On Friday, August 22, the science students of Classes 11 and 12 visited the National Physical Laboratory (NPL), one of India’s premier research institutes. The day began with an introductory video highlighting NPL’s fields of expertise, mainly metrology, the science of measurement. This was followed by a short quiz on SI units and the institution's history, which tested our basic knowledge in these fields. 

Our campus tour included four laboratories. The first stop was the Crystal Lab, where we learned how crystals, widely used in electronics and optics, are grown. We were introduced to the SEST (Slow Evaporation Solution growth Technique), a method used to obtain high-quality crystals through controlled evaporation.

Next, we visited the Rheology Lab, which studies fluid dynamics. The highlight here was a ferrofluid, which behaves like an ordinary liquid until exposed to a magnet, when it instantly forms spiky, solid-like structures. Watching this transformation was both fascinating and thought-provoking.

Our third stop was the Force, Hardness, and Torque Lab, a large hall filled with heavy machinery. Here we saw how load sensors are calibrated (measuring unknown weights using known ones), and learned how the hardness of materials is tested. The demonstrations showed us how fundamental concepts of physics are directly applied in engineering and industry.

Finally, we reached the most exciting part of the visit- the Helium Lab. We learned about the different boiling points of helium, nitrogen, and air, as well as the processes used in gas liquefaction. The discussion became especially engaging when real-life applications of liquid nitrogen, from maglev trains to MRI machines and food preservation, were explained. Live demonstrations made the session unforgettable: leaves, water, and balloons froze instantly, and when liquid nitrogen was poured onto the ground, it created a misty cloud and left a cooling sensation on our feet.

Overall, the visit to NPL was highly educational and inspiring. It gave us not only a deeper understanding of scientific concepts but also a clear view of their practical applications in daily life. The experience was both memorable and motivating.