<instructions>Your goal is to analyze the following comment and estimate how highly it will be upvoted by the Hacker News community.</instructions><comment><author>santaclaus</author><text>Well an underground volcano or something could inject energy into the system so you are probably ok, thermodynamically.</text><parent_chain><item><author>jfries</author><text>Ah the circular river. Very rare but useful to extract energy from.</text></item><item><author>dsmithatx</author><text>I immediately thought of Devil&amp;#x27;s Kettle Falls reading this.  I had to Google it and found that 4 months ago scientist have decided it flows back into itself.  They have a plan to put a large amount of dye in during low water and see where it reconnects.</text></item></parent_chain></comment><story><title>Undersea rivers we know little about</title><url>http://www.bbc.com/future/story/20170706-the-mystery-of-the-massive-deep-sea-rivers</url></story>
<instructions>Your goal is to analyze the following comment and estimate how highly it will be upvoted by the Hacker News community.</instructions><comment><author>jameshart</author><text>most rivers are circular - just that the upstream water flow is invisible, by virtue of being in water vapor form.</text><parent_chain><item><author>jfries</author><text>Ah the circular river. Very rare but useful to extract energy from.</text></item><item><author>dsmithatx</author><text>I immediately thought of Devil&amp;#x27;s Kettle Falls reading this.  I had to Google it and found that 4 months ago scientist have decided it flows back into itself.  They have a plan to put a large amount of dye in during low water and see where it reconnects.</text></item></parent_chain></comment><story><title>Undersea rivers we know little about</title><url>http://www.bbc.com/future/story/20170706-the-mystery-of-the-massive-deep-sea-rivers</url></story>