General Relativity Simulation Contest
Description of Contest
The purpose of this Contest is to prove General Relativity.
The Contest consist of the following task:
- Write one general purpose program (any programming language will do) which simulates the movement of n objects over a certain period of time.
- The simulation method used (algorithms), should be based on the Rules of General Relativity.
- The program should be able to simulate and demonstrate the following examples:
- Forward movement (perihelion shift) of the planet Mercury (43 arc sec angle) around the Sun.
- The bending of light around the Sun (1.75 sec).
- The movement of a binary star system. The stars should spiral together.
- A clock in a space ship around the Earth.
- Twin paradox (SR). i.e. at least two clocks should be included.
- The behaviour of black holes.
- The results of the simulation should match actual observations.
For the rules of General Relativity see the following: General Relativity with John Baez
For the most elaborate list of links for General Relativity see:Relativity on the World Wide Web by Chris Hillman, maintained by John Baez
For a technical discussion about the problems with numerical simulations regarding General Relativity see:Numerical Relativity
If you want more about celestial mechanics simulations informal newsletter, The Orrery , which thrives on the topic. For a subscription: E-mail Greg Neill
For a nice site with lots of information about simulations try the following: A Scale Model of the Solar System , E-mail Bob Jenkins
F
Program Evaluation
The winner is the program that, of the 6 examples or less, the closest matches observations.
The exact value of those observations is still open for discussion. Input from you, the readers, is highly appreciated.
Program Evaluation - Some Thoughts
IMO to define the rules of the observations is not so easy.
General speaking there is a time component and a distance component.
A very important starting assumption is that the whole measuring system must be based on one concept. It is wrong to state that within the solar system we use one concept and for outer galactic distances an other. In fact the most global system should be your starting point.
One way by measuring distance is by using clocks and lightsignals. If it takes 2 minutes or two years for a signal to come back than the distance is respectivily one light minute and one light year. The problem is when (i.e. at which moment) and what means one light minute resp. one light year.
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To answer the first question when you could claim one minute (resp. one year) after the start of the experiment (i.e. when the signal was transmitted), but is that correct?
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To answer the second question is even more complex. One light year is the total distance (forwards plus backwards) travelled in one lightyear of a reflected light signal.
The problem is what is that distance. You want to give it a value in meters (or km).
- You can solve this issue by performing a test on Earth using a standard length and a standard clock. The result will be a measure of the speed of light on Earth at the place where you performed that experiment.
Consider the definition of the speed of light c. For example consider that the speed of light is 300000 km /sec. What does that mean?
It means that a lightsignal travels in 1 second 300000 km. or 300000 times "The number of seconds in one Year" km. in one year or 300000 times "The number of seconds in million Years" km. in million years.
But this also raises different questions:
- what is a second. How do we measure one Year?
- what are 300000 km.?
- is this valid every where?
- is space expansion involved?
The most important question to answer is: "Is light in any way physical influenced by the fact that space (the universe) expands"?
IMO the most practical solution is to define a 3D grid centered around the centre of our Galaxy and only to use one Earth based clock and to consider this one clock at rest in this 3D grid. That means no moving clocks and no length contraction are involved.
In fact you make the whole system absolute and no SR effects are involved.
How to enter the Contest
In order to participate the only thing that has to be done is to sent an e-mail to nicvroom@pandora.be with the following information:
- Name of the group or person that is responsible for the entry.
- the URL or ftp where the entry can be investigated.
All the rights stay with the author of the entry.
The primary purpose of the contests is to write a general purpose program using the General Relativity Theory.
However if someone believes that he or she can write a program which can simulate the same observations more accurate using a different set of rules, than this is also allowed.
The following alternative rules are possible:
- Newton's Law.
- Special Relativity Theory.
-
Post-Relativistic Gravity or PG by Ilja Schmelzer
- Autodynamics by Ricardo Carezani
- The Harmonics Theory by Ray Tomes
-
Model Mechanics by Ken Hon Seto
- * Fractal Physics
- * Divergent Matter Model (Parallel World(s))
- * Project Omicron Removed as of 8/1/2016
- * Jack Martinelli,s Theory - A Deeply Unified Field Theory
- * John Doan's Theory - A Challenge to Einstein's Theory
- Radiant Pressure Model of Remote Forces by Stan Byers
- Distance-time theory (D=cT) By Keith Maxwell Hardy
- * The Absolute Reference Frame (Eather Theory and At Theory)
For a copy of a program which demonstrates the At Theory select: obarr.bas E-mail: Gerald L. O'Barr
- Other. Please specify Law or Theory and URL with details.
