Would there have been any relativistic effects if there was no ultimate speed?
What do you mean by relativistic effects? Departures from newtonian physics? Those are changes in the way we explain these effects. They are not changes in the way Nature behaves, just changes in the way we expect it to behave. People have been observing the way magnets attract iron for centuries, if not millennia. The fact that Einstein explained this as an effect of relative motion is a monumental accomplishment.Would there have been any relativistic effects if there was no ultimate speed?
Probably not. But it's difficult to be sure we share an understanding of what the word "relativistic effects" means. The reason I say probably not is based on the following mathematical argument (and a few vague memories). If we take the relativistic transform equation, the Lorentz transformWould there have been any relativistic effects if there was no ultimate speed?