Absolutely nothing captured on digital film of the great outdoors this month so instead; science! And not even interesting science.
The pokey thing on the left is a hydrophone (a fancy microphone), whilst the chunky thing on the right is an ultrasound transducer (a fancy speaker), both suspended in water. The transducer is sending out sound into the water which the hydrophone can hear. We can move the hydrophone around to listen at different places in front of the transducer and therefore "map" the sound field.
And why do we do this? Science!
