0:00:00.000,0:00:02.000
Hi, this is Najib,

0:00:02.000,0:00:03.350
this video is about a Cheikh

0:00:03.350,0:00:05.800
claiming that the Earth is fix and not moving.

0:00:05.800,0:00:07.000
Why, because,

0:00:07.000,0:00:09.000
if the Earth was moving,

0:00:09.000,0:00:11.000
and a plane wanted to go from Ashariqa (KSA) to China;

0:00:11.000,0:00:12.000
if this plane kept static in the sky,

0:00:12.000,0:00:14.000
it is China that would come to it ! [br](as earth is turning)

0:00:14.000,0:00:16.000
let’s watch the video:

0:00:16.000,0:00:18.000
(Cheikh) “So the earth is static, [br]not moving

0:00:18.000,0:00:19.000
The logical arguments, God bless you,

0:00:19.000,0:00:21.000
we go to the Ashariqa airport,

0:00:21.000,0:00:23.000
we want to go to China,

0:00:23.000,0:00:24.000
on the plane,

0:00:24.000,0:00:24.000
clear?

0:00:24.000,0:00:27.000
stay focused:

0:00:27.000,0:00:29.000
this is earth, if you say that it is spinning,

0:00:29.000,0:00:32.000
if we take off from Ashariqa,

0:00:32.000,0:00:34.000
in an international frlight to China,

0:00:34.000,0:00:36.000
the earth is spinning, right?

0:00:36.000,0:00:37.000
Ok, if the plane stopped in the sky,

0:00:37.000,0:00:40.000
wouldn’t China come to it !?

0:00:40.000,0:00:41.000
Right or not,

0:00:41.000,0:00:43.000
China would come or not !?

0:00:43.000,0:00:46.000
Now if earth is spinning this way [br](like the cup of water in his hands),

0:00:46.000,0:00:49.000
whatever the plane is doing to reach china [br]it will never catch it,

0:00:49.000,0:00:53.000
as China would be also following the earth [br]in its spinning movement.

0:00:53.000,0:00:56.000
So how would you reach China !?

0:00:56.000,0:00:57.000
(Najib) The video is longer than that,

0:00:57.000,0:00:59.000
and contained another type of arguments,

0:00:59.000,0:01:01.640
mixing up Science and religious texts.

0:01:01.640,0:01:04.440
And this is a whole issue,

0:01:04.440,0:01:05.420
but in this video,

0:01:05.420,0:01:07.000
I would like to tackle this particular part of his video.

0:01:07.000,0:01:11.000
And by the way I take the opportunity to [br]congratulate the Cheikh for his methodology !

0:01:11.000,0:01:13.000
The cheikh is using Nature observation,

0:01:13.000,0:01:16.000
to extract general rules of Nature.

0:01:16.000,0:01:19.000
This is at the core of Natural Sciences.

0:01:19.000,0:01:23.000
The idea this Cheikh is putting here [br]belongs the greek scientist Aristotle,

0:01:23.000,0:01:25.000
who lived in the fourth century BC,

0:01:25.000,0:01:30.000
and was among the natural scientist and philosophers [br]with the highest influence on the old world.

0:01:30.000,0:01:34.000
(map showing Alexander The great empire, [br]Aristotle’s student, expanding)

0:01:34.000,0:01:39.000
And it is completely normal that his ideas end up [br]in muslim scholars’ texts in the middle ages,

0:01:39.000,0:01:43.000
which have probably been used by our Cheikh.

0:01:43.000,0:01:46.000
Aristotle said that it is impossible [br]for the Earth to be spinning,

0:01:46.000,0:01:47.000
Why ?

0:01:47.000,0:01:49.000
because if it was doing so,

0:01:49.000,0:01:52.000
and if we consider someone throwing an arrow vertically,

0:01:52.000,0:02:01.000
than the arrow wouldn't be back to the same place because, [br]Earth would have moved in between.

0:02:01.000,0:02:02.000
The idea sounds reasonable,

0:02:02.000,0:02:04.000
and we can’t blame aristotle,

0:02:04.000,0:02:05.000
nor the old muslim scholars

0:02:05.000,0:02:08.000
or not even this Cheikh to think about it.

0:02:08.000,0:02:09.000
But the question is:

0:02:09.000,0:02:14.000
is this idea corresponding to the reality of our world?

0:02:14.000,0:02:18.000
Aristotle ideas remained accepted for [br]centuries all around the region,

0:02:18.000,0:02:24.000
and the first one to challenge it [br]and verify it was Galileo.

0:02:24.000,0:02:28.000
Galileo lived in the 17th century, in Italy.

0:02:28.000,0:02:31.000
He explained the error done by Aristotle in [br]a book he wrote in the late days of his life,

0:02:31.000,0:02:34.000
the book sparked a revolution in natural science.

0:02:34.000,0:02:40.000
The book was named “Discourses and Mathematical Demonstrations [br]Relating to Two New Sciences”.

0:02:40.000,0:02:43.000
Or simply put: “Two New Sciences”.

0:02:43.000,0:02:45.000
In this book, Galileo described the following experiment:

0:02:45.000,0:02:47.000
if we are on a moving ship

0:02:47.000,0:02:48.000
and went up to the top of the mast

0:02:48.000,0:02:51.000
to let down a pebble from above.

0:02:51.000,0:02:52.000
If Aristotle was right,

0:02:52.000,0:02:55.000
the pebble shouldn’t fall vertically to the bottom of the mast,

0:02:55.000,0:02:59.000
but should be left behind while the boat is moving forward.

