If you have any leftover chewing gum, give it to me .... “That’s all for today. Do you have any questions? Well then, please do your best to the end.” The six people in the room were listening to the leader’s instructions absent-mindedly as usual. One of them had a chewing gum in her mouth. Are physical quantities measurable? How can time-varying information be perceived? In physics, the answer is simple. That is, the measured quantity at a point in time is uncertain. But now let’s extend the challenge to include not only quantitative measurement but also qualitative understanding. How is changing information in general captured? The leader, who was applying hair conditioner to his hair, left the room. However, I wondered how closely others had listened to the leader’s instructions earlier. I mean, just now he said “until the end”. To the last? I think it’s reasonable to say that “from now on” or “this week too” would be more appropr...