Gravity Simulator - Welcome (Terms of Use)

coveysd

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Re: Welcome (Terms of Use)
Reply #120 - 07/23/11 at 17:07:16

1) Yes, I first installed GS 2.0 on the same computer, and ran it against the Apophis simulation.

2) Two of the betas I downloaded into the Gravity Simulator directory. Neither worked at all (they just go compute bound).
I downloaded the third beta, codeoptimizer.dll, and a different resume.gsim into a subdirectory. It failed the same way.

3) I copied A2004MN4.gsim into the gravity simulator directory, renamed it to resume.gsim, and tried the 2011FEB01 beta, which failed as before. Then I tried the original 2.0, and it worked perfectly. Note that when I did the copy and rename, Windows required me to provide admin privileges. I figured that's not a problem, because the regular 2.0 worked fine.

4) I renamed codeoptomizer.dll, it still failed the same way. I noticed that it is using 13% cpu, not 100%. But I'm running a quad core processor, with dual threads on each, so maybe that is 100% on the one thread of the one core.

5) I'm USA (St. Augustine, Florida)

I had thought the problem might be related to running a 64-bit Windows 7.

I just tried the 22APR2007 beta (in its own directory), and it worked correctly with the resume.gsim provided in the directions. I exited and tried it again, and it failed (it becomes non-responsive, doesn't even title the time window). I then renamed the A2004MN4.gsim as resume.gsim, ran the original GravitySimulator.exe in this directory, and it is MUCH faster with this version of codeoptomizer.dll. I created another virgin copy of resume.gsim (from A2004MN4) and tried the beta again - it immediately went non-responsive.

Any other ideas? Anything I can do to help isolate the problem?

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Tony

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Re: Welcome (Terms of Use)
Reply #121 - 07/23/11 at 17:57:41

At the moment, I'm stumped. If 2.0 runs on your computer, then the betas should too.

I could try making a setup.exe for the beta version. Perhaps installing it on your computer rather than simply downloading an executable will solve the problem. But this will have to wait, as I'm out of town for a week.

You'll probably like the next beta version if you're working with asteroids and how their orbits are modified. It has dynamic time step, so you can let the sim run at fast time steps, and the sim slows down for you when an asteroid passes close enough to a planet to compromise accuracy.

Version 2.0 is still very capable. In the meantime you could work with it until I figure out a fix for you. Thanks for the bug reports!

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EDG Ultimate Member oh, crumbs!!! Posts: 611 Gender:	Re: Welcome (Terms of Use) Reply #122 - 07/24/11 at 11:07:02 Quote from coveysd on 07/23/11 at 17:07:16: I had thought the problem might be related to running a 64-bit Windows 7. I'm running it on 64-bit W7 too and it works fine for me...
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coveysd

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Re: Welcome (Terms of Use)
Reply #123 - 08/02/11 at 10:12:32

Tony et. al,

I'd like some advice. My primary interest is modelling asteroid deflection.

My first target is Apophis, and I've been playing with the A2004MN4.gsim model, and I decided to update it with the latest data from Horizons to see if the expected tiny differences in updated data made a difference in the April 13, 2029 close encounter.

I queried Horizons for Sun-centered coordinates for Apophis, the Earth, and Moon on 08-MAR-2028 and carefully entered the new data (and new start time) into a copy of the model. I also made appropriate changes for "geosynchronous".

Unfortunately, even with a step size of 1 second, this model shows Apophis missing the Earth by about 200,000 km on 14-APR-2029 (and on the wrong side).

I've triple-checked my numbers and dates.

What did I do wrong, or what should I do differently? Barycenter coordinates? Do I need to add in Jupiter, Venus, and/or Mars to get it right with the longer simulation?

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Tony

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Re: Welcome (Terms of Use)
Reply #124 - 08/02/11 at 11:14:19

Can you post your .gsim file?
It sounds like you did everything correctly. At a time step of 1 second you should have good results. I just tried what you described, and even at time step 256 my results were much better than 200,000 km. Here's my sim:
http://orbitsimulator.com/gravity/simulations/Apophis2028March8.gsim

Are you still having trouble with the beta versions? I'm back home and can help you with that now.

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coveysd

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Re: Welcome (Terms of Use)
Reply #125 - 08/03/11 at 07:57:43

Tony,

I don't see a difference between your numbers and mine! (At least for the Sun, Earth, and Apophis)

But I still see the difference in the results.

