Homeless posted the following regarding an article that talked about the concept of the earth rotation, and threw in some stuff about leap seconds and atomic clocks too. created quite a thread.

maybe I am a sucker for the underdog, but I do want him to find a home for his intellect, or even a tent if we can. so I will reply below.

>>>>>
>>>>>
Thank you for the courteous reply.

Now, I think visually. So I see a straight line for the atomic clock that does not vary in seconds for each year. The time is constant year after year.

Lets say, for theory sake, 1000 seconds per year.

Seconds Atomic Clock:

year 1 1000
year 2 1000
year 3 1000

etc.

But the time of the earth to revolve varies, because its slowing down, so it's not constant like the atomic clock.

Seconds for Earth Rotation:

year 1 1000
Year 2 1001
Year 3 1002

Thus, the slowing down of the earth needs to be adjusted into the atomic clock, which omits it.

From what the article posted said, this is how I understand it. There has to be an adjustment to the atomic clock to account for the variable rate of the earth's spin.

Correct my visual picture, if you can.

Thank you
>>>>
>>>>



Hard to be visual in text, but I will give it a shot. First there are three concepts mentioned in the article. They are lumped together and a little misleading, they talk about the earth slowing down, and indicate in that paragraph the rates that are legit for it (probably because they quoted the scientist that told them about it.) Let's call that the earth slowing fact.

now there is also the mention of leap seconds that are added to the atomic clock, lets call that leap seconds.

third there is the concept of a definition of seconds. redefined in 1967 using atomic principles. Let's call that atomic time.

The only real thing these all share in common is they have something to do with time.

So what is time? Lets stay with classical definitions for now (to not wind you up in the theory of relativity and all that)

Time is a measurement we make to differentiate between now and a moment ago or now and a moment from now. Human kind has found this a useful concept, especially because we see cyclic things around us all the time (lol you see it is in our very vernacular) the sun rises and sets, the moon orbits, we breath in and out.

I bring up breath because like most measurements things originated with our experience. An ounce of water is about what you can swallow, a foot was a foot, an inch was a thumb, and a second, that was a about the time of a heartbeat. Of course the cycle rate of a heart beat can vary, men realized this and used pendulums on clocks to tick out seconds. but the definition of a 'second' itself is totally arbitrarily and they said we ought to link this to something else that repeats, how about a day, or a revolution of the earth (we were getting pretty good at astronomy then so we could measure that pretty well.) so already in our history the definition of a second has changed. by 1967, we are getting pretty good at figuring out atomic stuff and we realize the tick tock of these atomic particles is super repetitive and consistent. this is checked by lots and lots and lots of people to prove it is true (there goes that science thing again) you might ask why we care about time so much at this point. but if you think about it it doesn't take much in terms of percent error in a clock to bug us. (a clock that is off by 10 minutes in a year is an error of only 0.0019% us humans don't like errors in clocks, if a clock is of 10 minutes in a month we call it a piece of crap, and that is an error of only 0.023%, we are far more accepting of errors elsewhere in our lives, 90% is usually an A on most tests. But not time, an A in time is 99.999%) We humans like accurate clocks.

So in 1967 we figured we got a better way to tell time, so lets use it. And we redefined the length of a second for a third time. Hopefully by now you can see that the actual length of a second is nothing more than an agreed upon definition. If you don't please go back and read the previous again, it is important to grasp this before understanding the next point.

So we have a grasp of atomic time, why and how it came to be a measurement we use.

Next lets talk about leap seconds and what they are and why. In the article they are brought up as a correction to the clock, that is a bit wrong, and there are a couple of reasons. 1 is the earth orbits the sun, once a year. and 2 the earth spins creating what we call days. Both of these things are pretty cyclic, but they do wobble even on a good day and are not as precise in keeping time as those atomic clocks. With the year most people get it pretty readily because we created leap days to deal with it. Our planet doesn't orbit the sun in an exact number of days (if I remember you are a computer programmer and understand the concept of an integer) well the number of days it takes to orbit the planet doesn't = 365, it is 365 plus a little bit. We let those little bits add up and stick them back into the calendar as leap days and leap seconds, Thus making it so that it always snows in December.

