Discussion Overview
The discussion revolves around Wien's law and its implications for black body emission, particularly in the context of how the Earth's atmosphere interacts with different wavelengths of electromagnetic radiation. Participants explore the effects of atmospheric absorption on the observed peak wavelength and temperature of black bodies, such as stars.
Discussion Character
- Debate/contested
- Technical explanation
- Conceptual clarification
Main Points Raised
- One participant questions whether the Earth's atmosphere absorbs shorter wavelengths, causing the peak to shift to larger wavelengths, making black bodies appear cooler, or if it absorbs longer wavelengths, shifting the peak to shorter wavelengths and making them seem hotter.
- Another participant asserts that the peak does not shift, arguing that absorbed frequencies simply become less present in the spectrum, which deviates from a perfect black-body spectrum.
- A different participant contends that the peak wavelength does shift according to Wien's law, suggesting that the observed temperature of stars from Earth is affected by atmospheric absorption, although the specifics of which wavelengths are absorbed remain uncertain.
- It is mentioned that the effect of atmospheric absorption can vary depending on the wavelength being considered, such as UV versus infrared.
- A request is made for references or quotes to support claims made about the topic.
- A later reply provides information about the Earth's atmosphere being opaque to UV radiation and more transparent in the infrared, indicating the complexity of the absorption spectrum and its implications for observed black body emissions.
- There is an acknowledgment that astronomers have developed techniques to account for atmospheric absorption effects in their observations.
Areas of Agreement / Disagreement
Participants express differing views on whether the peak wavelength shifts due to atmospheric absorption, with no consensus reached on the matter. The discussion remains unresolved regarding the specific effects of atmospheric absorption on black body emission.
Contextual Notes
Participants note that the discussion involves assumptions about the nature of atmospheric absorption and its impact on observed spectra, which may depend on specific conditions and definitions.