There is nothing instant about “instant”.
Not in coffee, not in two shakes of a lambs tail (or a coffee spoon) and not in love at first sight.
In the latter article I gave the example of the Earth rotating around a non existent sun after for some reason the sun ceased to be; the transmission of information that the sun ceased to be (one parameter being the existence of gravity) would take some 8 minutes to reach the Earth. The Earth would therefore remain in orbit around a non existent sun for those transitional 8 minutes.
Archimedes had his brainwave whilst he was taking a bath. I had mine during a shower, watching the waste water spiral down through the plug hole. In true Archimedian style I thought to myself “Screw it.”
Why? Surely there must be something out there that can exceed the speed of light.
And I might have found it.
Let’s return to our orbiting Earth (or at least, remain firmly affixed to it’s surface, thanks to our gravitational friend).
As far as we are concerned, sitting (or showering) on the Earth, everything is hunky dory until the Sun disappears, the light goes out and we are flung into space obeying Newton’s second law of motion (i.e. that we travel in a straight line at constant speed unless an external force [in this case, the Sun’s gravity] is applied.
We know that the sun must have vanished 8 minutes ago, so let’s call that moment t = 0 and the present t = 8.
So from the perspective of the Earth at t = 8 we know that the sun vanished at t = 0.
And on the sun, the sun vanished at t = 0. At the same time, i.e. at t = 0. The event of our hindsight knowledge and the event itself was simultaneous.
Is hindsight instantaneous?
I think the example shows that the progression of time across space is instantaneous, although I do concede that it’s a bit strange to give time a speed when it is itself a term in the equation! (speed = distance divided by time!
I’ll conclude with a quote from Bill Nye (more time and time travel quotes here):
â€œWhen we see the shadow on our images, are we seeing the time 11 minutes ago on Mars? Or are we seeing the time on Mars as observed from Earth now? Itâ€™s like time travel problems in science fiction. When is now; when was then?â€ â€“ Bill Nye.