
Computer Modeling Should Become a Popular Hobby - kercker
http://www.qrg.northwestern.edu/papers/files/simhobby-local.htm
======
ssivark
Agree broadly with everything in the article. However, I have one point to
add:

> Physical models that reproduce behavior are limited by the physics of the
> world, while computer models have much looser bounds.

This is also one of the weak points of computer modeling. The outputs are
strongly influenced by modeling assumptions, and without feedback from
reality, one can easily be deluded towards wrong models. The computer
simulation encodes the _map_ not the _territory_. This is particularly true in
hard to model fields like economics & finance. As long as one appreciates
that, computer modeling is a powerful tool.

Regarding what would make modeling more accessible to computer users, I think
the answer is an environment where users have access to the full live system
(few boundaries) and can tweak it in real-time, with right feedback loops. Eg:
Smalltalk, Lisp.

~~~
btown
"All models are wrong, but some are useful" \-
[https://en.wikipedia.org/wiki/All_models_are_wrong](https://en.wikipedia.org/wiki/All_models_are_wrong)

~~~
AllegedAlec
I like how Paulien Hogeweg phrased it too: "thinking in the most interesting
simplification" [0]

I always thought the 'but models are wrong' is quite a weak excuse. Newtonian
physics is a wrong model of how the universe works. Using it though; we put a
man on the moon. Einsteinian physics are incomplete, but it allows us to use
satellites moving at roughly 10KM/s to pinpoint our location to within a few
metres.

A model's usefulness is not about how accurately it describes what is
happening, but about whether it describes what happens _at a certain meso-
scale_ accurately.

[0]:
[http://www.labtimes.org/labtimes/issues/lt2011/lt07/lt_2011_...](http://www.labtimes.org/labtimes/issues/lt2011/lt07/lt_2011_07_26_29.pdf)

~~~
phkahler
>> Einsteinian physics are incomplete, but it allows us to use satellites
moving at roughly 10KM/s to pinpoint our location to within a few metres.

Funny. I know how GPS works and that knowing the SAT locations is critical,
but I never thought about how fast they are moving. They need to transmit
their own position and time with great accuracy. In particular, don't they
have to transmit their time and position _at the time of transmission_? That
is a more interesting problem than I realized.

~~~
PeterisP
GPS satellites aren't really transmitting their location at any particular
time, they're transmitting the so-called ephemeris and almanac data that has
information about their orbits so that _you_ can calculate their position at
the time of transmission.

~~~
crankylinuxuser
And if you have a ADALM-PLUTO, you can download the brdc file (ephermis) and
spoof all 12 satellites to a location of your choosing here:
ftp://cddis.gsfc.nasa.gov/gnss/data/daily/2019/brdc/

[https://github.com/Mictronics/pluto-gps-sim-
win32](https://github.com/Mictronics/pluto-gps-sim-win32)

------
diydsp
Recommend adding (1996) to title. That doesn't take away from it, it just
shows how prescient the thought was.

~~~
Animats
Yes. It goes further back than that. That's what Alan Kay thought Smalltalk
should be for. Read "Personal Dynamic Media".

Going forward, there are the persistent shared modifiable virtual worlds, from
There to Second Life to SineSpace and beyond. There are many good 3D CAD
systems now, and the pro ones have some simulation capability. There's
Minecraft and its imitators.

We have the capability, and sizable numbers of users. It's not mainstream, but
it's in wide use.

~~~
PinkMilkshake
Alan Kay (and others) developed a 3D collaborative world in Smalltalk called
Croquet [1]. Definitely one of the most interesting virtual worlds I've come
across.

[1]
[https://en.wikipedia.org/wiki/Croquet_Project](https://en.wikipedia.org/wiki/Croquet_Project)

------
zokier
It is a shame that the field is pretty undeveloped still after 20 years. Only
recently there have been popping up few consumer CADs (fusion360/onshape), but
those are still quite limited and of course do not satisfy free software user
like me. Setting up decent physical simulations seems yet another whole
endeavor even if you got your model done. There are few physics engines
available, but using them seems to require fair amount of work even just for
basics. Then comes the social sharong aspect that the article mentions as
"Shared federated simulation environments". While I don't think that we need
such fully immersive shared environment that the author envisioned, just being
able to share models and simulations for exploration on the web would be nice.
Being able to get nice photographic-like visualizations would be then the
cherry on top this whole thing.

