
to
in the next few minutes I will tell you
how to practice science but how
practice it
emulating imitating experiments
important big experiments but
doing it with home materials with
simple materials and also cheap and
to get started
I will speak of what is arguably
the most expensive writing instrument
the history
the million dollar pen in
the sixties when states
united began to develop the
apollo program
as you well know to bring man
to the moon it was essential to get there first
that the Russians about all that
they soon realized that the
astronauts and they’re going to need a
instrument that could work in
weightless conditions face down
under water and in extreme conditions
of temperature were put to work and
tells the story that they spent a
million dollars of the time
I’m talking about 60 years ago or so
to build a ballpoint pen
the Russians also got a
instrument that do the same
they used a pencil this story as such
is not quite true, and if it is
true that volleyball exists and you can
buy our pasta but I was
there also serves to tell you about
introduce the idea that I want to convey
today to do science to do
experiments have fun with science
not accept to miss a pasture
many times it is enough to have a little
ingenuity
let’s start with a question
simple if I said it will ask us
I have a heavy one heavy nut and one
light sheet of paper
if I release it at the same time from the same
height
which do you think will come first to
floor
I’m going to do, I’m going to do, like,
something that almost everyone or everyone tells me
that will drop the nut
let’s try it to see if it’s true me
I have the chair here to make it more
spectacular if I do not kill myself
effectively the Turkish arrives first
well now the question is whether I
I wonder why the nut arrives
first surely also maybe not
all but many would tell me jce because
has more mass has a greater weight then
so we have a problem if that is
the answer because the 17th century
Mr. galileo galilei that almost
sure you all know he came to the
conclusion showed that all the
bodies fall the same time they fall with the same
speed
regardless of its mass
there is a very beautiful story that says that
he reached that conclusion by throwing balls
of different mass and of different size
from the top of the pisa tower
sure this story more than one will
ever heard there was ever
regret to tell you that your story is not
certain did not throw the ball from the tower
from pisa reached that conclusion
using inclined inclined planes
of wood like those you can see in the
image how she came to that conclusion
like those planes like michael would say
ende the psoe in his book history
endless that I recommend reading that is
another story and it deserves to be told in
another moment well how can we then
check that galileo was right
Well this explanation of
why the role that later than the
nut is because the paper offers a
greater friction greater friction with the
air
that’s why it takes longer to fall
problem we look for a site that does not have
air that does not have a friction atmosphere
and we do the experiment a site like that
if we go back to the beginning of the story
the moon there is no air there is no
atmosphere the experiment could be done
true
we arrived a little late we were
advanced in July 1971 the lord
davis scott
the commander of the apollo 15 mission
did precisely that experiment in the
lunar surface
dropping a hammer and a pen with
why its lunar module is a
falcon although it may not look good
that day and it’s time in a hand a
hammer they carry a pen and beige that
arrive at once to the ground which
showed that the ‘law of today law
I really was right
obviously we are not going to go to
the moon but can not can not
ride a moon without atmosphere in the
salon we can do
we can pull wit and for that
let’s use an ancestral technique that
we learned in school when in
when everyone was all
well, some of us were children, we’re going to
make the paper have the friction
same or similar to the nut and what
I do what we will do playing that technique
ancestral told us is I’m going to do
a ball of paper that simple to one
ball if possible
The tighter me better here
three hands missing and we’re going to test if
really side the role of before now
which is a ball arrive or not at the same time
the same height nut
you had to tighten how well I tell you
let go and come at a time with which
we have shown that galileo has
reason only using a bit of
ingenuity without having to go to the moon
I’m talking about the air I’m talking about
of atmosphere and another point you know that
the air that surrounds us has a weight what
which means that it exerts a pressure and
I ask you how strong that strength
as from strong to prison or said from
another way if I now say that I
palm of the hand I’m holding the
weight equivalent to a stone of 50
kilograms
What I think is going to give four
options the first gym buoy all
the days and that’s why he endured without
weight problems
the second one I’m exaggerating and it’s not
true that is holding 50 kilos
it may be the third
I have an equal bionic arm to hold
what they throw at me and the fourth would be that
it’s true that I’m going west
holding the weight of 50 kilos of air
may surprise you but the answer
correct is precisely the fourth my
hand is holding 50 kilos and 50
kilos and why it is not broken by how
the atmospheric pressure acts
I am receiving a pressure that
they support an atmospheric pressure by
up but that pressure
atmospheric acts with equal intensity
below, so together, my
hand does not support pressure so it does not
It breaks this strong depression
atmospheric well worth this or union
because it works but it came without
explain how strong the pressure
atmospheric to be able to demonstrate or not
in an elegant way we would need
horses dogs horses I will tell you
a little battle for it we have to
travel in time to May 8,
year one thousand 654 to the German city of
magdeburg
there his former mayor and an amateur physicist
amateur Mr. Otto von Gerich e
on her and von guericke at least the
German through the screen made a
very eye-catching experiment to show
how strong the pressure was
atmospheric and already passing to sell
a vacuum pump that he had invented
in fact it was apparently all a
assembly that was what this man did
He took two metal hemispheres from some
25 centimeters radius more or less and
he put them in contact as a visa and the
drawing without any type of coupling
he just put them in contact and he made
the vacuum inside with your pump has
been advertising and once inside
that empty sphere had hooked her
16 horses 8 for each side and put them
to pull in directions in senses
opposites but for more than what
they tried on the horses not
they managed to separate the encounter sphere
they let in a little air in the
sphere sphere separated single
this was the first test of the strong
important than atmospheric pressure
since that day this gentleman is
world famous and even google him
honors
how can we check what
strong that is the happiest person here
I’m going to propose two ideas the first
would be to take advantage of the fact that
scientific toys toys
science
and we could buy something like this
It’s a toy version by
four sides wonders of the
von guericke spheres this rubber for
make it very empty
I’m going to close the squeeze hard and with
this syringe I will make the vacuum
there we make empty so I can
well that would be my sphere and now for
that you see to see if it works well I will
lift a bottle that has water worth
there is that sphere they are only
subject to atmospheric pressure
this bottle weighs about a kilo
that is an option
another cheaper option simpler and
homemade is a game I will teach here
bottle or an empty bottle of
plastic
step 1 I took the empty bottle and the
Silver is with all our strength
on a table something like that
well now say ice and venezuela can
exist without any problem
I’m fighting the pressure
atmospheric but like the air too
external support falls within the bottle
no problem
Step 2 Do the same thing again
crush the bottle as much as you can
yes with desire and now you put the
stopper will try to stretch the now
you will see
I’m not exaggerating it costs us a lot
more because I’m fighting against
atmospheric pressure but now not
He let in the air to help me
stretch the bottle and here I am watching
how strong is the ftc damn
atmospheric pressure vale is a
experiment that you can do at home and
check how strong the pressure is
atmospheric good
in summary I have told you two
simple experiments to emulate
important projects and they responded
to important questions of science
you can find many more
examples on the internet and even if you
dare in books and if you do
leave friends of two tips already for
finish that are not mine are two
great thinkers the first the lord
Confucius a thinker of ancient China
what they said they told me and do not forget
I saw it and I understood it I did it and what
I learned and the second Mr. albert
Einstein should do everything so simple
as possible but the simplest
already to finish a sentence of the writer
mark twain famous for his irony and his
sarcasm
this gentleman said the human being is a
experiment and time will show if
it was worth it
thank you very much
[Music]
[Applause]
to
to
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