Over 111 years after it sank, the Titanic continues to fascinate and surprise the public. For instance, did you know that it was found by a team that was pretending to look for the wreck of the Titanic? Or that – despite what the Internet believes – it partly imploded as it sank? Or that a couple got married on the deck of the Titanic in 2001?

One such strange fact has made its way around Reddit this week, that – despite exploration of the submerged wreck since its rediscovery in September 1985 – no human remains have ever been found on board. 

“I’ve seen zero human remains,” James Cameron, director of Titanic, who has visited and explored the wreck 33 times and claims to have spent more time on the ship than the ship's captain, told the New York Times in 2012. “We’ve seen clothing. We’ve seen pairs of shoes, which would strongly suggest there was a body there at one point. But we’ve never seen any human remains."

It's the sort of fact that sends conspiracy theorists into a frenzy, but there are perfectly good reasons why we haven't found the bodies of over 1,500 people who died as the ship went down.

One reason is the lifejackets worn by many passengers and crew. While they did not fulfil their main brief of keeping their wearers afloat long enough for rescue, once their occupants passed away they remained buoyant. A storm following the sinking likely quickly swept the bodies away from the wreckage site quickly, while the ocean currents of course took them further away in the intervening century.

Bodies trapped in the wreckage itself likely also disappeared, thanks to the work of deep sea scavengers – fish and other organisms. But bones have been found on other far older shipwrecks, so why not the Titanic? That part may be to do with the depth.

"The issue you have to deal with is, at depth below about 3,000 feet [914 meters], you pass below what's called the calcium carbonate compensation depth," deep-sea explorer Robert Ballard explained to NPR. "And the water in the deep sea is under saturated in calcium carbonate, which is mostly, you know, what bones are made of. For example, on the Titanic and on the Bismarck, those ships are below the calcium carbonate compensation depth, so once the critters eat their flesh and expose the bones, the bones dissolve."

There are those who believe that in sealed off parts of the ship such as the engine room, where fresh oxygen-rich water that scavengers rely on may not have been able to get in, there may still be some preserved bodies. But 111 years after the ship sunk, the idea that we might find recognizable remains seems increasingly unlikely.