Some people would hear this and think "darkness" but darkness is not the
opposite of light, it is merely the absence of
light. The opposite of light (some sort of anti-photon) would be something that when introduced into an environment would reduce the amount of light in that environment without affecting the
source of light output.
Example: You have a room with two 100-
watt bulbs which are both on, you would turn on this "anti-
photon" generating device and the
room would appear dimmer without having to turn off one of the bulbs
In the same vein the view that "the opposite of love is not hate, it's apathy" cannot truly be considered true, apathy is the absence of love, but not it's opposite.
Apathy is not the opposite of love