Final answer:
The passages suggest that early explorers and thinkers like Ibn al-Haytham, Euclid, and Ptolemy focused on theories of vision and light interaction without evidence that they understood light coming from algae. They made significant contributions to the field of optics but did not document recognition of biological light sources.
Step-by-step explanation:
Based on the information from the passages, it can be inferred that early explorers and thinkers did not have a concrete understanding that light could come from algae. While Ibn al-Haytham, Euclid, and Ptolemy had theories about how vision worked and how light interacted with the eye, their ideas were based on the emission of light rays from the eyes or from objects, not the biological sources of light such as bioluminescent algae. Furthermore, John Goodricke's study of Algol's brightness variations pertained to astronomical observations rather than biological light sources. Thus, although early thinkers made significant advances in understanding light and vision, the concept of light produced by algae is not reflected in their documented theories or observations.