notebook Density of stars on the surface of the sky

2021-03-27-density-of-stars-on-the-surface-of-the-sky.ipynb

@@ -35,7 +35,7 @@
     "The full details of my musings are available in this [blog post](https://laurentperrinet.github.io/sciblog/posts/2021-03-27-density-of-stars-on-the-surface-of-the-sky.html).\n",
     "\n",
     "PS: the other part of my question (can such a model be used to fit the density of stars in different areas of the sky?) will be for another time...\n",
-    "PS2: I have not talked about [Olbers' paradox](https://en.wikipedia.org/wiki/Olbers%27_paradox), while this may be related, in particular now that I read about the literature pointed in the [brightness section](https://en.wikipedia.org/wiki/Olbers%27_paradox#Brightness)...\n",
+    "PS2: I had not talked about [Olbers' paradox](https://en.wikipedia.org/wiki/Olbers%27_paradox)... see below\n",
     "\n",
     "---\n",
     "\n",