I'm too nice to ignore non-Christians...
Well, folks... all of you who asked my to explain vectors... I appreciate the vote of confidence, but it is not as if I reveal some hidden wisdom or make the ultimate killer argument...
But I have to slightly disagree with Kinable's statement here that I used to start this post, and get him to be notified.
His response - responses even - to the argument that Flat Earthers' proposed arguments of showing how "water sticks to a ball due to gravity" was rather dismissive, mocking and did demonstrate that he didn't understand some fundamental facts
of the model that his is dismissing. Please take note that I did
not say "fundamental facts of reality".
It is just about the model he attempts to criticize... and gets wrong because he doesn't understand it.
It is akin to me dismissing the biblical accounts of the crucification based on my objection that you cannot crucify squirrels, and when someone corrected me and explained that Jesus wasn't a squirrel but a human, I would respond with "Yeah, that is your excuse, that Jesus was a human... but you still cannot show that the Romans executed squirrels!"
Now I repeatedly offered to provide him with a correct and understandable explanation for his mistake... three times.
And I got ignored.
Yes, these kind of threads can go rather fast... but even then, there aren't that many participants, and not even all of them gang up on a single poster and a single post.
This forum makes it quite easy to track specific responses to single posts, and notify the user that such a responses has been made.
Yes, it can happen that you miss some responses... but if that happens constantly, it is much more likely that the user simply does not
want to address the point that was made.
So, no, Kinable, you are not "too nice too ignore non-Christians". You do that, deliberately... because it seems you do not
want to understand.
Jesus was a squirrel and I won't listen to anything you tell me otherwise, la la la la la la!
Well... perhaps I am wrong, and it is for some other reasons that you keep ignoring my polite and well-meaning offers. Perhaps you will still be able to stand up and admit your flaws and mistakes.
You may be bothered that I am an atheist, but this concept has nothing to do with atheism or Christianity. It is just simple mathematics. Any math teacher, any physics teacher will tell you the same, give you the same examples.
And as it so happens, I have been a math teacher.
Also, non of that is "fiction" or "indoctrination". You can see a lot of that stuff in daily life, and you can do your own simple tests to find out if what I would tell you is correct or not. It takes a little bit of effort... but learning just does.
So, for all who are still interested after this rant, let's dive into the very basics of vector maths and its application for physics.
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As Kinable has not deigned to give me any informations about how much of that stuff he already knows, I will start at the beginning.
Subduction Zone has already explained the basic concept in #345. A vector is a value that has both a size and a direction.
It is commonly represented by an arrow. The length of the arrow determines the "size", the relative position of the "arrowhead" and the "base" determines the "direction".
It is a mathematical element that has various usefull applications in physics... just like "numbers" in general do.
"Numbers" can be seen as a special type of vector... a vector that has just one dimension, one line of travel, and can point forward or backward.
This also gives us our first insight into "vector mathematics". You can add or subtract vectors, just like numbers.
Adding vectors happens when you have one vector and place the base of a second vector at the "head" of the first.
The new resulting line from "base of first vector" to "head of second vector" will be the sum of the two vectors.
This is easy to visualize on a number line, or with two rulers. Or pencils, or whatever else you have handy.
Subtraction works in a similar way. In order to subtract one vector from another, you can simply add the negative of that vector. The negative of a vector is an arrow of the same length, but having its start and endpoint swapped.
Again, this is easy to visualize.
Two- or more dimensional vectors work in very much the same way... they just are not limited to a line. Addition and subtraction still work in the same way.
Now how can this be applied to "the real world" - physics.
Vectors can be used in every case where you have a physical property that has both a magnitude, a "size" and a direction.
Velocity is one of the examples that Subduction Zone already mentioned.
Imagine a treadmill. The band is moving at a certain speed in a certain direction. You are walking on it at a certain speed in another direction. The resulting motion... whether you stay on, rush ahead or fall off at the back is the result of both your movement and the bands.
Imagine a number of treadmills placed side by side, all running at the same speed. You are going to to walk across them, from one side to the other, walking straight ahead.
Your own motion with move you forward. The motion of the treadmill's band will move you sideways. Your resulting movement will be diagonal.
Another example - and finally we will come to the point, puh! - are forces.
A "force" in physics is something that causes an object to move (or to be precise: to change its state of motion).
So, it results in an object having velocity. "Velocity" is simply the concept of "direction" and "speed" combined: where the object moves, and how quickly it gets there.
So the "force", too, has a direction, and because obviously you can determine to what kind of speed you want to get an object, it also has a size.
Thus it can be represented mathematically by a vector.
Imagine a game of "tug-of-war" here. Two people pulling on a rope. The endresult of the pull is determined by the power of the participants. When both parties are of equal strength, they won't move at all.
Imagine a three-way game of "tug-of-war". Now the motion isn't limited to a forward-backward direction, it can go all over the place... but still, the resulting movement will be the sum of all the parties' efforts combined.
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And now, finally finally, after all that lengthy mumbling that might not have been necessary if Kindale had simply responded to my offer and told my what he already knew about vectors... we will come to the "excuse"... the earth is too big.
(And again the disclaimer: I am talking about the
model that he is criticizing. I am not talking about how or whether it applies to reality.)
Gravity is a force of attraction between to objects with mass. It can induce a change in the state of motion in objects (simply called "falling down").
The size of the force of gravity is dependent on both of the masses. The more mass either of the objects have, the bigger the force. So the size of the force is proportional to the product of the two masses.
The size of the force of gravity is also dependent on the distance of the two masses. The farther away, the smaller the force. Because of the spatial distribution, it is proportional to the
square of the distance.
So, in mathematical terms: F(Gravity) = (Mass1*Mass2)/(Dist*Dist)
(When you look up this formula, you will find another factor, called the "gravitational constant". This factor doesn't change anything about the relationship, it is just used to bring the values in line with our commonly used units of measurement.)
The direction of the force of gravity is along the line between the two masses. For simplicity's sake, both this as well as the distance is calculated using a point in the center of mass of the objects. (This can be shown to be valid, but would go too far here. If anyone is interested, I am happy to explain... perhaps even use some pictures. But for now, I am just lazy.)
So, to come to the final final final conclusion.
The force of gravity between objects can be represented by a vector... a line with a certain length and direction.
When you take "water" (let's represent it by a single droplet) and a "ball", they will attract each other, relative to their mass and the distance between them.
In the same way, there will be a force of attraction between the water and the earth... which we cannot simply get rid of in our experiment.
Yes, the final question: in which direction will the water move? In which direction is the force of attraction the greatest?
In the direction of the ground of course. The force of gravity is relative to the mass... and the earth is a lot lot lot lot more massive than any object that you could reasonably experiment on. You simply cannot ignore the earth... and ignoring it is just what the Flat Earthers do.
It is not that the earth is "too big". It is that it is "big", and it is "there". It's the elephant in the room of pouring water over a ball.
