Originally posted by wirehead
Do you really think there's any consistent, logical reason to choose your unit of time to be 1/86,400 of a day? Doesn't that strike you as extremely arbitrary?
You mean to tell me that an ancient civilization, completely isolated from our own, would sit down to standardize their unit of time measurement and say, "Hmmm, yes, 1/86,400 of a solar day, that makes the most sense!"
Originally posted by Bedlam
Any fixed length is fixed. The meter's length was arbitrarlly chosen. As is the duration of a second - there's no innate reason to choose that fraction of a day.
Although part of the decimal metric system, the second derives its name from the sexagesimal system, which originated with the Sumerians and Babylonians, and divides a base unit into sixty minutes, minutes into sixty seconds, seconds into sixty thirds, etc. In angular measure, it is the degree that is subdivided into minutes and seconds, while in time, it is the hour."
The greatness of Sumer can be measured in other spheres, too. Its sexagesimal system has reached us via the exact sciences. Our astronomers still divide the circle into 360 degrees with each degree divisible into 60 minutes and each minute into 60 seconds. The division of the hour into 60 minutes of 60 seconds each is also a legacy of Sumer. Whenever we look at a clock, we are reminded of our debt to Sumer.
Originally posted by yampa
Originally posted by wirehead
Do you really think there's any consistent, logical reason to choose your unit of time to be 1/86,400 of a day? Doesn't that strike you as extremely arbitrary?
You mean to tell me that an ancient civilization, completely isolated from our own, would sit down to standardize their unit of time measurement and say, "Hmmm, yes, 1/86,400 of a solar day, that makes the most sense!"
Originally posted by Bedlam
Any fixed length is fixed. The meter's length was arbitrarlly chosen. As is the duration of a second - there's no innate reason to choose that fraction of a day.
Guys?
Wikipedia entry for metric time. That is, SI time.
en.wikipedia.org...
Although part of the decimal metric system, the second derives its name from the sexagesimal system, which originated with the Sumerians and Babylonians, and divides a base unit into sixty minutes, minutes into sixty seconds, seconds into sixty thirds, etc. In angular measure, it is the degree that is subdivided into minutes and seconds, while in time, it is the hour."
That is 60 seconds x 60 minutes x 24 hours = 86400
Cyrus Gordon writes in 'The Common Background of Greek and Hebrew Civilizations'
The greatness of Sumer can be measured in other spheres, too. Its sexagesimal system has reached us via the exact sciences. Our astronomers still divide the circle into 360 degrees with each degree divisible into 60 minutes and each minute into 60 seconds. The division of the hour into 60 minutes of 60 seconds each is also a legacy of Sumer. Whenever we look at a clock, we are reminded of our debt to Sumer.
So you are both incorrect to say that 86400 seconds per day was picked out of thin air by western scientists in the modern era.
The Sumerians/Babylonians, and the modern scientists implementing the metric system had lots of reasons to choose a system utilising 86400 seconds in a day. These reasons can be sourced from scientific principles. I see no reason the architects the pyramids could not have discovered these principles themselves.
Originally posted by Harte
If you see no reason, then let me tell you one.
The Ancient Egyptians did divide the day into 24 hours, as did the other cultures you mention.
This is not speculation by the way. It is a fact that every day, an hour was a slightly different amount of time in Ancient Egypt.
Only much MUCH later did the Greeks establish a standard hour length for telling time.
Harte
Originally posted by yampa
We are not talking overall trends in Egyptian measuring systems here (although they may offer insight), we are talking about whether it is possible for the architects of the Great Pyramid to have had a concept of the modern,speed of light - 299 792 458 m / s and whether they could encode some approximation of that number by constructing a building on a latitude using a measurement system which is very close to one we use today.
These guys are trying to argue that the idea is a non-starter because the ancients used a different set of measures, and that the modern metric implementation of seconds is an arbitrary figure. But I have just shown at least one ancient culture which used exactly the same measurements of time as the modern SI system.
