Radiometry Workshop

During this practical workshop, we explored the nature and behavior of electromagnetic waves through two complementary experiences: constructing a radio receiver and manipulating light through polarization. The main objective was to understand how energy travels through space and how we can interact with it, whether to transmit information (sound) or to filter the visible spectrum (light).
1. Building the Homemade Radio In the first stage, we delved into the radio frequency spectrum. The challenge consisted of assembling a basic receiver circuit (likely a crystal radio or simple LC circuit) capable of capturing signals without the
need for a complex power source.
• The Process: We connected key components such as the coil (inductance) and the capacitor to create a resonant circuit. I learned that the antenna length and tuning are critical to "catch" the specific frequency of a commercial
station.
• The Result: It was fascinating to observe how, by adjusting the circuit, we were able to demodulate the signal and transform invisible electromagnetic waves into audible sound through the earpiece. This demonstrated the principle of resonance and the omnipresence of radio waves in our environment.
2. Light Polarization Experiment The second part of the workshop focused on the visible spectrum, specifically on the wave property of light. The instructor used polarized panels or sheets to show us that light does not vibrate in a single direction, but in multiple planes.
• The Observation: We were shown how a polarizing panel acts like a "grid" or "fence" that only allows light waves vibrating in a specific orientation to pass through.
• The Angle Phenomenon: The most revealing moment was when a second filter was superimposed, or the angle of incidence was changed. By rotating the panel 90 degrees relative to the polarized source (or relative to a second filter), the light was blocked almost completely. I understood that by crossing the axes of polarization, the passage of the wave is prevented, physically demonstrating that light behaves as a transverse wave.
Cholula, Jalisco, Mexico