This document describes thought experiment 4 The thought experiment is called : Duel in the mist

When finished return back to CHAPTER 3 text.

Consider a lonely man (A). What all lonely man do, at least in fairy tales, he falls in love with a lonely woman (W). There is only one snack, the woman of his dreams is married. In the beginning this creates no problem but again, like in all true stories, her husband (B) soon finds out. To make this story short, there will be a duel.

Early in the morning both man (A and B), an observer (O) and the woman (W) go to the field, where the duel will take place. However there is one big problem, over the field there hangs a heavy fog. Immediately this creates chaos, because no one can see each other.

The observer, being the leader, gives everyone a bell, with a different tone. So now each one can hear (at least when they ring their bells) where all the others are. As you will understand, the only way of communication is by sound. There is one problem with using a bell to communicate: time. There is difference in time when someone rings a bell and when you here it.

In order to start the duel (O) collects the two man, leaves (A) behind and walks away with (B). After 40 steps (O) tells (B) to stop and then the observer (O) walks back 20 steps into the direction of (A). There the observer stops and shouts READY and FIRE. Most probably nothing will happen, because neither A nor B know in which direction to shoot.

To make the duel more realistic (O) will tell (A) to start ringing his bell, when he walks away with (B). The same (O) will tell to (B) when (O) walks back towards (A). Now there is a better chance that (A) can hit (B) because by (B) ringing his bell (A) knows where (B) is. The same is true for (B).

In test 1 you will see (A), (B) and observer (O). The rest is easy to follow.

Now perform the program: THOUGHT4.EXE

From the Test Selection Display:

Select test 1

The outcome is maybe as expected. Now see what happens in case the position of the observer (O) changes.

Now perform the program: THOUGHT4.EXE

From the Test Selection Display:

Select test 2

Now perform the program: THOUGHT4.EXE

From the Test Selection Display:

Select test 3

The most equal way to duel is test 3 i.e. when the observer is in the middle between A and B. The question is: where is the middle.

To solve this problem the observer has a bright idea. He informs the two man the following:

        First there will be a count down (Three, Two , One)
        After each count both have to ring their bells.
        Then he will shout READY 
        When they hear READY they again ring their bells
        When he (the observer) hears their bells he will shout FIRE
        When they hear FIRE they shoot.

The strategy behind this approach is that every time the observer hears the bells he has to check if he hears both bells at the same time. If no he has to change his position and to continue with the count down. If yes then he is in the middle and he can shout READY and later FIRE.

Now perform the program: THOUGHT4.EXE

From the Test Selection Display:

Select test 4

Suppose their blows a wind in the direction from A to B

Now perform the program: THOUGHT4.EXE

From the Test Selection Display:

Select test 5

Now perform the program: THOUGHT4.EXE

From the Test Selection Display:

Select test 6

Of course every time after shouting FIRE the observer (O) falls on the ground, because he wants not to become hit himself.
Where the woman stays we leave in the middle.

Before continuing the reader should be aware of two important facts: in the above demonstration we neither use light (propagation is sound) nor clocks. Clocks are typical used to measure speed and that is not the topic of this demonstration.

The most important demonstration is test 4. In that case there is an disturbance which can influence the demonstration.

Two types of disturbances can be visualised:

        Wind in any direction.
        No wind but we can place all the participants on a moving platform
        (a train) which again can move in any direction.

Suppose we first do a test without any disturbances and then two tests with each of those disturbances separate.

Does the observer observes any difference ?

How does this influence the outcome of the demonstration ?

Return back to CHAPTER3.TXT

In order to simulate the different conditions the parameter selection display is used

From the Parameter Selection Display the following parameters can be changed:

        0 = Select test display

        1 = Set standard parameters.

        2 = Screen mode. Valid values are 7,8,9 and 12. Standard value = 9
        3 = Wait time in second. Physical wait time between each simulation  
            cycle. Standard value = 0.5
        4 = Basic Speed.          Standard value = 10  

        5 = Delta time in seconds between each calculation cycle. 
            Standard value = 1