Chasing something that doesn't exist

Question

I'm trying to find a word or short phrase that would describe chasing something that doesn't exist.

My restriction is that it can't be referencing something that would only make sense in our world (things like "chasing the white whale" as it's a reference to Moby Dick)

I'm writing a book that does not take place on earth. So referencing our literature, specific places on earth, or specific cultures on earth don't really work well with the setting.

I'll be taking a look at worldbuilding.stackexchange.com as well, but for reference for those who comment or come back to view this question.
The world the story takes place in is similar to earth in regards to atmosphere, environments, and natural phenomenon. Things like "chasing the rainbow" would work.

As for context in how I'm trying to use this. Two people are having a tense conversation. Person 1 is attempting to convince Person 2 to join a group that has made person 1 very idealistic promises. Person 2's reply is “You paint a pretty picture, but it’s one drenched in the blood and death of every nation. You use to be so smart, so tactful, now you’re nothing but a fool chasing after a _______________.”

Answer 1

"Chasing after the wind" sort of flows with that example sentence you provided

Answer 2

Wild goose chase: (via dictionary.com)

Definition:

a wild or absurd search for something nonexistent or unobtainable

Example:

a wild-goose chase looking for a building long demolished

Answer 3

"chasing rainbows" seems like a good choice.

• trying to achieve something that is not possible or practical TFD

e.g. He wanted to go into show business, but friends told him to quit chasing rainbows.

I'm always chasing rainbows
Watching clouds drifting by
My schemes are just like all my dreams
Ending in the sky... (lyrics by Joseph McCarthy)

or

• "to reach for the unreachable star" as in "The Impossible Dream".

e.g. "The problem is I'm always trying to reach the unreachable star."

Answer 4

Fool’s errand

an attempt to do something that has no chance of success: Billions of dollars have been spent on long-range weather forecasting, but it’s a fool’s errand.

Answer 5

How about chasing shadows? It could also mean things that once were or that one is always trailing behind. But it is always something that you will not catch.

Or chasing/following/looking for a red herring. Chasing something not related, that leads you away (intentional or not). You could also consider using this in a more poetic way if you for instance have established some other creature with a natural color previously in your story (not necessarily required if you phrase it well), say a blue blob, you could reference a red blob thus inventing an idiom that fits your universe while still familiar and understandable to the reader.

Answer 6

A pipe dream

From M-W:

A hope, wish, or dream that is impossible to achieve or not practical.

Origin:

From the fantasies brought about by the smoking of opium.

While opium may not exist in your world, if a similar narcotic was established, the meaning could be maintained.

...now you're just a fool chasing a soma dream.

Answer 7

will-o-the-wisp, Cambridge English Dictionary

something that is impossible to get or achieve:

Full employment is the will-o'-the-wisp that politicians have been chasing for decades

From Wikipedia

A will-o'-the-wisp....is an atmospheric ghost light seen by travellers at night, especially over bogs, swamps or marshes. It resembles a flickering lamp and is said to recede if approached, drawing travellers from the safe paths

From The Free Dictionary

It is believed to be due to the spontaneous combustion of methane or other hydrocarbons originating from decomposing organic matter

A will-o'-the-wisp in the technical sense could not occur on the Moon, or Mars any more than a white whale could. However, on a planet with enough water, free oxygen and organic compounds, it could.

So...a will-o'-the-wisp is not

referencing something that would only make sense in our world.

Answer 8

Chasing phantoms would describe chasing something that doesn't exist.

Answer 9

Snipe hunt

Via The Free Dictionary:

n.

1. An elaborate practical joke in which an unsuspecting person takes part in a bogus hunt for a snipe, typically being left alone in the dark with instructions not to move until the snipe appears.

2. A futile search or endeavor.

Via Wikipedia:

A snipe hunt or fool’s errand is a type of practical joke that involves experienced people making fun of credulous newcomers by giving them an impossible or imaginary task. The snipe hunt may be assigned to a target as part of a process of hazing, but the word “sniper” is derived from a marksman with enough skill to shoot one.

