diff --git a/interactions.py b/interactions.py
index e5c8084..0e388d4 100644
--- a/interactions.py
+++ b/interactions.py
@@ -44,11 +44,7 @@ cyc_edge_adj = [
 # === interaction parameters ===
 
 frame_rate = 24
-
 inductance = 0.001
-
-therm_conduct = 0.001
-
 drain = False
 drain_rate = 0.1
 
@@ -59,39 +55,6 @@ current = 30*[0]
 
 # === main loop ===
 
-def heat_evolution():
-  for e, f in cyc_edge_adj:
-    flow = therm_conduct*(current[e] - current[f])
-    current[e] -= flow
-    current[f] += flow
-    if drain:
-      current[v] *= 1 - drain_rate
-
-def wave_evolution():
-  # use verlet integration, first updating the currents and then using the new
-  # currents to update the charges.
-  for e in range(30):
-    u, v = edges[e]
-    current[e] += inductance*(charge[u] - charge[v])
-  for e in range(30):
-    u, v = edges[e]
-    charge[u] -= current[e]
-    charge[v] += current[e]
-  if drain:
-    for v in range(12):
-      charge[v] *= 1 - drain_rate
-
-def show_data(screen):
-  energy = 0.5*(sum(q*q for q in charge) + inductance*sum(i*i for i in current))
-  text = font.render('energy', True, (255, 255, 255))
-  screen.blit(text, (20, viewsize))
-  text = font.render(str(energy), True, (255, 255, 255))
-  screen.blit(text, (120, viewsize))
-  text = font.render('charge[0]', True, (255, 255, 255))
-  screen.blit(text, (20, 30 + viewsize))
-  text = font.render(str(charge[0]), True, (255, 255, 255))
-  screen.blit(text, (120, 30 + viewsize))
-
 if __name__ == '__main__':
   # set up display and clock
   pygame.init()
@@ -103,10 +66,6 @@ if __name__ == '__main__':
   # set up background
   background = pygame.Surface(screen.get_size()).convert()
   background.fill((32, 32, 32))
-  text = font.render('press [j] or [k] to pluck', True, (255, 255, 255))
-  background.blit(text, (340, viewsize))
-  text = font.render('hold [space] to drain', True, (255, 255, 255))
-  background.blit(text, (340, 30 + viewsize))
   
   to_light = 0
   while True:
@@ -114,11 +73,11 @@ if __name__ == '__main__':
     for event in pygame.event.get():
       if event.type == pygame.KEYDOWN:
         if event.key == pygame.K_j:
+          charge[0] += 10
+          charge[11] -= 10
+        elif event.key == pygame.K_k:
           charge[0] += 100
           charge[11] -= 100
-        elif event.key == pygame.K_k:
-          charge[5] += 100
-          charge[7] -= 100
         elif event.key == pygame.K_SPACE:
           drain = True
         pygame.draw.aaline(screen, (255, 255, 255), (0, 0), (viewsize, viewsize))
@@ -128,11 +87,17 @@ if __name__ == '__main__':
       elif event.type == pygame.QUIT:
         quit()
     
-    # clear screen
+    # print data
+    energy = 0.5*(sum(q*q for q in charge) + inductance*sum(i*i for i in current))
     screen.blit(background, (0, 0))
-    
-    # show data
-    show_data(screen)
+    text = font.render('energy', True, (255, 255, 255))
+    screen.blit(text, (20, viewsize))
+    text = font.render(str(energy), True, (255, 255, 255))
+    screen.blit(text, (120, viewsize))
+    text = font.render('charge[0]', True, (255, 255, 255))
+    screen.blit(text, (20, 30 + viewsize))
+    text = font.render(str(charge[0]), True, (255, 255, 255))
+    screen.blit(text, (120, 30 + viewsize))
     
     # show state
     for e in range(30):
@@ -146,9 +111,19 @@ if __name__ == '__main__':
         vertices[edges[e][1]],
       )
     
-    # evolve state
-    wave_evolution()
-    ##heat_evolution()
+    # evolve state. use verlet integration, first updating the currents and then
+    # using the new currents to update the charges.
+    for e in range(30):
+      u, v = edges[e]
+      ##current[e] *= 1 - resistance
+      current[e] += inductance*(charge[u] - charge[v])
+    for e in range(30):
+      u, v = edges[e]
+      charge[u] -= current[e]
+      charge[v] += current[e]
+    if drain:
+      for v in range(12):
+        charge[v] *= 1 - drain_rate
     
     # step
     pygame.display.flip()