Two Basic Blackbody Radiation quesions

This link shows the general plot of energy emitted by a blackbody against frequency. My two questions regarding this plot are:

1. Is the frequency in the plot the frequency of EM radiation emitted by the blackbody?

2. Why does the energy fall off after reaching a maximum?

The explanation my book gave was somewhat confusing, it says "Plank's spectral energy density ultimately falls to 0, because at very high frequencies, there is not enough thermal energy to produce even one photon." If it's refering to the frequencies of the emitted EM radiation, wouldn't there still be photons present?

Any help is appreciated.


1) the plot shows how much energy is emitted by the radiation at each frequency by a body at 5000K. The horizontal axis is frequency, the vertical axis is the amount of energy radiated at the frequency.

2) It takes a certain amount of energy to create a photon of given frequency; the higher the frequency, the more energy is required. There's enough energy in the heated object to create a very large number of low frequency photons but only a few higher frequency ones, and the higher the frequency the fewer photons.

Want to reply to this thread?

"Two Basic Blackbody Radiation quesions" You must log in or register to reply here.

Physics Forums Values

We Value Quality
• Topics based on mainstream science
• Proper English grammar and spelling
We Value Civility
• Positive and compassionate attitudes
• Patience while debating
We Value Productivity
• Disciplined to remain on-topic
• Recognition of own weaknesses
• Solo and co-op problem solving

Hot Threads