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I was surprised to find the 'stringy' texture of intergalactic structure which these intense simulations seem to concisely capture , was also generated -roughly
by strainer 9y ago
I was surprised to find the 'stringy' texture of intergalactic structure which these intense simulations seem to concisely capture , was also generated -roughly, by a very naive simulation which I applied to a few thousand points:
http://imgur.com/a/hu1On http://imgur.com/a/hu1On
The process which changed homogenously random points in a cube into those stringy messes, didnt even include gravitation. It pulsated the points and diddled random neighbours ever-so-slightly closer to each other over a few million iterations.
I realise that academic universe simulations like this examine with great insight, more subtle features but i found it interesting that the basic stringy texture does not require precise forces to self arrange.
- lutorm 9y agoI suspect the texture will look basically similar under any scheme where stuff is attracted more strongly the closer they are. It's a basic feature arising from the "the dense get denser" characteristic of gravity.
- strainer 9y agoHowever the structure seems only present at huge scales. We dont even see it in nebula.
- are_you_kidding 9y agoThe Crab Nebula: https://www.nasa.gov/sites/default/files/images/430453main_crabmosaic_hst_big_full.jpg https://www.nasa.gov/sites/default/files/images/430453main_c... described in a journal article 30 years ago: http://adsabs.harvard.edu/full/1988ApJ...327..853R http://adsabs.harvard.edu/full/1988ApJ...327..853R
- strainer 9y agoare_you_kidding its a wonderful image but the texture of the strings is a bit different - its more 'furry' I wouldn't be sure that is due to gravitational attraction, possibly electromagnetics involved?, maybe not but such nebulas are a bit exceptional - at the large scale universe structure there doesnt seem to be any exception - the whole lot is stringy.
- pavel_lishin 9y ago> diddled random neighbours ever-so-slightly closer to each other over a few million iterations Isn't that gravitation?
- strainer 9y agoIt was a random attractive function that did not even apply an inverse square law.
- disconcision 9y agowould you mind elaborating a bit? you say the process moved random neighbors closer to each other, but what do you mean by neighbors? i'm assuming you don't mean particles that are directly adjacent. if the method for selecting which particles to move together is distance-dependent then it's possible an inverse-square law got baked into it just by virtue of the shape of euclidean space.
- strainer 9y agoFor sure I can see that inverse square effect can get involved unintentionally, but the function didn't apply it intentionally and it would have introduced non-inverse-square derived effect. After this early experiment ive tried multiple types of quasi-gravity and quasi-electromagnetism - it is very tricky to arrange a viable 'quasi-force' just by relying on properties of the coordinate system or such. For this I was developing 'spatial splitting' routines, i was taking the end cells of the splitting routine and just moving there contents a little bit towards their centers. While this was going on the 'universe' was also expanding, contracting and turning inside out in a neverending series of big bang and crunches. It looked pretty. The stringification occured with a few different 'end cell' testing functions i happened to try out. I just noticed it wasnt difficult to bring about that structure, unlike other structures which are more difficult to bring about - like accretion disks.
- pavel_lishin 9y agoCould you post your code somewhere?