diff --git a/book/content/modelling/06_heat_transfer/01_fundamentals.ipynb b/book/content/modelling/06_heat_transfer/01_fundamentals.ipynb
index 8d1d0eb5..b6edc52d 100644
--- a/book/content/modelling/06_heat_transfer/01_fundamentals.ipynb
+++ b/book/content/modelling/06_heat_transfer/01_fundamentals.ipynb
@@ -185,7 +185,7 @@
     "\\mf Nu = \\frac{h L }{k}\n",
     "$$\n",
     "\n",
-    "with a given characteristic length scale $\\mf L$ and the heat conductivity $\\mf k$. In general, the Nusselt number is a function of other dimensionless numbers (Reynolds $\\mf Re$ and Raylight $\\mf Ra$):\n",
+    "with a given characteristic length scale $\\mf L$ and the heat conductivity $\\mf k$. In general, the Nusselt number is a function of other dimensionless numbers (Reynolds $\\mf Re$ and Rayleigh $\\mf Ra$):\n",
     "\n",
     "* forced convection: $\\mf Nu = f(Re, Pr)$\n",
     "* natural convection: $\\mf Nu = f(Ra, Pr)$\n",
@@ -213,7 +213,7 @@
     "The electromagnetic spectrum. Source: [Wikimedia Commons](https://commons.wikimedia.org/wiki/File:EM_Spectrum_Properties_edit.svg).\n",
     ":::\n",
     "\n",
-    "The emitted energy spectrum, $\\mf I$ as a funktion of the wave frequency $\\mf \\nu$, of the so called black body radiation is given by Planck's law\n",
+    "The emitted energy spectrum, $\\mf I$ as a function of the wave frequency $\\mf \\nu$, of the so called black body radiation is given by Planck's law\n",
     "\n",
     "$$\n",
     "\\mf I(\\nu, T) = \\frac{2h\\nu^3}{c^2} \\frac{1}{e^\\frac{h\\nu}{k_B T}-1}\n",