Blackbody Radiation

Blackbody radiation induces attractive force stronger than gravity

Perfectly non-reflective objects, called blackbodies, produce blackbody radiation when at a uniform temperature. Although the properties of blackbody radiation depend on the blackbody’s temperature, this radiation has always been thought to have a net repulsive effect. Now in a new study, scientists have theoretically shown that blackbody radiation induces a second force on nearby atoms and molecules that is usually attractive and, quite surprisingly, even stronger than the repulsive radiation pressure. Consequently, the atoms and molecules are pulled toward the blackbody surface by a net attractive force that can be even stronger than gravity. The new attractive force—which the scientists call the “blackbody force"—suggests that a variety of astrophysical scenarios should be revisited.

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Blackbody radiation induces attractive force stronger than gravity

Perfectly non-reflective objects, called blackbodies, produce blackbody radiation when at a uniform temperature. Although the properties of blackbody radiation depend on the blackbody’s temperature, this radiation has always been thought to have a net repulsive effect. Now in a new study, scientists have theoretically shown that blackbody radiation induces a second force on nearby atoms and molecules that is usually attractive and, quite surprisingly, even stronger than the repulsive radiation pressure. Consequently, the atoms and molecules are pulled toward the blackbody surface by a net attractive force that can be even stronger than gravity. The new attractive force—which the scientists call the “blackbody force"—suggests that a variety of astrophysical scenarios should be revisited.

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Think back to our question from ghandirocks about whether or not there could ever be a black flame. We brought up Planck’s Law to try and figure this out, which describes the light (or EMR) given off by something hot. Flame colors can have different explanations, but the most common is that flames are hot and have particles in them.

The Clear Science Staff fired up our computers and plotted the emissive power from Planck’s Law (qλ) depending on the temperature of the hot thing. It’s a weird-shaped function you see above, which tends to have a maximum (and it’s a log scale) in the visible light region between what we call ‘violet’ and 'red.’ You might already know this: that hotter things tend to burn blue and colder things burn red.

For a flame not to emit any visible light, it just needs to be really cold, like 500 K. This is 227 °C or 440 °F, which might be a slightly high oven temperature when you’re cooking. Most flames burn around 2000-3000 °C, so that would be a very cold flame. Remember though, this is just to make the flame colorless. For it to be BLACK it would have to absorb light instead of emitting it. So if there were lots of particles, like a very sooty flame, and it were also cold like this, then yes you could think of it as a black flame.

What Happens When a Black Hole Runs Out of Fuel?

Black holes are one of natures most feared (and misunderstood) features, but like most other things, they have weaknesses and if something has a weakness, it can die.

That presents a question; Would exhausting a black hole’s fuel supply effectively kill it? Find out here; http://bit.ly/WK1Nw0

Image Credit: Mark A. Garlick

Your light is ultraviolet. Because saying "you're hot" is way too mainstream

i found this interesting thing called blackbody radiation, thermodynamic thing explaining that a body, or stuff, or matter, has this peculiar spectrum depends on its temperature.

well it explains why fire can have a various colorful appearance : candlelight glows in red, gas stove glows in blue, and else.

other things in room temperature (above zero), glow in infrared (which means we’re so cool that we glow infrared). and things that are so hot, beyond the spectrum of white, will glow in ultraviolet.

that also explains the stiff dylans’ song titled “ultraviolet”. yesss, your light is ultraviolet. because saying ‘you’re hot’ is way too mainstream.

phys.org
Blackbody radiation induces attractive force stronger than gravity

Perfectly non-reflective objects, called blackbodies, produce blackbody radiation when at a uniform temperature. Although the properties of blackbody radiation depend on the blackbody’s temperature, this radiation has always been thought to have a net repulsive effect. Now in a new study, scientists have theoretically shown that blackbody radiation induces a second force on nearby atoms and molecules that is usually attractive and, quite surprisingly, even stronger than the repulsive radiation pressure. Consequently, the atoms and molecules are pulled toward the blackbody surface by a net attractive force that can be even stronger than gravity. The new attractive force—which the scientists call the “blackbody force"—suggests that a variety of astrophysical scenarios should be revisited. 

Read more at: http://phys.org/news/2013-07-blackbody-stronger-gravity.html#jCp