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Om El-Sayed as a Ballerina-Ahmed Tarek,TedxTanta
today I'm not going to talk about inventions,
I have had a run in with inventions but today I'm going to talk about something new
lets go back to back in time 10,20,30,40 years and remember our first math lesson
and remember the teacher walking into class for the first math lesson at school
I wonder does anybody remember that lesson nobody remembers?!
I think that first lesson was adding and subtracting
I'm sure we all remember that lesson
I wonder did the teacher start by saying that
adding is a simple mathmatical operation that adds 2 mathmatical values to equal a third mathmatical value of a bigger quantity?!
while subtracting is also a simple mathmatical operation that subtracts 2 mathmatical values from each other to equal a third value that represents the difference between the 2 values?!
or did the teacher start by
I wonder if I have 2 balls in this hand and one in the other
and added this one with the other two what will it equal
I am sure all the kids will say 3 balls
and that is the operation of adding
but what if I have 3 balls in this hand and I take away one
how many will be left?
I am sure all the kids will say 2 balls
and that is the operation of subtracting
I think that we agree that, when the teacher was explaining this lesson
she didn't use the definition in the book or the one agreed on by the mathmatical scientists
but because she believes she was talking to little kids, she found a simplified way to teach the kids
but a problem that we have is that we think that simplifying information is for kids only
but not for adults or even doctors
no simplifying is for kids
and in my opinion that fact is not right
that simpliyfing is something that should be done any sort of people
and what the teacher did is not something uncommon, no its a science and this science is called science communication
about which I am here to talk today,which in arabic is called "Al-Twasol Al-Elmy"
Science Commincation is a science where a connection is made between scientists and normal people
not only scientists but also anyone that has any scientific information can use this science to get his/her point accross
to make the information easy and understanble
and make experments on it to make it exciting and simple
so that the people find it interesting and benifitial
and what I came to show you today is
a few examples on science communication
I will show you today 3 examples
the first example talks about a physical equation
the second example talk about a physical theory
the third example talks about a physical law
and each one of these examples I will demonstrate them in 3 to 4 minutes with these weird experments you see next to me
and hopefully you will be convinced that you can explain a complicated scientific fact in a simple exciting way
we must of have been on a plane before has anyone ever thought
how an airplane stays up in the air the answer to this question is in two words
Bernoulli 's equation
we all know that for an airplane to fly it must have huge engines
which thrust air in a very high speed
this air come out from that back which pushed the plane forward
but what makes the plane go up
the shape of the winges the shape of the winges which is curved from the top and straight from the bottom
as you can see the wings have to be curved from the top and striaght from the bottom
thats why when the plane thrusts water from the back in a very high speed these winges slice through the air
dividing the air into two halfs
a half that flow on the top of the plane and a half that flow on the bottom of the plane
as you can see the wing is curved on the top which means
that the distance crossed by the air on the top is more than the distance covered by air on the bottom
beacuse the wing is curved
well aren't the air particals on the begining of the wing the same the air particals meeting in the end
this way we can say that the distance crossed by the air on top of the wing is longer then the
the distance on the bottome of the wing
that way the air speed ontop of the wing is higher than the air speed on the bottom
now we can say we have achieved Bernoulli's equation
what does Bernoulli's equation say?
It states that
that the speed on any fluid "fluid" meanining gas or liquid
correspones inversely to the pressure of that same fluid
so what does "fluid" mean? it means Gas or Liquid
the fluid in this case is the air
and the air here correspondes inversely with its pressure
so when the speed of the air increases its pressure will decrease
and when its pressure increases then the speed will decrease
that way when the speed is high then the pressure will be low on the top
and when the speed is low then the pressure will be high on the bottom
still some people might not be convinced
imagine a crowded street and an empty street
the crowded street will have alot of pressure while the empty street will have less pressure
a car in a crowded street will go faster same as the air speed when the pressure is low
and when the pressure of the street is lower the cars go faster same as the air speed when the pressure is lower
the car will like to move from the crowded street to the empty street same the air when it moves from the bottom of the plane to the top
which means the air will move the bottom to the top pushing the wings up making plane fly!
i think that now we all have a general idea of how a plane flys
but lets try it practicaly
lets give it a try
imagine if I have a straw and a ball like these here
if I blow in the straw from the bottom what do you think will happen to the ball?
It will fly! well then what is the scientific explanation for this
It is that the gravity pushes the ball down but the air pushes the ball up
but imagine if I hold the straw this way what will happen?
the air will push the ball like this and gravity will push the ball this way
so it is only natural that the air push like this and the gravity will push it down
let's try it !
that is when the straw is straight what if its tilted?
as we all saw, even though the straw was tilted
the ball still didn't fal
and that is because the air pressure coming out of the straw is low
and the air speed is very high because i blew into the straw
and that means when air speed is high then the air pressure is low
like we said when the cars are speeding in the street that means that the pressure on it is low
which means its not corwded
and the air pressure outside is higher than the air coming out of the straw
the air always moves from high pressure to the lower pressure
and pushes the ball from all sides
thats why the ball stays still and doesn't fall
and that was the first equation which was
Bernoulli's equation and using it in flying
now lets move the seconed theory which is
physical phenomenon
when I was younger I like to play with electricty
I used to enjoy taking 2 screws and placing them in the electricty socket
and get so excited when I see the houses electricty on and the smell of something burning
and see the electricty sparks fly
it used to upset me when I would put the plug in the electricty socket
and still sparks! why does it spark! I didn't do anything wrong!
but later I found out that it was my fault
but rather is a physical phenomenon called the electric arc
and this phycical phenomenon appears when
two electric charges have a big deference in the discharges and the distance between them is very small
causing the electricty to spread in the air and produce that spark that we see
which has the scientific name of electric arc