Copper vs Optical fibre
Copper and Optical fibre are genuine alternatives to one another — a choice somebody actually makes — and differ on 1 measured property, density most clearly.
Copper vs Optical fibre
These are different kinds of thing (element, material). Fewer properties mean the same thing across both, so a like-for-like reading may not be available.
Copper
Cu
A soft, ductile metal with exceptional electrical conductivity, and one of the first metals humans worked.
Optical fibre
Glass so clear you could see through kilometres of it — the material that carries essentially all long-distance communication.
| Property | Copper | Optical fibre |
|---|---|---|
| Atomic number Only one of the two has a figure we can stand behind, so there is nothing to compare. | 29 | Not known |
| Density | 8.96 g/cm³ higher | 2.2 g/cm³ |
| Electrical conductivity Only one of the two has a figure we can stand behind, so there is nothing to compare. | 59.6 MS/m | Not known |
| Melting point Only one of the two has a figure we can stand behind, so there is nothing to compare. | 1084.62 °C | Not known |
| Mohs hardness Only one of the two has a figure we can stand behind, so there is nothing to compare. | about 3 | Not known |
| Molar mass Only one of the two has a figure we can stand behind, so there is nothing to compare. | 63.546 g/mol | Not known |
| Refractive index Only one of the two has a figure we can stand behind, so there is nothing to compare. | Not known | 1.44–1.47 |
| Thermal conductivity Only one of the two has a figure we can stand behind, so there is nothing to compare. | 401 W/(m·K) | Not known |
Choosing between them
Optical fibre is recorded as a substitute for Copper — stronger.
What it gives up: Carries no power, cannot be spliced with hand tools, and is pointless over the last few metres.
In this application, on the evidence cited above.