new_contents: import math
  import pygame
  import random
  
  
  pygame.init()
  Pi = math.pi
  
  #-- SCREEN CHARACTERISTICS ------------------------->>>
  background_color = (255,255,255)
  (width, height) = (300, 200)
  
  #-- PARTICLE DEFINITION ---------------------------->>>
  class Particle:
      def __init__(self, (x, y), radius):
          self.x = x
          self.y = y
          self.radius = radius
          self.color = (255, 0, 0)
          self.thickness = 1
          self.speed = 0.1
          self.angle = 0
  
      def move(self):
          self.x += math.cos(self.angle) * self.speed
          self.y += math.sin(self.angle) * self.speed
  
      def display(self):
          pygame.draw.circle(screen, self.color, (int(self.x), int(self.y)), self.radius, self.thickness)
  
  #-- RENDER SCREEN ---------------------------------->>>
  screen = pygame.display.set_mode((width, height))
  screen.fill(background_color)
  
  number_of_particles = 20
  particles = []
  for n in range(number_of_particles):
      radius = random.randint(5, 20)
      x = random.randint(radius, width - radius)
      y = random.randint(radius, height - radius)
  
      particle = Particle((x, y), radius)
      particle.speed = random.random()
      particle.angle = random.uniform(0, Pi*2)
  
      particles.append(particle)
  
  
  #-- RUN LOOP --------------------------------------->>>
  running = True
  while running:
  
      #-- move particles -------------------------->>>
      '''
      A particle.angle of 0 moves particles vertically at a given speed.
      Directions chosen arbitrarily, defined in the particle.move(), and subject are to change.
      Use the unit circle for all other motions:
          down => 0 rad.
          up => Pi rad.
          right => Pi/2 rad.
          left => 3 * Pi/2 rad.
          ... and all the angles betwixt
      '''
      for particle in particles:
          particle.move()
          particle.display()
      pygame.display.flip()
      screen.fill(background_color)
  
      #-- detect pygame events -------------------->>>
      for event in pygame.event.get():
          if event.type == pygame.QUIT:
              running = False
  
subject: Add module where particles randomly disperse