Originally posted by Bedlam
Originally posted by yampa
We are not talking overall trends in Egyptian measuring systems here (although they may offer insight), we are talking about whether it is possible for the architects of the Great Pyramid to have had a concept of the modern,speed of light - 299 792 458 m / s and whether they could encode some approximation of that number by constructing a building on a latitude using a measurement system which is very close to one we use today.
These guys are trying to argue that the idea is a non-starter because the ancients used a different set of measures, and that the modern metric implementation of seconds is an arbitrary figure. But I have just shown at least one ancient culture which used exactly the same measurements of time as the modern SI system.
The number they "encoded" is one that's only that number if you are using SI meters and standard seconds. What's so hard about that? The Egyptians did not use meters, because that didn't happen until the 18th century. And it was first defined by France, as two marks on a metal bar.
If you don't use THAT length, and fixed length standard seconds, you will NOT get that number. If they were trying to pass down the speed of light it would have been in whatever units THEY used, and you'd have gotten a different number. Just like you get a different number if you use miles per second.
In 1668, Wilkins proposed using Christopher Wren's suggestion of a pendulum with a half-period of one second to measure a standard length that Christiaan Huygens had observed to be 38 Rhineland or 39 1⁄4 English inches (997 mm) in length.[3] In the 18th century, there were two favoured approaches to the definition of the standard unit of length. One approach followed Wilkins in defining the metre as the length of a pendulum with a half-period of one second, a 'seconds pendulum'.
Originally posted by Bedlam
reply to post by yampa
A 1/2 second pendulum doesn't give you a meter. It's close, but it's not one. And it'll give you a different number.
Originally posted by CosmicCitizen
Read The Great Pyramid Decoded, by Peter Lemesurier.....I read it many years ago and found it quite fascinating.
www.amazon.com...
Originally posted by Bedlam
edit to add: Seriously? You're trying to argue that the Egyptians found some location where a 1/2 second pendulum gives you the modern value? Why? Why would they do that? Oh, look, on this mountain we found a number for the speed of light that'll be right in about 4000 years! Joy! Come on.edit on 3-1-2013 by Bedlam because: (no reason given)
Originally posted by yampa
Originally posted by Harte
If you see no reason, then let me tell you one.
The Ancient Egyptians did divide the day into 24 hours, as did the other cultures you mention.
This is not speculation by the way. It is a fact that every day, an hour was a slightly different amount of time in Ancient Egypt.
Only much MUCH later did the Greeks establish a standard hour length for telling time.
Harte
You didn't actually read what I said, did you? I do see a reason and I can think of several reasons to use base 60 to represent time. But your response is historically inaccurate, as I have just shown via posting links showing that the Sumerians had a base 60 system for representing time, and they also had a 86400 second day. That is part of the archaeological record, so I think you need to update your facts.
The Egyptians are the first group of people that we can reasonably prove took timekeeping seriously as a culture. Many believe that the Sumerians were thousands of years ahead of the game, but proof of this is only speculative.
Around 3500 B.C., the Egyptians built obelisks—tall four-sided tapered monuments—and placed them in strategic locations to cast shadows from the sun. Their moving shadows formed a kind of sundial, enabling citizens to partition the day into two parts by indicating noon. They also showed the year's longest and shortest days when the shadow at noon was the shortest or longest of the year. Later, markers added around the base of the monument would indicate further time subdivisions.
Save for one glaring exception, days have been divided into twelve hours since Babylonian and Egyptian times. In Babylon, this was due to the Sumerian practice of counting by 5's and 12's, which was carried over. In Egypt, the days were divided into ten hours, but two hours of twilight (at dawn and dusk) made the total twelve, as well.