~~~
mojomark
>>(fusion360/onshape), but those are still quite limited and of course do not
satisfy free software user like me.

Fusion360 is free (1). I used it for a while; though I didn't get into all of
the features so I didn't really explore the physical simulation capabilities
in depth, but I know it's supported to a degree (2). I'd imagine the FEA
engine isn't as rigorous as paid software like say, Autodesk Inventor or
Solidworks.

As someone who does a fair amount of 3D modeling, I've always thought sketchup
was on the right track. It's also available in a free version of course, and
the 3D warehouse has a ton of pre-made models in it that I use all the time.

From my experience, I would say the community-built sketchup plug-ins
available are decent, but definitely hit-or-miss. I've never found a good
(i.e. non-buggy and well-supported) 'physical simulation' plug-in for
sketchup, but I haven't checked the plugin store in a while. That, and some
plugins require sketchup pro, which isn't free. In the free software domain,
I'd say basic Sketchup is good for quick mock-ups, whereas Fusion 360 can be
used for higher precision modeling.

1\. [https://www.autodesk.com/campaigns/fusion-360-for-
hobbyists](https://www.autodesk.com/campaigns/fusion-360-for-hobbyists)

2\. [https://www.udemy.com/fea-simulations-with-
fusion-360-static...](https://www.udemy.com/fea-simulations-with-
fusion-360-static-structural-focus/)

~~~
qaute
Usually, CAD programs are written for just one of several domains, outside of
which they don't work as well:

\- Fusion360/SolidWorks/Onshape/Catia/NX are engineering CAD programs. They
are designed to make geometrically (relatively) simple parts with exacting
dimensions (think vector SVG vs raster PNG) that will fit in mechanical
assemblies with other parts. Models (e.g., airplanes) are often simulated for
strength (FEA) and fluid flow (CFD). There are no good open source versions
(FreeCAD is trying).

\- SketchUp/AutoCAD are for architectural and civil purposes. These create
buildings, which often have even simpler geometric features but multiple
floors and plumbing and electrical runs and HVAC and other layers. I don't
know too much about these.

\- Blender/Maya/3dsMax are for "artistic" purposes. They can sculpt very
complex shapes from triangular approximations, but are can't hold exact
dimensions very well (raster PNG vs vector SVG). They are used for computer
graphics (movies, games). I'm not an expert in these, either.

I tend to design robots with Fusion, and it's definitely better for my
purposes than SketchUp (no easy watertight meshes, assemblies, simulation),
but know people who work in different domains who therefore use other
programs.

------
sevensor
I've had a lot of fun with agent-based and discrete event simulations. Hook it
up to a visual and it's basically a game. Writing a basic simulation engine is
also a lot of fun. Simulation is also the only application where I've felt
comfortable with classical object-oriented modeling. I always find that object
oriented programming forces me to deal with a lot of emergent complexity, but
when you're doing simulation modeling, emergent complexity is the whole point.

~~~
gglitch
Sounds awesome. Can you say more? What languages or environments, what kinds
of things you're modeling, other writeups?

~~~
sevensor
NetLogo is fun for toy agent-based simulation models. It includes visuals. For
discrete event simulation, I recommend SimPy. If you like animations and
you're willing to trade some personal info for free stuff, Simio has a free
version that supports mixing discrete event and agent based simulation.

Edit: I realize I only answered about half of your question. I was in grad
school when I did simulation modeling, this was about 5 years ago. I was
working on modeling industrial processes. Simulation is great in that context
because at a certain point queueing theory breaks down. I can't tell you how
many talks I sat through that derived exciting conclusions from the assumption
that all arrival processes are Markovian.

------
platz
> The fog surrounding economic projections, and the other uses and abuses of
> statistical evidence in politics, might lift at least a little.

The perpetual historical failure of academic economic modelers is a
counterexample to this line of thinking; to think non-academically trained
folks would fare better is laughable

~~~
Nasrudith
It might be good for thinking critically however. That could result in a
technical truth - if nobody is fooled by models then they won't be used to
deceive. If everyone can pick out and point to what is missed or inappropriate
models it could and emerging absurdities. I suspect in that regards it is more
a way to teach critical thinking.

