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4
Vol. 2. No.1
“Pedagogy, Education and Innovation in 3-D Virtual Worlds”
April 2009
Guest Editors
Leslie Jarmon
Kenneth Y. T. Lim
B. Stephen Carpenter
Editor
Jeremiah Spence
Technical Staff
Andrea Muñoz
Amy Reed
Barbara Broman
John Tindel
Kelly Jensen
This issue was sponsored, in part, by the Singapore Internet Research Centre,
the Department of Radio, TV & Film at the University of Texas at Austin,
and the Texas Digital Library Consortium.
The Journal of Virtual Worlds Research is owned and published by the
Virtual Worlds Research Consortium,
a Texas non-profit corporation.
(http://vwrc.org)
1
Vol. 2. No.1
ISSN: 1941-8477
“Pedagogy, Education and Innovation in 3-D Virtual Worlds”
April 2009
Second Life physics:
Virtual, real or surreal
?
By Renato P. dos Santos, ULBRA - Universidade Luterana Brasileira, Brasil
Abstract
Science teaching detached itself from reality and became restricted to the
classrooms and textbooks with their overreliance on standardized and repetitive
exercises, while students keep their own alternative conceptions. Papert, displeased
with this inefficient learning process as early as 1980, championed physics
microworlds, where students could experience a variety of laws of motion, from
Aristotle to Newton and Einstein or even “new” laws invented by the students
themselves. While often mistakenly seen as a game, Second Life (SL), the online 3-D
virtual world hosted by Linden Lab, imposes essentially no rules on the residents
beyond reasonable restrictions on improper behavior and the physical rules that
guarantee its similitude to the real world. As a consequence, SL qualifies itself as an
environment for personal discovery and exploration as proposed by constructivist
theories. The physical laws are implemented through the well-known physics engine
Havok, whose design aims to provide game-players a consistent, “realistic”
environment. The Havok User Guide (2008) explicitly encourages developers to use
several tricks to cheat the simulator in order to make games funnier or easier to
play. As it is shown in this study, SL physics is unexpectedly neither the
Galilean/Newtonian “idealized” physics nor a real world physics virtualization,
intentionally diverging from reality in such a way that it could be called hyper-real.
As a matter of fact, if some of its features make objects behave “more realistically
than real” ones, certain quantities like energy have a totally different meaning in SL
as compared to physics. Far from considering it as a problem, however, the author
argues that its hyper-reality may be a golden teaching opportunity, allowing surreal
physics simulations and epistemologically rich classroom discussions around the
“what is a physical law?” issue, in accordance with Papert’s never-implemented
proposal.
Keywords: Second Life, physics, realism, hyper-real, surreal.
This work is copyrighted under the Creative Commons Attribution-No Derivative Works 3.0
United States License by the Journal of Virtual Worlds Research.
Journal of Virtual Worlds Research- Second Life physics 4
4
Second Life physics:
Virtual, real or surreal
?
By Renato P. dos Santos, ULBRA - Universidade Luterana Brasileira, Brasil
Among all the virtual worlds that exist today, Second Life (SL), which appeared in 2004
almost out of the blue, has now the largest user base. Its older competitors like AlphaWorld,
Active Worlds, the Croquet Project, and other virtual worlds, all have different strengths, but
none of them matches the popularity with the general public and the commercial companies that
SL has conquered (Bestebreurtje, 2007).
SL is an online 3-D virtual community developed by Linden Research, Inc. founded by
Philip Rosedale, better known in the SL world as Philip Linden (Linden Lab Management, n.d.).
SL is hosted and operated by Lab of Linden Research, Inc., also known as Linden Lab. The
entire world of SL, called the grid, (including all avatar data, objects, landscapes, textures, and
texts) is hosted on servers run by Linden Lab. SL is still seen as a game, but its residents have
disputed this notion because there are essentially no rules imposed on the residents
(Bestebreurtje, 2007). The only exceptions are the restrictions on areas that are not open to the
general public and the physical rules that make objects to interact realistically. To access it, users
only have to download and install client software locally. Once logged, SL users, called
residents, can walk around, explore the world, enjoy the 3-D scenery, fly, drive cars and other
vehicles, interact with other avatars, play, or create objects. There are a wealth of resources for
building complex objects, with many different textures, such as chairs, clothes, jewels, vehicles,
guns, and even entire buildings. In fact, most of SL world has been built by the residents
themselves, which has been characterized as a shift of culture from a media consumer culture to
a participatory culture (Jenkins, 2006).
