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  2. Heat lightning - Wikipedia

    en.wikipedia.org/wiki/Heat_lightning

    The actual phenomenon that is sometimes called heat lightning is simply cloud-to-ground lightning that occurs very far away, with thunder that dissipates before it reaches the observer. [2] At night, it is possible to see the flashes of lightning from very far distances, up to 100 miles (160 km), but the sound does not carry that far. [3]

  3. Thermal management of high-power LEDs - Wikipedia

    en.wikipedia.org/wiki/Thermal_management_of_high...

    Most of the electricity in an LED becomes heat rather than light – about 70% heat and 30% light. [1] If this heat is not removed, the LEDs run at high temperatures, which not only lowers their efficiency, but also makes the LED less reliable, shortens its lifespan. Thus, thermal management of high power LEDs is a crucial area of the research ...

  4. Passive infrared sensor - Wikipedia

    en.wikipedia.org/wiki/Passive_infrared_sensor

    A PIR motion detector used to control an outdoor, automatic light. A camera trap with PIR motion detector. An indoor light switch equipped with PIR-based occupancy sensor [1] A PIR-based motion detector is used to sense movement of people, animals, or other objects. They are commonly used in burglar alarms and automatically activated lighting ...

  5. Heat detector - Wikipedia

    en.wikipedia.org/wiki/Heat_detector

    A residential heat detector. A heat detector is a fire alarm device designed to respond when the convected thermal energy of a fire increases the temperature of a heat sensitive element. The thermal mass and conductivity of the element regulate the rate flow of heat into the element. All heat detectors have this thermal lag. Heat detectors have ...

  6. Fata Morgana (mirage) - Wikipedia

    en.wikipedia.org/wiki/Fata_Morgana_(mirage)

    Fata Morgana mirages significantly distort the object or objects on which they are based, often such that the object is completely unrecognizable. A Fata Morgana may be seen on land or at sea, in polar regions, or in deserts. It may involve almost any kind of distant object, including boats, islands, and the coastline.

  7. Which 38 Republicans voted against Trump's plan to keep the ...

    www.aol.com/38-republicans-voted-against-keeping...

    The U.S Capitol is seen after U.S, President-elect Donald Trump called on U.S. lawmakers to reject a stopgap bill to keep the government funded past Friday, raising the likelihood of a partial ...

  8. Photoresistor - Wikipedia

    en.wikipedia.org/wiki/Photoresistor

    Ambient light falling on the photoresistor causes the streetlight to turn off. Thus energy is saved by ensuring the light is only on during hours of darkness. Photoresistors are also used in laser-based security systems to detect the change in the light intensity when a person or object passes through the laser beam.

  9. 9 Health Issues That Can Cause Sensitivity to Light

    www.aol.com/news/9-health-issues-cause...

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