[imtringued]

Put two computers one light second away from each other. Let them sum up a list of numbers in parallel and wait for the result which takes exactly 1 second. Now lets say that one sum operation is equal to one unit of time which also happens to be equal to one second. Simply run the sum operation and after it is done increment the time counter of the computers and repeat this 10 times.

Now you ask the computers: "How much time has passed?" The computers answer: 10 time units. After you place the two computers one light minute apart, you ask the computers again and they answer: 10 time units.

The morale of the story is that while you can measure time accurately, actually defining a timescale is completely arbitrary and if the timescale is arbitrary then the distance light can cross within that timescale is arbitrary as well.

>The Speed of causality is hand crafted for our scale.

Of course it is! It was handcrafted by humans!