Program 18: Big Bang simulation

Introduction and Purpose

The purpose of the program QBasic BIGBANG.BAS is to demonstrate:
1. The Big Bang in a simple linear world model.
The model assumes that the speed of light is not influenced by the expanding space.
2. That the expansion speed of space is a function of distance.
3. That the observed age of a galaxy is a function of distance. How further away how younger.
4. That the youngest observed galaxy is a function of expansion rate (multiple times c)
For a copy and a description of "the same" program in Visual Basic 5.0 or Visual Studio 2010 select:
Visual Basic Big Bang simulation program "VB BigBang.exe" and "VB2010 BigBang.exe
This program also simulates Milne's Universe.
For a general introduction to world models select this: 3 World models

To get a copy select: BIGBANG.BAS
To see the listing of the program select: BIGBANG.HTM
Execution file select: BIGBANG.EXE and: brun45.exe

Program Operation

The program demonstrates the Big Bang over a period of 15 b year subdivided in periods of 1 b year by means of 150 galaxies or clocks. The 150 galaxies are randomly scatered over the Universe. The Observer is at the centre. Each BillionYear is identified by a different colour.

Input for the program is the expansion factor of Space.
• First enter 1
• In the second run enter 3
• In the third run enter 0.3
• Finally enter 0 to end the program
The expansion rate of the Universe is equal to the expansion factor times c (speed of light).
• An expansion factor of 1 means that the Universe expands with a speed of c. At the end of the demonstration, the simulation shows that the youngest galaxies you can see now are roughly 7.5 billion year old and the oldest 15 b year
• At the end of the simulation the total size of the universe is 15 b lightyears.
• An expansion factor of 2 means that the Universe expands with a speed of 2c. At the end of the demonstration, the simulation shows that the youngest galaxies you can see now are roughly 5 b year old. That means you can see further back in time
• At the end of the simulation the total size of the universe is 30 b lightyears.
• With an expansion factor of 10, at the end of the simulation you will be able to see the state of the Universe very close at the moment of the Big Bang.
• With an expansion factor of 0.3, at the end of the demonstration, you will only see the galaxies between 12 and 15 b years.

Program Description

 ``` D /| / | / | / | / | / | / | / | / | / | / | / | / | / | / | / | / C / . | e / . | . / . | . / . | d . | /| . . | / | . . | / | c | / | . | . A / | . | . . | / . | a | / . | |. | . | / . | . | | . | / . . | | | . | / . | | | . | BB...............................O 0 5 8 11 16 ``` The sketch left demonstrates how the program operates. Suppose that expansion factor is 2c. The line BB-O is the time axis t The line OACD is the x axis. The line BB-D represents is the line x=2t. This is the radius of the world model. The line BB-C represents the the path of a galaxy at a factor p from the radius with p between 0 and 1. The line BB-C is represented by the equation x=2*p*t The line oacde is the linecone through O. This line is represented in this case by x=16-t. In general x=age-t The time of point d is calculated as 2t = 16 - t or 3t = 16 or t = age/3 The time of point c is calculated as 2pt = 16 - t or 2pt + t = age or t = age /(2p+1) The distance is for point c is equal to 2p*age*c / (2p+1)

Feedback

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Created:29 December 2001
Modified: 15 July 2004
Modified: 5 Februari 2014