Anyone who bought a first-generation digital scale 25 years ago encountered a strange problem. When you weighed yourself daily, your weight fluctuated by a few hundred grams each day. There were many theories about what caused this. But in the end, it turned out to be a rather peculiar technical glitch.
A scale has a spring in the middle to absorb your weight. The first generation had a sensor either in front of or behind this spring. So, if you stood on the scale and leaned slightly forward or backward, it affected the sensor’s reading.
The second generation has two sensors, one to the left and one to the right of the spring. So the scale can tell you not only how much you weigh, but also that, for example, 43% of your weight rests on your left foot.