Quick Answer
If electrical influence propagated instantaneously, long-distance electrical control and communication would have no propagation delay in the hypothetical model. However, real electromagnetism is tied to finite-speed field propagation, so making electricity instantaneous would require changing fundamental physics. Circuit behavior and electromagnetic safety would also change.
Electricity is not a substance flowing instantly through a wire from a power plant to a device. Electromagnetic fields transmit energy and information at finite speeds.
Power grids react instantly
In the thought experiment, commands and changes in electrical systems could propagate without transmission delay. That could simplify some control problems, although resistance and energy storage would still matter unless those changed too.
Communication changes
Electrical communication across cables would have no propagation delay. This would remove one physical limit on latency, although processing and storage would still take time.
Computers would not become infinitely fast
A computer’s speed depends on transistor switching, memory access, heat removal and architecture. Instant signal propagation would remove one limit but not all of them.
The physics becomes inconsistent
Special relativity is built around a finite invariant speed. An instantaneous electromagnetic interaction would require a fundamentally different theory of spacetime and causality.
SpeculativeThis is a change to the foundations of physics, not a simple improvement to electrical cables. The usual electromagnetic equations do not permit instantaneous propagation of information.
The bottom line
Instant electricity would remove propagation delay but would also rewrite electromagnetism and causality. The interesting consequence is therefore as much about physics as technology.
A note on our approach: Every article on WhatIfLab separates what current science establishes from what remains genuinely speculative. Where we cite a figure or finding, it reflects published, mainstream research at the time of writing — not a prediction dressed up as fact.