Relativity Lite

8 | Relativity Lite times thinner than the narrowest line this printer can draw at 300 dots per inch. Even if you could draw it, you cannot see any difference between c t and c τ , so no time dilation comes into our everyday experience. v t c t c τ c t Figure 5. The sequence of fours steps for v = 70 miles/hour. RELATIVITY BITES This is not to say that time dilation does not affect our lives. The Earth is bombarded by cosmic rays that produce showers of particles called muons in the upper atmosphere. Half of a given group of muons decays within two-millionths of a second (two microseconds ) when they are at rest. That is, they have a proper half-life of two microseconds. After another two microseconds, half of those remaining decay, leaving one-fourth, and so on.