Question: how did the person who invented time, know how to put it in 60 minute and seccond intervals? and why did they only make the clocks go to 12 hours when there is 24 in a full day?

Hi Chloe, I love this question! Before clocks, time was measured in “seasonal hours”, which were basically one twelfth (12 comes from the Babylonian culture) of the time that the sun was above the horizon that day (and below the horizon for night hours). So these hours varied in length and weren’t very convenient. When the clock was invented, we needed a more precise way of keeping time, and the standard length hour was introduced. When they decided they wanted smaller standard units of time as well, they looked back to the Babylonian mathematicians for the number 60. The Babylonians loved the number 60, I don’t know why. So they divided hours into 60 minutes, and minutes into 60 seconds. I agree that it is highly impractical and if we were inventing it today from scratch, we would do it much differently.

Chris is pretty spot on. 12 hours was also used as during the equinox (Spring or Fall) on the equator, you have 12 hours of daylight, and 12 hours of nighttime, making it a sensible division to start with. And as Chris, said people loved the number 60 (because it is divisible by 2, 3, 4, 5, 6, 10, 12, 15, 20, and 30).

Chris and Brad are right about how the time units were developed. Did you know that even angles is on the sexagesimal (base 60) numerical system? We know that there is 360 degrees in a circle, but most people probably don’t know that there are 60 minutes of arc in a degree, and 60 arcseconds in a minute of arc.

Hi Chloe, I love this question! Before clocks, time was measured in “seasonal hours”, which were basically one twelfth (12 comes from the Babylonian culture) of the time that the sun was above the horizon that day (and below the horizon for night hours). So these hours varied in length and weren’t very convenient. When the clock was invented, we needed a more precise way of keeping time, and the standard length hour was introduced. When they decided they wanted smaller standard units of time as well, they looked back to the Babylonian mathematicians for the number 60. The Babylonians loved the number 60, I don’t know why. So they divided hours into 60 minutes, and minutes into 60 seconds. I agree that it is highly impractical and if we were inventing it today from scratch, we would do it much differently.

Here is an article I found that explains it better than I do:

http://www.scientificamerican.com/article.cfm?id=experts-time-division-days-hours-minutes

0Chris is pretty spot on. 12 hours was also used as during the equinox (Spring or Fall) on the equator, you have 12 hours of daylight, and 12 hours of nighttime, making it a sensible division to start with. And as Chris, said people loved the number 60 (because it is divisible by 2, 3, 4, 5, 6, 10, 12, 15, 20, and 30).

0Chris and Brad are right about how the time units were developed. Did you know that even angles is on the sexagesimal (base 60) numerical system? We know that there is 360 degrees in a circle, but most people probably don’t know that there are 60 minutes of arc in a degree, and 60 arcseconds in a minute of arc.

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