The ease in which new users can join SL, combined with support from several
educational and library groups, discussion forums and a wide range of free communication,
graphics, design, and animation tools, makes many educators from around the world see SL as a
versatile environment to conduct pedagogical activities (Calogne & Hiles, 2007). Bradley
(2008), for example, relates how in his Introduction to Organic Chemistry students created a life-
size model of a molecule around which the teacher is able to walk, with the students, and
comment real time. Calogne and Hiles as well as Conklin (2007) list various educational uses of
Second Life, including Art, Law, Religion, English, Programming, Geography, Politics,
Economy, Mathematics, Biology, and physics teaching.
The first idea that comes to mind is to use SL to offer courses online. But, this author
aligns himself with Eliëns, Feldberg, Konijn & Compter (2007) in considering this approach
rather naïve and outdated while there are other much more appealing alternatives such as
simulations and modeling (Borba & Villarreal, 2005).
Although many authors stress the SL “potential” for simulations that promote physics
learning, this author did not succeeded in finding any concrete example of physics simulation.
There are, however, many artifacts left to free manipulation by visitors in places like the Institute
of Physics Experimenta, situated in the coordinates Rakshasa (207, 26, 25). Furthermore,
researchers at Denver University are planning to build the first virtual nuclear reactor to train
new nuclear engineers (Medeiros, 2008).
Journal of Virtual Worlds Research - Second Life Physics 5
5
The physical verisimilitude of the metaverse, in the sense that an avatar cannot pass
through walls and stones tossed into water will behave as expected, relies on the obedience to
physical laws and principles such as gravity, buoyancy, mass, friction, and so forth. This
obedience is usually ensured by means of third-party software called physics engine. Vehicles
are one application of the physics engine.
Differently from other metaverses, such as Google Lively, where physical laws are not
seriously taken into account, SL is possibly the most realistic virtual environment in the market,
as objects are controlled by the Havok software. This powerful software has been used in
creating many internationally acclaimed films over the years such as Troy, X-Men: The Last
Stand, Harry Potter and the Order of the Phoenix and The Chronicles of Narnia: Prince
Caspian, among others (Havok in the movies, n.d.).
In this work, SL physics will be studied through a comparative analysis between the
Newtonian physics taught in schools and the SL world physical features and physically
interesting LSL functions, as described in the following sources, in addition to the author’s own
experiences:
• Havok Physics Animation v. 6.0.0 PC XS User Guide ;
• LSL Portal ;
• Guidelines for educators;
• LSL Wiki;
• SL Wiki; and
• SL Wikia.
Also discussed are the differences found between SL physics and that physics that is
taught at School within the framework of the notions of Reality in Science and of Virtuality,
according to Lévy (1998) and Eco (1986).
After this analysis, pedagogical implications and alternatives, based on Papert’s (1993)
never-implemented physics microworlds proposal will be discussed.
Second Life Physics Analysis
“Morpheus: [. . .] yet their strength and their speed are still based on a world that is built on
rules” (Irwin, 2002).
The Second Life world consists of many interconnected, uniquely named simulators,
referred to as sims or regions. Each simulator keeps track of the objects and agents within its
region, simulates physics, runs scripts, and caches and delivers object and texture data within the
sim to clients.
The aim in Havok’s (2008) design is to provide simulation that gives the game-player a
consistent environment to explore (p. 374). In principle, Havok deals with Newtonian mechanics,
or the high school laws of motion that describe the behavior of objects under the influence of
other objects and external forces (p. 375).
SL, through its Linden Scripting Language (LSL), offers resources to attach behaviors to
objects such as fountains, guns, or vehicles so that an object can change its color, size, or shape,
while it can move, listen to your words, talk back to you, or even talk to other objects. LSL
Journal of Virtual Worlds Research - Second Life Physics 6
6
follows the familiar syntax of a C/Java-style language and features almost 400 built-in functions
for manipulating physics and avatar interaction, many of which of special interest to physical
studies in this metaverse. For example, llGetPos()
2
and llGetVel() return vectors that are the
object’s region position and velocity, respectively; llGetOmega() returns its angular velocity,
while llGetForce() and llGetTorque() return vectors representing the force and the torque,
respectively, acting upon the object.
As Havok deals with game genre specific problems like vehicle simulation, human
ragdolls, physical interaction of keyframed characters within a game environment, and character
control (2008), it does not even try to simulate any physics beyond Mechanics, excluding any
possible electromagnetic or nuclear interactions.
While many physical quantities have their physical counterpart in SL, certain quantities
have quite different definitions in SL when compared to the Newtonian physics ones, as will be
seen below.
Time
Still today, time, one of the most fundamental physical quantities, usually refers to the
classical Newtonian conception of an "absolute" and "equably" flowing time, used to compare
the intervals between events and their durations and to sequence them, therefore making possible
to quantify the motions of objects and to formulate a prescription for the synchronization of
clocks. This, of course, is quite different from Einstein’s proposal of a new method of
synchronizing clocks using the constant, finite speed of light as the maximum signal velocity,
which gave birth to the Theory of Relativity.