The same thing happens with days, the time it takes for the earth to complete a rotation of its axis doesn't divide equally into the atomic seconds we use now. so ever so often we slip in a leap second, (note this is a different leap second that above, but I use the terminology because the article you read did it too.) This keeps our clock in sync with the days, and keeps 12AM the middle of the night and noon the middle of the day. This is an area that you are having difficulty grasping. that is because the definition of a second changed. Pre 1976 we divided up the day into seconds and post 1967 we redefined it as a function of atomic processes. in that redefinition the second got just a little bit shorter. thus creating this need for adjustment every 18 months that you are talking about. It has nothing to do with the earth slowing at all we haven't even gotten to that point yet. The article that you read (as often happens when popularizing scientific or technical topics, lumped together this issue in with the previous one incorrectly. I am sure you have read articles in trade journals that make similar mistakes about programming, but are able to see past that to the original intent simply because of your knowledge in that area)

Now to the third topic, the earth slowing. yep, it is, and in the middle of the article, that amount is stated correctly. The error it makes is in tying that by inference to the 'leap seconds' mentioned later in the piece. It is slowing and over 650 million years the math works out to a couple hours in a day. Not so much to worry about compared keeping noon in the middle of the day and winter in december though!

Quick summary:
- A second is an arbitrary definition of time.

- Days and years don't divide equally into seconds, there is a little bit left over.

- People like integers in our clocks and on our calendars, that's why there isn't 365 1/4 days on the calendar. and 24.001 hours on a clock.

- Because of all this we invented leap days and leap seconds so that over time noon doesn't drift into midnight and december doesn't become the time I go water skiing at the lake.

- Yep, the earth is slowing down, but it is pretty insignificant compared to the other things involving time that we care about.


Homeless I invite you into my 'tent of understanding' have a bowl of soup before you go on your way looking for a home. If you grasp what I have listed above we can proceed to much funner topics such as the theory of relativity and how it affects time! Without this foundation though none of that will make any sense at all.



Edited 1 time(s). Last edit at 01/24/2013 05:01PM by sparkyguru.

bump so homeless gets a chance to read it

one more bump for our beloved wandering intellect.

I wouldn't encourage him - this is the 4th thread on the topic and if he hasn't figured it out by now he never will.

I realize its a long shot, but somewhere inside of me is this eternally optimistic teacher that believes anyone can understand with the right explanation.

also think of it this way, it is good practice for explaining things to those TBMs that just have a hard time grasping things that seem so obvious to us.



Edited 1 time(s). Last edit at 01/24/2013 07:51PM by sparkyguru.

Thank you for the thorough response. I do very much appreciate your civil approach and your time to explain your point of view and to try and "help" save me from my delusions, as they are called in here.

Bottom line answer is you don't agree with the author's paragraph in which he clearly writes that the leap second is due to the earth slowing down, that he has mixed things up, implying he is misquoting someone else, and that he is wrong and misleading. (He misled me.)

This reminds me of the theological debates in which the two scholars start debating facts in history and those at the bottom who are debating don't have access to the source documents or historical perspectives to resolve the debate, and each operate on different assumptions, and as such, can never close in agreement. They have a limited view of Greek and Hebrew--but they study Strong's enough to think the do know Greek and Hebrew, but in reality, it's not their profession and they take the best shot at explaining the data. Both are biased, and therefore, both debate from those biases. The idea of the earth slowing is not the debate, but by how much.

Bottom line, I believe I was a bit closer to the paragraph that was written in the article, but there is disagreement on the data, with a difference of interpretation.

Anyone can Google and find scientists who write different things about the subject, and one would think that in science everyone would be in agreement. Unfortunately, that just is not the case.

You are treating this as a debate scripture and basically quoting the article as if it were scripture.

You asked if the article was in error, and due to the inference of the leap seconds to correction for the slowing of the earth I proved it was in error.

actually it is quite easy to see that drawing this conslusion based in only the material in the article is also in error. early on in the article it states the rate of slowing couple hours over 650 million years, then at the end it talks about leap seconds at a much much higher rate. If you take take it as fact that the leap seconds are used to compensate for the slowing, then the data at the beginning of the article is in error likewise if the data at the beginning is correct, then the statement at the end is wrong.

When you read something like this that is internally inconsistent it should set off alarm bells that something is wrong, either facts are stated wrong or misconstrued simply because it is internally illogical.

