Time dilation and length contraction are two fundamental concepts in special relativity. Time dilation refers to the phenomenon where time appears to pass more slowly for an object in motion relative to an observer at rest. Length contraction, on the other hand, describes the contraction of an object's length along the direction of its motion as measured by an observer in a different frame of reference.
In special relativity, these effects are not experienced simultaneously by a single object. The magnitude of time dilation and length contraction depends on the relative velocity between the observer and the object in motion. However, the key aspect is that these effects are relative to the observer's frame of reference. So, an observer in one frame of reference may observe time dilation and length contraction for an object in motion relative to them, while an observer in a different frame of reference may not observe these effects or may observe them to a different extent.
To put it simply, an object in motion will experience time dilation from the perspective of an observer at rest relative to the object. However, the same object will not experience length contraction from its own frame of reference. The length contraction is observed by an observer in a different frame of reference relative to the object.
It's important to note that these effects are not contradictory but rather consequences of the relativistic nature of spacetime. They arise due to the invariance of the speed of light and the relative nature of space and time measurements in special relativity.