In the context of special relativity, time dilation and length contraction are closely interconnected phenomena that arise due to the relative motion between observers. According to the theory, as an object's velocity increases, time dilation occurs, meaning that time appears to pass more slowly for the moving object as observed by a stationary observer. Simultaneously, length contraction occurs, where the length of the moving object appears to shorten in the direction of motion as observed by a stationary observer.
These effects are not separate or independent but are interconnected consequences of the relativistic framework. The magnitude of time dilation and length contraction depends on the relative velocity between the observer and the moving object. As an object's velocity approaches the speed of light, the effects become more pronounced, and the object's relativistic mass increases as well.
Experiments that have confirmed the predictions of time dilation and length contraction, such as the famous muon decay experiments, involve observing particles moving at high speeds relative to the observer. In these experiments, muons, which are unstable particles with a short lifetime, are created at high speeds in Earth's upper atmosphere and then detected at the surface. The fact that a significant number of muons reach the surface is evidence of time dilation, as their lifetimes are extended due to their high velocities relative to an observer at rest.
While it is theoretically possible to imagine scenarios where time dilation is observed without significant length contraction, such cases would involve highly specific and contrived setups. In general, the effects of time dilation and length contraction are inseparable consequences of special relativity and occur together in real-world situations involving relative motion.