Now I don't know if it was intentional or if the writer simply mussed up the two ideas. But either way it mislead you to the wrong conclusion. My guess based on reading typical science pieces that the writer mistakenly inferred the two ideas were the same.

All it takes to understand is a bit of knowledge of what 'time' is. I provided you that. I can only show your intellect the bridge to understanding, it is up to you to walk across it.

your last statement that everyone in science is in total agreement is an incorrect idea. The entire basis of the scientific process is that it is always open to challenge. There are typically two types of challenges, true scentific challanges that involve predictions and repeatable tests, and pseudoscientific ones that are dogma and opinion driven. It is a beautiful thing that google lets us see others opinions. But that also means anyone can post any theory they have and claim scientific basis.

hundreds of thousands of tests have been ran on the movements of the planets and the measurement of time. trust me or not its your choice.

Sparkyguru

Although your article was a nice summary of principles, it did not really address the visual picture I have in my mind and the assumptions I am making, so it doesn't close it for me in terms of the leap year second. To me, a better explanation to close the argument is that perhaps the year is not a perfect 365.250000000000000 days. If there is some fraction of a discrepancy in that number, then the leap year every four years will not close the equation, and it may be the cause of the leap second. That would make much better sense to me than what either biased sides of science argue about the slowing earth. When we begin to micro analyze data down to a second, the room for margin of error increases, and thus, a wrong assumption "somewhere" would drive all the calculations off. Now of course, I do *presume* that science has the exact numbers, which I am not privy to. But in my analysis to make a proper examination of the data, surely they are not stupid enough to uses 365.25 days rounded to two decimal points. I'd need to see ALL of the data, to confirm assumptions and close off other areas of possible error or presumption.

Since I'm not privy to all the needed data, I cannot confirm the calculation and follow through with the comfort level I would need to close the issue on the 1 second "leap". This is an example I'm trying to give you that in the end, a certain degree of "trust" is required for someone who is not a scientist. And from that perspective, I view it similar to believers depending on theologians to interpret the data to form conclusions about the Bible. And thus, you ended with "trust me or not, the choice is yours". I see reading the Ensign no different than reading scientific journals. The trust issue is at the center of science. Unless I'm a scientist and actually can look at all the data and confirm the assumptions are reasonable, then I must lean on trust instead.

The argument that hundreds of thousands of experiments have been done and I should trust in them is again moving my brain and choice into someone else's lap. Now, you claim the scientist I quoted is wrong. Others will argue that some other scientist is wrong. Christian scientist make the claim they have evidence, but it is rejected (such as trees found vertical in strata that is supposed to be hundreds of millions of years of "vertical time", or human foot prints found inside dinosaur footprints, that contradict the current theories, which then is refuted by other scientists) Bla Bla Bla It's the same chatter I found in religions that I finally left.

To me, I care not to trust another man's opinion. I can formulate my own. In the end, I have to make my own choice, and that is molded by my personal experience and what I actually see and reason out.

I *refuse* to ever say again, "I know this is true," when it comes to something I cannot see. Thus, I choose to believe what I do based on what I can see for myself, and unless it's clear and visible, I hold it as opinion, either my opinion, or someone else's. To me, that is the safest course to take. I can certainly choose to believe whatever I want to, as long as I identify the assumption behind it and are comfortable with them. I'm not comfortable with the assumptions made in science regarding macro evolution.

The leap second has nothing to do with the leap year. I'll try to use the way you visually laid it out and hopefully this will help clarify it for you homeless.

Here is what you had.

Seconds Atomic Clock:

year 1 1000
year 2 1000
year 3 1000

etc.

But the time of the earth to revolve varies, because its slowing down, so it's not constant like the atomic clock.

Seconds for Earth Rotation:

year 1 1000
Year 2 1001
Year 3 1002


First let's look at each day before we lay out each year. Divide the day into 24 hours. Each hour is 60 minutes, each minute is 60 seconds. There are 86,400 seconds in a day.

Now before we get to how much the earth is slowing, let's say for theory's sake that because it has slowed, there are now 86,400.002 seconds in a day.

Seconds Atomic Clock:

day 1 86,400
day 2 86,400
day 3 86,400

etc.

Seconds for Earth Rotation:

day 1 86,400.002
day 2 86,400.002
day 3 86,400.002

etc.

