“After hydrogen, the most common thing in the universe is stupidity.” - Albert Einstein.

"In the sciences, the authority of thousands of opinions is not worth as much as one tiny spark of reason in an individual man." - Galileo Galilee.

Elon Musk very likely has an IQ BELOW 120.

there is an implicit contradiction in this statement. That is the so called "people who study nuclear physics seem to think their opinions on measurable intelligence should be heeded because they after all, being nuclear physicists (smart and talented people) gives them insight on topics (like measuring IQ) of which they are NOT trained for. Being nuclear physicists, what do they know about the topic of measured IQ?
The statement is an example of the use of circular logic

@TimTuolomne think you might be correct. I met him a long time ago before he became famous and that was the impression I had. It was a gathering of researchers discussing advances in space technology and how it might be used. He didn’t really seem to understand the science aspects, but was very clever about prompting it. But that is just my opinion and might be wrong.

@Jurecki. Agreed. From most of his public statements - particularly those in my fields of expertise, he has shown almost no understanding of the governing principles. For example, no intelligent person will build electric cars until there is a significant advance in batteries, except some personality like P.T. Barnum. There has not been a significant increase in charge density in 50 years, in spite of hundreds of billions of dollars of investment; aside from photoelectrics, the worst investment in history.

@TimTuolomne yes, worked with engineersdoing research for me with batteries for space application and we were making these cells pumping our rapid currents (without blowing up) and he is using lithium batteries like we buy in the grocery store? What a joke.

take note - NODD asked about Mental "age" - not IQ...which is really a question about age appropriate maturity in ability to analyze and problem solve...kind of a dumb question.

@iThink. As you surely know, the definition of IQ = (mental age)/(physical age), and by definition 100 is at the top of the “bell-shaped” curve; meaning half the population has a “mental age” below their physical age.

In conclusion Jurecki is right. The answer is 42.

"A common mistake that people make when trying to design something completely foolproof is to underestimate the ingenuity of complete fools."

“Forty-two,” said Deep Thought, with infinite majesty and calm.

@iThink, I like that quote by Douglas Adams! I shall appropriate it for my collection, thank you.

@TimTuolomne just remember to credit Douglas Adams and his book Hitchhikers Guide to The Galaxy when you use it. Don't want to be seen as a plagiarist. LOL

Nor would there be a reason.

An impossible question raises the issue of comprehension.

One fool can ask more questions than a thousand wise men can answer.