Currently there exist biometric sensors that can measure things like (i) our heart rate, (ii) how many steps we’ve taken during the day, and so forth.
Question: Do there exist biometric sensors that can measure fluctuations in our energy levels?
Note that when I speak of “energy levels,” I’m not referring to anything spiritual. Instead – the way I’m using the phrase – if someone is feeling a high “energy level,” he will feel that he has a relatively high capacity to perform physical work, socialize with people, and so forth. On the other hand, if a person is feeling a lower “energy level” (in the way that I’m using the phrase), he might just want to chill out by himself or go to a sleep.