So far we still haven't included how much the earth is slowing down by. All we are looking at is that there is slightly more seconds in a day for the earth's rotation than for an atomic clock. Now add up those .002 sec every day for 365 days to lay out the years. (365 x .002 = 0.73)

Atomic clock:

year 1 .000
year 2 .000
year 3 .000

Earth's rotation:

year 1 .730
year 2 1.46 (.730 + .730 = 1.46)
year 3 2.19 (.730 + .730 + .730 = 2.19)

etc.

You can see that a "leap second" is needed just to keep the atomic clock in time with the earth and so far we haven't even included for slow down. The extra second shows up between year 1 and year 2 because .730 (that came from adding each day of the year) gets added to every year.

For this example, that 1 second every eighteen months is only the difference between two clocks and has nothing to do with the earth slowing down further. If the earth never slowed down again, leap seconds would still be needed. This is where people make the mistake when they say that the earth slows down by one second every eighteen months. It is not true.



The earth slows down by .005 sec per year per year

It takes 200 years for the earth to be 1 second slower.

1 sec/.005 sec/yr = 200 years

Here is an example with the math for 370 million years ago:

.005 sec/yr/yr x 370 million yr = 1,850,000 sec/yr

1,850,000 sec/yr/86,400 sec/day = 21.4 days/yr.

370 million years ago a year was 21.4 days longer.

365.25 + 21.4 = 386.65 days in the year.

24 hrs x 365.25 days = 8766 hrs per year.

8766 hrs/386.65 days = 22.7 hrs/day

370 million yrs ago the day was 22.7 hrs long.

Doing the same math for 4.6 billion years gives a 14 hr day.

Thank you for the information.

First, my numbers assume in the initial year1 that the rotation of the earth is syncronize at 1000 seconds with the atomic clock--they are identical. Year 2 and 3 are different based on the earth slowing down only, and the atomic clock being a constant rate for 1000. This is based on the reasoning of the article I posted, which article is being challenged.

Secondly, where does the calculation of the earth slowing down at .005 seconds originate? How is it determined?

Third, I do not believe the leap second comes from the leap year, for I presume the scientists don't round the 365.25 days/year number to 2 decimal places and that they use the exact number out to many decimal places. I was just pointing out that certain assumptions need to be confirmed before validating the conclusions. That's all. And I don't have all the data to confirm it.

Fourth, your math is find, and I understood it the first time you explained it, but it assumes the earth is not slowing down fast enought to make any difference in the numbers, and that is not what the article stated. Thus, the article is being challenged. Based on the article and what it says, I believe my numbers represent it.

Thank you for taking the time to explain it with numbers and showing what you meant, that the leap second is a change in clock methods. Unfortunately, that's not what the article said.

that was a nice layout of the calculation mike!

to homeless
you are right scientist do know the length of a year and a day, and the have extra parts of seconds in them. finding this out is really quite easy. I am not sure why you are saying you are not privy to that data. This is the reason scientists publish their data. it is published so it can be challenged. it only becomes accepted after going through lots of challenges, and if a better theory comes along later that fits the world better the previous theory is scrapped or modified. many here are willing to dig up links and post them for you, but your need to argue ever dot and tittle is frankly making people want to give up on it. I think even if I gave you a link to the data right now you would come back with some other exception or reason to not change your mind on this.

please note your assumption is that the person writing the article was a scientist. he was not, he is a journalist. it is easy to look up their credentials as well. I also noted that a scientist in the comment on the article pointed out that they had gotten it out of whack.

Sure at some point you have to trust someone, and that does kinda put it in the 'faith' realm. such is life. For me this is well established fact. and pretty easy to prove with a little thoughtful research. if you want to trust me fine, if you want to dig for the facts of how long a year and a day are to check me that is fine too. in fact I encourage it!! I am as sure of those facts as the sun coming up tomorrow. but don't take my word for it check them.

The article I based my facts on was written by a PhD:

http://www.pgccphy.net/rec/rec008-leapsec.pdf

Dr. D.G. Simpson
Department of Physical Sciences and Engineering
Prince George’s Community College
November 20, 2010

from the paper you just quoted

"Leap seconds are introduced partly because of
this gradual increase in the length of the day, and partly because 1 second defined by
atomic clocks is slightly shorter than 1 second would be if based on the Earth’s rotation:
our atomic clocks run slightly too fast, so we have to set them back occasionally."


this is exactly what I said, note the 'second of the atomic clock is a little shorter than would evenly divide up a day.

he goes on to describe the day being 23 hours long around the time of the dinosaurs. which is also consistent with the way I described it. it is a factor, just not near as big a factor as the slightly longer day.

if you look at the effect of the slowing of the earth and go through all the math that he lists out, you will get the really small number of leaps due to the earth slowing and the rest is do to the day being actually a little longer than the 86,400 seconds assigned to it.

