Mr. A: We saw in the previous issue that the Sun emits large amounts of charged particles (mainly electrons and protons). When it is active (approximately every 11 years), the amount of these charged particles increases significantly.
Dad: And if I remember correctly, the interaction of these particles with the atmosphere and the Earth’s magnetic field creates the Northern Lights (aurora borealis) with its beautiful colors.
Mr. A: This year (2023) is the year when the Sun is particularly active and emitting large amounts of particles. These particles are trapped by Earth’s magnetic field, mainly around the North and South Poles.
Mom: Can I finally speak too? We had also heard the next song.
Little A: The northern lights!
Captain GG: Normally, the same physical process that creates the northern lights (aurora borealis) also creates the southern lights (aurora australis).
Little Α: But around the South Pole, there are only penguins to admire the southern lights. Can you imagine a penguin holding a camera and taking a photo of the night sky with the colors?
Captain GG: I suggest we take my ship to the South Pole to see the aurora australis ourselves. What do you say?
Dad: How will we go? Are we going to cross the equator too?
Captain GG: I suggest that we start from Piraeus, pass through the Strait of Gibraltar, and then continue sailing in the Atlantic Ocean parallel to Africa. Yes, indeed, we will cross the Equator.
Little A: So, are we starting then?
Dad: It’s hard for me to understand how even the Rock of Gibraltar belongs to England. North of the rock is Spain, while south is Morocco.
Captain GG: I don’t know either. Let’s head to Casablanca and enjoy some traditional Moroccan couscous.
Mom: They have other delicious dishes as well, cooked in their traditional vessel called Tajine.
Little A: What is this cooking vessel? Can I cook for my friends?
Mom: Tajine is a conical pot that has been used for centuries in Morocco to prepare slow-cooked dishes with meat or fish, vegetables, and spices.
Captain GG: I say we should have a plate of Harira. Usually, it’s a dish with vegetables, rice, and spices. It’s very spicy, but I like it a lot.
Daphne: After we eat, will we go to the little islands across?
Mr. A: To the Canary Islands?
Δάφνη: Ναι. Στην Τενερίφη και στην Λα Πάλμα έχει τηλεσκόπια να δούμε.
Mr. A: The high mountains on these islands make them ideal locations for astronomical observations.
Daphne: From what I’ve heard from my dad, Dr. Vag, the most famous scientific telescopes are the Teide Observatory in Tenerife and the Roque de los Muchachos Observatory in La Palma.
Dad: I’m confused about these islands again. They are Spanish, autonomous, in the Atlantic Ocean next to Africa. But why are they Spanish?
Mr. A: I don’t know. What I know is that on the island of La Palma, there is the largest optical telescope with a diameter of 10.4 meters (known as the Great Telescope).
Daphne: I know that WHT (William Herschel Telescope) is there. It has a diameter of 4.2 meters and can operate in both optical and near-infrared. Astronomers, using this telescope, discovered the first indications of a black hole at the center of our galaxy.
Little A: They also have beautiful beaches on those islands! Shall we go for a swim?
Dad: And where is the equator?
Captain GG: Further south.
Mr. A: I’ve heard that when you drain the bathtub after your bath, the water swirls clockwise before disappearing down the bathtub drain, into the pipe.
Little A: That’s how it happens in the toilet when you flush it with the cistern.
Daphne: This happens if you are in the northern hemisphere of the Earth. If the bathtub and toilet are in the southern hemisphere, the water swirls in the opposite direction.
Dad: I’ve heard the same happens with tornadoes.
Mr. A: Meteorology and oceanography are influenced by the Coriolis effect acting on the air and the Earth’s oceans. In general, the Coriolis forces are due to the Earth’s rotation around its axis.
Mom: It’s very hard for me to believe this. Little A, please stop pulling the flush!
Little A: But I’m experimenting!
Daphne: I want us to try to explain how the Coriolis forces work and why there is a difference in rotation between the northern and southern hemispheres of the Earth.
Have you seen the above game in playgrounds? It spins around and around. It’s probably called a carousel!
Mr. A: Should I continue because I know where you’re going with this? Let’s assume that the carousel is spinning around and around. A person sits on a green chair. Another person sits across from him on the other green chair. As the carousel spins, one person throws a ball to the other person across from him. Unfortunately, he never manages to hit him. If the carousel is spinning clockwise, the ball ends up on the left side of the second person. If it’s spinning counterclockwise, the ball goes to the right side of the second person.
Daphne: This is somewhat how the Coriolis forces work. That’s why there’s a difference between the northern and southern hemispheres of the Earth.
Dad: Let’s continue our journey then, to reach the equator. I think Uganda is on the equator.
Mr. A: Let’s see how they explain these forces in the next videos, then.
Little A: Shall we continue now and go see the penguins and the aurora australis?
Daphne: Here we are – both penguins and the southern lights.
Captain GG: We managed to see the penguins and the aurora australis! Now, let’s return to Greece. We had a wonderful time again.