This is a pretty epic phenomenon that I had not previously known before in which pickles emit light as if they were lightbulbs when electricity is applied. The light emitted is mainly monochromatic, that is of a few wavelengths, and is due to the electricity reacting with the sodium or other salt ions in the pickled cucumber. Interestingly, mainly just one side of the pickle is lit up and which The Action Lab hypothesizes might be due to asymmetric electric resistance in that which ever side first obtains a spark-gap to start the reaction then dominates the reaction as heat is generated and more sparks occur causing more ions to emit light.
Later in the video, he shows that the pickling process can be speed up by removing all of the air bubbles within a cucumber while it is inside a salt solution so that the air gets replaced with the salt solution, thus causing instant pickling. Amazing stuff!
