A cosmic microwave background microwave background...
The Planck scale
On adding a cutoff
Doppler effect sweater: Blue shifted when the source approaches the observer...
The Rabicycle: featuring Bloch sphere wheels, ground state ground, hbar handle bar, and Bell state bell
The Quantum Vacuum
A bird-brained physicist
A snowflake under the microscope
An open quacktum system interacting with a bath
A knot related picture
...red shifted when the the source recedes away