Byrd:

Sorry for the great delay in your response...lots of unfortunate happenings in recent weeks.

From yours: “…I'm not sure what this has to do with my reply to your original post…”

Mine: The problem was your answer to my question of "who” invented the second of time. You replied with the answer of a timing system used today...nothing to do with the "invention" of long ago that is being discussed.

Perhaps my choice of words was incorrect or confusing since you cannot "invent" the system as originally used so many years past...you can only "design" one. Therefore the question should have read:
Who "designed" the "second" of time?
Since I also refer to measures at Giza...then I am asking for evidence of the second at that time of construction or before (2,450BC or earlier).

From yours: I was answering the question of who produced a device that measured seconds... and it's in the Wikipedia article.

Mine: Another point of confusion.
I never asked anything about a “device”.

From yours:
In the case of 6/pi, I doubt they could accurately measure something that fell during a time period

Mine: That's a good point Byrd and I was hoping for someone to challenge what I posted.
Yes...it does seem unlikely that they could measure to such accuracy...but you have yet to see the supporting evidence. I will provide it before the week’s end.

From yours:
“…unless you have some evidence of Egyptian chronometers that I'm not familiar with? The ones I know of are water clocks and candles and daylight and solar markers like sundials...and heartbeats….”

Mine: Again...you are misdirecting from the question.
There was no suggesting the Egyptians designing the system of measure...I specifically asked who.
Also…do not underestimate water clocks and sundials if you are unfamiliar with their use. The sundial is Earth's “most” accurate timing device...you can't change that simple “fact” and the shadow cast by the Sun is its visual confirmation.
Mechanical timers can only run on an “average” setting for an Earth’s day measure. As I stated before, the length of an Earth day varies every day of the year, therefore any mechanical or isotope system can only work as an average measure for the second.
Forget the heartbeat...not worth discussing at this point...too inaccurate...probably never used.

Yours: but we all know that gravity works and I'm pretty sure that folks here know about the variations in speed depending on whether the measurement is taken at sea level or higher and depending on slight gravitational anomalies in the region.

Mine: We all know that objects fall to the ground, if you let them drop...but do you know how to calculate the time required for an object to fall a specified distance at the Giza site? The builders of the site did...! I doubt if there is more than one individual in this group that knows how to do it...do you?

Yours: Again, to answer your question, it may have been the Germans who invented a standardized second in 1560 or thereabouts, but the first fairly accurate one was done after 1657 and Christain Hugyens…”

Mine:
Sorry Byrd...I think there is another misunderstanding here.
From your URL...
"...Christiaan Huygens, however, is usually credited as the inventor. He determined the mathematical formula that related pendulum length to time (99.38 cm or 39.13 inches for the one second movement) and had the first pendulum-driven clock made..."

I know you are attempting to help, but it's not what was being asked. Huygens "used" the second of time to set the length of the pendulum...it's the reverse of the question asked.
Also from that same URL

"...Water clocks, along with the sundials, are possibly the oldest time-measuring “instruments”, with the only exceptions being the gnomon and day-counting tally stick.[1] Given their great antiquity, where and when they first existed are not known and perhaps unknowable...Other regions of the world, including India and China, also have early evidence of water clocks but the earliest dates are less certain. Some authors, however, write about water clocks appearing as early as 4000 BC.[2]..."

Now this is more of what I was seeking, but it gives no reference to the designers of the “second” or the first peoples to use a day divided into a 60 second minute of a 60 minute hour of a 24 hour day.

Yours: "...Gallileo, by the way, timed the fall (roll down an incline, actually) of objects by starting and stopping a stream of water and weighing the water..."

Mine: Yes...he was an intelligent fellow...tried many things until he got it right.

Yours: "...So, to answer your question (still) it appears the second wasn't measured and standardized until 1657. If they'd been doing it earlier, the Greeks would have picked it up from the Egyptians..."

Mine: Let's leave the Greeks out of this one...we may have to leave the Egyptians out of it also.

BTW…Great conversation…I hope you follow through and become involved with my future postings on this topic.

Best.
Clive