This preview shows pages 1–4. Sign up to view the full content.
This preview has intentionally blurred sections. Sign up to view the full version.
View Full DocumentThis preview has intentionally blurred sections. Sign up to view the full version.
View Full Document
Unformatted text preview: 1.2 . Figure 1.2: The blackbody spectrum as measured by COBE. The problem with the classical (RayleighJeans) law for blackbody radiation is that it does suggest emission of infinite amounts of energy, which is clearly nonsensical. Actually it was for the description of this problem Planck invented Planck's constant! Planck's law for the energy density ate frequency for temperature is given by (1.2) The interpretation of this expression is that light consists of particles called photons, each with energy . If we look at Planck's law for small frequencies , we find an expression that contains no factors (Taylor series expansion of exponent) (1.3) This is the RayleighJeans law as derived from classical physics. If we integrate these laws over all frequencies we find (1.4) for Planck's law, and infinity for the RayleighJeans law. The result has been experimentally confirmed, and predates Planck's law. Figure 1.3: A comparison between the RayleighJeans and Planck's law...
View
Full
Document
This note was uploaded on 11/09/2011 for the course PHY PHY2053 taught by Professor Davidjudd during the Fall '10 term at Broward College.
 Fall '10
 DavidJudd
 Physics, Thermodynamics, Radiation

Click to edit the document details