Here's why:

* The Electromagnetic Spectrum: Visible light is just a small part of the electromagnetic spectrum, which encompasses all forms of electromagnetic radiation.

* Wavelength and Energy: Gamma rays have extremely short wavelengths and very high energies compared to visible light.

* Human Perception: Our eyes are designed to detect wavelengths within the visible light range. Gamma rays have far too much energy for our eyes to perceive.

Think of it this way:

* Visible light is like the middle section of a rainbow.

* Gamma rays are like a much higher frequency and energy sound that we can't hear.