Comments about the Letter in Nature: Challenging local realism with human choices

Following is a discussion about this Letter in Nature Vol 557 10 May 2018, by the Big Bell Test Collaboration
To read this Letter select: https://www.nature.com/articles/s41586-018-0085-3

• The text in italics is copied from the article
  
• Immediate followed by some comments
  

In the last paragraph I explain my own opinion.

Introduction

A Bell test is a randomized trial that compares experimental observations against the phylosophical worldview of local realism in which the properties of the physical world are independent of our observation of them and no signal travels faster than light.

This sentence does not say anything because it does not give any detail of what is involved. etc. etc.

A Bell test requires spatially distributed entanglement, fast anf high efficiency detection and unpredictable measurements settings.

The comments are the same as for the previous sentence. Specific the sentence does not explain what spatially distributed entanglement is and how this is measured in advance. The same for the two other concepts mentioned.

Reflection 1 - Supplementary information

The Supplementary information you can read here:
https://static-content.springer.com/esm/art%3A10.1038%2Fs41586-018-0085-3/MediaObjects/41586_2018_85_MOESM1_ESM.pdf
The Supplementary Information shows more detail about the 13 experiments explained on page 215.
The problem with each of these experiments is that they do not demonstrate anything physical, directly.
They demonstrate for example that the Bell inequality can be violated. The problem is what does that physical mean, in each of these cases.
For example: does it mean, within the scope of the experiment, that there are physical signals, faster than light, involved? It is not clear.

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