The Discovery of Black Light

2021 ◽  
Author(s):  
Dan Howitt

|This article is the beginning of a reexpresson, and partial revision, of my book Black Light. The questions that I discuss in this article are listed in the below list of sections. In Sections 7, 8, 27, and 28, I discuss my discovery of black light. |The theoretical discovery of black light (that is, the thought experimental discovery of black light): The black spatial field in, for example, a “dark” room is actually, I argue, black light; and it is emitted from everything in the spatial field of the room (that is, the relatively empty space, and all objects). If, hypothetically, the black light in the above room was removed, we, when we would look into the spatial field of the room, would be blind, despite that we have the capacity to see. |The observational discovery of black light: There is no such thing as a “colorless” visual field for observers: A “colorless” visual field would be a visual field of blindness for observers, despite that they have vision, and that their eyes would be open. The black visual field is not, as is commonly stated, “the absence of photons”, “the absence of visible light”, and the, as such, absence of color: If it were, then it would be “colorless” (that is, not black), and, as such, a visual field of blindness for observers. |The experimental confirmation of black light via neurophysics: In Section 28, I demonstrate that particular EEG experimentation that was done on test-subjects in various conditions provides evidence or proof that the black of the black visual field that strikes our retinas is black light.

2018 ◽  
Vol 27 (2) ◽  
pp. 403-411
Author(s):  
Kristjan Laasik
Keyword(s):  

1966 ◽  
Vol 49 (3) ◽  
pp. 405-421 ◽  
Author(s):  
Mathew Alpern ◽  
Donica Dudley

Around a dim light viewed in a dark room can be seen faint blue-gray arcs which occupy that part of the visual field corresponding to the retina where the arcuate nerve fiber bundle passes from macular ganglion cell bodies to the optic nerve. These blue arcs of the retina are an entoptic phenomenon in which action potentials of the arcuate nerve fiber bundle presumably excite adjacent neurons. The experiments here described show that the light stimulus initially evoking the blue arcs excites cones and not rods as has been generally believed until now. Another commonly held idea is that the blue arcs are produced by bioluminescence or fluorescence associated with the action potentials in the arcuate nerve fiber bundle. The experiments described here disprove this hypothesis.


2020 ◽  
Vol 17 (1) ◽  
pp. 45-55
Author(s):  
Najiya Sundus Kadavath Meethal ◽  
Velumuri Lokapavani ◽  
Rashima Asokan ◽  
Lingam Vijaya ◽  
Ronnie Jacob George

Purpose: To compare patient preference for Swedish Interactive Threshold Algorithm (SITA) standard 24-2 protocol in Humphrey visual field analyzer (HVF) and full threshold N-30 protocol in frequency doubling perimetry (FDP) by primarily evaluating their perception about the test procedure and test targets along with surveying the factors that influence the patient concentration during perimetry and elements that determine the level of perimetry task difficulty. Methods: This study enrolled a subset of subjects from the Chennai Glaucoma Study. Each subject underwent a comprehensive ophthalmic examination after which they were randomly allocated to perform HVF and FDP with a 30-minute interval between the two procedures. SITA standard 24-2 protocol in HVF and full threshold N-30 protocol in FDP were used. This was followed by the administration of a questionnaire that mainly assessed the components such as (a) the patient preference for test procedure and test targets, (b) the factors influencing the patient concentration during perimetry performance, and (c) the impression about the level of perimetry task difficulty. The patient responses from the survey for each of the subcategories were obtained and analyzed using Chi-square test. Results: A total of 42 subjects with a mean age of 59.7 (SD 9.7) years were included, among which 18 (42.86%) were male and 24 (57.14%) were female. Thirty-two (76.19%) subjects felt both FDP and HVF were easy to perform, eight subjects (19.05%) felt that both perimetry techniques were difficult to perform, and two subjects (4.76%) found FDP procedure was easier than HVF, whereas the distribution was not statistically significant (Chi-square, p = 0.7). Pressing the button as a response to peripheral stimulus perception and inability to maintain steady central fixation for prolonged duration were the most commonly reported factors that influenced the level of difficulty of the perimetry tasks. A dark room ambience set for performing HVF was preferred by 32 (76.20%) subjects. Conclusion: There was no significant difference in the patient preference for test procedure and peripheral test targets. A black central fixation as in FDP and dark room ambience set for HVF were preferred.


Author(s):  
Shawn Williams ◽  
Xiaodong Zhang ◽  
Susan Lamm ◽  
Jack Van’t Hof

The Scanning Transmission X-ray Microscope (STXM) is well suited for investigating metaphase chromosome structure. The absorption cross-section of soft x-rays having energies between the carbon and oxygen K edges (284 - 531 eV) is 6 - 9.5 times greater for organic specimens than for water, which permits one to examine unstained, wet biological specimens with resolution superior to that attainable using visible light. The attenuation length of the x-rays is suitable for imaging micron thick specimens without sectioning. This large difference in cross-section yields good specimen contrast, so that fewer soft x-rays than electrons are required to image wet biological specimens at a given resolution. But most imaging techniques delivering better resolution than visible light produce radiation damage. Soft x-rays are known to be very effective in damaging biological specimens. The STXM is constructed to minimize specimen dose, but it is important to measure the actual damage induced as a function of dose in order to determine the dose range within which radiation damage does not compromise image quality.


Author(s):  
C. Jacobsen ◽  
J. Fu ◽  
S. Mayer ◽  
Y. Wang ◽  
S. Williams

In scanning luminescence x-ray microscopy (SLXM), a high resolution x-ray probe is used to excite visible light emission (see Figs. 1 and 2). The technique has been developed with a goal of localizing dye-tagged biochemically active sites and structures at 50 nm resolution in thick, hydrated biological specimens. Following our initial efforts, Moronne et al. have begun to develop probes based on biotinylated terbium; we report here our progress towards using microspheres for tagging.Our initial experiments with microspheres were based on commercially-available carboxyl latex spheres which emitted ~ 5 visible light photons per x-ray absorbed, and which showed good resistance to bleaching under x-ray irradiation. Other work (such as that by Guo et al.) has shown that such spheres can be used for a variety of specific labelling applications. Our first efforts have been aimed at labelling ƒ actin in Chinese hamster ovarian (CHO) cells. By using a detergent/fixative protocol to load spheres into cells with permeabilized membranes and preserved morphology, we have succeeded in using commercial dye-loaded, spreptavidin-coated 0.03μm polystyrene spheres linked to biotin phalloidon to label f actin (see Fig. 3).


2019 ◽  
Vol 6 (21) ◽  
pp. 3693-3697 ◽  
Author(s):  
Jiu-Jian Ji ◽  
Zhi-Qiang Zhu ◽  
Li-Jin Xiao ◽  
Dong Guo ◽  
Xiao Zhu ◽  
...  
Keyword(s):  

A novel, green and efficient visible-light-promoted decarboxylative aminoalkylation reaction of imidazo[1,2-a]pyridines with N-aryl glycines has been described.


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