Time dilation can be explained within the framework of special relativity, without invoking the concept of an aether. Special relativity is a theory developed by Albert Einstein that describes the behavior of space and time in the absence of gravitational effects.
According to special relativity, the passage of time is not absolute but depends on the relative motion between observers. Two fundamental principles of special relativity are:
The principle of relativity: The laws of physics are the same in all inertial reference frames. An inertial reference frame is a coordinate system in which an observer at rest or moving with a constant velocity can describe the laws of physics without the need for acceleration.
The constancy of the speed of light: The speed of light in a vacuum is constant for all observers, regardless of their relative motion.
From these principles, time dilation arises as a consequence. When two observers are moving relative to each other, they will measure different elapsed times for the same event. This effect becomes significant as the relative velocity approaches the speed of light.
To illustrate this, let's consider a thought experiment: imagine two observers, A and B, where A is stationary and B is moving at a high speed relative to A. If B carries a clock and passes by A, both A and B will measure different elapsed times for the clock.
From observer A's perspective, observer B's clock will appear to be ticking slower due to time dilation. This means that less time will have passed on B's clock compared to A's clock for the same event.
Similarly, from observer B's perspective, observer A's clock will also appear to be ticking slower due to time dilation. Again, less time will have passed on A's clock compared to B's clock for the same event.
The effect of time dilation has been experimentally confirmed in various ways, such as through the use of high-speed particle accelerators and precise atomic clocks.
It is important to note that time dilation is not a consequence of an aether or any medium through which light propagates. Rather, it arises from the fundamental properties of space and time as described by special relativity, which do not require the presence of an aether.