The informality could be a boon - less reason to stick to the rules of tenure
knifefighting.

------
llamataboot
I'd love to see more "gamey" and fun platforms for agent-based modeling (Sims,
but with different types of goals to tweak!) and something for system dynamics
modeling.

There's been a few runs at both, but for how poor human brains are at
intuiting things about non-linear systems, and how desperately we need to
understand them, more things in this area would be great!

~~~
troquerre
Factorio is a great game that teaches system dynamics without having that as
an explicit goal

------
Theodores
VRML became really good a couple of years after this with SGI's CosmoWorlds. I
built some incredible things with it, with my actual sister as if we had gone
back to childhood with the LEGO bricks out. In fact my sister's well paid
career is entirely due to how impressive the VRML that fitted on a floppy disk
was. Funny to think that you also applied for jobs by post back then.

Admittedly the texture rendering was not up to modern gaming standards but
everything worked and existed on a beautiful imaginative plane - much like how
a little bit of imagination is needed with LEGO.

But then we realised nobody else was on the trail. Our models were far in
advance of anything published online. Only the SGI demos were cooler than what
we had come up with. Then there weren't many of those beyond the demo disk
that came with new SGI machines (and needed the power of an SGI machine).

The tools - Cosmoworlds - were fantastic and not hard. I particularly liked
the audio aspect, being able to have different music play in a scene and for
the stereo to move around as you explored a scene. If I was a musician then I
would have wanted my album played that way.

But no musician thought to put their traxxx in a 3D virtual world, online for
the world to hear. They had distribution in those days so the required VRML
viewer could have been distributed on CD to solve the problem of that ten
minute download over dial up.

3D then became the cottage industry that it remained, only done in games
companies or by specialists doing things like oil exploration, CAD or other
things like TV adverts. Despite the wonders of CosmoWorlds it never became
this accessible thing that people wanted to play with in a Lego like way.

After my sister and myself pushed VRML so far my sister ended up working in a
world where the interactive exhibits she was to be building for one of the
world's greatest museums would only ever be flat and two dimensional. The
portfolio of awesome interactivity that got her the job never made it past the
bureaucracy, committees and bullshit of the regular world. It was a glimpse of
a future that was never going to happen, a high note of creativity to never be
reached again. We downsize our dreams, from 3+ dimensions to 2.

The problem wasn't us or SGI's CosmoWorlds. It was everyone else. We are not
that adventurous as a species. On a given day the finest mountain tops with
the most awesome views only have a small amount of people there, not seven
billion people. Even though getting there needs no more effort than putting
one foot in front of the other for half the day.

------
vinceguidry
I wonder if there's not a more basic reason for the observations of the
author. When I code as a hobby, my main goal is to make sure that no effort is
wasted. I get precious little free time to hobby code as it is, so every
minute spent in front of a text editor that's not driving forward to the
desired goal feels almost physically painful.

The last thing I want to do in my off time is fiddle endlessly with all the
endless layers of friction.

To hobby is to demand instant gratification. The land of hobby seems to want
to be connected to the land of research. But research is only truly useful
when the desire for instant gratification can be dispelled.

If I'm reading the author correctly, computer modeling _might_ be that magical
land where hobby and research can commingle. Where instant gratification can
produce tangible research results.

I'm not convinced. Is it really a matter of tooling? Because it seems to me
that any kind of modeling that would actually have research potential is going
to have to be invented. So now my hobby involves research _and_ invention?

Maybe after I retire.

~~~
logram
Hopefully I didn't misunderstand what you meant, but I'd argue that a hobby is
exactly not instant gratification. That I would call entertainment.

In my opinion the gratification of a hobby comes from enjoyment of the process
itself. For example, if you play music, drilling through the same couple of
measures until it sounds right might not pay off until the end, which might
take hours and hours of work across many days. If you don't enjoy the process
then you won't take it up as a hobby, but that doesn't mean there is constant
gratification. Even more, the end result might not be as good as a
professional product -- but it's yours and it's the journey that counts.

