I'm currently writing something that explores the phenomenon of inside jokes, in which I use an astrophysicist joke that is meant to be undecipherable to the average reader. It was recommended to me by someone who, as it turns out, has as little understanding of physics as I do. After finishing a first draft, I've heard from an astrophysicist that the joke makes no sense. The reasons are so obvious that even I should have been able to realize how badly off this is. Here is the original version:
A young astronomer came rushing into the office of the head astronomer and announced: "Sir! I have just made an astonishing discovery! However, there is good news, and bad news! I have just discovered a new galaxy, that has just appeared, and is only 14 light years away from our own!", replied the young astronomer. "My God, that's fantastic, that's wonderful, amazing, etc. What bad news could there possibly be about that?" the old astronomer queried. The young astronomer replies, "Sir, it's BLUE!"
The joke is meant to be that the galaxy is blue-shifting, i.e. coming at us to destroy everything. But (as you obviously know) the distance/scale makes no sense; there are blue galaxies visible to us, which doesn't mean anything; and a galaxy actually coming towards our own will take billions of years to collide and means nothing to our solar system. I get it.
My questions are:
Could it be that the original joke-teller may have meant a new star/solar system (and would it make a difference whether it was described as a "star" or "solar system")?
I've understood that stars in other galaxies have been observed (or theorized?) to move at close to the speed of light. So would it be possible to have a super-fast star 14 light years away (or closer?), and that a collision would be imminent during a human lifetime?
Most importantly, I've seen a lot of jokes based on the Doppler effect and the color blue, even though blue-shifting doesn't necessarily mean turning blue. There's the famous bumper sticker, "If this sticker looks blue, you are driving too fast." None of that makes sense, either, right? Why are these jokes still understandable? I'm thinking of this as a kind of meme--like the countless jokes that are based on a man's voice going falsetto when he loses his testicles, which would not actually happen.
Just for my own curiosity and understanding, could really heavy-duty blue-shifting actually result in a star looking totally blue to the naked eye, or no? Everything I read uses the words "bluer" or "blue-shifting", but I can't seem to find descriptions of how celestial objects might actually look like.
My most important question is, of course, would the adjusted version of the joke make sense. It doesn't need to be funny, it can be tremendously un-funny, but can it be told in a way that has a semblance of internal logic, and is understandable to a physicist? Thank you!