Future Posthumous Autobiography
sivers.org
sivers.org
I make prophecies. I write them down and seal them in envelopes, then I wait. When one is proven false, I just throw it away. When it comes true, I put the still-sealed envelope into an old shoebox.
My posthumous autobiography is going to be filled to the brim with stories of receiving messages from beyond, writing down what the voices say, and putting the notes in sealed envelopes inside a shoebox.
Wouldn't it be easier to just write down things that happened already and pretend you predicted them?
Write down every possible winner of the 2020 Presidential election in an envelope. Include people who are still massively long-shot candidates and not even running right now, like Oprah Winfrey and Michelle Obama. Provide whatever proof you like that you wrote these down today. Throw away everything that doesn't fit in another year and a few months. Boom, you're psychic. Especially if one of those long shots pans out!
This scheme generates the proof that you wrote it down early, unlike the "claim prophecy after the fact".
But what proof is there? Newspaper clippings from today's news in the envelope? That's hardly conclusive proof it was written on that day.
One solution would be to encode the prophecy into a blockchain, and reference that in the envelope. This way there's multiple witnesses that you did something that day at least.
You now have a timestamped thing from before it happens that verifies you made the claim long ago, but you've destroyed the evidence that it was effectively random.
Others quickly pointed out that you can mail yourself an unsealed envelope and put something in it after it arrives.
That's the basic scheme. Variants on this idea have been in use for centuries. Modern hash schemes, including those used in the blockchains, make it trivial, albeit at the price of byte-for-byte precision; you just have to provide reasonable evidence that something existed at some point in time, which is easy with twitter, facebook, google, and literally thousands of other places you can stick arbitrary content that will end up with a timestamp that you can reasonably claim you have no ability to forge.