1. Many philosophers have written about *nothingness*, see
    [Nothingness][1]. 
    
    Best known for this subject is Heidegger in his book "Being and
    Time" (German original: Sein und Zeit). The German term for *the
    nothingness* is “das Nichts”.
 2. The lingustic problem with the term *nothingsness* is that the term
    reifies the negation. To negate a statement does not create a new
    noun. And because there is no new noun, one cannot ask for
    properties of the noun *nothingness*. 
    
    Therefore the main criticism of using the term *nothingness* is its
    tendency to create philosophical pseudo-problems.
 3. Quantum fluctuations are a physical – not a philosophical – concept,
    see [Quantum fuctuations][2]. Quantum fluctuations are the
    spontaneous creation and annihilation of particles from the vacuum. I assume that’s what Krauss’ book speaks about. 

    Quantum fluctuations play an important role in quantum field theory. They
    are considered the seed for structure formation in cosmology
    during the early time of our cosmos. See Alan Guth [Inflation and
    the New Era of High-Precision Cosmology][3].

 


  [1]: https://plato.stanford.edu/entries/nothingness/
  [2]: https://en.wikipedia.org/wiki/Quantum_fluctuation
  [3]: https://physics.mit.edu/wp-content/uploads/2021/01/physicsatmit_02_cosmology.pdf