In your own words, define what is meant by time dilation in special relativity theory. Provide a similar definition for length contraction. Give an example in which the effects of time dilation are actually observed.

Answer: Time dilation and length contraction are phenomena occurring in special relativity theory. Time dilation refers to the slower experience of time by an observer in a moving frame of reference compared to a stationary observer. Length contraction refers to the apparent shortening of an object's length in a moving frame of reference in the direction of motion when compared to a stationary observer. Both effects become more pronounced as the relative speed between the observers gets closer to the speed of light. A real-life example of time dilation is the decay of muons that are created in the Earth's upper atmosphere by cosmic rays, resulting in an apparent increase in their lifespan as they travel at high speeds towards the Earth's surface.