⚡ It's a shock! How can light increase its speed again after leaving a denser environment?

[@mariakatariina8751]

If a flow of music passes through a group of lavatanssijat, a lot more (at least seemingly more 🤔) energy is emitted, than there initially was in the music that was brought in.
Alike if light a fire with a match.

[@engiscie]

In fact, it is quite an interesting example! :)