Friday, May 07, 2021

Number twenty


This morning I reached #20 in the production score of the probable-prime top-discoverers leaderboard. I was already at #20 by number of probable primes and it is relatively unusual to be in the same position in both lists. Of the 1438 probable primes noted, all but 52 are Leyland primes. My work on finding more Leyland primes continues unabated as my current worksheet clearly shows:


Intervals #18-#20 are done. Interval #22 shows 34 recent finds of an expected 100 or so by this time next month. That will push me to #19 on the number leaderboard and possibly to #18 on the production score list. Alas, I will still be several dozen short of my strived-for 1500 Leyland-prime finds. Being so close is incentive enough to continue. Once interval #22 is completed I will be looking at Leyland numbers ranging from 300000 decimal digits length up to 305000 decimal digits. I don't think there are enough probable primes in this region to make up the deficit but it will bring me much closer.

Saturday, May 01, 2021

Much ado about directed energy attacks


I'm increasingly annoyed by the lack of skepticism in the current round of media hype about "directed energy attacks". After the first reports of an "acoustic attack" made their debut in 2017, I was certain that an element of mass hysteria was at play. I have just come across Robert Bartholomew's excellent analysis in Skeptic that arrives at a similar conclusion.