Also “33 times more massive than the sun” means 34 times the mass of the sun.

Oh boy, this sent me down a memory lane. I remember arguing long and hard with my math teacher in elementary school that "two times as massive" and "two times more massive than" are not the same thing, but she did not agree. That's the point where I learned that the grownup world is weird and sometimes it's easier to just smile and nod.

For me, it was the science teacher in middle school who insisted that rivers couldn't flow north, because on a globe, north was up.

Even pointing out the Nile didn't change her mind; I imagine there's a denial joke to be made there.

"That's the point where I learned that the grownup world is weird"

That's a generous thing of you to say.

How many people really want to be proven wrong? I'd like to think I am. Maybe I should make a t-shirt:

    Happy to proven wrong *

    * But only by people who reciprocate

would you say the same for "33 times longer"? that ut means "34 times the length"?

for me "more X" and "Xer" are the same thing, so I don't get your system

Considering fractions might help you understand where he's coming from. If you say something is "0.5 times as long as a one meter thing" you would expect it to be 0.5 meters, but if it's "0.5 times longer than a one meter thing", you would expect it to be 1.5 meters. The same logic applies when you ditch fractions and use integers.

0.5 times longer is nonsense

0.5 times shorter makes sense