1.1 --- a/org/movement.org	Sat Feb 18 10:28:14 2012 -0700
     1.2 +++ b/org/movement.org	Sat Feb 18 10:59:41 2012 -0700
     1.3 @@ -9,7 +9,7 @@
     1.4  
     1.5  * Muscles
     1.6  
     1.7 -Surprisingly enough, terristerial creatures only move by using torque
     1.8 +Surprisingly enough, terrestrial creatures only move by using torque
     1.9  applied about their joints.  There's not a single straight line of
    1.10  force in the human body at all!  (A straight line of force would
    1.11  correspond to some sort of jet or rocket propulsion.)
    1.12 @@ -17,23 +17,23 @@
    1.13  In humans, muscles are composed of muscle fibers which can contract to
    1.14  exert force. The muscle fibers which compose a muscle are partitioned
    1.15  into discrete groups which are each controlled by a single alpha motor
    1.16 -neuton. A single alpha motor neuron might control as little as three
    1.17 +neuron. A single alpha motor neuron might control as little as three
    1.18  or as many as one thousand muscle fibers. When the alpha motor neuron
    1.19  is engaged by the spinal cord, it activates all of the muscle fibers
    1.20  to which it is attached. The spinal cord generally engages the alpha
    1.21  motor neurons which control few muscle fibers before the motor neurons
    1.22 -which control many muscle fibers.  This recruitment stragety allows
    1.23 -for percise movements at low strength. The collection of all motor
    1.24 +which control many muscle fibers.  This recruitment strategy allows
    1.25 +for precise movements at low strength. The collection of all motor
    1.26  neurons that control a muscle is called the motor pool. The brain
    1.27  essentially says "activate 30% of the motor pool" and the spinal cord
    1.28 -recruits motor neurons untill 30% are activated. Since the
    1.29 +recruits motor neurons until 30% are activated. Since the
    1.30  distribution of power among motor neurons is unequal and recruitment
    1.31  goes from weakest to strongest, the first 30% of the motor pool might
    1.32  be 5% of the strength of the muscle.
    1.33  
    1.34 -My simulated muscles follow a similiar design: Each muscle is defined
    1.35 +My simulated muscles follow a similar design: Each muscle is defined
    1.36  by a 1-D array of numbers (the "motor pool"). Each entry in the array
    1.37 -represents a motor neuron which controlls a number of muscle fibers
    1.38 +represents a motor neuron which controls a number of muscle fibers
    1.39  equal to the value of the entry. Each muscle has a scalar strength
    1.40  factor which determines the total force the muscle can exert when all
    1.41  motor neurons are activated.  The effector function for a muscle takes
    1.42 @@ -42,9 +42,9 @@
    1.43  motor-neuron will apply force in proportion to its value in the array.
    1.44  Lower values cause less force.  The lower values can be put at the
    1.45  "beginning" of the 1-D array to simulate the layout of actual human
    1.46 -muscles, which are capable of more percise movements when exerting
    1.47 -less force. Or, the motor pool can simulate more exoitic recruitment
    1.48 -strageties which do not correspond to human muscles.
    1.49 +muscles, which are capable of more precise movements when exerting
    1.50 +less force. Or, the motor pool can simulate more exotic recruitment
    1.51 +strategies which do not correspond to human muscles.
    1.52  
    1.53  This 1D array is defined in an image file for ease of
    1.54  creation/visualization. Here is an example muscle profile image.
    1.55 @@ -140,7 +140,7 @@
    1.56  
    1.57  =movement-kernel= creates a function that will move the nearest
    1.58  physical object to the muscle node. The muscle exerts a rotational
    1.59 -force dependant on it's orientation to the object in the blender
    1.60 +force dependent on it's orientation to the object in the blender
    1.61  file. The function returned by =movement-kernel= is also a sense
    1.62  function: it returns the percent of the total muscle strength that is
    1.63  currently being employed. This is analogous to muscle tension in
    1.64 @@ -148,7 +148,7 @@
    1.65  post. 
    1.66  
    1.67  * Visualizing Muscle Tension
    1.68 -Muscle exertion is a percent of a total, so the visulazation is just a
    1.69 +Muscle exertion is a percent of a total, so the visualization is just a
    1.70  simple percent bar.
    1.71  
    1.72  #+name: visualization
    1.73 @@ -240,7 +240,7 @@
    1.74  <p>The worm is now able to move. The bar in the lower right displays
    1.75    the power output of the muscle . Each jump causes 20 more motor neurons to
    1.76    be recruited.  Notice that the power output increases non-linearly
    1.77 -  with motror neuron recruitement, similiar to a human muscle.</p>
    1.78 +  with motor neuron recruitment, similar to a human muscle.</p>
    1.79  </div>
    1.80  #+end_html
    1.81