Entries for the Extra Contest should identify one of the above.
For a full list of possible candidates for this Extra Contest have a look at:
Ending Date of the Contest
Starting Date of the Contest: 9 August 1996
There is no ending date to the contest. Participants can re-issue their solution as they like.
A list of entries received will be maintained.
The order in the list identifies a rating. The best program is at the top.
Prices
There are no formal prices in this contest.
If you do not like that may be the following contest is more suited for you: Relativity ?? $50.000 (US) Awards for Mathematical Proof. However the readers of the newsgroup news:sci.physics.relativity doubt that this price will ever be awarded.
Entry example
For an example of a possible solution to this contest is the program GRAVITY.EXE (51 kB) by Jens Joergen Nielsen
For a short description of the program see the following: 3D Simulation of Gravity
This very nice general purpose program, based on Newton's Law. This program is unfortunate hors concourse because no comparison is included with actual observations.
A program which generates relativistic orbits about rotating and non-rotating black holes of various masses written in FORTRAN by Steve Bell is at: General Relativity Papers
There is no comparison with actual observations. See Feedback date 20/11/97 for more detail.
A program which generates images of far objects distorted through a black hole written in PASION simulation language by Stanislaw Raczynski is at: Simulating General Relativity. PASION translator requires PASCAL compiler to generate executable code. The program is also used to simulate a relativistic orbit of a planet. However there is no comparison with actual observations. See Feedback date 21/01/03 for more detail.
Results of the Contest
No Entries received for the General Relativity Contest.
- Apperently it is very difficult by the GR community to write one program to simulate all or less of the 6 examples.
- For the entry which comes the closest see feedback of 20/11/97 by Steve Bell
- For an entry which simulates Example 1 (For an arbitrary planet) and Example 2 (But uses a Black Hole instead) see 21/01/03 by Stanislaw Raczynski
One Entry received for the Extra Contest.
- Entry by R.L. Collins. For methode used see Feedback dated 3/9/97.
Entry is within scope of contest, however only solves example 2.
The MathCad program used to calculate the deflection is available on request to the author.
One entry in the category Special Relativity is the excellent program Relaty by Guido Wuyts. The program demonstrates the twin paradox. There is no comparison with actual observations. See Feedback date 21/11/97 for more detail.
Astronomy programming
If you are interested in astronomy programming you may want to check out the home page by E-mail: Eric Bergman-Terrell
His web site is: http://www.ericht.com/
You can also download Astronomy Lab 2 from that web site. http://www.ericbt.com/astronomylab2. Astronomy Lab is an astronomy prediction, graphing, and simulation program.
Feedback
- 1/9/96 Good luck with your project, be sure to announce it in the relevant newsgroups.
- 15/12/96 The list of examples 1-5 is rather biased to relativity (I know that was done intensional)
- 16/12/96 This is a wonderful spirit of scientific enquiry.
- 24/12/96 Whatta contest.
- 3/9/97 I'm not quite sure whether this entry is acceptable, and in the
spirit of the contest.
As you surely know, the deflection of
starlight, on passing the rim of the sun, is 1.75" of arc.
The direct tug of gravity on the apparent mass of a photon, E/cc, gives
only half this deflection although it accounts fully for the increase
of the energy of a Mossbauer photon falling in earth gravity.
In the paper:"Gravity Slows the Speed of Light" , available on the internet at
publish.aps.org/eprint as:
"aps1997aug08_002", I show that the missing deflection can be found by
recognizing that the speed of light decreases in a gravitational
field from c to v=c/[1+GM/rcc].
Using this, the deflection of starlight is wholly explainable without reference to GR.
E-mail: R.L. Collins .
- 20/11/97 I see there is a GR programming contest. The program of mine that you have a link to has been thouroughly tested, not just by myself but was peer reviewed by people from the Am. Institute of Physics, so I know it
gives the correct orbital data. There have been several articles in past
publications of a journal called Computer in Physics
http://www.aip.org/cip/ciphome.htm that have gone into how to simulate
GR movement in quite a bit of detail, just like the articles I have
written.