Nights were also divided into twelve hours, in most cases, making the 24 hours we are familiar with. But until the development of accurate timepieces in the 1600's, the hours of the day and night were not usually the more or less uniform hours we are used to. In the summer, the daylight hours were lengthened, and the nighttime hours shortened, and in the winter, the process was reversed, so that whether the Sun was up for a long time, or a short time, there were always twelve hours of day, and twelve hours of night. So if a farmer rose at dawn, it was always at the same time of day, regardless of the time of year.
Originally posted by Harte
Now, you made a claim. Can you back it up like I have?
What have you got that can show that your statement that I'm "historically innacurate" is true?
In Sumer, everything, including time, was counted using base 6 (actually base 12, IIRC) including time. There's no evidence that they divided the day into equal portions though. Just hours, minutes and seconds.
As you can see from the Ancient Egyptian practice I stated earlier and posted again in the above quote, division of days into seconds doesn't mean each second was the same length.
I believe you would profit from reading up on the methods they used to tell time. You'd see that neither culture was capable of measuring a (modern) second, or even a minute.
Sexagesimal (base 60) is a numeral system with sixty as its base. It originated with the ancient Sumerians in the 3rd millennium BC, it was passed down to the ancient Babylonians, and it is still used — in a modified form — for measuring time, angles, and geographic coordinates.
One legacy of Sumer we all carry in our pockets in the shape of a watch, whose face is a direct reproduction of the twelve double hours of the Sumerians, with its further divisions of sixty minutes and sixty seconds
Nevertheless, counting by dozens was very popular in sumeria: there were 12 double hours in a day and 12 months in a year
Originally posted by yampa
Originally posted by Harte
Now, you made a claim. Can you back it up like I have?
What have you got that can show that your statement that I'm "historically innacurate" is true?
In Sumer, everything, including time, was counted using base 6 (actually base 12, IIRC) including time. There's no evidence that they divided the day into equal portions though. Just hours, minutes and seconds.
As you can see from the Ancient Egyptian practice I stated earlier and posted again in the above quote, division of days into seconds doesn't mean each second was the same length.
I believe you would profit from reading up on the methods they used to tell time. You'd see that neither culture was capable of measuring a (modern) second, or even a minute.
What makes you think everything in Sumer was counted only in base 6 or 12? I can produce dozens of references which show the Sumerians frequently used sexagesimal (base 60). I think there is evidence of usage of many bases by the Sumerians.
Originally posted by yampa
Also, you keep mentioning the variable length of the solar day, but there are ways for smart people to get around that. I personally assume that some people at some time in all these ancient cultures knew about Solar, Lunar or Lunisolar and Sidereal measurements. There are many ways to average and balance ratios of these measurements to produce stable measurements of time (and indeed, uniform length).
Originally posted by Harte
There are many ways today. Are you aware of any mathematical method the Ancient Egyptians may have used to accomplish this?
Also, note that what you are assuming here is not evidenced in the archaeological record, as I pointed out.
Lastly, still no evidence of my "historical inaccuracy?" Not surprising to me, since my statements involving Egyptian timekeeping were perfectly accurate.
Harte
Originally posted by yampa
Ok, since I don't have evidence of the Sumerians keeping an exact timed hour, I will correct my accusation to 'you are likely historically inaccurate in saying Greeks were the first to mechanically measure a periodic hour'. I'm basing this on the fact sidereal time was apparently known throughout Mesopotamia (as evidenced by the sidereal zodiac). Sidereal time does not change its period like solar time. A pendulum counted using against the movements of the stars and the rotation of the earth could provide constant seconds and hours. As long as you don't patronise the ancients, there is nothing too controversial about that possibility.
Originally posted by yampa
There is no archaeological record for the Great Pyramid, obviously, this is why we have to speculate. As I already said, the general trends of a multi-millennial culture are not relevant here, nor is it important whether the Sumerians widely used and recorded accurate hours. The question is - is it possible for a group of people to derive the speed of light using only the natural structure of numbers, astronomical measurements and basic tools like pendulums. Personally, I'm open minded to the possibility.