- I like magnets -- some [[ideas]]:
  - [[magnetic computing]]
  - [[magnetic 3d printing]]
  - [[magnetic assists]]
    - In general magnetism seems like an amazing way to transfer momentum?
  - [[magnetic gears]]
    - As in the little devices I've built
- Today (actually yesterday) I saw a great video on the [[principle of least action]] and it blew my mind a bit. It also introduced me to diffraction grating effects -- which I had heard about but hadn't grokked/seen demonstrated.
  - The fact that angular momentum is quantized... wow. Also it introduced me to [[diffraction gratings]], which I had heard of only in passing.
  - And angular momentum has the same unit as action: Joule-second.
  - This all made me think also of...
    - Could you use diffraction gratings at astronomic scales to see into the past? E.g. by making visible light from a star that has taken a longer (slower) path to get to us.
    - The effect that makes lights 'stretch out' in one direction in some mediums, like water (think of night lights reflected on a lake) or... the effect that is apparent in my chrome kitchen countertop that is quite something and I sometimes call the [[rainbow folding]]). I'm unsure if these are really related but something about the discussion about the paths that light can take made me think of it.
  - All in all I really enjoy thinking about [[physics]] as of late.
  - -> [[Action principles]] and [[Lagrangian]] are both interesting over at Wikipedia.