Blackbody effect hypothetical question

  • Context: Undergrad 
  • Thread starter Thread starter Badmouton
  • Start date Start date
  • Tags Tags
    Blackbody Hypothetical
Click For Summary

Discussion Overview

The discussion revolves around the blackbody effect and whether an object can be so hot that it emits no visible light. Participants explore the relationship between temperature and the spectrum of emitted radiation, particularly focusing on the transition of emitted light from the visible spectrum to ultraviolet and x-rays as temperature increases.

Discussion Character

  • Debate/contested

Main Points Raised

  • One participant questions if an object can be so hot that it emits no visible light, suggesting that increased heat moves the emission away from the visible spectrum.
  • Another participant argues that the emitted radiation spectrum includes all wavelengths, noting that while the peak may shift to ultraviolet or x-rays, visible light is still emitted.
  • A third participant reinforces the idea that as a body is heated, the energy emitted in all wavelength bands, including the visual spectrum, increases, despite a relative increase in UV or x-ray emissions.
  • A later reply mentions the concept of 'blue hot' and references blue stars as an example, indicating that there is a point where objects can emit light in the blue spectrum.

Areas of Agreement / Disagreement

Participants express differing views on the relationship between temperature and visible light emission, with no consensus reached on whether an object can emit no visible light at high temperatures.

Contextual Notes

Some assumptions about the nature of blackbody radiation and the definitions of visible light may not be fully articulated, leading to potential misunderstandings in the discussion.

Badmouton
Messages
7
Reaction score
0
According to the blackbody effect, can something be so hot that it emits no visible light?
I say this because the more heated an object is, the more it moves away from the visible light spectrum, does that apply until there is no light at all?
 
Science news on Phys.org
Not really. The spectrum of the emitted radiation includes all wavelengths. What happens is that the peak moves to ultraviolet or even x-rays, but it is still visible.
 
As you heat a body, the energy it emits in any particular wavelength band strictly increases, so even though you are proportionally increasing the amount emitted in UV or x-ray, you are still increasing the amount in the visual spectrum.
 
Nabeshin said:
As you heat a body, the energy it emits in any particular wavelength band strictly increases, so even though you are proportionally increasing the amount emitted in UV or x-ray, you are still increasing the amount in the visual spectrum.

As demonstrated here:-

F18-02%20Planck%20black%20body.jpg


I would like to know if it ever gets 'blue hot'.

Google says yes - blue stars.

http://outreach.atnf.csiro.au/education/senior/astrophysics/photometry_colour.html
 
Last edited by a moderator:

Similar threads

  • · Replies 29 ·
Replies
29
Views
5K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 5 ·
Replies
5
Views
2K
  • · Replies 19 ·
Replies
19
Views
18K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 8 ·
Replies
8
Views
2K
  • · Replies 4 ·
Replies
4
Views
4K
  • · Replies 19 ·
Replies
19
Views
3K
  • · Replies 17 ·
Replies
17
Views
4K
Replies
8
Views
5K