E-mail: Steve Bell .
- 21/11/97 I regularly welcome people around here to download my simple QBprogram
"Relaty" , or its compiled version, and besides others, at my site
http://www.ping.be/wugi/qbasics.htm
It contains animation for the usual SR bestiary: world lines, light
clocks, length contraction, time dilatation, the twin paradox, and, not
to be neglected, the difference between measurement conclusions and
actually "looking at" an object...
E-mail: Guido Wuyts .
- 3/8/98 I have a few problems with your contest as stated. Your statement says
that the program must conform with ACTUAL OBSERVATIONS. Item 3 in the
list is not even properly accounted for by relativity in regards to the
DI Herculis binary system which continues its tradition of not matching
the predicted perihelion shift. No one has ever tested item #5 (for
macroscopic bodies) and we do not know what the ACTUAL OBSERVATIONs
would be. Also, in regards to item #6 we have no observations of black
holes whatsoever, only inferences about what we are observing. For these
reasons I feel your contest is presumptive and biased in that you
require alternate theories to match supposed observations which do not
exist in the first place and require your contestants to "match" a
theory which we already know fails item #3. This is a poorly stated
problem!
- 6/8/98 I just came discovered your "General Relativity Simulation Contest" on the internet. Are you still accepting entries? If so, I would like to prepare an entry based on a model that I developed which matches the observations predicted by General Relativity but which is not based on General Relativity Theory.
- 18/9/98 In response to the various criticisms I read, General Relativity is no more and no less of a theory than Quantum mechanics. It is the best (and most accurate) theory of the physical world we have right now. Although some
favor the Yilmaz Theory , it has at least as many problems as GR itself has.
I believe that the next big theory will result from the unification of GR
and QM, making modifications to *both* theories.
- 30/05/00 My name is R.L. Collins, and I previously entered this contest with
an eprint dealing with the deflection of star light. See:3/9/97
A better solution is discussed in the eprint publish.aps.org/eprint "aps2000jan14_001".
This is not GR. It is the mass-metric theory, which recognizes the changes of mass by speed and also by gravity. With these modifications of mass, the solutions of problems 1 and 2 are very simple. It also easily solves the Shapiro time delay problem, a problem not included in your list but which is one of the classical tests of GR.
A revised version of this paper has been submitted to phys. rev. d, and is under consideration for publication.
E-mail: R.L. Collins .
r.l. collins
- 21/01/03 Hello,
I would like to participate with my simulations. The page of my program is
http://www.raczynski.com/pn/genrel.htm
From that page you can download the complete article with detailed experiments description.
- Sincerely,
E-mail: Stanislaw Raczynski .
Universidad Panamericana
McLeod Institute for Simulation Sciences
Mexico City -
-
24/12/05 I would like to participate in the Extra Contest with the method I have developed. I have written a program that can do the following:
- Simulate the Forward movement (perihelion shift) of the planet Mercury (43 arc sec angle) around the Sun.
- Simulate the bending of light around the Sun (1.75 sec).
- I have not attempted to solve for "The movement of a binary star system. The stars should spiral together." yet. My theory needs more development to achieve this. However, I believe it is possible within the scope of my
approach.
- and 5) The program I have written does not deal with clocks (unless you consider an orbit to be a clock). However, the equations presented in my book Time, Matter, and Gravity do. Therefore, I believe my approach will answer questions ( in an understandable manner) related with steps 4 and 5 of your contest.
- Idem
- With respect to a black hole. In my approach a black hole does note form. However, I predict an object that could be interpreted by modern observations to be a black hole. I need to update my program so that it will have the numerical accuracy to model the motion of objects and light near the surface of such and object. I plan to complete this in about a month.
You can read about my approach and download an Excel based program for doing the calculations at: http://anderson.morris.home.att.net You can also download a copy of my book Time, Matter, and Gravity which gives a full derivation of my approach. I think you will find the equations to be simple and easy to understand.
After I read up on your website, I will submit some feedback for you.
Thanks for the contest. I am glad to see it.
Sincerely,
- E-mail: Morris Anderson.
-
Created: 9 August 1996
Modified: 23 december 1999
modified: 28 January 2003
Modified:28 December 2005
Modified: 8 January 2016
"Extra Contest" links
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