Photon-axion conversion induced by intergalactic magnetic fields causes an apparent dimming of distant sources, notably of cosmic standard candles such as supernovae of type Ia (SNe Ia). We review the impact of this mechanism on the luminosity-redshift relation of SNe Ia, on the dispersion of quasar spectra, and on the spectrum of the cosmic microwave background. The original idea of explaining...

Extreme ultraviolet spectroscopic observations of one coronal mass ejection event are used to examine the onset phase of the eruption. We find significant dimming of million K plasmas in the low corona under the ascending CME, the activation of an adjacent prominence and 2 million K ‘hot spots’ which may be associated with the CME footpoints. In particular, we show that the dimming is due to a ...

This paper presents a simple alternative of automatic luminous control for electronic ballasts operating in selfsustained oscillating mode feeding fluorescent lamps to energy saving. The luminous flux level control is based on a signal from a lighting dependent resistor, which measures the luminous flux level. The dimming feature is obtained using switching frequency variation. Thus, the circui...

We propose a high dynamic range (HDR) liquid crystal display (LCD) with pixel-level local dimming. The device structure consists of a pixelated LCD dimming panel to control the backlight intensity entering the master LCD panel. According to our analysis and test cell experiment, this dual-panel display system possesses exceedingly high contrast ratio (> 1,000,000:1) and high bit-depth (> 14 bit...

Fluorescent lamps were first introduced to the world in the 1939 World’s Fair. They are low-pressure mercury discharge lamps. Since then, the fluorescent lamps have been the mainly lighting source due to their merits of high color rendering, soft-visualization, long life, and energy-saving. Unfortunately, however, all gas discharge lamps cannot directly connect to a voltage source and require a...

Betelgeuse, one of the most studied red supergiant stars, dimmed in optical by ~1.2 mag between late 2019 and early 2020, reaching an historical minimum called "the Great Dimming." Thanks to enormous observational effort date, two hypotheses remain that can explain Dimming: a decrease effective temperature enhancement extinction caused newly produced circumstellar dust. However, lack multi-wave...

Because type Ia supernovae (SNs) are anomalously dimmed with respect to the flat (qo = 0.5) Friedman Expanding Universe model, I was surprised to find that the brightest cluster galaxies (BCGs) are not anomalously dimmed. Based on the absence of anomalous dimming in BCGs, the following conclusions were reached: • Since the light from the SNs and BCGs traverses the same space, the current hypoth...

A lighting controls study performed over a three month period provided data that can be used to determine the impact of manual switching and dimming controls on occupant behavior and attitudes and on energy use. Data were analyzed for 58 private offices on a single floor of a modern office building in Boulder, Colorado. Each office was equipped with a ceiling-mounted infrared motion sensor, a d...

Dimming and brightening aftereffects occur after exposure to a temporal luminance sawtooth stimulus: A subsequently presented steady test field appears to become progressively dimmer or brighter, depending on the polarity of the adapting sawtooth. Although described as "dimming" and "brightening," it is plausible that a component of the aftereffects is based on contrast changes rather than on l...