How can I run multiple void loops that do not depend on each other
like there
Those loops (loop2() and loop3() ) are just names for functions, controlled by the scheduler library.
Nothing else.
They could also have been named function2 and function 3 ...
It's simply like @Septillion said:
Simply, you can't
Have a look at the link, which was already cited in the previous posts, and that's what is the only possibility for doing things (almost) at the same time in several "loops" / functions:
http://forum.arduino.cc/index.php?topic=223286.0