Can you fathom the depths of big data? The word fathom is a measurement of depth of the ocean, but it has also come to mean the ability to understand something. Fathom comes from faethm, meaning ‘the two arms outstretched.’ It’s 6 feet or 1.8 meters measurement is based on a standard human scale. The length of rope dropped overboard is handily measured across the span of a sailor’s armspread. The term makes the metaphorical jump to describe concepts that we are able to get our arms around; ideas are things to be grasped. As James Geary describes in his book on metaphor, “This is the primary purpose of metaphor: to carry over existing names or descriptions to things that are either so new that they haven’t been named or so abstract that they cannot be otherwise explained.”