Time dilation is a key prediction of Einstein’s theory of special relativity, stating that a moving clock ticks more slowly compared to a stationary one, from the perspective of an outside observer. In other words, time passes differently for observers in different frames of motion.
What Causes Time Dilation?
- According to special relativity, the laws of physics are the same for all observers moving at constant speeds.
- But when an object moves close to the speed of light, time appears to slow down for that object relative to a stationary observer.
- This doesn’t mean the person on the moving object feels time slowing — for them, everything feels normal — but an outside observer sees their clock ticking more slowly.
Real-World Evidence:
- GPS satellites experience time dilation because they move fast relative to the Earth’s surface. Their onboard clocks must be adjusted to match Earth-based time.
- Muon particles created in the upper atmosphere live longer when moving at high speeds than when at rest — another confirmation of time dilation.
- It’s also a concept used in science fiction, like the idea of “aging more slowly” during space travel.
Why It Matters:
- Time dilation shows that time is not absolute; it depends on how fast you’re moving.
- It’s essential for high-precision technologies like satellite navigation.
- It helps scientists understand extreme environments like black holes or particle accelerators.