The prophetic ball is more interesting than what you think

This crystal ball is located just outside the Meteorological Office of Darwin Airport in Darwin, Australia. It is not a prophetic tool we often hear in ancient stories. In fact, it is a scientific device from the 19th century and still in use today.

As its name suggests, Campbell-Strokes Sunshine Recorder or Campbell-Stokes sunlight intensity deposit is a device that measures the intensity of the sun . The way it works is no different from how a thermometer measures the temperature of the environment and objects.

Campbell-Strokes Sunshine Recorder or the Campbell-Stokes sunlight-depositing machine.

This device includes a crystal ball 4 inches in diameter (more than 10cm) that focuses the rays of the sun onto a calibration sheet. The heat of the converging light ray will burn a part on the sheet to help the viewer to rely on it to reference sunlight intensity information.

This device was named after its inventor in 1853 - Sir John Francis Campbell

More surprisingly, Campbell is not a scientist, he is a well-known author and scholar. At that time, transparent glass spheres were used to quantify paper and users noticed that sometimes they left scorches on paper if exposed to sunlight.

Of course, this is not a new discovery. Because the mirrors and lenses were used by the ancient Greeks to focus sunlight long before. The most well-known evidence is the record of the famous mathematician Acsimet using a giant parabolic spherical mirror to burn the Roman army's ships during the battle to protect the homeland of Syracause. he was in the 2nd century BC.

This is a device used to measure sunlight intensity.

Campbell inspired the story and began tinkering with creating his own meteorological device - a simple and effective tool for measuring and recording the intensity of the sun.

At the first prototype, Campbell used an empty glass sphere filled with water that was attached to a wooden bowl. From here, he can determine the intensity of sunlight depending on the depth of the burn.

This device quickly resonated in meteorological circles and one of them contributed to improving this invention. Accordingly, in 1879, an Irish physicist replaced wooden frames with metal frames, and used replaceable paper cards to help record and store data about sunlight intensity. be more convenient.

Today, the Campbell-Stokes sunlight-depositing machine is still being used in many meteorological agencies and observatories worldwide.

This device quickly resonated in meteorological circles and one of them contributed to improving this invention.

Although gradually replaced by electronic sensors that are compact and have higher accuracy. This device continues to be a valuable source of information for at least a century - An effective tool for students and professionals to gain a deeper understanding of the sun.