In SL, being a Massive Multiplayer Online Reality Game, time is needed to keep things
moving in (or out of) sync with everything else. However, SL physics can be impacted by
network lag and server load, and therefore may not be particularly accurate. All physics and
scripts generate simulator lag which can make avatars experience a slowed-down (slow-motion,
"bullet-time") movement from its usual region frames per second (FPS) value of 45.0, as
returned by the llGetRegionFPS( ) function. When the sim server cannot keep up with the
processing of its tasks, it will use a method called time dilation to cope with it. Time dilation will
slow script time and execution down to the limit when time dilation value reaches zero and script
execution halts. The function llGetRegionTimeDilation() returns the current region simulator
time dilation, the ratio between the change of script time to that of real world time, as a float
value that ranges from 0.0 –full dilation – to 1.0 – no dilation (LSL Wiki,
llGetRegionTimeDilation and LSL Portal, llGetRegionTimeDilation). A collection of lag
reduction tips is provided at LSL Wiki under Lag.
While SL is able to run qualitative experiments and to cope with simple mechanics
experiments with a corresponding decrease in accuracy, it will definitely not give response time
down to milliseconds consistently (Guidelines for educators, 2008, Technical essentials, § 5).
Mass
The concept of mass is one of those basic physical concepts whose real significance is
never fully disclosed in textbooks or lecture courses (Jammer, 1997). In fact, it is a rather
abstract concept whose meaning evolved from the ancient metaphysical opposition of matter and
spirit to the present relativistic equivalence to energy or to space-time curvature. However, its
Journal of Virtual Worlds Research - Second Life Physics 7
7
most common meaning is still related to the object's resistance to accelerate when a force is
applied on it.
In SL, mass is the measure of translational inertia, the tendency of a body to resist
accelerations, expressed in lindograms (Lg). The mass of an object is reported by functions
llGetMass() and llGetObjectMass(). For example, a typical avatar mass is around 2 Lg.
Contrary to the Newtonian (1947) definition of mass as arising from the product of its an
object’s density and volume, in SL object mass depends only on its size and shape, not on its
material type, set through the constant PRIM_MATERIAL to one of the eight different available
materials, such as glass, metal, flesh, and so forth. However, avatar mass depends only on its
height, irrespective to its fatness, thickness, muscle, or other factors. Attachments will not alter
avatar mass, except for shoes, which change avatar height and therefore its mass.
Gravity
In physics, gravity – or, more generally, gravitation – refers to the natural phenomenon
by which objects attract one another. A direct consequence of it is the well-known weight force
that every object experiences.
In SL, every physics-enabled object with mass
m
will be subject to a constant force P
given by
2
m/s8.9⋅= mP
applied in the negative z-direction to simulate the acceleration under gravity (LSL Wiki, n. d.,
Gravity). However, the function llSetBuoyancy() can cancel the effects of gravity, as seen below.
Acceleration
In Havok (2008), the quantity acceleration has the usual physical definition as “the rate of
change of velocity over time” (p. 380). In Newtonian terms, the acceleration
a
of an object with
mass
m
, when subject to the action of a force
F
, is given by
m
F
a=
.
However, the SL function
llGetAccel()
, instead of returning its acceleration, returns the
vector (llGetForce()/llGetMass()) + <0, 0, -9.8>
which is a sum where the first term corresponds to the dynamical object acceleration, due to the
action of some force, as seen above, and the second term is a vertical downwards acceleration
that simulates the terrestrial gravity effect (
LSL Wiki
, n. d., llGetAccel).
For an object resting on the floor, the value for its acceleration, as returned by
llGetAccel()
, should be always <0, 0, 0>, which corresponds to real world physics, if we consider
a normal force acting on the object by the floor which exactly offsets the force of gravity.
Journal of Virtual Worlds Research - Second Life Physics 8
8
However, random, fast-changing values for llGetAccel() were observed for a still object,
as shown in Figure 1. This is possibly due to the action of the omnipresent SL “wind,” whose
velocity can be obtained through the function llWind() (LSL Wiki, n. d., llGetAccel),.
Although aerodynamic or hydrodynamic effects of viscosity with air or water have not
been implemented, the value for the acceleration of a free-falling object, initially equal to the
gravitational acceleration, will be gradually reduced to zero in order to simulate the air resistance
effect that makes the objects asymptotically approach a terminal velocity, as in the real world.
