how would the world seem to us if we could see the subatomic particles?
Answers
Subatomic particles, the hadrons and leptons you ask about, are so small they are difficult to detect individually, and elaborate apparatuses are designed for detecting the presence of and measuring the properties of individual particles. Here is a describing a fairly typical, large detector for subatomic particles. These detectors are designed to measure the effects of particles when they pass. They may leave a trail of ionized gas, for instance, or a flash of light when they collide with leaded glass. People have seen with their eyes these flashes of light and sparks one can make with the ion trails. An older technique is to expose a liquid just about ready to boil to high-energy particles, and then to take a picture as the bubbles left in the path of the particle start to expand. Here is a describing one particularly large bubble chamber, along with a photograph of bubble trails left by subatomic particles.
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