RJN wrote:

After midnight when the APOD appeared, I showed a person I know hoping to get a "Cool!" response. But this APOD made that person sad. The dead cartoon cat made them remember a recently deceased real cat of which they were fond. Apparently the thought of a dead cat -- and possibly killing a cat -- even a virtual cat -- weighs heavily on people's minds. Oops. And so maybe the tie-in to Schrodinger was less appealing than I thought.

https://en.wikipedia.org/wiki/Wigner%27s_friend wrote:
<<

**Wigner's friend** is a thought experiment proposed by the physicist Eugene Wigner; it is an extension of the Schrödinger's cat experiment. The thought experiment posits a friend of Wigner who performs the Schrödinger's cat experiment after Wigner leaves the laboratory. Only when he returns does Wigner learn the result of the experiment from his friend, that is, whether the cat is alive or dead. The question is raised: was the state of the system a superposition of "dead cat/sad friend" and "live cat/happy friend," only determined when Wigner learned the result of the experiment, or was it determined at some previous point?>>

https://www.mersenne.org/primes/?press=M74207281 wrote:
GIMPS Project Discovers

Largest Known Prime Number: 2

^{74,207,281}-1

<<On January 7, 2016, at 22:30 UTC, the Great Internet Mersenne Prime Search (GIMPS) celebrated its 20th anniversary with the math discovery of the new largest known prime number, 2

^{74,207,281}-1, having 22,338,618 digits, on a university computer volunteered by Curtis Cooper for the project. The primality proof took 31 days of non-stop computing on a PC with an Intel I7-4790 CPU. This is the fourth record GIMPS project prime for

Dr. Cooper and the University of Central Missouri. Dr. Cooper's computer reported the prime in GIMPS on September 17, 2015 but it remained unnoticed until routine maintenance data-mined it. The official discovery date is the day a human took note of the result. This is in keeping with tradition as M

_{4253} is considered never to have been the largest known prime number because Hurwitz in 1961 read his computer printout backwards and saw M4423 was prime seconds before seeing that M

_{4253} was also prime.>>

A Mersenne prime is a prime number of the form: M

_{p}= 2

^{p}-1

We know that M

_{2}= 2

^{2}-1 = 3 is a Mersenne prime

We know that M

_{3}= 2

^{3}-1 = 7 is a Mersenne prime

We know that M

_{7}= 2

^{7}-1 = 127 is a Mersenne prime

We know that M

_{127} = 170,141,183,460,469,231,731,687,303,715,884,105,727 is a Mersenne prime

Neuendorffer Conjecture:

**M**_{170,141,183,460,469,231,731,687,303,715,884,105,727} is a Mersenne prime.