| 24-10-2017 18:19 |
Wake★★★★★
(4034) |
Surface Detail wrote:
Into the Night wrote:
Surface Detail wrote:
For example, the Earth is currently rotating faster than it was in 1970, so that a modern day is roughly 1ms shorter than it was then.
No, it is not. National time coordinate stations disagree with you.
Yes, it is. And no, they don't.
The simple fact that leap seconds have been added less frequently over the past decade than in the 1970s tells you that the Earth must be spinning faster now than it was then.
This is, of course, just a temporary aberration due to changes in the Earth's moment of inertia. In the long term, the Earth will continue its gradual slowing trend as angular momentum is transferred to the moon through tidal effects. In the future, ever-increasing numbers of leap seconds will be needed, assuming we continue using the same time system.
The day most assuredly is growing longer. But hardly enough to mention since the actual variations in the length of a day due to the orbit of the Earth are around 8 seconds per day shortest to longest.
Should it have anything more than a passing interest that the length of a average day changes on the order of parts per 10,000 per century
from the normal orbital variations?
Talking about that with you-know-who is like discussing relativity with Mr. Ed. |
| 24-10-2017 19:00 |
Surface Detail★★★★☆
(1673) |
Wake wrote:
Surface Detail wrote:
Into the Night wrote:
Surface Detail wrote:
For example, the Earth is currently rotating faster than it was in 1970, so that a modern day is roughly 1ms shorter than it was then.
No, it is not. National time coordinate stations disagree with you.
Yes, it is. And no, they don't.
The simple fact that leap seconds have been added less frequently over the past decade than in the 1970s tells you that the Earth must be spinning faster now than it was then.
This is, of course, just a temporary aberration due to changes in the Earth's moment of inertia. In the long term, the Earth will continue its gradual slowing trend as angular momentum is transferred to the moon through tidal effects. In the future, ever-increasing numbers of leap seconds will be needed, assuming we continue using the same time system.
The day most assuredly is growing longer. But hardly enough to mention since the actual variations in the length of a day due to the orbit of the Earth are around 8 seconds per day shortest to longest.
Should it have anything more than a passing interest that the length of a average day changes on the order of parts per 10,000 per century
from the normal orbital variations?
Talking about that with you-know-who is like discussing relativity with Mr. Ed.
According to measurements made by the International Earth Rotation and Reference Systems Service, used for the graph I posted earlier, the length of a (sidereal) day reached a maximum in 1972, was about 2ms shorter by 1988, increased by about 1ms by 1993, then dropped by about 2ms to reach a minimum in 2003. Since then it has increased by about 1ms.
As I already stated, the rotation of the Earth is indeed gradually slowing as a result of tidal forces, but superimposed on this are fluctuations due to changes in the Earth's moment of inertia. These can be great enough to more than cancel out the tidal slowing over a timescale of decades so that, for a while, the Earth's rotation speed actually increases a little (as it did between, say, 1972 and 1988). |
| 24-10-2017 19:28 |
Wake★★★★★
(4034) |
Surface Detail wrote:
Wake wrote:
Surface Detail wrote:
Into the Night wrote:
Surface Detail wrote:
For example, the Earth is currently rotating faster than it was in 1970, so that a modern day is roughly 1ms shorter than it was then.
No, it is not. National time coordinate stations disagree with you.
Yes, it is. And no, they don't.
The simple fact that leap seconds have been added less frequently over the past decade than in the 1970s tells you that the Earth must be spinning faster now than it was then.
This is, of course, just a temporary aberration due to changes in the Earth's moment of inertia. In the long term, the Earth will continue its gradual slowing trend as angular momentum is transferred to the moon through tidal effects. In the future, ever-increasing numbers of leap seconds will be needed, assuming we continue using the same time system.
The day most assuredly is growing longer. But hardly enough to mention since the actual variations in the length of a day due to the orbit of the Earth are around 8 seconds per day shortest to longest.
Should it have anything more than a passing interest that the length of a average day changes on the order of parts per 10,000 per century
from the normal orbital variations?
Talking about that with you-know-who is like discussing relativity with Mr. Ed.
According to measurements made by the International Earth Rotation and Reference Systems Service, used for the graph I posted earlier, the length of a (sidereal) day reached a maximum in 1972, was about 2ms shorter by 1988, increased by about 1ms by 1993, then dropped by about 2ms to reach a minimum in 2003. Since then it has increased by about 1ms.
