# Sphinx-related riddle

My 3rd grader brought an assignment home about the Giza plateau, and one of his questions was the following riddle:

What creature with one voice walks on four legs in the morning, on two at noon, and on three in the evening?

This totally puzzles me; the only thing I can think of is an unfortunate human being who's been through a lot the night before (silly joke on my part).

Can you solve the Sphinx's riddle?

• The afterthought is - we are going from 4 legs (stage 1) in the morning to 3 in the evening - what this may be related to - being tired??? With my IQ of 147 I swear to God cannot figure this out....HELP!!!!! Commented Jan 21, 2016 at 10:50
• Wikipedia has much to say on the matter of this classic riddle. TVTropes does, too. (warning: TVTropes link contains a link to TVTropes) Commented Jan 21, 2016 at 11:02
• Isn't this a duplicate??? Commented Jan 21, 2016 at 13:27
• @Insane Eh, maybe. But this riddle is literally the first thing that comes up when you google "Sphinx" and 3rd grader was expected to find the answer. I think the result is the exact same. It should not be encouraged (upvoted). Commented Jan 21, 2016 at 14:40
• @TrevorPowell - having been bitten by the TV Tropes time sink, I had to laugh at your warning about its link :-) Commented Apr 2, 2018 at 3:08

I must confess that I've always been a bit puzzled by the standard answer that literally everyone gives to this puzzle, which relies on weird metaphorical interpretations of what are fundamentally quite common, ordinary, well-understood words.

Particularly since there's a simple (and frankly, rather obvious) answer which doesn't require you to pretend that words mean anything other than what the dictionary says that they mean.

This more sensible answer:

My cat.

walks on four legs in the morning

In the mornings, my wife and I watch the morning news, while seated on the sofa. Invariably, the cat walks across us, stepping on all four of our legs.

on two at noon

At noon I'm at home (due to an injury which is currently keeping me from work), but my wife is at work. So when my cat walks across the sofa while I watch the news at noon, she only walks on my two legs.

and on three in the evening

In the evening, my wife is usually quite tired from her long day, and so will doze on her side on the sofa, as we watch the evening news together. So when the cat walks across the sofa in the evening, she steps on both of my legs, but only the uppermost of my wife's legs.

I think we can all agree that this is a far simpler answer than that other one which requires redefining the words used by the riddle.

I mean, I'm as much of a fan of The Humpty Dumpty theory of language as the next guy, but.. it does sort of cheapen the solution to a riddle if you could only get an answer by inventing new meanings for the words. Right?

• +1 for interpreting 'walking on' as walking on other people :^) Commented Jan 21, 2016 at 14:39
• +1 This had me rolling, lol. Commented Jun 12, 2019 at 21:42

What creature with one voice walks on four legs in the morning, on two at noon, and on three in the evening?

Humans

Explanation:

four legs in the morning

As a child, you crawl.

two at noon

During adulthood, you walk.

on three in the evening

As an elder, you walk with a cane.

• Assuming OP is not in France, I would presume that this riddle given to a third grader would be this classical answer. Commented Sep 1, 2016 at 12:09
• @EngineerToast Why not in France ? Commented Sep 7, 2016 at 11:40
• @Guildias Because 3rd grade in France (3ème) is the grade for 14 year olds. I can see a teacher giving a more challenging, not-what-you'd-expect puzzle to a 14 year old than they would to an 8 year old. (There may very well be more countries where "3rd grade" is late in the education system but France is the one of which I already knew.) Commented Sep 7, 2016 at 12:09
• @EngineerToast Oh ok. Since France have an inverse system for the grade, we don't call it "3rd grade" in english. Everyone does the conversion FrenchGrade -> Age -> EnglishGrade. Commented Sep 7, 2016 at 12:16
• @Guildias TIL more about translating between French and English. Commented Sep 7, 2016 at 13:04

Me. 2 days ago (30/08/2016).

four legs in the morning

I overslept and had to really really run fast in order to get in time for an exam. When I got to the university I runned like a dog (hand and legs) through the staircase until I got to the classroom (They let me in).

two at noon

When I finished the exam I had time to spare, so I just simply walked without problems.

three in the evening

I had a friendly soccer match on the evening. My right boot broke (Yep.) on a sprint and I crashed into a wall with my knee. I went to the hospital and I'm still walking with 3 legs since I'm on crutches.

Bonus:

I met a boy at the hospital that was on crutches too. Maybe he was your 3rd grader.

The Riddle of the Sphinx originated in Ancient Egypt and carried over into Ancient Greek culture by way of Greek scholars studying at the Library of Alexandria. I believe the original author of the Egyptian version was someone interested in astronomy. The answer is "The Sun", not "man". It can be physically demonstrated with two sticks placed in the ground during the setting of the sun. I have included a link to the solution I wrote a few years back explaining exactly how to do this and explains the reasoning behind what I believe to be the solution. Something kids interested in science will enjoy.

First know that a man by the name of Eratosthenes used a stick to determine the circumference of the earth. One thing that led him to that conclusion is that at noon, in a place he called Syene, the sun would cast no shadow, as it was directly over or above. So, what does Eratosthenes, a stick, the sun, and shadow have to do with the solution? To see the solution, you simply have to go into an open field at sunset with two straight sticks. Take one stick and place it in the ground; it will cast a shadow.

Take the second stick and place inside the shadow of the first stick.

Leave your sticks for the night and come back in the morning. What would you see? Because we live on a giant globe that is tilted at 23.4 degrees you would see the effect of the sun casting the shadow at a different angle, and you would also see the solution to The Riddle of the Sphinx.

So how can the sun be said to walk on four feet in the morning, two at noon, and three in the evening? You “mute” its “voice” by using shadow. In the morning, the two sticks are casting two shadows, and we can think of them as four legs. At noon, mayber not in your particuliar part of the world, but certainly in Syene, the sticks would cast no shadow, because the sun is directly over the sticks.

In the evening when the sun sets the two shadows will merge into one shadow again, giving the appearance of two sticks with one long shadow, and therefor only three legs.

Best! William

• Not meaning to discount any research you might have done, but are there other scholars who agree with your interpretation? You sent a link citing your own website with links to what appears to be your own work, not published in a peer reviewed journal. If you are going to claim definitively that the answer is the sun rather than the more commonly accepted one, more evidence is warranted. At the very least you should write out the evidence here as answers should be self contained. Commented Jun 12, 2019 at 22:58
• You are correct, it is my own work. As for peer reviewed journal, I am not an academic, I graduated high school by one assignment and the only time I stepped onto a college campus was to teach Military Science at Oklahoma State University. More evidence? Kind of a vague question. I invite you to take two sticks to a field and try it for yourself. Looking forward to your comments. Commented Jun 13, 2019 at 0:33
• It may not be the traditional interpretation, but it's definitely an interesting and well-thought-out one. IMHO, if Trevor Powell's not-entirely-serious answer has 21 upvotes, then this deserves a few as well. +1. Commented Jun 13, 2019 at 11:06
• Thanks for adding the content to your answer! Much improved. I might remove the language saying this is "the" answer but it is a good answer now. By the way you don't need a degree to submit a paper for peer review, anyone can do it. You would probably need more evidence than the original author being interested in astronomy for this to be accepted though. Commented Jun 13, 2019 at 13:29