What is an example of a conjecture that was proven wrong for "very large" numbers?

12 isn't prime: it's composite. So is 121. So is 1211. So is 12111. So is 121111. So is 1211111. So is 12111111. This seems to be a persistent pattern. Let's keep going. Seven 1's, compos…

Top stories for Long   What is an example of a conjecture that was proven wrong for "very large" numbers? Alon Amit, PhD in Mathematics; Mathcircler. • Updated April 21, 2023 12 isn't prime: it's composite. So is 121. So is 1211. So is 12111.... Read more » 2.1K 63   Have you ever faced a programming error that made you question reality, like a basic math operation failing? What was the fix? Toni Koqi • Answered June 16, 2025 I was developing the main application for my master's thesis, which involved a genetic algorithm I had significantly optimized, making it magnitudes faster than common impl... Read more » 73   Why is it a bad idea to retire early? Phil Main, A Black Jack player for 40+ years • Answered August 6 Not sure at what age you're calling early, but I retired at age 59 1/2. That being said, I have found retirement to be the best job I have ever had. But retiring early does... Read more » 257 44   If macOS is Unix, and Linux was inspired Unix, then what is Windows based on and why was it implemented like this by Bill Gates? Thomas Alexander Stephens • Answered May 22, 2016 There's a huge amount of path dependency in how Windows, OS X and Linux came to exist as they are. In Bill Gates's initial strategy, devised in the 1970s, Unix was to be the... Read more » 2K 132   I am going to a picnic or I am going on a picnic . Which one is correct? Gold Hunter Retired, 44 years Geology experience, MSc, CPG, Retired • Answered December 25 That is a rather subtle distinction, in my opinion. I would say 'I am going to a picnic', if somebody else is having a picnic, and I am invited to it. I would say 'I am going... Read more » 72 9   Have you ever seen an employer fire someone without realizing what a crucial role the employee played? Bug-Z • Answered March 2, 2025 I once saw an employer play "lay off a whole department and replace with cheaper employees" with every department. They kept the occasional employee who was willing to deba... Read more » 576 21   Are push-in wire connectors safe? Michael, former Licensed Commercial and Amateur Radio Operator. (1965-2022) • Answered August 4, 2021 Yes and no. I attended an electrical fire investigation class at the Ohio Fire Academy while I was still a Fire Inspector. One of the projects was to determine the appearan... Read more » 133 22   Claude Paquet, former Retired Reporter • Posted May 21, 2025 VOYAGER 1 IS RESURRECTED! A new twist in the eternal adventure of the Voyager probes! The probes took off from our planet in 1977 and are still operational. They have more resources than we think: l... Read more » 894 79   Why do so many developers not deliver unit tests with their code? Why do so many engineers/developers lack this skill? Also, should one consider himself a professional level engineer if they do not deliver unit tests along with their code? Joshua Gross, Associate Professor of Computer Science at CSUMB • Answered January 4 I'm a firm believer in unit tests. In my last major software engineering job, I was hired to get a module back on track. One of the people assigned to it was watching her hu... Read more » 228 45   What happens if sugar is put in concrete? Sourav Chaubey, Technocrat at Government of India,Central.P.W.D • Updated February 9, 2020 One of my friends had this question in a BARC-2014 interview. The interviewer asked him "What if I threw my tea on the concrete." See, that was an indirect form of what you... Read more » 3.4K 246   How did Euler find the E number? Terry Moore, M.Sc. Mathematics, University of Southampton (1968) • Answered November 14 How did Euler find the E number? Actually the first references were in 1618, but without actually calculating the number. It arose from Napier's logarithms. Jacob Bernoulli d... Read more » 50 7   Was the MiG-25 faster than the SR-71? Camila Hall, History Enthusiast at The Independent (2012-present) • Posted Jan 3 MiG-25 Foxbat and SR-71 Blackbird are the two of the fastest aircrafts that have ever been constructed. The SR-71 was faster compared to the other. MiG-25 was able to fly to Mach 2.83 and the SR-71... Read more » 233 24 Read more in your feed

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