What does "crossing the stream" mean? I have been through "Cross the stream where it is shallowest" but I also sometimes see this phrase without the "where it is shallowest" part. For example, today I saw this phrase being used in one of the comments in Stack Overflow:

With negative weights Dijkstra I found the most expensive path in the graph: one that crosses the streams.

  • 3
    Would you happen to have some context for the use? It could be just someone abbreviating a longer phrase, or it could be a reference to something completely different (for example, a Ghostbusters reference..)
    – tanantish
    Oct 8, 2012 at 11:50
  • @tanantish I provided a link to the context
    – Geek
    Oct 8, 2012 at 12:00
  • It's a cultural reference to the movie 'Ghostbusters'. Also, stream is a very mild metaphor for path.
    – Mitch
    Oct 8, 2012 at 12:06
  • I suppose that for having an answer your question would have made us aware of the presence of a suitable bridge near the stream, for example; but, as it stands, the question is unaswerable for the lacking of additional informations. If you might be interested to improve the question, I suggest you to add, at least, an image of the stream.
    – user19148
    Oct 8, 2012 at 12:08

3 Answers 3


Score one for dumb guesses. Specifically in the link you've provided, it's a reference to Ghostbusters (as in, the film) :D

Roughly translated, it's along the lines of "that's a really bad thing you're about to start doing/are in the process of doing"

Specifically, early on in the film there's a scene and some dialog which introduces the concept of "crossing the streams" as a Very Bad Thing. The relevant quote is on IMDB here in all its glory and here's the video clip.


Ghostbusters reference aside, cross that river, cross that stream, and cross that bridge can all be generic phrases that mean doing something, figuring something out, or getting past some obstacle.

Oftentimes, they are used to allude to some problem in the future:

Paul: Well, that explains how you intend to fix the roof, but what about the gutter?
Saul: We'll cross that bridge when we get to it.

Here, Saul is wanting to concentrate on one problem at a time, perhaps figuring that he'll have a better idea of how to best fix the gutter after the roof itself is repaired.


One of the cited stack-overflow references was specifically to Ghost Busters, where they had two energy streams from 'weapons'. Crossing them with each other would be fatal.

A picture is worth 1000 words department:

Typically, something like this ? :-) !!!!!!!!!
Don't try this at home !!! - even if you DO have two immense Tesla coils in your lounge.

  • Note: This image is a 1 frame "screen grab" from the above You tube video. If that is impermissible on this site then please remove. It seems to me that this would constitute "fair use" in the educational context but others may disagree and the Imgur licence terms may mess this up.

enter image description here

  • I don't think there's a problem with fair use and copyright, only with relevancy to the OP's question. Oct 8, 2012 at 15:00
  • @AvnerShahar-Kashtan - " relevancy ..." -> :-). It's not Ghost Busters, but it's a pretty graphic demonstration of the sort of the thing that the 'Ghost Buster' had in mind when he said it. Oct 8, 2012 at 19:33

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