After watching this video, you’ll be able to answer these questions:

– What is the main use of isospin?

– Why is it called spin?

– Who introduced the concept?

– What are the two kinds of isospins nowadays?

– What does the weak isospin decide?

# How to Measure Gravitational Waves

After watching this video, you’ll be able to answer these questions:

– How does LIGO work?

– Does a gravitational wave also stretch light?

– If yes, is this a problem for our measurement?

# Photoemission Spectroscopy

After watching this video, you’ll be able to answer these questions:

– How does a PES work?

– What is the Fermi level?

– What’s a work function?

– How can you measure the local density of states of electrons?

# Causality & Light Cones

After watching this video, you’ll be able to answer these questions:

– How does a timelike/spacelike/lightlike vector look in a Minkowski diagram?

– What do we mean by timelike / space like separation?

– How do you draw the light cone in a Minkowski diagram?

– How can you use the light cone to decide on causality?

# Snell’s Law

After watching this video, you’ll be able to answer these questions:

– What is the refraction index?

– Which component of the momentum doesn’t change when passing through a surface?

– How is a beam of light affected when entering water from air?

– State Snell’s law!

# Density of States | Free Electrons

After watching this video, you’ll be able to answer these questions:

– Where can the model of free electrons be applied?

– How is the number of states in a material determined?

– What does the density of states in 1d/2d/3d look like?

– What is a Van Hove singularity?

# Dimensional Analysis

After watching this video, you’ll be able to answer these questions:

– How do you go from natural units to SI units?

– What are the four steps in dimensional analysis?

– How are mass, length and time related in natural units?

# Free Electron Dispersion Relation

After watching this video, you’ll be able to answer these questions:

– How can you calculate the relativistic energy-momentum relation?

– Why do we need a low-energy approximation?

– What are the term appearing in this low-energy approximation?

– What is the relation between the dynamic mass and the rest mass?

– What is the dispersion relation of a free electron gas?

# Units & s²-Hyperbolas

After watching this video, you’ll be able to answer the following questions:

– How is the Minkowski metric related to Minkowski diagrams?

– What’s the angle between the old and new coordinates?

– Why do all points on a hyperbola s^2=const describe the same time/length?