Cursed be he who moves my bones
There are many small things wrong with The Da Vinci Code, but the biggest problem is one it shares with many, many other books, both mysteries and science fiction. In all of these stories someone wants to communicate a message to a specific audience, while keeping it secret from everyone else. So he hides the message in a puzzle that our heroes can piece together in an entertaining fashion, with clues scattered in scenic locations. The problem is that the puzzle usually seems like a very inefficient way of communicating a message to his audience while protecting it. The puzzle could end up stumping whoever is supposed to solve it, so the message never arrives. Or some random guy could figure it out, and the message isn't secret any more. Or both. In every case it seems that anyone ingenious enough to set up the puzzle could think of a better way to deliver his message.
There are some cases in which the puzzle idea works - there was an Isaac Asimov story where a dying man made an absolutely straightforward attempt to communicate his message, and it was everyone else's misunderstandings that made it a puzzle. And there's one SF scenario I've thought of where the easiest and most efficient way to send a secret message also poses an interesting puzzle. More details below the cut.
We begin with time travel - involuntary and one-way only. Some poor resident of the year 2500 finds himself in our past, say the early twentieth century. He does not enjoy it there, and desperately wants to return to his own time. An ordinary human being wouldn't have many options at this point, but 500 years of genetic engineering have given our time traveller some useful abilities. Specifically, he can find some inhospitable place, lie down, and go into suspended animation for 500 years. It's crucial that no-one wakes him up prematurely, and equally crucial that someone wakes him up around the proper time. It's also important that he doesn't change history too much in the interim. So, how to send a message that only the future will understand?
He could play tricks with memory crystals and holograms - if he hadn't left all his hardware behind in 2500. Instead he gets a flat rock, and a smaller, harder rock. He carves I AM IN SUSPENDED ANIMATION AT THESE COORDINATES EIGHT ZERO POINT ONE FIVE FIVE SOUTH NINE ONE POINT NINE SIX FOUR EAST DO NOT WAKE ME UP UNTIL MAY 28 2500 on the rock, and throws it into a landfill which will be the subject of an archaeological dig 600 years later. The only reason this works is that in 2400 his country adopted a completely new alphabet, with the letters invented from scratch. To anyone who digs up the landfill before then, his message is unreadable.
Well, not quite unreadable. Each letter of the new alphabet corresponds to one sound in his language, so if the writing is treated as a code a rough transliteration of his message into the Latin alphabet can be generated. If a circle represents the "p" sound, some transformation of the message will replace all the circles with p's. His alphabet has some featural components too: the shapes of p and b and v and f and m will be related, which will make assigning letters easier. Then it's just a matter of reading a message written in a language that doesn't exist yet. If you're lucky it'll be your own language, with centuries of sound change working on it. Once you've done that, it's off to bring the time traveller into the twentieth-first century - although he certainly won't be pleased to see you, and digging up a live and angry 26th century genetically-engineered man could be far more dangerous than any mummy. Or even William Shakespeare.
There are some cases in which the puzzle idea works - there was an Isaac Asimov story where a dying man made an absolutely straightforward attempt to communicate his message, and it was everyone else's misunderstandings that made it a puzzle. And there's one SF scenario I've thought of where the easiest and most efficient way to send a secret message also poses an interesting puzzle. More details below the cut.
We begin with time travel - involuntary and one-way only. Some poor resident of the year 2500 finds himself in our past, say the early twentieth century. He does not enjoy it there, and desperately wants to return to his own time. An ordinary human being wouldn't have many options at this point, but 500 years of genetic engineering have given our time traveller some useful abilities. Specifically, he can find some inhospitable place, lie down, and go into suspended animation for 500 years. It's crucial that no-one wakes him up prematurely, and equally crucial that someone wakes him up around the proper time. It's also important that he doesn't change history too much in the interim. So, how to send a message that only the future will understand?
He could play tricks with memory crystals and holograms - if he hadn't left all his hardware behind in 2500. Instead he gets a flat rock, and a smaller, harder rock. He carves I AM IN SUSPENDED ANIMATION AT THESE COORDINATES EIGHT ZERO POINT ONE FIVE FIVE SOUTH NINE ONE POINT NINE SIX FOUR EAST DO NOT WAKE ME UP UNTIL MAY 28 2500 on the rock, and throws it into a landfill which will be the subject of an archaeological dig 600 years later. The only reason this works is that in 2400 his country adopted a completely new alphabet, with the letters invented from scratch. To anyone who digs up the landfill before then, his message is unreadable.
Well, not quite unreadable. Each letter of the new alphabet corresponds to one sound in his language, so if the writing is treated as a code a rough transliteration of his message into the Latin alphabet can be generated. If a circle represents the "p" sound, some transformation of the message will replace all the circles with p's. His alphabet has some featural components too: the shapes of p and b and v and f and m will be related, which will make assigning letters easier. Then it's just a matter of reading a message written in a language that doesn't exist yet. If you're lucky it'll be your own language, with centuries of sound change working on it. Once you've done that, it's off to bring the time traveller into the twentieth-first century - although he certainly won't be pleased to see you, and digging up a live and angry 26th century genetically-engineered man could be far more dangerous than any mummy. Or even William Shakespeare.