As I already stated, the rotation of the Earth is indeed gradually slowing as a result of tidal forces, but superimposed on this are fluctuations due to changes in the Earth's moment of inertia. These can be great enough to more than cancel out the tidal slowing over a timescale of decades so that, for a while, the Earth's rotation speed actually increases a little (as it did between, say, 1972 and 1988).
Since you have absolutely no idea what caused this study and how these time changes were measured you should not speak authoritatively about them. As I've said many times - most studies are not peer reviewed even when the claim is that they were. And most studies are eventually proven to be incorrect.
We cannot that accurately judge the length of a day because the variations caused both by the orbital variations of the Earth and the fact that the Earth is not perfectly round and does not have it's mass in a perfectly central location are not known. The core rotates at a different speed than the mantle so this changes the center of mass of the Earth.
We CAN judge the tidal slowing through calculation of the retreat of the moon and that can be accurately judged by laser radar measurement.
Do not give a lot of credence to studies that make silly claims about time periods of rotation of planets. |
| 24-10-2017 19:42 |
Surface Detail★★★★☆
(1673) |
Wake wrote:
Surface Detail wrote:
Wake wrote:
Surface Detail wrote:
Into the Night wrote:
Surface Detail wrote:
For example, the Earth is currently rotating faster than it was in 1970, so that a modern day is roughly 1ms shorter than it was then.
No, it is not. National time coordinate stations disagree with you.
Yes, it is. And no, they don't.
The simple fact that leap seconds have been added less frequently over the past decade than in the 1970s tells you that the Earth must be spinning faster now than it was then.
This is, of course, just a temporary aberration due to changes in the Earth's moment of inertia. In the long term, the Earth will continue its gradual slowing trend as angular momentum is transferred to the moon through tidal effects. In the future, ever-increasing numbers of leap seconds will be needed, assuming we continue using the same time system.
The day most assuredly is growing longer. But hardly enough to mention since the actual variations in the length of a day due to the orbit of the Earth are around 8 seconds per day shortest to longest.
Should it have anything more than a passing interest that the length of a average day changes on the order of parts per 10,000 per century
from the normal orbital variations?
Talking about that with you-know-who is like discussing relativity with Mr. Ed.
According to measurements made by the International Earth Rotation and Reference Systems Service, used for the graph I posted earlier, the length of a (sidereal) day reached a maximum in 1972, was about 2ms shorter by 1988, increased by about 1ms by 1993, then dropped by about 2ms to reach a minimum in 2003. Since then it has increased by about 1ms.
As I already stated, the rotation of the Earth is indeed gradually slowing as a result of tidal forces, but superimposed on this are fluctuations due to changes in the Earth's moment of inertia. These can be great enough to more than cancel out the tidal slowing over a timescale of decades so that, for a while, the Earth's rotation speed actually increases a little (as it did between, say, 1972 and 1988).
Since you have absolutely no idea what caused this study and how these time changes were measured you should not speak authoritatively about them. As I've said many times - most studies are not peer reviewed even when the claim is that they were. And most studies are eventually proven to be incorrect.
We cannot that accurately judge the length of a day because the variations caused both by the orbital variations of the Earth and the fact that the Earth is not perfectly round and does not have it's mass in a perfectly central location are not known. The core rotates at a different speed than the mantle so this changes the center of mass of the Earth.
We CAN judge the tidal slowing through calculation of the retreat of the moon and that can be accurately judged by laser radar measurement.
Do not give a lot of credence to studies that make silly claims about time periods of rotation of planets.
Seriously? You think the International Earth Rotation and Reference Systems Service is fabricating its measurements of the Earth's rotation? Why would they do such a thing? Is this another Marxist plot? |
| 24-10-2017 20:16 |
Wake★★★★★
(4034) |
Surface Detail wrote:
Wake wrote:
Surface Detail wrote:
Wake wrote:
Surface Detail wrote:
Into the Night wrote:
Surface Detail wrote:
For example, the Earth is currently rotating faster than it was in 1970, so that a modern day is roughly 1ms shorter than it was then.
No, it is not. National time coordinate stations disagree with you.
Yes, it is. And no, they don't.
The simple fact that leap seconds have been added less frequently over the past decade than in the 1970s tells you that the Earth must be spinning faster now than it was then.
This is, of course, just a temporary aberration due to changes in the Earth's moment of inertia. In the long term, the Earth will continue its gradual slowing trend as angular momentum is transferred to the moon through tidal effects. In the future, ever-increasing numbers of leap seconds will be needed, assuming we continue using the same time system.
The day most assuredly is growing longer. But hardly enough to mention since the actual variations in the length of a day due to the orbit of the Earth are around 8 seconds per day shortest to longest.