Wikipedia has several sources you can check as well. it mentions the leap seconds there too
http://en.wikipedia.org/wiki/Second

The average length of a solar day on Earth is about 86,400 seconds (24 hours) and there are about 365.2422 solar days in one mean tropical year.

I also suggest you write the author of the paper and ask him what he meant. ask him how big a factor the length of the day vs the seconds is and how big a factor the slowing of the earth is when it comes to adding in leap seconds.

I do have to wonder though, if he confirms what I endeavored to teach you will you still reject it out of hand?

This argument became very simplified by the navy link that identifies the slowing of the earth to 1 millisecond *per day* or .356 seconds per year. This takes us right to the day itself, which cuts through all the mumbo jumbo calculations and puts the turd on the table to look at, from your perspective, that is. See post about the two clocks article that was linked by Michaelm. Thanks for your reply.

PS. Where is the .005 seconds per year slowing of the earth orginating from? How is it calculated? Do you know? That seems to be used in many calculations, but it needs to be verified, in my mind. It doesn't fit into 1 millisecond per day.

Edited to delete brain fart.



Edited 1 time(s). Last edit at 01/25/2013 10:41AM by Richard the Bad.

Homeless,
Please cut and paste from the navy article where this rate of slowing is claimed.

I posted two long posts to Michaelm that goes into more detail below. Thank you for keeping the discussion civil:

"Measurements show that the Earth currently runs slow, compared to atomic time, at about one millisecond per day. These data are generated by the USNO using the technique of Very Long Baseline Interferometry (VLBI). VLBI measures the rotation of the Earth by observing the apparent positions of distant objects near the edge of the observable universe. These observations show that after roughly 1000 days, the difference between Earth rotation time and atomic time would be about **one second**. Instead of allowing this to happen a leap second is inserted to bring the two times closer together. We can easily change the time of an atomic clock, but it is not possible to alter the ***Earth's rotational speed*** to match the atomic clocks."

Homeless said "This argument became very simplified by the navy link that identifies the slowing of the earth to 1 millisecond *per day* or .356 seconds per year."

You are reading it wrong. It says "Measurements show that the Earth currently runs slow, compared to atomic time, at about one millisecond per day." That does not mean that it is slowing down at that rate. It means this:

Seconds Atomic Clock:

day 1 86,400
day 2 86,400
day 3 86,400

etc.

Seconds for Earth Rotation:

day 1 86,400.001
day 2 86,400.001
day 3 86,400.001

Homeless asked "Where is the .005 seconds per year slowing of the earth orginating from? How is it calculated?"

The slowing down is increasing the length of the day "by about 0.0014 second each century."
http://highered.mcgraw-hill.com/sites/dl/free/0073512133/906990/Unit_07.pdf

Here is how the .005 is calculated:

0.0014/100 years = 0.000014 per year

0.000014 x 365.25 = .005

It is not uncommon for articles dealing with science in news media to have problems. The writers do their best but things can be quite confusing. It can be very frustrating to read contradictory things in newspapers and magazines. When that happens to me I try to get to the scientist's published work when I can.

Homeless said "where does the calculation of the earth slowing down at .005 seconds originate? How is it determined?"

For the example I gave, I used it from this source.
http://ncse.com/cej/3/3/as-world-turns

This link explains that the United States Naval Observatory measures the rotation of the earth.
http://www.usno.navy.mil/USNO/tours-events/2012_Leap_Second%20Press%20Release%20-%20120120.pdf

Homeless said "Fourth, your math is find, and I understood it the first time you explained it, but it assumes the earth is not slowing down fast enought to make any difference in the numbers, and that is not what the article stated. Thus, the article is being challenged. Based on the article and what it says, I believe my numbers represent it."

