Time Dilation [Slowing down of a process]
By Johny Jagannath
Time dilation is a fancy word for 'slowing down of a process'. In physics, the process can be anything. Let us say there are ten people in a house and that it takes 30 seconds for them to get out of it. This is a process. It is a process where 10 people exit a house in a fixed amount of time, that is 30 seconds. If this process takes 50 seconds instead of the usual 30 seconds we just witnessed a slowing-down-of-a-process or time dilation.
This idea was first proposed by an Irish physicist named, Joseph Larmor in 1897, in reference to his theory of electrons in the context of electrons orbiting a nucleus. If an electron took X seconds to complete a single revolution, then a slowing-down-of-a-process is said to have occurred if the electron takes longer than X seconds to complete a single revolution. What causes this slowing-down-of-a-process? Larmor suggested that acceleration causes electrons to slow down. This has been been verified, of course.
Let us go back our initial example of a house and ten people exiting it in 30 seconds, and see what happens when this house is subjected to acceleration or made to move in a circular path at high speeds [same as a particle accelerator experiment, where slowing-down-of-processes are often performed and measured].
When our house [with inhabitants] is made to move in a circular path at high speeds, the house and its inhabitants experience centrifugal forces, that will pin all the people to a wall, and it would take a lot of strength for anyone to move at all in a situation like this. Therefore, no one will be able to get out of this house in the usual 30 seconds. They may take an hour or so to get out. Therefore, we just witnessed a slowing-down-of-a-process owing to acceleration [or circular motion].
The animation to the right shows two spheres. In our example, the house can be thought of as a sphere with a door. The animation shows two houses. One that is stationary. The other that moves in a circular path. We have just seen that centrifugal forces get in the way of a house that moves in a circular path, causing the inhabitants to take a longer time to exit it. The red sphere and the blue sphere to the right, demonstrate this effect via a clock animation. Notice that the blue clock is faster than the red clock.
Our house-and-inhabitants analogy also works for the Ives-Stilwell experiment and the muon experiment, which are often cited as proof for slowing-down-of-a-process via acceleration or circular motion. In the Ives-Stilwell experiment, light emitting ions were used. First the ions were stationary and their light emissions were recorded. Next, the ions were accelerated at high speeds, to see if the emission pattern changed. The reader by now, probably understands that an ion can be thought of as a spherical house with light as its inhabitants. When the house is stationary, all the light exits the house/ion at regular intervals. When the house accelerates, the contents inside the house experience a force that will push them back towards one of the walls. It is similar to what a passenger feels when a car accelerates. A passenger feels like she is being pushed back into the seat. This is the same force that causes the light inside an accelerating ion to take a little longer to exit the ion-sphere. This slowing-down-of-emission of light owing to acceleration was verified in the Ives-Stilwell experiment. Therefore, the house-and-inhabitants analogy works for all experiments that prove, time dilation, including the muon experiment.
In the muon experiment, the decay time of a muon is considered. A muon is created in the upper atmophere when a cosmic ray proton [traveling at 99.94% of the speed of light] interacts with the upper earth atmosphere. They have a very short decay time [2.2 microseconds] and are not expected to reach the surface of the earth. But they routinely do, reach the earth's surface. This has been taken as proof of slowing-down-of-a-process at high speeds. Let us analyse this carefully via the house-and-inhabitants analogy. We have a stationary muon, with some content in it, that is going to escape the muon-sphere in 2.2 microseconds. When a muon interacts with the earth's atmosphere, it will undergo some acceleration [or deceleration] which the contents of the muon experience as fictitious forces that delay the exit of the contents of the muon-sphere. This delay is estimated to be about 30 microseconds, which is why they reach the surface of the earth, [from the upper earth atmosphere, where they are produced]. Therefore, yet again we used Newtonian physics to explain the slowing-down-of-a-process, in this case, we're referring to the decay process of a particle [muon].
I had no idea that Larmor was the first person that came up with the idea of time dilation. Wiki also says that the Lorentz-Einstein transformations were published by Larmor two years before Lorentz and eight years before Einstein.
Parallel to the development of Lorentz ether theory, Larmor published the Lorentz transformations in the Philosophical Transactions of the Royal Society in 1897 some two years before Hendrik Lorentz (1899, 1904) and eight years before Albert Einstein (1905).
It is important to note that Lorentz' theory and by extension Special Relativity, do not provide any mechanism to explain why processes slow down in the above experiments. The slowing down mechanism in current theories is an action-at-a-distance concept. The house-and-inhabitants analogy is a mechanism that I came up with using Newtonian physics or Classical physics when I was writing this article.
I later looked up some papers written by Lorentz where I found a paragraph that led me to believe that Lorentz was very close to figuring out the house-and-inhabitants analogy to explain the slowing-down-of-processes that were observed in the many experiments that were performed after Lorentz first wrote this in 1900.
The first question is whether an ion rotates in a magnetic field. Actually, we should expect that. Since if an ion is present, and if a magnetic field is caused, then a rotation arises, as it can easily be derived from the formation of induced currents. Of course this is also the case when the ion flies into an already existing magnetic field. The velocity of rotation will depend on the magnitude of the mass; if only apparent mass is present, and even a corresponding moment of inertia, then the rotation velocity has a certain value. If, however, a real moment of inertia is added, the rotation is slowing down. Unfortunately I can not find any phenomenon, from which we could conclude anything about this rotation.
The line in red is closely tied to the question of the physics associated with the rotation of an ion/muon. In classical physics rotations give rise to centrifugal forces that have real physical consequences. As it stands now, Lorentz-Einstein theory does not have a physical explanation for why certain processes slow down owing to acceleration or circular motion.
This effect arises neither from technical aspects of the clocks nor from the fact that signals need time to propagate, but from the nature of spacetime itself.
Spacetime as we already know is a chart of numbers and is not a physical entity. Therefore, Lorentz-Einstein theory simply resorts to action-at-a-distance to explain slowing-down-of-processes.