If time travelers from the future were to visit you, it would be difficult for them to quickly prove their authenticity.
Temporal passwords. At the start of each year, you devise a new password. You commit the password to memory, but you never write it down or divulge it to anyone until Dec. 31, when you submit it to the Temporal Password Registry, which publishes it and promotes its dissemination.
Prior to their visit, time travelers from the future can look up your temporal password in the registry for the year in which they plan to visit you. Their ability to communicate a password that you have not yet shared with anyone provides evidence that they are actually from the future.
The year 2021 is the first year the Temporal Password Registry will be open to the general public.
If you would like to participate, sign up below to receive two reminder emails.
The first reminder email will arrive on or around Dec. 31, 2020. It will remind you to commit your temporal password to memory and offer tips about how to ensure you don't forget it.
The second reminder email will arrive on or around Dec. 31, 2021. It will prompt you to enter your temporal password into the registry for publication and dissemination.
What if I don't believe bidirectional time travel is possible? Should I still participate?
Absolutely! Having a robust Temporal Password Registry sets the stage for time travelers to be able to demonstrate their authenticity, and a purported time traveler's ability to correctly identify a person's temporal password would be positive evidence (although not conclusive evidence) that time travel is possible. But a robust Temporal Password Registry that is never invoked by purported time travelers is a form of negative evidence. It doesn't prove that time travel is impossible, but it raises the question, "If time travel is possible, why haven't we observed any time travelers using the registry to prove their authenticity?"
How can you ensure that the Temporal Password Registry will be long-lived, and that people in the future will have access to it?
The level of effort will depend on the level of interest. The more people who sign up to participate in the registry, the more steps will be taken to keep the registry online and available well into the future. The plan for now is to keep the registry online and publicly accessible indefinitely.
Are there restrictions on temporal passwords? Can my temporal password be an advertisement for a website?
The maximum length of the temporal password will be 120 characters, enough to construct a complete sentence. There will be some screening and filtering of submissions to keep out bad actors, spam, etc., so please don't choose a temporal password that could be construed to be an advertisement, or that defames someone, or that would be viewed as anything other than innocuous. Unfortunately, your temporal password can't be pre-screened for acceptability, so you'll just have to choose wisely.
If a purported time traveler is able to successfully identify my temporal password, and I'm confident I've never divulged it to anyone, what should I do?
That's entirely up to you. Help them save the world, maybe? But please don't do anything that would put you or others at risk. You should absolutely not agree to engage in any illegal activity, and you should probably think twice about allowing them to romance you.
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