There is one experiment that you can do that will prove once and for all that the earth is a spinning globe, and not a flat dome covered disk.
The experiment will enable you to observe the Coriolis effect, which proves beyond a shadow of a doubt that the earth is a globe. There are many more experiments one can do to show that the world is spherical, however this one cannot be explained away without retreating to the ridiculous.
If you are wondering why I should bother to use my energies to state what is obvious to most people on the planet. It is because there is a growing number of people who entirely believe the world is flat.
They have come to these beliefs because they have isolated themselves on internet islands where everyone believes the same thing. The claims that they have been exposed to, have piled false fact on top of false fact, which paints a picture that is entirely believable to the flat-earther, but has no basis in reality.
So if you are a flat-earther seeking the truth, or you simply know some and want to give a credible scientific argument to refute their claims, then read on.
The Coriolis Misconceptions With Bart Simpson
Before we carry on, let us just briefly identify exactly what the Coriolis effect is and clear up any common misconceptions about this physical phenomena.
In 1995 the Fox Network broadcast an episode of the Simpsons called Bart v Australia, in the episode Bart gets an Australian boy to check which way the water flows down his toilet. The reason he does this is because Lisa alerts Bart to the Coriolis effect, which describes (amongst other things) how water flows when it is being drained.
Put simply, water that has been Coriolis effected will flow counterclockwise when it is being drained in the Northern hemisphere, and clockwise when being drained in the Southern hemisphere (and straight down on the equator).
Even though the effect is very real, the Simpsons (probably for reasons of dramatic storytelling) slightly misrepresented the phenomena and therefore sparked lots of misguided debate about the effect, a lot of which has been pounced on by the Flat Earth Society.
Toilets have jets which enable them to flush, they also have specific designs, these two major factors can have implications on how the water flows down your toilet. Even with sinks where no jets are present, there can be other contributing factors like the design of sink and nature of drain pipes leading away from the sink, plus there will always be some rotation in a body of water in a sink.
The only way to properly observe water that has been Coriolis effected is to set up a very carefully controlled experiment, one which we shall talk about in the next section.
The Coriolis Experiment
The particular experiment I will detail, was done by 2 major youtubers, they are; Derek from Veritasium and Dustin from Smarter Every Day.
What you'll need:
1 paddling pool that can be drained from the bottom.
A flat surface
1 spirit level
Plastic piping (3 metres)
Food Colouring
1 Plane Ticket.
8 wooden planks
Hammer & Nails
Cordless Drill
Black Marker Pen
Preparation:
Use your spirit level to make sure that the surface you are going to use is flat, use the wooden planks to create the base to a raised platform.
Next nail the chipboard to your frame, once you have checked again that the whole structure is flat, if not, prop up accordingly with chips of wood and/or stone.
Drill a hole through the centre of the board, for the piping.
Next place the pool on the platform and attach the piping to the bottom of the pool.
Fill the pool, if you are in the Northern hemisphere fill the pool in a clockwise motion, which is the opposite way you expect the water to drain, this ensures that filling does not effect the final result..
Leave the pool to settle so that there is no rotational motion on the pool, place a matchstick or similar on the surface of the pool to test that it is still.
Once the water is still place drops of the food colouring at the four cardinal points of the pool, giving a north/south/east/west cross. Again if you are in the Northern hemisphere place the drops in a clockwise motion, doing the opposite if you are in the Southern hemisphere.
Open the tap on the piping and drain the pool and observe.
Next fly to the opposite hemisphere and repeat, failing that contact somebody living in the opposite hemisphere and get them to do the experiment and report the results back to you.
Proof Analysis
So why does this prove the earth is round? The first part of the experiment proves that the earth is spinning, as the reason we get the effect is as the pool rotates with the earth, the outer edges of the water have further to travel than the inner areas.
Thus when we start to drain the pool we get a lag between how fast the outer and inner water is moving, this causes some water to get ahead of the drain and some to lag behind, creating a spinning effect.
When we do the experiment in the opposite hemisphere, it proves that the earth is spinning in the opposite direction. This of course cannot be possible on a flat earth model, we all spin one way, or not at all.
If the earth is spinning one way in London, and the opposite way in Sydney, then this proves that the world is round.
It is not only on draining water that we see the Coriolis force effects, we see it in the weather too. In the Southern hemisphere cyclones rotate clockwise and storms in the north spin counterclockwise. Again, clear proof that the earth is round.
If you are a flat-earther, I urge you to do these experiments for yourself; this will help you understand the nature of our world a lot better than this article or any video on youtube can.
Once you have proved to yourself that the world is not flat, you don't even have to declare it, just quietly move away from your previously held misconceptions and move on with your life.
Video Proving Coriolis Effect