The examples I used in the math are not exact at all but it is important to realize that even if the earth stopped slowing down tomorrow and became as regular in it's current rotation as an atomic clock's accuracy, there would still be a need for leap seconds because it has already slowed down, making the day little longer than the atomic clock's. That is what I wanted you to see. I'm not sure if you got that yet because of your comment "it assumes the earth is not slowing down fast enought to make any difference in the numbers".

You might still have the misconception that the leap seconds are a measurement of the rate that the earth is slowing down. They are not. See: http://www.usno.navy.mil/USNO/tours-events/2012_Leap_Second%20Press%20Release%20-%20120120.pdf

"Confusion sometimes arises over the misconception that the occasional insertion of leap seconds every few years indicates that the Earth should stop rotating within a few millennia. This is because some mistake leap seconds to be a measure of the rate at which the Earth is slowing. The one-second increments are, however, indications of the accumulated difference in time between the two systems."

This link explains the subject too.
http://blogs.discovermagazine.com/badastronomy/2012/06/30/wait-just-a-second-no-really-wait-just-a-second/

The article you based your numbers can be very confusing.

Here's an example of what I'm taking about. Here is a quote from the second link listed from the US navy:

"Measurements show that the Earth currently runs slow, compared to atomic time, at about one millisecond per day. These data are generated by the USNO using the technique of Very Long Baseline Interferometry (VLBI). VLBI measures the rotation of the Earth by observing the apparent positions of distant objects near the edge of the observable universe. These observations show that after roughly 1000 days, the difference between Earth rotation time and atomic time would be about **one second**. Instead of allowing this to happen a leap second is inserted to bring the two times closer together. We can easily change the time of an atomic clock, but it is not possible to alter the ***Earth's rotational speed*** to match the atomic clocks."

1 second every 1000 days calculates to .365 seconds per year. It's about half of the .67 seconds per year referenced in the article I posted, which is the assumption I was using. If uses that rate times 4.5 billion years, it is about 47 days of time.

Assuming the .365 difference quoted above is because the atomic clock is constant and the rotating earth is slowing down, then again, the logic does not get me to .005 seconds per year.

I looked at the first link, and although it references this .005 number, it gives no indication of how it is derived or its real source. It says its an "accepted rate". What does that mean? Where's the source calculation? I don't trust it just because it is "accepted". But I can calculate the .365 seconds per year from the navy measurements.

I have not read the third or fourth link. Is the calculation for the .005 rate in there?

Michaelm,

I read the other two links. Now I see where those on the board are getting these ideas. You are regurgitating the literature like a "science Ensign" on the living room table. For example, the link has a cute writing here:

"Imagine you have two clocks. One thinks there are 86,400 seconds in a day, the other thinks that there are 86,401, so the second clock runs a tad bit slower than the first [ie but at constant rate]. Every day, it’s one second behind, clicking over to midnight one second after the first clock does [at a constant rate]. Mind you, it keeps accurate time according to its own gears: every day has 86,401 seconds, so it’s not slowing down [constant rate].

"However, to keep it synchronized with the other clock, we’d either have to subtract a second from the second clock (yikes, terminology is a bit confusing there!) or add one to the first clock every day. So we’d need a leap second every day, but not because the clock is slowing. It’s only because it runs at a different [but constant] rate."

My comments: The logic in this explanation breaks down when applied to the "real world" because we have two clocks, yes, but the definition of a "second" is the same for the two clocks. It is the "second" defined by the atomic clock. Thus both clocks use the same definition of a second, which was decided in 1967. As such, the logic in the article shatters like glass. The reason the seconds need to be added is because the earth rotation is *NOT* constant. It slows down by 1 millisecond EACH MONTH, according to the US navy. Thus, the definition of a "second" as the earth rotates is different each month because the rate of spin is not constant.

The quote above, however, assumes that each clock has a different "CONSTANT RATE" to define a second, with separate rates, and as such, it confuses the readers, like everyone here that believes the logic, that it's simply two clocks out of sync. The fact is, however, that there is only ONE definition of a second, which is the atomic second.

Look at it this way. I will make it dramatic. Imagine having a clock on the wall that did not keep a consistent time. Each day the hands went slower and slower and slower, until they stopped. That's the earth's rotation. If the earth stopped spinning, that's the end of time because the earth would no longer be earth as we know it. No one would be on earth to change the atomic clocks. Everyone would be dead, let's presume.

