An Essential Distinction

We must make an essential distinction.
On one side, we have the electromagnetic spectrum including visible light. This side can be measured by instruments.
On the other side, we have a "field" of energy (sometimes called "subtle energy") that can never be measured by any instrument and that can never be "seen" with our common physical senses. This does not mean that it can never be detected. Its effect can be seen in the material level of reality and it's actual presence can be intuited.
If we keep this essential distinction constantly in mind we can begin to distinguish between the various observations, experiments and experiences recorded in the literature throughout the course of human history.
Here is a reference to the distinction:
http://www.holosuniversity.net/pdf/NLoeffler_Dissertation.pdf
"According to the definition of ISSSEEM, subtle energies are believed to move within the so-called ‘etheric’ (or subtle) energy body. ISSSEEM further asserts that “it is traditionally accepted that expansions of consciousness often are related to changes in subtle energies that cannot be quantified. These latter ‘energies’, which are said to be associated with interactions and with transcendence, may not, in fact, actually be involved with known physical fields.
William Tiller, professor emeritus of Materials Science and Engineering at Stanford University, has been studying subtle energies and the interface of science and consciousness for many decades. In his paper titled “What are Subtle Energies” he refers to subtle energies as real energies that are not directly observable because they function at a different level than observable reality. According to Tiller, they function ”at the level of the ‘vacuum’, the negative energy, chaotic Dirac Sea.” Subtle energies are those energies beyond the four known energies of electromagnetism, gravitation, the strong nuclear force and the weak nuclear force, which are needed to explain anomalous phenomena. Tiller further states that a magnetic vector potential “appears to play the role of ‘bridge’ between the subtle, unobservable energies and physically observable energies associated with electric and magnetic fields.”" (Nicole Löffler)