Hi!
To describe a light bulb as a "darkness absorber" is really funny,
but such a "negative interpretation" is often used. An example:
Assume we are in a helicopter, observing the traffic along a highway.
The highway is packed with cars, almost bumper-to-bumper, going at a
uniform speed of 55 m.p.h. From time to time there are some gaps
("holes") between cars. Would you not say that these gaps are also
moving at 55 m.p.h.?
Regards Emilio