The following videos show the development of the final debate (in a large group), in which each group (which previously debated the problem among its members, trying to reach a conclusion to defend it before the rest) stands on one side and the teacher in the medium, trying to moderate and encourage the discussion.
The full large group discussion can also be viewed in this playlist:
https://www.youtube.com/watch?v=V_bke_HR1mQ&list=PLeYiS71kqNZAjvuCE5EMGAxtUUrMRvxJu
The two groups agree that permanent sunset is possible.
One condition is that the speed of the plane is equal to that of the Earth, and this is feasible.
For the sunset to be permanent, the plane must cross a meridian (time zone) every hour.
There is discussion about the idea of
"airplane speed = earth speed"
and the conclusion is reached that they must have opposite meanings.
The engines are turned on to fight against the force (of attraction, referring to gravity).
They are both wrong, because the Earth goes one way and the plane goes the other. Betty is wrong, because the plane is not stopped. If she were, they wouldn't always see the sunset the same.
But they, being inside the atmosphere, are rotating with the Earth.
Use of the sphere to explain the heliocentric model.
But the plane, being inside the atmosphere, will move with the Earth.
No, because that's what the engines are on for.
Well then the plane is also moving.
The atmosphere also moves with the Earth. .. (the teacher interrupts to give the floor to a student who had not participated).
The Earth moves, but the plane cannot stay still.
Who is right, John or Betty? Both. The plane moves and the Earth moves.
If the Earth makes this movement, and the plane wants to go the other way, it has to move.
The plane, being in the atmosphere, is dragged by the rotation of the Earth. If it is on a country, it does not leave it.
Therefore, it cannot be still.
The case of a satellite would be different, since it is outside the atmosphere.
Satellites don't move because they are attracted, too.
The plane does not fly outside the atmosphere, so it has to be in motion.
(teacher): So who is right (John or Betty)?
The plane does not move with respect to the Sun. So, regarding space (what Betty says)...it's still.
You are a little right.
(teacher): A little bit right? You distribute (the reason) like in cakes.
It is being said that it depends on the point of view. In that case, what will be the most logical point of view?
The plane moves and the Earth moves. And they do it at the same speed. Otherwise, I wouldn't be able to see it (the permanent sunset).
Therefore, it has to move one hour along each meridian, to go at the same speed as the Earth. This way it would always be in the same position.
(teacher): I'm going to read John's sentence: "The plane flies so fast that it prevents the Sun from setting behind the sea."
He is right.
Well, the Sun doesn't move. The only thing that moves is the Earth.
The Earth moves and the plane moves.
If it moved more slowly, then the Earth would block the Sun.
(teacher): So what do we tell John?
That he is wrong.
Well, I think not.
(teacher): I am going to repeat John's phrase again, and you are going to say if he is right or not.
(teacher): You say John is right. So, I say: "Therefore, the Sun moves", right?, because it says that the Sun sets behind the sea.
No, what is set is the sea in front (of the Sun).
(teacher): So, is John right?
Totally, no. He is wrong about the Sun setting.
He is a little right one and a little right the other.
(teacher): And us, who will we agree with?
If he says that the Sun moves, he is not right.
But he is right when he says that the plane is moving very fast.
John is right because he says the plane moves, and Betty is right because he says the Earth moves.
The teacher reads Betty's sentence and provokes an avalanche of interventions about her statement that the plane is stopped in space.
The plane is not stopped.
Regarding space, yes it is.
In space it is still, but in the atmosphere it is moving.
The plane is making the rotation of the Earth, it would not be still.
(teacher): So, is Betty right or not?
No, because if the plane had no speed it would be making the same rotational movement as the Earth, it would not be still.
He would be standing still, but at the same time moving.
The teacher repeats Betty's sentence in parts:
"The Sun does not move." Is there a mistake there?
No.
"The Earth is rotating beneath us"
There.
No, not there. It doesn't fail, as long as the plane moves. If it stays still, it would go with the Earth.
(the student explains this idea with the help of the Earth's sphere and a pen representing the airplane).
(teacher): Is that pen standing still?
It is stopped, but it goes with the Earth.
It is stopped, but it goes with the Earth.
Está detenido, pero se va con la Tierra.
It is stationary, but it is leaving with the Earth.
Está estacionario, pero se va con la Tierra.
It is stationary with respect to space, but moves with respect to the Earth.
(teacher): Do you see that pen standing still?
Regarding the Earth, yes.
(teacher): But do you see him standing still?
No. Oh, of course, we are seeing it as if we were in space.
(teacher): Let's analyze what Betty says: "The Earth is rotating." What would this be what Betty says? (using the terrestrial sphere). "And we're standing in space." What's wrong, Betty?
Yes she could.
But they are in the atmosphere, not in space.
The plane has to move. It seems to be stopped, but...
If that happened, you would see the Sun change. You would see it change from day to night.
(teacher): Let's see, how is that? Do it there, with the Earth (sphere).
This sphere (left) is the Sun, and if you nine the Earth (right sphere), you always look at the Sun in the same position.
Then you would look at it the entire trip.
Clear.
The thing is that then, there, the pen would be in motion.
(teacher): Would it be moving?
Yes, regarding the Earth, yes.
(teacher): Would the pen be moving? (pointing to the pen at rest): Look there.
Regarding the Earth, yes.
(teacher): And regarding the Sun?
No.
(teacher): So, John answers: "How are we standing still, if the plane's engines are running?"
Because it has to exert a force opposite to that of rotation. He is flying against the force of rotation.
(teacher): Are you right, John?
The plane moves. That's clear.
(teacher): Why is it clear?
It depends from where you look at it.
If you are on Earth, you don't appreciate rotational motion.
(teacher): If you are on Earth, the plane is moving. And the sun?
Also.
(teacher): What if you are in the Sun?
The Earth moves, and the plane is stopped.
(teacher): And which of the two points of view will be more correct?
The one of the Sun.
The one from the Earth, because you live on the Earth.
That of the Sun, because then you are at a point that is still. And then Betty would be right.
(teacher): Would Betty be right?
Yeah.
But... well, I don't think so.
That's what happens on escalators. If you are walking at the same speed (down, if they are up), you are in motion, but you are always in the same position. If you go faster than the treadmill, you are still moving, but you are moving too.
It depends on where you look at it.
(teacher): Precisely, the theory of relativity deals with these things.