Temperature and color - why hot objects glow red?

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Discussion Overview

The discussion revolves around the phenomenon of why hot objects tend to glow red as they are heated, exploring concepts related to thermic radiation and blackbody radiation. The scope includes theoretical aspects of thermodynamics and radiation spectra.

Discussion Character

  • Exploratory, Technical explanation, Conceptual clarification, Debate/contested

Main Points Raised

  • One participant inquires about the reason behind hot objects glowing red, suggesting a curiosity about the underlying principles.
  • Another participant explains that the color change is related to the thermic radiation spectrum, noting that as an object like iron is heated, it emits radiation that transitions from infrared to red, then to orange, yellow, white, blue, and ultraviolet.
  • A mathematical relationship is presented, indicating that the peak wavelength of emission is inversely proportional to the temperature of the object, referencing the concept of a blackbody.
  • Links to external resources on black body radiation and Planck's law are provided for further reading.
  • A suggestion is made to explore the ultraviolet catastrophe as an interesting topic within thermodynamics.
  • One participant humorously asserts that red is cold and blue is hot, while cautioning against touching red-hot steel, which introduces a potential misunderstanding about color and temperature correlation.

Areas of Agreement / Disagreement

Participants present varying perspectives on the relationship between color and temperature, with some agreeing on the thermic radiation explanation while others introduce conflicting notions about color associations. The discussion remains unresolved regarding the implications of color perception in relation to temperature.

Contextual Notes

There are limitations in the discussion regarding the assumptions made about color perception and temperature, as well as the potential misunderstanding of color associations. The mathematical relationship mentioned may depend on specific definitions of blackbody radiation.

Who May Find This Useful

This discussion may be of interest to those studying thermodynamics, radiation physics, or anyone curious about the properties of heated materials and their emissions.

i.mehrzad
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Is there any reason why most hot things alost always begin to get the tinge of red??
 
Science news on Phys.org
hi mehrzad...yeah there is a reason...it is related to their thermic radiation spectrum...when you heat up an object like a piece of iron...it will emit higher energetic radiations...from Infra-Red it changes to Red...then Orange...Yellow...White...Blue...UV...and so on

(wavelength peak)=(B)/(Temperature)----»for a blackbody
 
if you want to know more about this branch of thermodynamics...look for ultraviolet catastrophe, it's interesting
 
Remember red is cold and blue is hot. I still don't recommend touching a piece of steel that is red.

CraigD, AMInstP
www.cymek.com
 

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