Just like in LaTeX, ‘^’ and ‘_’ are used to indicate super- and subscripts. Again, these can be used without embedding them in math-mode delimiters. To increase the readability of ASCII text, it is not necessary (but OK) to surround multi-character sub- and superscripts with curly braces. For example
The mass of the sun is M_sun = 1.989 x 10^30 kg. The radius of
the sun is R_{sun} = 6.96 x 10^8 m.
To
avoid interpretation as raised or lowered text, you can quote
‘^’ and
‘_’ with a
backslash: ‘\^’ and ‘\_’. If you write a text where the
underscore is often used in a different context, Org's convention
to always interpret these as subscripts can get in your way.
Configure the variable
org-export-with-sub-superscripts to globally change
this convention, or use, on a per-file basis:
#+OPTIONS: ^:{}
With this setting, ‘a_b’ will not be interpreted as a subscript, but ‘a_{b}’ will.