diff --git a/journal/2021-04-09.md b/journal/2021-04-09.md
index 20e63933f..85adaa640 100644
--- a/journal/2021-04-09.md
+++ b/journal/2021-04-09.md
@@ -10,4 +10,7 @@
     - [[rainbow folding]]
 - [[tree simulator]]
 - [[great news]]
-- [[sam harris]]
\ No newline at end of file
+- [[sam harris]]
+- [[eric weinstein]]
+  - [[joe rogan]]
+  - [[planet hof]]
\ No newline at end of file
diff --git a/planet-hof.md b/planet-hof.md
new file mode 100644
index 000000000..f05abe851
--- /dev/null
+++ b/planet-hof.md
@@ -0,0 +1,4 @@
+# planet hof
+
+- [[go]] http://www.math.toronto.edu/~drorbn/Gallery/KnottedObjects/PlanetHopf/
+