On the other hand, as there is no “real” air resistance, “any impulse off the vertical (gravity) axis
will cause the object to keep moving forever” (LSL Wiki, n. d., llApplyImpulse).
As a consequence of the points above, users are advised to trackvelocity and measure its
changes to get the actual acceleration values, which means to use the well-known acceleration
formula
t
v
a∆
∆
=,
where
v
∆
denotes a velocity change during a certain time interval
t
∆
.
Figure 1. Random Acceleration in a Still Object.
Energy
In physics, the concept of energy was developed by various scientists since the eighteenth
century, initially with the purpose of studying free falling objects and collisions, and it was
formalized through the discovery of various conversion processes until the middle of the
nineteenth century. It is a very abstract, theoretical concept and its conceptualization comes from
Journal of Virtual Worlds Research - Second Life Physics 9
9
the principle of conservation of energy (Elkana, 1974). Throughout history, various forms of
energy were defined, including kinetic, potential, electric, and chemical, which are
interconvertible.
In Havok (2008), “energy management is concerned with identifying objects in a scene
that are not doing very much and removing these from the physical simulation (known as
deactivating or turning off the object) until such time as they begin to move again” (p. 379).
Therefore, SL “energy” is somehow nearer to activity in Havok.
In SL, energy is a dimensionless quantity ranging between 0.0 and 1.0 and used to control
how effectively scripts can change the motion of physical objects: if the energy of an object is
100 percent, LSL functions will have their full effect; yet, if it has a value lower than 100
percent, the same action on the same object will have a proportionally smaller effect, and when it
reaches 0, actions will have no effect at all (LSL Wiki, n. d., Energy).
Instead of the usual physics kinetic energy, calculated in terms of its mass
m
and its
velocity
v
as
2
2
1
mvE =, in SL, energy behaves more like a momentum transfer
p
(
mv
p
=
).
This makes it easier to achieve high speeds with light objects (small m) but vehicles will
probably cause smaller damages in collisions.
An object expends energy when scripts call functions to change its motion but objects
continuously receive energy from the SL grid through a stipend at a rate of 200/mass units of
energy per second until the 1.0 full energy limit. Kinetic functions demand energy at different
rates and some of them may even not be able to act on heavy objects if they “eat” energy faster
than the grid can refill it (LSL Wiki, n. d., Energy). See, for example, the function
llSetBuoyancy() below.
Contrary to physics, where energy is defined only for the system where the object is
inserted, in SL, energy is stored inside the object, in an impulse energy “reservoir” proportional
to its mass (SL Wikia, n. d., Impulse Energy). Each time an object is rezzed (the act of making an
object appear in this metaverse by dragging it from a resident's inventory or by creating it via the
edit window) or its mass is changed (as in by changing its size or shape), its energy is reset to 0.
It should be noted, however, that the “real” object energy value is inaccessible, since the
llGetEnergy() function merely returns object activity “as a percentage of maximum” (LSL
Portal, n.d., llGetEnergy()). But, contrary to what one could think, in the real world, too, one
cannot directly access the energy of a system by a simple measurement – there is no energy-
meter. As Sexl (1981) explains, “the total energy of a system has to be calculated from
observable quantities like velocities, distances, charges and so on.” This is the exact procedure
one will have to follow to obtain the energy value in SL.
Friction
In physics, friction is the contact force resisting the relative lateral motion of solid and/or
fluid surfaces in contact. It depends on the normal force exerted between the surfaces, as a result
from the objects’ weights; heavier bodies will show higher friction. It also depends on the
materials in contact and on their surface roughness, both quantified by a coefficient of friction.
In SL, friction is defined as “the effect of multiple collisions with other objects, e.g. air or
water molecules” (LSL Wiki, n. d., Friction). This definition, however, describes other effects
Journal of Virtual Worlds Research - Second Life Physics 10
10
known as drag forces, such as air and water resistance, which also depend on the speed of the
object moving through the medium. Moreover, drag forces, which increase with object speed,
can reach the force of gravity value, canceling it and imposing a constant terminal velocity on the
object (see Acceleration above).
In SL lighter, less massive objects are simply affected to a lesser extent by friction than
heavier, more massive ones under identical conditions. Although there is no coefficient of
friction to be altered, an object's friction can be indirectly changed by modifying its material type
among the available ones, listed here from least to most friction: glass, metal, plastic, wood,
plastic, rubber, stone, and flesh (LSL Wiki, n. d., Material). On the other hand, object buoyancy,
as set by function llSetBuoyancy(), affects friction (LSL Wiki, llSetBuoyancy).
As before mentioned, aerodynamical or hydrodynamical friction effects were not
implemented in SL, except for air resistance on free falling objects.