I've attached my gsim file. It has the same objects as your A2004MN4.gsim, plus (1) I added a duplicate to Apophis called "New", which I then apply a series of thrusts to, and (2) I added Jupiter to see if that would help (it made no difference). It worked much as I thought, bringing Apophis close to the Moon in April of 2030. Then I tried to apply the latest numbers, and it doesn't work.

Note my simulation does turn on graphics and changes the focus and scale a couple of times. I generally start it, turn off graphics, and let it run until they turn back on by themselves around April 12, 2029, in time for the close approach. Incidentally, I'm mostly applying thrusts of the order of a few cm/s per month (things we can do with ion thrusters).

It's probably something simple and stupid I did, and can't see!

Also, I don't see where you get your numbers for the 2004MN4 January object, so it is simply wrong. At one point I just ran your model backward until 08-MAR-2028 and used those numbers, but somewhere I screwed that up.

And I still don't have the beta working. I was hoping a real "beta install" might help, although I don't see why!

Best regards,
Steve Covey
http://RamblingsOnTheFutureOfHumanity.com/

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APOPHIS_new.gsim

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EDG Ultimate Member oh, crumbs!!! Posts: 611 Gender:	Re: Welcome (Terms of Use) Reply #126 - 10/24/11 at 01:12:05 Tony, it would seem that your antispam measures have been failing recently... are there any anti-spam mods for YABB?
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Tony YaBB Administrator Posts: 1054 Gender:	Re: Welcome (Terms of Use) Reply #127 - 10/24/11 at 17:41:03 I may switch to the new version soon. I don't know if its any better. I might disable registration. Anyone wanting to register can send me an email
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EDG Ultimate Member oh, crumbs!!! Posts: 611 Gender:	Re: Welcome (Terms of Use) Reply #128 - 10/25/11 at 01:59:53 I'd really recommend switching to phpbb3 to be honest - it's much better. I'm not sure if you could port over the posts from here, but you could keep this as an archived forum and start afresh on a new phpbb3 one maybe?
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MissEuropa

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Re: Welcome (Terms of Use)
Reply #129 - 06/01/12 at 17:16:33

Hello!
Validation complete?
I'm a NMSU astrophysics major who is currently researching p type binaries and their potential for hosting terrestrial Earth like planets. I've been using gravity simulator for about two years now.
My current project is modeling a p type binary with at least one planet to demonstrate stability of orbit. I found interest in this topic after reading the Rare Earth Hypothesis's conclusion that a planet without a moon would be inhabitable for complex life. Though I do not necessarily agree with this conclusion I'm intrigued in finding other ways that tidal forces can be present on a planet without a large moon.
I look forward to learning what I can from the forum.

Miss Europa

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Athena YaBB Newbies I Love YaBB 2! Posts: 1	Re: Welcome (Terms of Use) Reply #130 - 07/10/12 at 10:40:31 Hello everybody. This is an interesting simulation. I am here to learn what makes 7-5-3-s.gsim work and then fiddle and make some changes.
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Basilisk

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Re: Welcome (Terms of Use)
Reply #131 - 09/06/12 at 19:58:07

Hey guys,

just introducing myself.
I am a screenwriter (actually I work in a team of screenwriters, you may call us legion, for we are many, lol), and we are working on a project writing the script for a TV series pilot that we should have up to delivery by this coming December.
I guess you folks are just the ideal crowd to help me with some questions I have. I've been trying to crunch Gravity Sim by myself, but I don't seem to get the handle of it.

I will post my question this weekend.

Thanks for having me in.

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Tony YaBB Administrator Posts: 1054 Gender:	Re: Welcome (Terms of Use) Reply #132 - 09/10/12 at 15:16:36 Welcome! We look forward to your questions.
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inetd

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Re: Welcome (Terms of Use)
Reply #133 - 12/03/12 at 21:14:37

Hi, guys!!

Glad to be here, and thank you for this!!
Short introduction: I am working in IT inducstry, computer networking. But very interesting in astrophysics, astronomy. And I am very happy to find this great Gravity Simulator - at least I do not need to write my own

(some ideas was present during last 5 years, but no time)

Thanks!!

CU,
Denys

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JDoolin

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Re: Welcome (Terms of Use)
Reply #134 - 12/29/12 at 17:20:10

Hello.

Jonathan Doolin here. Long time Special Relativity enthusiast. Second-time astronomy professor. Learning as much as I can so I can teach it!

While looking up some things about the plutoids I happened across this animation: http://en.wikipedia.org/wiki/File:OrcusandPlutoRotatingFrame.gif After a little more googling, I think I found the software that made it!

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