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Hi, this is Najib,

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this video is about a Cheikh

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claiming that the Earth is fix and not moving.

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Why, because,

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if the Earth was moving,

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and a plane wanted to go from Ashariqa (KSA) to China;

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if this plane kept static in the sky,

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it is China that would come to it ! 
(as earth is turning)

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let’s watch the video:

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(Cheikh) “So the earth is static, 
not moving

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The logical arguments, God bless you,

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we go to the Ashariqa airport,

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we want to go to China,

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on the plane,

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clear?

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stay focused:

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this is earth, if you say that it is spinning,

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if we take off from Ashariqa,

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in an international frlight to China,

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the earth is spinning, right?

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Ok, if the plane stopped in the sky,

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wouldn’t China come to it !?

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Right or not,

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China would come or not !?

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Now if earth is spinning this way 
(like the cup of water in his hands),

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whatever the plane is doing to reach china 
it will never catch it,

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as China would be also following the earth 
in its spinning movement.

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So how would you reach China !?

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(Najib) The video is longer than that,

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and contained another type of arguments,

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mixing up Science and religious texts.

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And this is a whole issue,

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but in this video,

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I would like to tackle this particular part of his video.

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And by the way I take the opportunity to 
congratulate the Cheikh for his methodology !

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The cheikh is using Nature observation,

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to extract general rules of Nature.

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This is at the core of Natural Sciences.

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The idea this Cheikh is putting here 
belongs the greek scientist Aristotle,

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who lived in the fourth century BC,

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and was among the natural scientist and philosophers 
with the highest influence on the old world.

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(map showing Alexander The great empire, 
Aristotle’s student, expanding)

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And it is completely normal that his ideas end up 
in muslim scholars’ texts in the middle ages,

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which have probably been used by our Cheikh.

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Aristotle said that it is impossible 
for the Earth to be spinning,

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Why ?

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because if it was doing so,

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and if we consider someone throwing an arrow vertically,

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than the arrow wouldn't be back to the same place because, 
Earth would have moved in between.

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The idea sounds reasonable,

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and we can’t blame aristotle,

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nor the old muslim scholars

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or not even this Cheikh to think about it.

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But the question is:

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is this idea corresponding to the reality of our world?

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Aristotle ideas remained accepted for 
centuries all around the region,

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and the first one to challenge it 
and verify it was Galileo.

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Galileo lived in the 17th century, in Italy.

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He explained the error done by Aristotle in 
a book he wrote in the late days of his life,

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the book sparked a revolution in natural science.

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The book was named “Discourses and Mathematical Demonstrations 
Relating to Two New Sciences”.

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Or simply put: “Two New Sciences”.

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In this book, Galileo described the following experiment:

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if we are on a moving ship

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and went up to the top of the mast

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to let down a pebble from above.

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If Aristotle was right,

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the pebble shouldn’t fall vertically to the bottom of the mast,

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but should be left behind while the boat is moving forward.

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Let’s figure out this by ourselves !

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Today we have a ship that moves way faster 
than boats of Italy in that period.

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This ship is named:

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...

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the car !

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I’m on the highway now driving at 120km/h,

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if Aristotle was right,

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this pebble, if thrown from the roof of the car,

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while falling, the back of the car should “catch up with it”.

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The pebble should either end up on the back seats, 
or even break the rear windows of the car.

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Let’s try !

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The pebble is falling vertically in the car,

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this proves that Aristotle was wrong.

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Galileo proved this in detail using the concept of reference frame.

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The reference frame is the place where we situate rigorously 
a phenomenon before studying its mechanics.

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In the reference frame of the car,

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this pebble is static,

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its speed is zero,

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while earth and the trees outside are moving 
with the speed of 120km/h in the opposite way.

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While for a tree outside:

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BOTH the car and the pebble are moving with a speed of 120km/h

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If my car was convertible,

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I would have been able to throw my pebble up higher in the air,

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the movement of the pebble in the reference frame 
of the car would still be vertical,

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while in the reference frame of the tree,

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the pebble would have a horizontale movement with a 120km/h velocity,

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Seem from the latter reference frame,

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its movement resembles that of a projectile,

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going up and then reaching the car back.

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The error made by Aristotle,

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is that he was not fixing the reference frame 
where he was studying the movement.

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As soon as we have a clear idea 
in which reference frame we are talking,

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things become clear.

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The plane of our Cheikh is like a butterfly,

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going from the front seat (Ashariqa),

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to the back seat (China).

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In the reference frame of the car,

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the rear seat is fix,

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it is not “coming” to the butterfly.

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In the reference frame of the tree,

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the butterfly has already a velocity of 120km/h,

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decreasing a little bit while the butterfly os going to the rear seat.

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All of this is true since the car has a constant velocity.

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In this case, we say that the reference frame 
of the car is a Galilean reference frame.

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If the velocity of the car suddenly changed,

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for example if I push on my breaks,

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it is no longer a Galilean reference frame,

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and the poor butterfly will hit the front window.

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If Earth did the same (suddenly stopped rotating),

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the american scientist Neil deGrasse Tyson 
explains in this video what would happen.

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I can tell you that it wouldn’t be a happy event.

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Now the conclusion I can draw from this story,

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is that our intuition can sometimes lead us in mistake,

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just like it did to Aristotle.

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Intuition sometimes works, sometimes not.

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The only way to figure out is to do the experiment,

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just like Galileo did.

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If the experimental result is not agreeing 
with our initial idea,

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we should accept changing our point view.

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This is the scientific method !

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The scientific method,

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with readiness to change one’s mind in its core principles,

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in which Arab scholars and philosophers played 
a key role to make it precise and rigorous,

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would later spark the scientific revolution in Europe,

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the same scientific revolution that is still 
happening all over the world.

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This is it, happy experimenting, and good bye.