"David" nospam@nospam wrote in message
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The books also say that if the antenna is vertical to groundplane the iamge
is in phase and reinforces the wave emitted by vertical.
If antenna is horizontal and close to ground plane, the image cancels out
wave emitted by antenna.

Is this what happens in real life?

Yes, once you throw in the (sometimes negligible, sometimes significant)
complications that real "ground planes" are finite in extent and have non-zero
loss.

What about fibre optic cable? If ordinary glass strands were used, when the
cable was bent, the light would be blocked and not travel any further.

Fiber optics aren't antennas; fiber optic "cables" are low loss (ideally
lossless) dielectrics clad in another dielectric with a different enough
permittivity to create total internal reflection. Using traditional
terminology, fiber optics are actually just a particular type of waveguide.