
The Largest Virtual Universe Ever Simulated - jonbaer
https://www.sciencealert.com/scientists-have-created-the-largest-ever-virtual-universe-inside-a-supercomputer
======
swashbuck1r
I predict the following quantum bug: Due to optimizations to prevent the need
to simulate every single particle in this universe...the people who evolved in
this universe are now perplexed that physics works so intuitively at the large
scale, but at the small scale, it seems to become bizarre and "not calculated
until you look".

~~~
radarsat1
You are suggesting that the nature of quantum mechanics is an argument for the
simulation hypothesis?

~~~
wuch
There is running joke about general relativity and quantum mechanics being a
demonstration of simulation hypothesis, i.e., floating point computations used
to simulate our universe break down under very small and very large scales.

~~~
jfoutz
And mass slows down time because the load increases

~~~
jhurliman
Related to this, Second Life has a concept of time dilation which is the ratio
of current simulator frame rate to ideal frame rate (30fps IIRC). As more
avatars, scripts, and physically simulated objects were put in a simulator the
time dilation increased.

~~~
JetSpiegel
Interesting, I first heard about this regarding EVE Online.

------
strainer
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.

~~~
pavel_lishin
> _diddled random neighbours ever-so-slightly closer to each other over a few
> million iterations_

Isn't that gravitation?

~~~
strainer
It was a random attractive function that did not even apply an inverse square
law.

~~~
disconcision
would 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
For 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
Could you post your code somewhere?

~~~
strainer
Ive put it up here -

[https://github.com/strainer/particloud55](https://github.com/strainer/particloud55)

There is a link in the readme to it running on webgl.

Its very old experimental code, i just noticed this stringifying happening on
a number of revisions.

The project is more substantial and mature now but it no longer stringifies
clouds \ :) /

[https://strainer.github.io/fancy/](https://strainer.github.io/fancy/)

~~~
pavel_lishin
Whoa, weird. It seems to coalesce into very regular rectangles for me!

~~~
strainer
heh, it begins forming those rectangles because each rectangle is a group of
particles which have been initialised with same velocity vectors. (Their
position is intialised randomly within one cube, but their velocities randomly
within multiple cuboids). This configuration is not essential for
'stringification' Its a just a snapsot of experimental/playful developement.

The distortion and eventual 'stringification' of the undulating point groups
occurs over minutes or hours of runtime.

------
erikpukinskis
This is the highest resolution image of the data that I can find:
[http://www.dailygalaxy.com/.a/6a00d8341bf7f753ef01bb09a3f2d2...](http://www.dailygalaxy.com/.a/6a00d8341bf7f753ef01bb09a3f2d2970d-pi)

------
askvictor
My recent thinking about simulations is that we might soon inadvertently
create life/consciousness while simulating something else. Which leads to
interesting ethical considerations - before switching off a simulation, should
we check for life? And how do we do that, given that it's going to be
completely alien?

~~~
idlewords
We can't even simulate a nematode worm right now. So the ethics are pretty
easy:
[https://en.wikipedia.org/wiki/OpenWorm](https://en.wikipedia.org/wiki/OpenWorm)

If you want to worry about overlooking artificial life, a more interesting
scenario is some kind of evolutionary pressure among malware, leading to a
computational equivalent of roaches or even crafty raccoons, stealing a living
from our internet-of-things trash cans.

~~~
askvictor
The problem is in how we define life and consciousness, particularly when they
are completely, unimaginably alien to us. Conway's Game of Life?

------
malkia
The precursor to the Matrix it seems!