Buoyancy
In physics, buoyancy refers to the vertical upward force on an object, such as a ship or a
balloon, exerted by the surrounding liquid or gas and equals the weight of the fluid displaced by
the object, according to Archimedes’s principle.
In SL, the buoyancy of an object is a dimensionless quantity and is set by the function
llSetBuoyancy(). The default value is 0.0. Values between 0.0 and 1.0 mean a gentler than
regular fall, the closer to 0.0 the closer to normal behavior. Setting this to exactly 1 will cause the
object to float as if no gravity exists and buoyancy greater than 1.0 will make it to rise. Negative
buoyancy values are allowed and will simulate a downward force, which will nonetheless also
cause the object to vibrate considerably on the ground while the physics engine tries to "settle" it
(LSL Wiki, n. d., llSetBuoyancy).
Buoyancy applies to “physical” objects only, as seen below. It is often used to make an
object like a balloon float up slowly, as if gravity did not affect it. Wind can cause the object to
drift.
It must be noticed that water has limited meaning in SL and buoyancy does not take
water level into account: the object will float up the same rate whether it is under or above water.
Unlike some other characteristics, this is cancelled if the script that sets buoyancy is removed
from the object. This function drains energy to keep the object floating. Therefore, it will not
make a 90 kg object to hover, unless an extra upward force is applied.
As one sees, SL buoyancy is quite different from the real life one and to get a more
accurate value for buoyancy, a simple llSetBuoyancy call does not suffice. It could be calculated
from the object's displacement based on volume and on the density of the material being
displaced.
Light
As in the most primitive conceptions of light (LaRosa, Patrizi, & Vicentini-Missoni,
1984), it is a phenomenon totally pervasive in SL life. It is part of the environment, simply “is
there” without any physical mechanism involved in its production or propagation. As expected,
the main illumination comes from the sun and the moon replicas in SL, and their direction and
their light intensity are uniform not only over the entire simulator but over the entire world. The
Journal of Virtual Worlds Research - Second Life Physics 11
11
sun and the moon are directly opposed to each other at all times, and as a result, the moon always
appears full. Their orbital centers and speed are such that SL day and night corresponds to three
and one RL hours respectively. Private island owners are even able to fix the position of the sun
irrespectively of the direction seen in most of the world (LSL Wiki, n. d., llGetSunDirection()).
On the other hand, any object, to a limit of six per region, can be made a light source
through the mere activation of a checkbox in its properties list, while the color and intensity of
the emitted light can also be easily set, as well as the distance it will reach and even its intensity
falling-off.
Physical and “Phantom” Objects
It must be noted, however, that all that has been mentioned above applies only to objects
made physical through the constant STATUS_PHYSICS. The attribute physical essentially
enables inertia and gravity to act on the object which can then be moved and rotated using
kinetic functions such as llMoveToTarget(), llSetForce(,) or llApplyRotationalImpulse(). A
moving physical object will follow the real world rules and come to a halt and settle, but that
depends on the object's velocity and/or its buoyancy, as a negatively buoyant object
proportionally bounces around more before it settles. An object subject to a continuous
impulse/collision will tend to never settle, however, unless it interpenetrates something.
Objects may also be made “phantom” by means of the constant STATUS_PHANTOM, in
the sense that it can freely pass through anything except the terrain, objects, and avatars, without
collision; phantom objects are not transparent, however. Curiously, phantom objects can be made
physical when they will start colliding with land; the difference between phantom and non-
physical objects is not clear.
On the Realism of Second Life Physics
“Morpheus: What is real? How do you define real? If you're talking about what you feel, taste,
smell, or see, then real is simply electrical signals interpreted by your brain” (Irwin, 2002).
“Cypher: I know this steak doesn't exist. I know that when I put it in my mouth, the Matrix is
telling my brain that it is juicy and delicious” (Irwin, 2002).
Bachelard (1934) argued “every fruitful scientific revolution has forced a profound
revision in the categories of the real” (p. 134). Therefore, in order to fully understand the present
thesis that, while SL physics is neither the Galilean/Newtonian physics nor a real world physics
virtualization but intentionally diverges from reality in such a way that it may be labeled hyper-
real, SL provides a richer environment for physics teaching than (still) positivistic lectures and
classical simulations, a brief historical discussion covering those different worldviews is needed.
Journal of Virtual Worlds Research - Second Life Physics 12
12
Real world ancient physics
Dynamics and kinematics appear in antiquity as philosophical discussions only. The
Aristotelian “Law” nullum violentum potest esse perpetuum
*
implies that as soon as the force
applied to the body ends, its motion ends too. This is in good accordance to our everyday
experience, to the intuitive physics we develop by ourselves by interacting with our environment,
and which will later constitute a serious learning obstacle to the Newtonian physics (McCloskey,
1983).
