Are There More Bricks or Photos?

Recently on The Online Photographer, I saw that in 1976 a leading commentator on photography asserted that “the world now contains more photographs than bricks.”

While I hate to be contrary (no I don’t! :)), I’m not convinced that the assertion about photographs and bricks is correct, even today. Regular readers will know I can’t resist an estimating challenge, so here goes…

Most estimates of the number of photos taken each year comes out somewhere near (but typically a bit below) one trillion, 10^12. As this number is growing exponentially, to get a total number of all photographs ever taken we can focus on recent years, and something in the range 5-10 trillion would probably cover it. However, we don’t retain all our shots. I dump about 50%. I don’t know how typical this is, but let’s use it as an estimating basis. So this gives use a number of “existing photographs” of a few (2-5) trillion.

Now bricks. This is more tricky. I estimate the number of bricks in a typical British family home at around 15-20,000. That provides shelter for an average 4-5 people, but we also spend time in other brick buildings (work, hotels, communal buildings), so let’s say 10,000 bricks per person in a “brick rich” environment like the UK.

But not everyone lives in a “brick rich” environment: for all sorts of economic, environmental and cultural reasons many buildings use other materials. So let’s assume that 10% of the world’s buildings are brick.

10,000 (bricks per person) x 10% & 7 x 10^9 (people) = 7 x 10^12 bricks. That’s still a couple of times greater than my estimate of the number of photos…

Now obviously as the numbers are (surprisingly) so similar and the number of photos is growing exponentially, the roles will soon be reversed. But I don’t think it was true in 1976.

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