This very short lecture introduces Wein's displacement law.
This lecture is needed if Wein's law homework is used.We saw previously that the spectral intensity can be expressed with respect to wavelength: \begin{align} S_{\lambda}(\lambda) &= \frac{2\pi h c^2}{\lambda^5}\frac1{e^{\frac{hc}{\lambda k_BT}}-1} \end{align} I mentioned that the peak intensity shifts to lower wavelengths at higher temperature. We can solve for the peak in the spectral intensity by taking a derivative. The resultin equation can
but the result is a non-linear equation that is a bit of a pain. So it's convenient to just have an equation. The result is known as Wien's displacement law, and states that \begin{align} \lambda_{\text{peak}} &= \frac{b}{T} \end{align} where \(b=2.9\times 10^{-3}\text{ m K}\) is called Wien's displacement constant.
computer Computer Simulation
30 min.
group Small Group Activity
10 min.
group Small Group Activity
5 min.
assignment Homework
group Small Group Activity
30 min.
thermodynamics intensive extensive temperature volume energy entropy
Students generate a list of properties a glass of water might have. The class then discusses and categorizes those properties.face Lecture
5 min.
thermodynamics statistical mechanics
This very quick lecture reviews the content taught in Energy and Entropy, and is the first content in Thermal and Statistical Physics.group Small Group Activity
30 min.
group Small Group Activity
30 min.
face Lecture
120 min.
paramagnet entropy temperature statistical mechanics
These lecture notes for the second week of Thermal and Statistical Physics involve relating entropy and temperature in the microcanonical ensemble, using a paramagnet as an example. These notes include a few small group activities.assignment Homework