Time Riddles
There are plenty of anecdotes about Einstein, which teach us a lot. The one I’m fan of is about his habit to take walks in the University campus, even during finals:
After giving an assignment to his students, Einstein invites his assistant to join him for a walk, while students write their answers. During this walk the assistant professor asks Einstein: “Last year’s final questions were the same, right? Perhaps this time students will just put the answers from last year, won’t they?” Einstein replies: “Answers have changed since.”
To the time riddles, and since Einstein was a huge fan of time, to say the least, let’s put him into action in the first one.
Cuckoo-Clock Riddle:
Einstein stayed in his off-the-grid country house for a weekend, and he did not bring his pocket watch that time. He has a cuckoo-clock in one of the rooms, but the clock stopped a while ago. Einstein winds up the clock and leaves the clock’s arms at 9:00 position, then he goes for a walk. He follows a trail leading to a nearby town square, and when he arrives there, he notices 12:43 on the tower clock. Einstein returns to his house by the same trail, and he sees 10:08 on his cuckoo-clock.
To what time will Einstein set the clock’s arms then?
Next two riddles are from “Time Matters, 5th edition” book, which is about the science and applications of time, from Einstein to Bob Lazar. You can read the preface on Medium and download free eBook.
Subway Riddle:
A man works downtown, and he finishes his work randomly between 5pm and 6pm. Then he comes to the subway, where trains go every 15 minutes in the direction where his girlfriend lives, and trains go every 15 minutes in the opposite direction, which is where his parents live. He takes the very first train that comes to the station. But here is the problem: His mom complains that he visits his parents only once a week on average. But the guy responds, and that is true, that he takes the very first train at his station.
How is it possible that on average only 1 of 5 days he comes to his parents and 4 of 5 days to his girlfriend?
Fuses Riddle:
Let’s say, you have a bunch of detonation cords, each burning time 1 minute sharp. Each cord burns unevenly: half of it may burn in 20 seconds, but then another half burns in 40 seconds. Unevenness in burning along a cord varies from cord to cord, but 1 min burning time from end to end for any cord is guaranteed. You have a matchbox full of matches. Start with a warm-up test: How to measure 1.5 minutes using such cords? Then try:
How to measure 45 seconds with such cords?
How do these riddles connect you to the Time Matters topics?
— Cuckoo-Clock Riddle gently introduces you to Einstein’s way of thinking — relativity.
— If you can solve the Subway Riddle, then you will understand the insight from Bob Lazar on how strong force and gravity are related (chapters 18 and 27).
— Solving Fuses Riddle manifests that you can think in two steps, and you can get that mass dilates time “first”, “then” time dilation causes gravity. Besides that, there are massless cases of gravity caused by time dilation alone.