According to Dugas (1955), Aristotle’s intuitive theories have their origin in observations
most routinely made in daily life, as they take the passive resistances to motion in account.
Therefore, Aristotle tried to build a real world physics.
Ideal-world classical physics
In the Scientific Revolution, Galileo avoided the endless medieval discussions about the
Aristotelian causes and focused on describing the course of the motion of falling bodies and
projectiles in an exact mathematical manner (Dijksterhuis, 1969). As a matter of fact, he arrived
at the correct conclusion that all bodies of any substance fall with the same acceleration only by
abstraction from the air resistance and considering motion in vacuum, a method which paved the
path for the Newtonian perpetual inertial motion (Crombie, p. 298). Doing so, Galileo put
himself – and physics – immediately and conscientiously out of reality as an absolutely slick
plane, an absolutely round sphere, both absolutely rigid, which are not found in our physical
reality (Koyré, 1978) but only in Plato’s World and, of course, in the abundant, standardized, and
repetitive end-of-chapter textbooks exercises. This, the Physics still taught in schools, restricted
to the classrooms and positivistic laboratories — hard, abstract and detached from student’s
everyday reality — is an ideal-world physics.
Counter-intuitive modern physics and surrealism
The introduction of technologies that enhanced the vision, such as the camera obscura,
the telescope, the zoopraxiscope, and many others, allowed for the creation of images that were
disconnected from the tangible and began to define the real (Jones, 2006). A well-known
example is Eadweard Muybridge’s pioneer study on the horse motion (Figure 2)
Journal of Virtual Worlds Research - Second Life Physics 13
13
Figure 2. The Horse in Motion, Eadweard Muybridge (1878).
It showed that horses never fully extended its legs forward and back, hooves all leaving
the ground (Eadweard Muybridge, 2009), as contemporary illustrators tended to imagine
(Figure 3):
Figure 3. Le Derby d'Epsom, Théodore Gericault (1821).
Such an “obvious” common sense, horse legs position was unfortunately not true. The
real position is non-intuitive and intangible, made conceivable only through an instrument:
phenomenotechnics (Bachelard, 1934, p. 12).
Journal of Virtual Worlds Research - Second Life Physics 14
14
On the turning of the century, our physical intuition took a major blow from Quantum
Mechanics, Relativity, and Chaos Theory with all their concepts such as entanglement,
gravitational lensing, and Hausdorff dimension that nobody understands (Feynman, 1967, p.
129). This fascinating physics populates imagination, sci-fi movies, and books but is
unfortunately almost absent from classrooms, reserved to physics majors. At the same time that
new physics was revolutionizing Classical Science and Popper’s Critical Rationalism was
refuting the Classical Scientific Method, Modern Art was questioning the axioms of the previous
age and struggling to find a language for the “new reality” revealed by the physicists, trying to
capture the essence of the schizoid wave-particle duality (Parkinson, 2008). Surrealism in
particular, according to Breton (1971), is based on the belief in the superior reality of certain
forms of association heretofore neglected. Most popular context of the word “surrealism” is
associated to political or social critiques through art but a few surrealist artists went further and
criticized the limited rationalistic and positivistic physics worldview through idiosyncratic
appropriation and juxtaposition of its parts as a means for imagination to recover its rights
(Breton, 1971). While the Copenhagen Interpretation of Quantum Mechanics states that we
cannot talk about the real, but only the representations we make of it, Magritte produced various
paintings in which he explores and denounces, in a witty and thought-provoking style, the
difference between the real world and its representation, such as in his well-known 1935 work La
Condition Humaine (Figure 4).
Figure 4. La Condition Humaine, Magritte (1935).
As was so well put forward by Bunge (2003), whereas Mechanism had proposed a
unified picture of nature, the new world-view looks like a cubist painting. It is not only mosaic: it
is also highly counter-intuitive.
Journal of Virtual Worlds Research - Second Life Physics 15
15
Virtual and hyper-real
In common use, the word virtual often designates the absence of existence, a fake or
illusory world, opposed to the real, material, concrete world. The term virtual comes from
Medieval Latin virtuälis, equivalent to Latin virtus, which means virtue, force, power. For Lévy
(1998) and for the Scholastics, virtual does not oppose to real but to the actual and is something
that is in a potential state, not yet expressed or actualized.
In our so-called post-modern era, more modern technologies – like film, television, or the
computer screen – created “realistic” images that did not rely necessarily on anything actual, but
rather, by tricking the eye, on realities that are simultaneously constructed subjectively by the
senses of the observer. People are now inundated by flickering images – legitimate cultural and
material heirs from the camera obscura, the magic lantern, and the stereoscope – that forms the
present discourse on virtual reality and virtual environments (Jones, 2006).
