I didn't get how making the noise with his finger and the glass related with the rain forest question. Is it not supposed to make sense? Sorry if this is a dumb question..
~"I love you, Hermione," said Ron, sinking back in his chair, rubbing his eyes wearily. p.449 HBP~
They were past the rain forest. Gretchen asked Sam what he thought the future would be like. Nothing about the rain forest. The sound he made was like a metaphor of what the future is. You take from it whatever way you see it. I get tranquility out of that, even tho his stories of Gen-dupes, etc., don't sound like a tranquil place. Maybe the rest is. Anyway, its not literal.
shareI think Sam felt that the reason Gretchens asking that question to him was testing him, maybe he felt so because of the expression on Ruby's face. So i guess he did that sound in order to make them think about the space,emptiness and vicious circle of life..it was a good answer coz he both managed to give a true answer that anyone could possibly give and pass the test.
shareSam was also stoned at the time, remember, so it could be another reason for that lateral demonstration...
shareIt's a Little Late but here's my response.
When Gretchen asks him what he thinks the future would be like he plays a single tone on his glass. I think he's saying there is no varity in the future. Everything, everyone, everyplace is the same. It's all monotone, a dull automatic place.
Sure things might be diffrent on the reservation but everywhere else conformity rules. The Gene-Dupes don't take kindly to individuality