Read this excerpt from Exploring the Titanic.

Soon I had spent more hours in the deep ocean than any other scientist. But the Titanic continued to haunt me. My oceanographic colleagues scoffed at my Titanic dreams and told me I should devote myself to "real" scientific projects.

Colleagues are

subjects in a science experiment.
friends who have different interests.
fellow workers in the same field of study.
family members who support each other