I’d like a smaller version of this put into a wristwatch with a radioisotope power supply, an ISO-8601 date/time readout, and a built in calculator for measurin

I’d like a smaller version of this put into a wristwatch with a radioisotope power supply, an ISO-8601 date/time readout, and a built in calculator for measuring time dilation effects with my spouse. A laser pointer would be cool too.