Genius I

[EverCurious]

Here is a question that I decided to post in the engineering section, since engineering is an apotheosis of innovation. I was just curious as to see what kinds of brilliant innovations this would spawn. I'll enter my answer to the problem on January 31st, however, I doubt my answer will be as good as some.

 

 

Suppose you were put into a room with no windows, and no visible doors. At the center of the room was a light fixture. Your watch, your cell phone, everything that told time, was removed. All you had was your clothes, a pen, a pencil with eraser, a paperclip, and several different coins. Your objective is to build a device which can tell you the time, or time passed, for twenty four hours.

 

How would you do it?

[YT2095]

just out of curiosity, this light fixture, is it working and with mains elec?

for instance using the 50 or 60Hz AC as a timebase?

not that this is my intention, it`s just for clarification

[lightwave]

Make a long pendulum with the coins and thread from your shirt. When swinging it marks off a 24 hour period very accurately. Use your thread and pencil to make a circle then mark off segments to represent hourly time in 24 segments each divided up into 60 portions. That way you can easily tell the passing of time to the minute. Observing the swings can tell you seconds.

 

Your thread and pencil easily make a round circle. Divide it into halves, then quarters then etc. Your paper clip could serve as an anchor to the pendulum in the ceiling.

 

At least you can note time passing. You still won't know the time unless you have access to a sighting of the sun. Calibration of the pendulum to midday is easy if you sight the sun's shadow and the standing pen can be used to mark minimum shadow etc. I assume the room has a ceiling so you can't see out. Was that a part of your idea?

 

A working light fixture will be needed as otherwise it'd be total darkness.

 

But that's an interesting idea to use the light as a source of timebase. It'd potentially mark the passing of time but there'd still be no opportunity from it for calibration.

 

Ancient people used a pendulum to derive a measure of length that was very accurate. The so called 'megalithic yard' which was 86.66656 cm.

[EverCurious]

Brilliant. I did consider a pendulum but I had no knowledge of its schematics so I tried a less accurate approach. My approach is plausible but not very possible, too many things can go wrong.

[EverCurious]

@YT2095

 

Yep. Standard lighting connected to the main.

[EverCurious]

Well today is answer day, and so far all I received was that pendulum. But anyway, here I go.

 

I decided to use the paper clip and connect a fiber, or length of string to the base of the light fixture, on the string, I thought that you can place a slip knot with a slight portrusion, on that extra portruding fiber, tie some coins as weights and the slip knot will slide ever so slowly. Now you can mark the amount the slip knot has slid for one minute and from there use the measurement to time any other length of time.

 

Its a rough sketch, but then again, I did say my answer would be the worst.

[EverCurious]

Another Idea may revolve around using the light fixture and a shadow...HINT HINT...

[lightwave]

I forgot to mention that the long pendulum when swinging stays in the same path as it was when originally set swinging. The earth, meanwhile, rotates under the pendulum. The pendulum appears to move in relation to the earth, while it is actually the earth which moves.

 

In any case, the pendulum marks off an intersection of a circle with each swing. After one earth rotation the pendulum has intersected the entire circle. The longer the pendulum the greater is it's stability.

 

I have no idea how to obtain accurate length measurements from pendulums but this has been done before. If anyone knows, please post here.

[JustStuit]

Well today is answer day' date=' and so far all I received was that pendulum. But anyway, here I go.

 

I decided to use the paper clip and connect a fiber, or length of string to the base of the light fixture, on the string, I thought that you can place a slip knot with a slight portrusion, on that extra portruding fiber, tie some coins as weights and the slip knot will slide ever so slowly. [b']Now you can mark the amount the slip knot has slid for one minute[/b] and from there use the measurement to time any other length of time.

 

Its a rough sketch, but then again, I did say my answer would be the worst.

This would involve being able to measure one minute on the machine which would involve something which tells time. Not to poke holes.

[EverCurious]

It's possible to count to sixty at a measured interval. I did tell you my method would be the weakest, yet it is still rough, and probably barely counts as an answer.

[JustStuit]

Oh I see. Estimate a smaller interval to achieve a more accurate result (however accurate it may be.)

[EverCurious]

yes...give me a break sasuke ;-) i thought of this when i was in a state of delerium from all that instant ramen.

[JustStuit]

lol nice reference. It is a nice idea to minimize error by calculating a smaller interval.