Neutrino vs. Photon — What's the Difference?

Neutrinos are subatomic particles with a very small, but nonzero mass and no electric charge, making them elusive as they rarely interact with matter. Whereas, photons are massless particles that carry electromagnetic energy and exhibit both wave and particle properties, making them fundamental to light and all forms of electromagnetic radiation.

Neutrinos can pass through most matter virtually undetected, traveling close to the speed of light, which allows them to penetrate stellar bodies and even Earth without interaction. On the other hand, photons interact with charged particles and are thus easily detectable; they can be absorbed, reflected, or refracted by various materials.

The detection of neutrinos requires large and sensitive underground or underwater detectors, like Super-Kamiokande in Japan, due to their weak interaction with matter. Conversely, photons are easily detected using even simple devices such as photodetectors or the human eye, due to their strong interaction with matter.

Neutrinos are important in studying processes that are inaccessible to photons, such as the core mechanisms of stars or supernovae, providing insights into areas that light cannot escape. In contrast, photons are crucial for observing and studying almost all astronomical objects and phenomena that are visible from Earth.

In the Standard Model of particle physics, neutrinos only interact via the weak nuclear force, one of the four fundamental forces, which is much weaker than the electromagnetic force that governs photon interactions. This difference illustrates their unique roles in the universe and in scientific research.