK for you?
Both children, together: Let’s
Child 1: …To eat
On the way the group walks
nearby a kiosk with two red plastic tables and white plastic chairs.
Father invites the kids to touch with their fingers first the red
tables and then the white chairs.
Child 1: The table seems to
be even hotter than the bench.
Child 2: But the chair is not
hot at all. How is it possible? Hmm, that means the red colour is
attracting the solar radiation and the white colour is reflecting
Father: That’s right.
Do you know, black attracts most of the Sun’s rays.
Child 1: Don’t mirrors
Father: The mirrors reflect
not only the light but also heat. Based on this observation, people
made concave mirrors (parabolic) that focus the heat in a point and
in this way they are obtaining a very high temperature able to boil
water in seconds. - Arriving at the workshop.- Here
we are, and we'll start immediately to catch the Sun before it goes
to bed. -
Taking some paper out of a drawer.-
First we make some drawings. Second we will make the solar cooking
Child 2: You too, with
the food! I thought that only he - pointing
at the other child - is the hungry one.
Father: I'll say! - I’m
also hungry, but the main reason of choosing to build a solar cooking
box is because its easy.
Father and children
are doing the drawings - camera focus on the drawings while Father
speaks about what they are doing.
The list of necessary materials and tools is also written down.
The camera is focussing on the materials and tools on a table.
The explanations are coming from off camera.
They cut the cardboard boxes, aluminum foil, and they already have
a steel plate and the glass to cover the boxes.
The work is finished and Father brings a pan with water and peaches.
They will prepare peaches compote. The pan and its lid are black matt.
Father: Why do you think the
pan and lid are matt black?
The red table was hotter than the whilte chairs
and I remember you said that black attacts the most heat.
- They are going outside and place the cooking box in a sunny
The sun is working…and, after one hour, three happy people
are enjoying the compote made with Sun power. Clean and cheap - sustainable.