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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]
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 ...
Mexico City at night, showing skyglow A map from 1996 to 1997 showing the extent of skyglow over Europe. Skyglow (or sky glow) is the diffuse luminance of the night sky, apart from discrete light sources such as the Moon and visible individual stars. It is a commonly noticed aspect of light pollution.
Round bulbs, often tinted red to reduce visible light, provide infrared radiant heat suitable for warming of people or animals, but the power density available is low. The development of quartz halogen linear lamps allowed much higher power density up to 200 watts/inch of lamp (8 w/mm), useful for industrial heating, drying and processing ...
Regardless of where you stand on sleeping in socks, Dimitriu says: "Generally, a cool bedroom and light, breathable sheets that let the body cool down at night will help everyone sleep more ...
PGA of America votes to give U.S. captain, players $200,000 stipend, increase charitable donation, even though "no players asked to be compensated."
The Sun appeared to rise two weeks earlier than expected; the real Sun had still been below the horizon, but its light rays followed the curvature of Earth. This effect is often called a Novaya Zemlya mirage. For every 111.12 kilometres (69.05 mi) that light rays travel parallel to Earth's surface, the Sun will appear 1° higher on the horizon.
“Wet-bulb” temperatures prevent the human body from being able to cool itself down. As the U.S. heat wave drags on, experts warn of deadly 'wet-bulb' temperatures. Here’s what those are.