Should it have anything more than a passing interest that the length of a average day changes on the order of parts per 10,000 per century
from the normal orbital variations?
Talking about that with you-know-who is like discussing relativity with Mr. Ed.
According to measurements made by the International Earth Rotation and Reference Systems Service, used for the graph I posted earlier, the length of a (sidereal) day reached a maximum in 1972, was about 2ms shorter by 1988, increased by about 1ms by 1993, then dropped by about 2ms to reach a minimum in 2003. Since then it has increased by about 1ms.
As I already stated, the rotation of the Earth is indeed gradually slowing as a result of tidal forces, but superimposed on this are fluctuations due to changes in the Earth's moment of inertia. These can be great enough to more than cancel out the tidal slowing over a timescale of decades so that, for a while, the Earth's rotation speed actually increases a little (as it did between, say, 1972 and 1988).
Since you have absolutely no idea what caused this study and how these time changes were measured you should not speak authoritatively about them. As I've said many times - most studies are not peer reviewed even when the claim is that they were. And most studies are eventually proven to be incorrect.
We cannot that accurately judge the length of a day because the variations caused both by the orbital variations of the Earth and the fact that the Earth is not perfectly round and does not have it's mass in a perfectly central location are not known. The core rotates at a different speed than the mantle so this changes the center of mass of the Earth.
We CAN judge the tidal slowing through calculation of the retreat of the moon and that can be accurately judged by laser radar measurement.
Do not give a lot of credence to studies that make silly claims about time periods of rotation of planets.
Seriously? You think the International Earth Rotation and Reference Systems Service is fabricating its measurements of the Earth's rotation? Why would they do such a thing? Is this another Marxist plot?
No, But I think that their numbers don't mean very much. Tell me - why did coffee become poisonous, then healthy, then poisonous and now healthy again?
Do you think that was a plot or only science learning from it's mistakes? How long do you suppose it will be before coffee is dangerous again?
The lawsuits against Johnson and Johnson for marketing talcum powder have been thrown out. One study says that it causes cancer. Well talc is used to prevent one type of cancer caused by the lungs sticking to the inside of their sack. They open you up and lubricate the lungs and sack with talc.
Will that treatment be found to cause cancer by some stupid study in the future causing law suits that could stop this treatment and cause the deaths from cancer in these sorts of cases?
If you worship science you are looking upon a false God. At least be aware that 2 milliseconds is about 2 x 10-^8. These are numbers that have extremely questionable meanings in the real world.
Edited on 24-10-2017 20:17 |
|
| 24-10-2017 20:28 |
Surface Detail★★★★☆
(1673) |
Wake wrote:
Surface Detail wrote:
Wake wrote:
Surface Detail wrote:
Wake wrote:
Surface Detail wrote:
Into the Night wrote:
Surface Detail wrote:
For example, the Earth is currently rotating faster than it was in 1970, so that a modern day is roughly 1ms shorter than it was then.
No, it is not. National time coordinate stations disagree with you.
Yes, it is. And no, they don't.
The simple fact that leap seconds have been added less frequently over the past decade than in the 1970s tells you that the Earth must be spinning faster now than it was then.
This is, of course, just a temporary aberration due to changes in the Earth's moment of inertia. In the long term, the Earth will continue its gradual slowing trend as angular momentum is transferred to the moon through tidal effects. In the future, ever-increasing numbers of leap seconds will be needed, assuming we continue using the same time system.
The day most assuredly is growing longer. But hardly enough to mention since the actual variations in the length of a day due to the orbit of the Earth are around 8 seconds per day shortest to longest.
Should it have anything more than a passing interest that the length of a average day changes on the order of parts per 10,000 per century
from the normal orbital variations?
Talking about that with you-know-who is like discussing relativity with Mr. Ed.
According to measurements made by the International Earth Rotation and Reference Systems Service, used for the graph I posted earlier, the length of a (sidereal) day reached a maximum in 1972, was about 2ms shorter by 1988, increased by about 1ms by 1993, then dropped by about 2ms to reach a minimum in 2003. Since then it has increased by about 1ms.
As I already stated, the rotation of the Earth is indeed gradually slowing as a result of tidal forces, but superimposed on this are fluctuations due to changes in the Earth's moment of inertia. These can be great enough to more than cancel out the tidal slowing over a timescale of decades so that, for a while, the Earth's rotation speed actually increases a little (as it did between, say, 1972 and 1988).
Since you have absolutely no idea what caused this study and how these time changes were measured you should not speak authoritatively about them. As I've said many times - most studies are not peer reviewed even when the claim is that they were. And most studies are eventually proven to be incorrect.
