Do Photons Cast Shadows?

The video explores whether photons, or light, can cast shadows. Initially, it seems they cannot, as photons are electromagnetic waves that don't interact directly. However, photons can interact indirectly through electrons, gravitational attraction, and high-energy collisions. The video explains these interactions, focusing on photon scattering and the cosmic microwave background radiation, which can block high-energy gamma rays, effectively casting shadows.

What is the initial assumption about whether photons can cast shadows?

Describe the three indirect ways photons can interact with each other.

How do super-high-energy photons contribute to the casting of shadows?

What challenges exist in observing interactions between photons?

Explain how cosmic microwave background radiation relates to shadows cast by photons.