0:02:59.000,0:03:00.000
Let’s figure out this by ourselves !

0:03:00.000,0:03:07.000
Today we have a ship that moves way faster [br]than boats of Italy in that period.

0:03:07.000,0:03:08.000
This ship is named:

0:03:08.000,0:03:09.000
...

0:03:09.000,0:03:10.000
the car !

0:03:10.000,0:03:14.000
I’m on the highway now driving at 120km/h,

0:03:14.000,0:03:15.000
if Aristotle was right,

0:03:15.000,0:03:18.000
this pebble, if thrown from the roof of the car,

0:03:18.000,0:03:21.000
while falling, the back of the car should “catch up with it”.

0:03:21.000,0:03:25.000
The pebble should either end up on the back seats, [br]or even break the rear windows of the car.

0:03:25.000,0:03:30.000
Let’s try !

0:03:30.000,0:03:34.000
The pebble is falling vertically in the car,

0:03:34.000,0:03:36.000
this proves that Aristotle was wrong.

0:03:36.000,0:03:40.000
Galileo proved this in detail using the concept of reference frame.

0:03:40.000,0:03:43.000
The reference frame is the place where we situate rigorously [br]a phenomenon before studying its mechanics.

0:03:43.000,0:03:45.000
In the reference frame of the car,

0:03:45.000,0:03:47.000
this pebble is static,

0:03:47.000,0:03:48.000
its speed is zero,

0:03:48.000,0:03:55.000
while earth and the trees outside are moving [br]with the speed of 120km/h in the opposite way.

0:03:55.000,0:03:58.000
While for a tree outside:

0:03:58.000,0:04:03.000
BOTH the car and the pebble are moving with a speed of 120km/h

0:04:03.000,0:04:05.000
If my car was convertible,

0:04:05.000,0:04:08.000
I would have been able to throw my pebble up higher in the air,

0:04:08.000,0:04:13.000
the movement of the pebble in the reference frame [br]of the car would still be vertical,

0:04:13.000,0:04:15.000
while in the reference frame of the tree,

0:04:15.000,0:04:23.000
the pebble would have a horizontale movement with a 120km/h velocity,

0:04:23.000,0:04:25.000
Seem from the latter reference frame,

0:04:25.000,0:04:27.000
its movement resembles that of a projectile,

0:04:27.000,0:04:32.000
going up and then reaching the car back.

0:04:32.000,0:04:33.000
The error made by Aristotle,

0:04:33.000,0:04:37.000
is that he was not fixing the reference frame [br]where he was studying the movement.

0:04:37.000,0:04:40.000
As soon as we have a clear idea [br]in which reference frame we are talking,

0:04:40.000,0:04:42.000
things become clear.

0:04:42.000,0:04:44.000
The plane of our Cheikh is like a butterfly,

0:04:44.000,0:04:46.000
going from the front seat (Ashariqa),

0:04:46.000,0:04:48.000
to the back seat (China).

0:04:48.000,0:04:50.000
In the reference frame of the car,

0:04:50.000,0:04:53.000
the rear seat is fix,

0:04:53.000,0:04:55.000
it is not “coming” to the butterfly.

0:04:55.000,0:04:56.000
In the reference frame of the tree,

0:04:56.000,0:05:00.000
the butterfly has already a velocity of 120km/h,

0:05:00.000,0:05:07.000
decreasing a little bit while the butterfly os going to the rear seat.

0:05:07.000,0:05:10.000
All of this is true since the car has a constant velocity.

0:05:10.000,0:05:15.000
In this case, we say that the reference frame [br]of the car is a Galilean reference frame.

0:05:15.000,0:05:16.000
If the velocity of the car suddenly changed,

0:05:16.000,0:05:19.000
for example if I push on my breaks,

0:05:19.000,0:05:20.000
it is no longer a Galilean reference frame,

0:05:20.000,0:05:23.000
and the poor butterfly will hit the front window.

0:05:23.000,0:05:24.000
If Earth did the same (suddenly stopped rotating),

0:05:24.000,0:05:28.000
the american scientist Neil deGrasse Tyson [br]explains in this video what would happen.

0:05:28.000,0:05:31.000
I can tell you that it wouldn’t be a happy event.

0:05:31.000,0:05:34.000
Now the conclusion I can draw from this story,

0:05:34.000,0:05:38.000
is that our intuition can sometimes lead us in mistake,

0:05:38.000,0:05:39.000
just like it did to Aristotle.

0:05:39.000,0:05:42.000
Intuition sometimes works, sometimes not.

0:05:42.000,0:05:47.000
The only way to figure out is to do the experiment,

0:05:47.000,0:05:49.000
just like Galileo did.

0:05:49.000,0:05:53.000
If the experimental result is not agreeing [br]with our initial idea,

0:05:53.000,0:05:55.000
we should accept changing our point view.

0:05:55.000,0:05:57.000
This is the scientific method !

0:05:57.000,0:05:59.000
The scientific method,

0:05:59.000,0:06:02.000
with readiness to change one’s mind in its core principles,

0:06:02.000,0:06:08.000
in which Arab scholars and philosophers played [br]a key role to make it precise and rigorous,

0:06:08.000,0:06:12.000
would later spark the scientific revolution in Europe,

0:06:12.000,0:06:16.000
the same scientific revolution that is still [br]happening all over the world.

0:06:16.000,0:06:19.000
This is it, happy experimenting, and good bye.