I'm sure people are familiar with corrugated plastic tubes that make
different sounds when you twirl them. You can hold one end above small
bits of paper on a table and twirl the opposite end. The bits of paper
rise up into the tube. My explanation is that by twirling the free
end, you are accelerating the tube away from the air inside (lab frame
of reference) or there's a centrifugal force pushing the air out
(rotating frame of reference). That creates a low pressure area at
that end, which would force air up into the tube. [I used to explain
this as a Bernoulli effect, but given the discussion a while back, I
am convinced that is incorrect] First, is my explanation correct?
Second, what causes the paper on the table to rise up into the tube?
Is it just the air being pushed into the tube dragging the paper along
with it?