Awesome acoustic levitation. “The essence of levitation technology is the countervailing of gravity. It is known that an ultrasound standing wave is capable of suspending small particles at its sound pressure nodes and, so far, this method has been used to levitate lightweight particles, small creatures, and water droplets….”
Might dark matter play a role in extinctions…? I don’t know but it sounds plausible at least.
Although statistical evidence is not overwhelming, possible support for an approximately 35×10^6 yr periodicity in the crater record on Earth could indicate a nonrandom underlying enhancement of meteorite impacts at regular intervals. A proposed explanation in terms of tidal effects on Oort cloud comet perturbations as the Solar System passes through the galactic midplane is hampered by lack of an underlying cause for sufficiently enhanced gravitational effects over a sufficiently short time interval and by the time frame between such possible enhancements. We show that a smooth dark disk in the galactic midplane would address both these issues and create a periodic enhancement of the sort that has potentially been observed… (PDF - Lisa Randall and Matthew Reece)
Image by Alan Stonebraker
Stopping Sound with Foam. Experiments with this foam (shown under a microscope) showed that at certain frequencies, the bubbles and the surrounding liquid vibrate out of synch in response to an ultrasound wave, completely suppressing the transmission of sound. (Via APS physics).