Last Word: This week’s new questions | New Scientist

Is there such a thing as an olfactory illusion, and what forces make a particle of fluid start spiralling down a pipe instead of flowing smoothly?

There are optical illusions and audio illusions. Is there such a thing as an olfactory illusion?Justin BakerMelbourne, Australia

J4JTCR Water vortex, studio shot.

What forces are acting on a particle of fluid that makes it start spiralling or moving helically down a pipe instead of flowing smoothly?Phil Moreyvia email

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