However, before the clock stopped, you need to keep adding seconds to the good clock, the atomic clock, that didn't keep slowing down. You need to measure in "atomic seconds" how long that the "slowing" clock takes to have its hands go around the clock twice for one day. Eventually, the time to measure the slowing clock would not be possible, since the hands would stop and the atomic clock would have to add infinity seconds to the numbers, making it meaningless.

Why is that? Because the definition of "second" is defined by the atomic clock, *not* the rotation of the hands of the clock that is slowing down.

And therefore, it is not because you are getting two "clocks" in sync with two constant rates, as the article implies, but the "atomic second" is used for *both* clocks, and one is a constant rate and one is not.

Now back to reality. The earth has not stopped spinning, of course, but the dramatic illustration makes the point clearer. It's too hard to see talking about a few seconds of time. Therefore, the reason atomic clock needs to be adjusted for a "leap second" is that the earth is not spinning at a constant rate, but it is always going slower and slower. The atomic clock, which defines the second, is not slowing down, and therefore, it needs to be adjusted for the earth slowing down.

My question is what is the amount of "time" that is added each year because the earth is slowing down. Until I see the calculation of the .005 seconds per year, the "accepted rate" by scientists, whatever that means, it sounds like to me the navy calculated rate of .365 seconds per year is more credible. However, that means that if we take the .365 rate back 4.5 billions years, it adds 47 years of time, which is unreasonable. The 6000 year assumption only adds 35 minutes.

I appreciate these four links, after reading them, I can see where the proliferation of logic that the "leap second" is just a recalibration of two different clocks that has been created, by using a **bad assumption** of two clocks with constant rates, leading to the wrong conclusion.

Now that I've identified that bad assumption, that should clear up the misunderstanding for you. It also gives a great example of why I look for the core "hidden" assumptions, so I can make sure I'm choosing the right ones.

TYPO ERROR on Month: "It slows down by 1 millisecond EACH **MONTH**, according to the US navy."

Correction: It slows down by 1 millisecond EACH **DAY**, according to the US navy.

Sorry about that!

Homeless,
I don't know if we are reading the same navy article, as the one I am reading, the leap second press release, in no way claims what you are saying it does.

So when you say you are not comfortable about the science regarding macro evolution does that mean that you are predisposed to reject any concept that supports it and also support and concept that rejects it?

if so that is the true root of your willingness to remain deluded on this topic. It doesn't get anymore basic than the approach I layed out to understand the topic at hand. only a directed willingness to not understand will make it not clear.

good luck and I hope you find a home for your intellect somewhere. you should try some of the ID boards or creationist places I bet they would welcome your comments.

cya

You've posted enough about the Pentateuch amd your thoghts on your god that you clearly don't believe your own statement.

And this debate on the atomic clock furthers that notion.

Raptor Jesus,

I beg to differ.

That said, thank you for knocking the s**t out of that Roman/Greek god "Jesus" that Paul and the Catholic Church created. Keep up the good work. The true God certainly must be pleased.

:-)

But the evidence in your writing about your beliefs says otherwise.

That is where you go off the rails. While the author mentions the leap second as being used to account for the slowing he does not state that it is the rate at which the slowing is occurring.

The leap second is used to account for variation in both the actual length of a day and for the actual length of a year. Go research leap years and leap seconds. They are derived from the de acceleration but are not the rate of de acceleration. You are confusing cause and effect.

So, according to the link from michaelm, the navy calculates the slowing of the earth to be .365 seconds per year. (1 millisecond per day) That is no where near the .005 "accepted" rate. See? Which one do I believe? Where does this .005 rate orginate from? Do you know? See my posts to michaelm above.

If we assume a "constant rate" back in time like we assume for radioactive dating, the .365 seconds per day slowing of the earth will not stuff into 4.5 billion years. Please explain. Thank you.

You do understand, that at least for C-14 dating, that fluctuations (very small, but fluctuations just the same) are recognized? At least in this case, your "constant rate" argument is a straw man.

http://c14.arch.ox.ac.uk/embed.php?File=calibration.html

Quote from the linK, "firstly the proportion of radiocarbon in the atmosphere has varied by a few percent over time".

As has been pointed out repeatedly, the leap second is added every 18 months not because the earth's rotation is slowing down (it is slowing down, but that adds an extra second about once every 600 years, not 18 months, iirc).

