Solar Heat Ray (Boiling Water)

Augustin-Jean Fresnel was a French engineer and physicist that invented a special lens for lighthouses during the early 1800s. Today, cheap fresnel lenses can be found in older-model projection televisions.

The Solar Heat Ray Experiment

Samsung projection television

Once open, the lens and screen are removed.

The screen and lens are taped together. Once the tape is cut, the screen and lens are separated.

Fresnel lens

Prior to building the lens frame, frame holder, and base, the lens is briefly tested to demonstrate the ray. The light is blinding and the surface temperature jumped above 160 degrees Fahrenheit (71.1 degrees Celsius) within a few moments.

A base is constructed to allow the frame holder the ability to swivel left and right.

A frame is constructed for the lens. The frame will have a bolt on each side to permit moving the beam from the lens up and down.

The frame holder is connected to the base. The frameholder can move freely to the left and right.

The base, frame holder, and lens frame are put together. The solar heat ray experiment is ready to begin.


A fire extinguisher is available in case of fire. An infrared thermometer will be used to measure temperature. Shades are used to guard against blinding light. Gloves prevent direct contact with hot surfaces.

A large magnifying glass is tested. A temperature of 234.3 degrees Fahrenheit (112 degrees Celsius) is recorded.

A small magnifying glass is tested. A temperature of 389.3 degrees Fahrenheit (189 degrees Celsius) is recorded.

The large solar heat ray experiment is tested. The infrared thermometer states a maximum range up to 500 degrees Fahrenheit. A temperature of 686.8 degrees Fahrenheit is recorded.

The temperature frequently moves out of range of the thermometer.

A jar of water is heated with the solar heat ray.

Steam rises from the jar of water. The heat causes the water to boil.