However, with such a multitude of technological resources at our disposal, virtual does
not seem to be enough. We live in a more to come consumer culture, according to Eco (1986).
For a game to be funnier, more exhilarating, more absorbing, its designer will make it “better.”
Even if the virtual environment implements physical laws, game designers may not want to
follow real world rules and allow, for example, players to drive faster, jump farther or bounce
harder than normal (Havok, 2008).
Those simulations that, to be labeled as true must look true, have the appearance of being
more real that the original – much like Caesar’s wife, who must not only be virtuous, but must be
seen to be virtuous (Plutarch, 1919) – Eco (1986, p. 13) designated as hyper-real. Notice,
however, that this is distinct from Baudrillard’s (1983) hyperreality, which is a sense of reality
created by technology and made so similar to true reality, as to be indistinguishable from it – not
more real than reality, as in Eco’s one. It should also not to be confused with Hyperrealism, a
genre of painting and sculpture so meticulously detailed as to resemble a high resolution
photograph.
SL physics
As discussed in the previous section, while SL implements various real world features
such as wind, air resistance, terminal velocity, and settling of moving objects, SL physics is not a
mere real world physics virtualization, as other important features such as water resistance were
not implemented. On the other hand, various physical quantities have quite different definitions
in SL when compared to the Newtonian physics ones, as seen in the previous section, and
therefore, it is not either a mere implementation of idealized Newtonian physics as offered by the
Havok engine.
Havok, while embodying Newtonian physical laws, also allows and even encourages the
building of hyper-real simulations, a path apparently followed by SL implementation. As a
matter of fact, Philip Rosedale, in an interview quoted in Eliëns et al. (2007), affirms that one of
the main reasons for the success of SL is “the fact that it offers a set of capabilities, which are in
many different ways superior to the real world.” Therefore, SL deliberately chose to implement
physics in a basically hyper-real way.
The author of the present study wants to stress, however, that SL can go far beyond that.
The possibility of making an object non-physical, switching off the standard SL physics and
programming new unusual physical behaviors through LSL scripts opens the door to imagination
Journal of Virtual Worlds Research - Second Life Physics 16
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and experimentation. As two very pale examples, Havok (2008) suggests alternative gravity
settings along an alternative axis. The Guide also suggests adding up to three times the normal
gravity to a car with the basic effect of “accelerating the subjective time” (Havok, p. 330). One
could use SL as a lab world, where one could easily make objects that repel themselves from one
another or that follow strange dynamical laws. The experimenter would, however, not do it just
for fun but mainly to liberate imagination and be able to critically question the closed
mechanistic, positivistic physics taught in schools. These motivations, resembling those of the
Surrealism approximation to modern physics, as discussed above, is the reason why the author
prefers to use the adjective surreal when referring to the possible use of SL as a simulator.
To sum things up, Havok physics can be interpreted as hyper-real as well as the usual
resident experience in SL. Yet, at the same time SL offers resources to build a surreal simulator
in this metaverse. Its pedagogical implications are interesting as will be discussed in the next
section.
Pedagogical Implications
Trinity: "The Matrix isn't real."
Cypher: "I disagree, Trinity. I think the Matrix can be more real than this world." (Irwin, 2002).
Most learners – including many science majors – have difficulty in understanding physics
concepts and models, both at the qualitative level and the quantitative formulation (Reif &
Larkin, 1992). That difficulty often arises from alternative conceptions (Driver, 1989) built from
their common personal experiences, based on a lifetime’s experience and is very difficult to
remediate with instructionist pedagogical strategies (Dede, 1995).
Papert, displeased with this inefficient learning process, has strongly defended the
introduction of IT in the classroom as a means to actively engage students in constructing mental
models and theories of the world since the 1970s. For Morgan & Morrison (1999), models are
mediators between theory and the real world, between classroom abstract scientific knowledge
and the student’s concrete, empirical experience. It must be remembered that simulation is not a
new concept, as scientists and programmers have used computers to simulate complex situations
like rocket trajectories (ballistic motion), liquid flows (fluid dynamics) and other complicated
projects probably since they started dropping off the assembly line (Havok, 2008, p. 371).
