For me, it may be that the toilet paper roll needs to have the open end away from the wall. I don’t want to reach under the roll to take a piece! That’s ludicrous!
That or my recent addiction to correcting people when they use “less” when they should use “fewer”
Sound is the vibration of a medium you don’t need ears for ultrasound to work
Actually incorrect. The vibration of a medium is still just a vibration of a medium. It’s our eardrum that vibrates, which is then converted by the brain into what we recognise as “sound”. Ultrasound is exactly the same thing. When they show us a video of “The sound of the planets”, that’s not what we would hear if we are out in space, we wouldn’t hear anything. That “sound” is just computers translating those waves into something that we perceive as a sound, the same way our brain does.
Until a pressure wave hits our eardrum, and gets converted, it’s not sound…it’s simply modulating pressure.