Blue Light from a Blackbody Radiator

[Arup Biswas]

From Wien's law it is seen that approx 6500K(Greater than sun's temp) needed to heat a body to blue! But we see so much blue light(uv ray)! Are they formed from any different mechanism rather than heating?

 

[Dale]

From Wien's law it is seen that approx 6500K(Greater than sun's temp) needed to heat a body to blue! But we see so much blue light(uv ray)! Are they formed from any different mechanism rather than heating?

Wein's law just describes the peak of the black body spectrum. A black body produces wavelengths both above and below the peak wavelength.

 

[Arup Biswas]

My point is can we heat a blackbody to get mostly Blue radiation??

 

[OmCheeto]

My point is can we heat a blackbody to get mostly Blue radiation??

Yes and no.

From my research this morning, "Blue" is kind of a laymanishy term.

 

[cjl]

You'll pretty much never see a blackbody that appears violet though, since the eye's sensitivity drops so much below 450nm that even a blackbody that peaks in the UV will appear to be a brilliant blue. There's a chart on the wikipedia article about stellar classification (https://en.wikipedia.org/wiki/Stellar_classification), but basically any blackbody over about 10,000K will appear blue-white to blue. There are several stars visible to the naked eye that are fairly bluish (Rigel and Vega spring to mind), but you'll get a much stronger color impression if you look at them through binoculars or a telescope, since dim light doesn't tend to provide much color (the rods in your eye are much more sensitive than the cones, but they do not convey color information).