diff --git a/src/aphorisms/thirteen.clj b/src/aphorisms/thirteen.clj
new file mode 100644
index 0000000..b2fcda5
--- /dev/null
+++ b/src/aphorisms/thirteen.clj
@@ -0,0 +1,77 @@
+(ns aphorisms.thirteen
+  (:require [thi.ng.math.core :as m]
+            [quil.core :as q]
+            [quil.middleware :as qm]))
+
+(def step-size 0.05)
+(def delta 0)
+
+(defn delta= [delta [ax ay] [bx by]]
+  (< (+ (Math/abs (- ax bx)) (Math/abs (- ay by))) delta))
+
+;; let's define some methods to generate different kinds of sequences
+
+(defn lissajous [a b]
+  (sequence
+   (comp (map (partial * step-size))
+         (map (juxt #(Math/sin (+ delta (* a %)))
+                    #(Math/cos (* b %))))
+         (take 1000 #_(Math/ceil (/ (* 2 Math/PI) step-size (* a b)))))
+   (range)))
+
+(defn sieve
+  ([] (sieve (drop 2 (range))))
+  ([xs]
+   (let [prime (first xs)]
+     (lazy-seq (cons prime (sieve (remove #(zero? (mod % prime)) xs)))))))
+
+(defn de-jong-attractor [a b c d]
+  (rest (iterate (fn [[x y]]
+                   [(- (Math/sin (* a y)) (Math/cos (* b x)))
+                    (- (Math/sin (* c x)) (Math/cos (* d y)))])
+                 [0 0])))
+
+(def primes (sieve))
+
+(defn setup []
+  (let [seed (->> (take 10 primes)
+                  (shuffle)
+                  (take 4))]
+    (q/frame-rate 30)
+    (q/color-mode :hsb 360 100 100 100)
+    (q/background 20)
+    {:attractor (->> #_(map #(/ % (apply max seed)) seed)
+                     (apply de-jong-attractor seed)
+                     (map (partial mapv #(* 125 %)))
+                     (partition 4))}))
+
+(def fibonacci (map first (iterate (fn [[a b]] [b (+ a b)]) [0N 1N])))
+
+(nth fibonacci 10000)
+
+(defn update-state [state]
+  (update state :attractor (partial drop 100)))
+
+(defn draw-state [state]
+  (q/no-fill)
+  #_(q/background 350)
+  (q/with-translation [(* 0.5 (q/width)) (* 0.5 (q/height))]
+    (q/stroke (+ 220 (mod (* (q/millis) 0.1) 80)) 60 90 1)
+    (doseq [[a b c d] (take 100 (:attractor state))]
+      (q/begin-shape)
+      (apply q/curve-vertex a)
+      (apply q/curve-vertex b)
+      (apply q/curve-vertex c)
+      (apply q/curve-vertex d)
+      (q/end-shape))))
+
+(q/defsketch twelve
+  :title "Twelve"
+  :size [500 500]
+  :settings #(q/pixel-density (q/display-density))
+  :setup setup
+  :update update-state
+  :draw draw-state
+  #_#_ :renderer :p2d
+  :features [:keep-on-top :no-bind-output]
+  :middleware [qm/pause-on-error qm/fun-mode])
diff --git a/src/aphorisms/twelve.clj b/src/aphorisms/twelve.clj
new file mode 100644
index 0000000..004e97c
--- /dev/null
+++ b/src/aphorisms/twelve.clj
@@ -0,0 +1,37 @@
+(ns aphorisms.twelve
+  (:require [thi.ng.math.noise :as n]
+            [quil.core :as q]
+            [quil.middleware :as qm]))
+
+(def noise-start 10.5)
+(def noise-step 0.01)
+(defn noise-seq [offset]
+  (map #(n/noise1 (+ offset noise-start (* % noise-step))) (range)))
+
+(defn setup []
+  (q/frame-rate 30)
+  (q/color-mode :hsb 360 100 100 100)
+  {:noise-move 0})
+
+(defn update-state [state]
+  (update state :noise-move (partial + 0.01)))
+
+(defn draw-state [state]
+  (q/background 350)
+  (q/translate (* 0.5 (q/width)) (* 0.5 (q/height)))
+  (doseq [r (take 100 (noise-seq (:noise-move state)))]
+    (q/stroke (q/map-range (* r r) 0 1 270 255) 35 100 10)
+    (q/with-rotation [(q/map-range r 0 1 0 q/QUARTER-PI)]
+      (q/with-translation [(q/map-range (* r r) 0 1 -75 50) (* -0.5 (q/height))]
+        (q/line 0 10 0 (- (q/height) 10))))))
+
+(q/defsketch twelve
+  :title "Twelve"
+  :size [500 500]
+  :settings #(q/pixel-density (q/display-density))
+  :setup setup
+  :update update-state
+  :draw draw-state
+  :renderer :p2d
+  :features [:keep-on-top :no-bind-output]
+  :middleware [qm/pause-on-error qm/fun-mode])