Visual Basic 5.0 program "VB Train" & "VB2010 Train" - Description and operation

Introduction and Purpose

The purpose of this document is to discus both programs "VB Train" & "VB2010 Train".
Both both are functional identical. "VB Train" is writen in Visual Basic 5.0 and "VB2010 Train" in Visual Basic 2010 Express.
Both programs are used to demonstrate the Length Contraction, a visible illusion by performing a simulation of a train around a race horse track.
To download an executable VB Train.exe select: VB
To download an executable VB2010 Train.exe select: VB2010
For more information goto: Implementation details



For a description of the mathematics (physics) involved see the above link. The importance of the program is that it is a simulation what an observer observes (sees) from a fixed point.

Operation - Control Display - Initial

Immediate after being started the program shows the Start and the Cancel push buttons.
Select the Start pushbutton.
The display changes. See picture 1
Picture 1
The purpose of the display is to select a simulation and to start the simulation.
Three simulations are possible:
  1. Type 1; This demonstrates a round track.
  2. Type 2; This demonstrates a race horse track
  3. Type 3; This demonstrates two long trains (Terrell rotation)
In order to select an experiment the Simulation parameter is used The initial value is 1: Round Track Simulation.
When the Simulation parameter is selected the value is incremented i.e. becomes the value 2. etc.
When the Select Pushbutton is selected the simulation starts.

Operation - Control Display

Operation of the simulation is done from the Control Display.
Picture 2
The Control Display contains four push buttons: "Stop", "Cancel","V >","V <,"V = 0" and "Freeze" The Display shows the additinal parameters:
  1. The parameter Length Contraction shows if length contraction is used. This parameter can be changed.
    means that no length contraction is involved
    means that length contraction is involved accordingly to the parameter Lambda
  2. The parameter v shows the actual speed of the train.
  3. The parameter c shows the speed of light.
  4. The parameter Time shows the local time of the watch of the observer.

Track Display

The track display shows the result of the simulation.

Picture 3
Length Contraction = Off

Picture 4
Length Contraction = On
Picture 5
Picture 6

Time Dilation / Clock Dilation

Time Dilation is standard implemented using Special Relativity. That means that the moving clock (on the train) runs slower than the clock at rest.
To demonstrate this you have to compare the parameter Time on the Control Display with the parameter Proper Time on the Track Display.
To demonstrate this, you have to do is to increase the speed of the train to a value larger than 10. When you do that you will observe that Proper Time runs behind Local Time.
The maximum will be reached when v = 30, which is equal to the speed of light. In that case the parameter Proper Time will become froozen.
In picture 3 & 4 both the time Local Time is 204 and the Proper Time is 200
In picture 5 the time Local Time is 91 and the Proper Time is 90
In picture 6 the time Local Time is 155 and the Proper Time is 152 and

Length Contraction

Length contraction is an option. To demonstrate Length contraction you have to change the parameter Length Contraction from OFF to ON.

The Command "V = 0"

The parameter "V = 0" is specific important to demonstrate Terrell rotation, Specific for Simulation 2 i.e. "The Race Horse Track" with parameter "Length Contraction" = OFF.
To demonstrate select "Start", Select Simulation 2, select "Select" and increase the speed to 5.

Terrell Rotation

In the simulation of Terrell Rotation two trains are used. For a description See: Terrell Rotation

Reflection 1 - General

Reflection 2 - frequency & Doppler effect

However there is one more issue. As part of the simulation the observed length of the train changes. Suppose the train emits a light with a certain frequency. What are the consequences with the observed frequency, if any.

Reflection 3 - Is Length contraction vissible?

What the three simulations show that it is very difficult to demonstrate Length contraction.
Specific the type 3 simulation with the two trains running in parallel make this clear.
This simulation can also be used to demonstrate what happens when you use a sphere instead of a rod (or a very short rod). In such a case the width becomes important.
Length contraction is difficult to observe when there is only one observer. The best way IMO to observe length contraction with a real experiment when you have a round track.



Original 24 April 2013
Modified 25 Mai 2013
Modified 10 April 2014
Modified 25 April 2015
Modified 29 September 2017

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