I say that instant gratification is entertainment because I would compare that
to playing games or watching a movie. There's no process there, it's just
gratification.

An example would be the people that make emulators as a hobby. Across their
journey they find so many special cases and undocumented behaviour that it is
certainly a lot of work riddled with unexpected obstacles. But exactly that is
the process of problem solving and ultimately what they enjoy.

~~~
vinceguidry
Music is a great example. I used to play guitar, I don't now because the time
investment needed to get to fulfillment is too heavy. I can pick up a guitar
and noodle around with it, but the impetus to take it seriously as a hobby is
just no longer there, because of all the perceived friction.

Of course, if I'd taken it seriously as a kid, I wouldn't have that friction
and I could count the guitar among my regular hobbies. I don't have that same
attitude towards the keyboard, which requires far less finger dexterity and
thus practice. I'll probably never pick up a guitar for more than a few
minutes ever again, but I can see myself buying a keyboard and stand and going
at a piece of music for ten minutes or so every day. (it's a bit of a
contrived example, the real reason I don't play my guitars at the moment is
because I don't like what it does to my fingers.)

This is what I mean by instant gratification. Everybody draws their line
differently, but it's hard to argue that the line doesn't or shouldn't exist.
A hobby is what you spend your excess time and money on without expecting a
financial return from it. Having an impact is fine, but commerce it isn't,
otherwise you call it a side project.

------
wmf
Tangentially related: if anyone (or their kids) is bored with voxels, try
Astroneer; it's more like virtual clay.
[https://astroneer.space/](https://astroneer.space/)

~~~
petermcneeley
But if you cant build a quad core CPU inside the game then whats the point?
[https://youtu.be/SPaI5BJxs5M](https://youtu.be/SPaI5BJxs5M)

------
CupOfJava
I want to model my home in 3D, with measurements. What's a good free
alternative to autocad for that?

~~~
Sileni
Doesn't have all the functionality that AutoCAD does, and there are some
usability issues if you're really comfortable in AutoCAD already, but I
imagine FreeCAD [0] would work well for your use case.

[0]: [https://www.freecadweb.org/](https://www.freecadweb.org/)

~~~
acidburnNSA
I'm particular the BIM workbench is looking pretty slick these days [1]

[1]
[https://www.freecadweb.org/wiki/BIM_Workbench](https://www.freecadweb.org/wiki/BIM_Workbench)

------
Quequau
Years ago I read "Growing Artificial Societies - Social Science from the
Bottom Up" by Joshua M. Epstein and Robert L. Axtell and was really motivated
to do computer modeling as some sort of hobby.

For me at least the problem was once I got their original model up and running
I wasn't able to sustain the focus to construct a graphical representation
that was compelling. So I never went back and debugged the stuff that I added
to model (not seriously anyway).

~~~
Quequau
lol and that comment just trigger an old google alert I have running on this
topic.

------
TaylorAlexander
Well I definitely spend most of my hobby time modeling 3D printed robots!

------
meheleventyone
I think it has, just not in the way the author intends here. This article was
basically written on the cusp of the game modding scene really taking off
online, followed by the indie game revolution of the early 2000's into what we
see today as a glut of games being released. The popular computer modeling
pastime is game development and exhibits much of what is talked about in the
article.

------
moron4hire
Definitely needs a "(1996)" on the title.

------
anonlastname
Many games have a modding community. A lot of these mods are usually
suprisingly detailed model packs.

------
dkuebric
Seems like the author was right; I'd look to Minecraft as the analogue for
model trains.

------
Joakal
For those that are developers/programmers, you might like OpenSCAD where
models are generated from code. I prefer it over knowing where/when to use
menu items.

As a bonus, the exports work with 3D printers.

Source: Printed parts of a hand as a hobby.

~~~
lkschubert8
I absolutely love the idea of OpenSCAD, but it's speed is extremely painful,
even for things that are geometric. As soon as you start trying to make
something more organic it crawls.

