Information travels at the speed of light in a vacuum, the same as it does in a fibre optic cable.
This is false.
There is a physics formula for calculating the speed of light in different mediums:
Speed of light in the medium = Speed of light in a vacuum/Refractive index of the medium
The refractive index of silica glass (what most fiber optics are made of) is 1.5, and the speed of light in a vacuum is 3x10^8 m/s, therefore
Speed of light in silica = 3x10^8/1.5 = 2x10^8
So you can see that information in fiber optic cables will travel at 2x10^8 m/s vs. 3x10^8 m/s in a vacuum, or about 33% slower.
This also does not take into account the fact that there is also a net slow-down effect because the light is bouncing off the sides of the cable as it travels.
Information travels at the speed of light in a vacuum, the same as it does in a fibre optic cable.
This is false.
There is a physics formula for calculating the speed of light in different mediums:
Speed of light in the medium = Speed of light in a vacuum/Refractive index of the medium
The refractive index of silica glass (what most fiber optics are made of) is 1.5, and the speed of light in a vacuum is 3x10^8 m/s, therefore
Speed of light in silica = 3x10^8/1.5 = 2x10^8
So you can see that information in fiber optic cables will travel at 2x10^8 m/s vs. 3x10^8 m/s in a vacuum, or about 33% slower.
This also does not take into account the fact that fiber optic cables are generally not perfectly straight, and there is also a net slow-down effect because the light is bouncing off the sides of the cable as it travels.