The leap second is there because the atomic second is a smidgen (I think that is the technical term :) too small. Every 18 months or so, we have to kick in an extra second to make of for those 800 million missing smidgens that occurred in the previous 18 months.

If the atomic second were a smidgen too big, we would have to drop a second every so many months. Frankly, I wish they had made it a smidgen too big. Then we wouldn't be having this ridiculous discussion.

Here's what would happen if the length of a day were in fact increasing by a second every 18 months:
The first leap second would be added in 9 months, from a half second because the atomic second being too short and a half second from the earth rotation slowing at the rate of 1 second every 18 months.

Here's where the important change comes in. The second leap second would not be added at 9 months. It would be a little bit sooner, because the atomic second, which was a bit too small to start with, is now a bit smaller still, because the earth slowed down. The second leap second would be at 8 months, 29 days, 23 hours, 59 minutes, and 59 seconds. And the third leap second would move up an additional second, and so on.

In the real world, the addition of leap seconds is not that precisely determined, because the other random changes to the length of a day make it so it is impossible to precalculate to the precise second when a leap second should be added. However, the theoretical result still holds in the sense that as the day gets longer, we have to add leap seconds more frequently - the 18 month update time would get shorter over the years.

The catch is that since days are getting longer, the leap second update interval is getting shorter, but at an excruciatingly slow rate. We're talking geologic time frames. I haven't bothered to sit down with some reference books and do the actual math, but I'm guestimating that it would take over a million years to shave a single day off the leap second update interval.

Damn, now I'm curious. I will sit down and do the math. I will return and report. But not today.



Edited 1 time(s). Last edit at 01/24/2013 09:35PM by Brother Of Jerry.

are you an engineer? your last comment about curiosity getting the better of you to do the math is something that would happen in my engineering team. Often someone throughs out a brain teaser or writes an odd problem on the white board and all us engineering types just have to solve it for ourselves lol.

we are the odd kids that liked story problems in school ;)

As for louis, he has shown considerable patience and an effort to help out wandering intellect look for a place to kick up his feet and take a load off. Kudos to him from me as well

I have a BS in math, though I hate abstract algebra and it hated me. I got an ABD (all but dissertation) in CS, and taught for half my adult life, and did "engineering" type math applications the other half.

My first assignment at my first job was determining if a proprietary floating point format was accurate enough to fly a plane in a 15 km circle, with a maximum error of 2 meters. That led to 7 or 8 years worth of experience right down in the blood and the guts and the beer of floating point arithmetic. I was a non-voting member of the IEEE 1394 floating point standard group.

Besides navigation software, I did low level graphics at WordPerfect, and did digital signal process for 3 years. I never fully understood the math, so I took a EE "Signals and Systems" course, where I finally figured out what a complex exponential is, and why an FFT works. That was pretty amazing. I was 60 when I took the course, and beat out all those smart ass 20 year old EE majors. Made my day. :)

I read Paul Nahin (An Imaginary Take, Dr Euler's Fabulous Formula) and Knuth's Concrete Mathematics for fun. So technically not an engineer, but I do have the soul of one, assuming engineers have souls!

Just an FYI, Homeless has been on this board for about a month now. He has posted 419 times, with a rough guess that 95% of those posts have been irrational arguments, expounding on his home grown religion, or simply being obstinate. These same arguments have been spun around and around several times (I think this is the third major debate on "time" that the board has had with him) and he has shown no sign of listening to rational arguments.

BC pointed out a few days ago that he follows the apologist pattern perfectly. He is an apologist for his religion.

He has built a cult of one for himself. The cognitive dissonance that he has is at an amazing level. Combine that with his arrogance and he's far from "Homeless", he is "Bunker" because the walls he built to protect his irrational world view is strong and immovable.

It is my opinion that he has an agenda for being here. Quite often he slips into the language of a "teacher", he thinks he's teaching this board about how evolution is flawed and how his world view is superior.

After a month of countless threads, and a large number of members of this board trying to get him to see reason, I just don't think it's going to happen any time soon. At best, he's a distraction, at worst, he's looking for converts.

But I can't really say, "don't try to help him", heaven knows I tried for some time. I guess I'm just trying to say, be aware of who he is. There's something about him that makes you think that if you can only get him to see things rationally, you can break into the bunker and everything will fall into place. But, I just don't think it's going to happen until he's willing to see it and that's not going to happen for a long time.