Papert, as early as 1980, offered a “Piagetian learning path into Newtonian laws of
motion” (Papert, 1993, p. 123). For Papert, the phrase laws of motion usually raises difficult
questions like What other laws of motion are there besides Newton's? (p. 124). To him, learners
should be acquainted with other laws of motion, not so subtle and counter-intuitive. This would
be viable in a physics microworld, where they could build an infinite variety of laws of motion,
progressing, thus, from the historically and psychologically important Aristotelian ones to the
"correct" Newtonian ideas and even to the more complex Einsteinian ones, via as many
intermediate worlds as they wish (p. 125), in a way that short-minded teachers “may refuse to
recognize as physics” (p. 122). And so many can be these worlds that “the logical distinction
between the ‘real world’ and ‘possible worlds’ has been undermined” (Eco, 1986, p. 14), in the
sense of immersion and experimentation, of distinction between possibility and necessity (Piaget,
1987). It is worth remembering that this experimental progression from Aristotelian physics to
Journal of Virtual Worlds Research - Second Life Physics 17
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Newton mechanics closely resembles the psychogenetic succession investigated by Piaget &
Garcia in their paramount work Psychogenesis and the History of Science (1989).
Various microworlds have been built, from the original Papert's Logo Turtles (1993) to
present educational environments with Augmented Reality (Azuma et al., 2001). However,
almost thirty years after Papert’s proposal, besides the primitive diSessa’s (Abelson, H. &
diSessa, A., 1981) Dinatarts, to our knowledge there is no microworld implementation which
allows the experimentation with physical laws, as conceived by Papert.
On the other hand, present high-performance computing and communications capabilities
create a new possibility (Dede, 1995). It allows learners to immerse themselves in virtual,
synthetic environments, like Alice walking through the looking glass, becoming avatars that can
collaborate and learn-by-doing using virtual artifacts to construct knowledge (Walker, 1990).
This possibility shifts the focus of constructivism, “‘magically’ shaping the fundamental nature
of how learners experience their physical and social context” (Dede, p. 1). According to Dede,
“this instructional approach enhances students' ability to apply abstract knowledge by situating
education in authentic, virtual contexts similar to the environments in which learners' skills will
be used” in the future (p. 1).
This mediation may be even improved in an immersive 3-D metaverse as SL, shifting the
education from the traditional classroom layout and dynamics to a multisensory learning
environment “where students can be part of the system that is being studied” (Calogne & Hiles,
2007). In fact, “Havok provides low-level access to core functionality so that you can construct
complex physical behaviors that are specific to your game and don’t come as standard with
Havok” (Havok, 2008, p. 96).
By comparing SL with a traditional simulation environment like Modellus, the SL
physics hyper-reality could, as previously discussed, constitute at first sight an obstacle to its
utilization as a simulation environment for physics teaching. However, it is this author’s
understanding that this same hyper-reality and, even better, its surreal potential, is a golden
opportunity. An SL physics lab could allow a surreal experimentation with successive or
generalized physical laws, as proposed by Papert, in a Piagetian historical-psychogenetic
framework (Piaget & Garcia, 1989) which could be pedagogically effective. At the same time it
would allow extremely rich epistemological discussions on the nature of physical concepts and
on issues such as what is a physical law? (Feynman, 1967), what is Science?, what kind of
reality does Science describe?, and who makes the Science decisions?, to name a few.
That is the proposal of the project this author is starting.
Conclusions
Trinity: "No one has ever done anything like this."
Neo: "That's why it's going to work." (Irwin, 2002).
Garcia, discussing the new Internet “upload” concept for education, warns that:
“Some authors foresee that in few years’ time textbooks will be totally replaced by
electronic media. Some of them believe that even classrooms will disappear. We cannot
predict what will happen in the future with our educational models, but changes will be
Journal of Virtual Worlds Research - Second Life Physics 18
18
enormous and many things that we do today will belong in museums. We have to be
prepared”(2008).
In this work it was shown that, after all, SL physics is neither the Galilean/Newtonian
idealized physics nor a real world physics virtualization; rather, it concludes that SL physics is
hyper-real and provides resources for building a surreal physics lab that allows experimentation
with successive or generalized physical laws. Also, it still provides a rich environment for
classroom epistemological discussions around the reality/unreality of the physical laws seen in
school, in good accordance with Papert’s (1993) never-implemented proposal.
That was the reason for our travel in Second Life hyperreality, “in search of instances [. .
.] where the boundaries between game and illusion are blurred .[ . .] and falsehood is enjoyed in a
situation of ‘fullness’” (Eco, 1986, p. 8).
Acknowledgements
The author of the present study deeply acknowledges the enlightening comments from
Prof. Dr. Maurício Rosa (Ulbra/PPGECIM) and the detailed and constructive comments from
two anonymous reviewers of my ambitious manuscript which helped me to make my points
clearer and stronger, as well as Felix Nonnenmacher’s meticulous copyediting that made a nicely
readable text out of my awkward and confusing phrases.
Journal of Virtual Worlds Research - Second Life Physics 19
19
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