A snipe hunt is a specific type of “wild-goose chase,” where a person embarks on an impossible search. Where a wild-goose chase may be accidental, a snipe hunt is always initiated by a second person, as a prank.

It should also be noted that Snipe do in fact exist, and they can be, and are hunted for sport. While the term ‘Snipe Hunt’ is most commonly used as described above, Snipe Hunting is ironically a real pursuit.

Answer 10

Chasing a chimera is an idiomatic expression that conveys the idea:

• A fanciful mental illusion or fabrication.

Chimera derives from:

• ( Greek Mythology) A fire-breathing female monster usually represented as a composite of a lion, goat, and serpent.

NGRAM: chasing a chimera.

• It left the world chasing a chimera instead of focusing effort on the culture of spirituality. It threw a possible great civilization under the pall and handicap of the most fantastic conception that ever misdirected the...From Who is this King of Glory?

Answer 11

"Trying to square the circle"?

That's impossible in any world/universe where pi is transcendental, or has a minimum polynomial of a degree which is not a power of two :-)

Other options would be "trisecting any angle" of "doubling the cube".

Answer 12

"Just a fool chasing dreams", seems very appropriate here (but leaves some ambiguity as to the attainability of the dream).

Answer 13

One term that will fit in nicely with the context is Mirage.

Chasing a Mirage

something that you hope for or want but that is not possible or real

M-W

something illusory, without substance or reality.

Dictionary

Specially this definition suits very well to the context

a hope or wish that has no chance of being achieved:

Cambridge

Mirage has a lot to do with sand and heat, your world will have plenty of them so the concept won't be alien to it.

Answer 14

On the other hand...

...you could probably get away with:

... now you’re nothing but a fool chasing a one-eyed, one-horned flying purple people eater.

I imagine your world is no more likely to have one of these than mine. :-)

Alternatively, you could just use a brand new made-up animal name that doesn't exist in your world either and allow the reader to infer your meaning from the context:

... now you’re nothing but a fool chasing after a (xibex | sneewart | some-other-made-up-animal-name.)

The advantage here is that you lend some authenticity to your world by suggesting it possesses its own folklore and allows a glimpse in to the shared local context that the native inhabitants all take for granted and use conversationally.

Answer 15

I would like to add to MrWonderful's answer.

I assume your world would have lore of it's own. Maybe some writer in your world has written a book about a purple whale(or anything else) and it's pursuers.

Have the "purple whale book" mentioned earlier in the story, make sure the reader knows about it. And then use the purple whale. Not only will this convey the meaning of chasing the unattainable but it will help immerse the reader further.

Answer 16

I would offer "catching smoke". It's using a common technology baseline (e.g. fire) which in many settings would be even more common than is the case with us, today.

But it's something nebulous, hard to catch, and ultimately pointless to do so. So has perhaps a slightly different meaning to 'chasing something that doesn't exist' - smoke clearly exists - but none the less, only a fool would try catching it.

Answer 17

quixotic

According to Merriam-Webster:

1 : foolishly impractical especially in the pursuit of ideals; especially : marked by rash lofty romantic ideas or extravagantly chivalrous action

Answer 18

A snark hunt.

The Hunting of the Snark is a poem by Lewis Carrol, author of Alice in Wonderland. It concerns a pointless hunt for a mythical beast conducted in an absurd fashion.

Before you down-vote this for referencing English lit, consider how Larry Niven named a species of creatures in his Known Space Universe the bandersnatchi, in reference to another of Carrol's poems, The Jabberwocky. Lewis Carrol references are always appropriate.

Answer 19

If you like the rainbow, you may also like hunting for a pot of gold:

the realization of all one's hopes and dreams; ultimate success, fulfillment, or happiness

This would be recognized, in our Terran culture, to refer to a leprechaun's pot of gold, hidden at the end of a rainbow.  I'm not clear whether this satisfies your universality constraint.  It doesn't refer to any specific literature from Earth, or any specific location.  It does refer to our culture/legends, but, if you're assuming that your bug-eyed-monsters speak English, why not assume that they have fables similar to ours?