Hourglass: What's the time?

Picked video by video from Institute of Physics (mixed channel): title plainly names a teaching subject. Channel transcript sample: Two of three samples are substantive educational content (historical explainer and a scientific lecture), while one is a vocational/promotional interview lacking real teaching structure.

A 3-minute video from Institute of Physics: “Hourglass: What's the time?”.

Video by Institute of Physics, played through YouTube's embedded player.