We cannot that accurately judge the length of a day because the variations caused both by the orbital variations of the Earth and the fact that the Earth is not perfectly round and does not have it's mass in a perfectly central location are not known. The core rotates at a different speed than the mantle so this changes the center of mass of the Earth.
We CAN judge the tidal slowing through calculation of the retreat of the moon and that can be accurately judged by laser radar measurement.
Do not give a lot of credence to studies that make silly claims about time periods of rotation of planets.
Seriously? You think the International Earth Rotation and Reference Systems Service is fabricating its measurements of the Earth's rotation? Why would they do such a thing? Is this another Marxist plot?
No, But I think that their numbers don't mean very much. Tell me - why did coffee become poisonous, then healthy, then poisonous and now healthy again?
Do you think that was a plot or only science learning from it's mistakes? How long do you suppose it will be before coffee is dangerous again?
The lawsuits against Johnson and Johnson for marketing talcum powder have been thrown out. One study says that it causes cancer. Well talc is used to prevent one type of cancer caused by the lungs sticking to the inside of their sack. They open you up and lubricate the lungs and sack with talc.
Will that treatment be found to cause cancer by some stupid study in the future causing law suits that could stop this treatment and cause the deaths from cancer in these sorts of cases?
If you worship science you are looking upon a false God. At least be aware that 2 milliseconds is about 2 x 10-^8. These are numbers that have extremely questionable meanings in the real world.
Given that you don't appear to understand how they measure the speed of rotation of the Earth, I hardly think you're in a position to dispute their figures. The fact that these figures are used to determine when to add leap seconds tends to indicate that they know what they're doing. Or do you think that's all some sort of con too? |
| 24-10-2017 20:37 |
James_★★★★★
(2225) |
Surface Detail wrote:
Given that you don't appear to understand how they measure the speed of rotation of the Earth,
sidereal ?
https://www.merriam-webster.com/dictionary/sidereal |
| 24-10-2017 23:27 |
Into the Night ★★★★★
(21588) |
Surface Detail wrote:
Into the Night wrote:
Surface Detail wrote:
For example, the Earth is currently rotating faster than it was in 1970, so that a modern day is roughly 1ms shorter than it was then.
No, it is not. National time coordinate stations disagree with you.
Yes, it is. And no, they don't.
The simple fact that leap seconds have been added less frequently over the past decade than in the 1970s tells you that the Earth must be spinning faster now than it was then.
The Earth is slowing, and the national time coordinate stations DO disagree with you.
Leap seconds were introduced to timekeeping in 1972. We've been adding one every year until we caught up. Now we add them at the slower rate. We're caught up. They are typically added only every two to three years or so now (the act of adding a complete second sometimes puts us slightly ahead for a year, so we skip a year. Our daylength doesn't come out to a multiple of years.)
Surface Detail wrote:
This is, of course, just a temporary aberration due to changes in the Earth's moment of inertia.
Nope.
Surface Detail wrote:
In the long term, the Earth will continue its gradual slowing trend as angular momentum is transferred to the moon through tidal effects. In the future, ever-increasing numbers of leap seconds will be needed, assuming we continue using the same time system.
Not any need. The change in the orbit of the Moon is not significant enough. The Earth will be consumed by the Sun before we need to change our timekeeping. After that, who cares?
The Parrot Killer
Debunked in my sig. - tmiddles
Google keeps track of paranoid talk and i'm not on their list. I've been evaluated and certified. - keepit
nuclear powered ships do not require nuclear fuel. - Swan
While it is true that fossils do not burn it is also true that fossil fuels burn very well - Swan |
| 24-10-2017 23:50 |
Into the Night★★★★★
(21588) |
Wake wrote:
Surface Detail wrote:
Wake wrote:
Surface Detail wrote:
Into the Night wrote:
Surface Detail wrote:
For example, the Earth is currently rotating faster than it was in 1970, so that a modern day is roughly 1ms shorter than it was then.
No, it is not. National time coordinate stations disagree with you.
Yes, it is. And no, they don't.
The simple fact that leap seconds have been added less frequently over the past decade than in the 1970s tells you that the Earth must be spinning faster now than it was then.
This is, of course, just a temporary aberration due to changes in the Earth's moment of inertia. In the long term, the Earth will continue its gradual slowing trend as angular momentum is transferred to the moon through tidal effects. In the future, ever-increasing numbers of leap seconds will be needed, assuming we continue using the same time system.
The day most assuredly is growing longer. But hardly enough to mention since the actual variations in the length of a day due to the orbit of the Earth are around 8 seconds per day shortest to longest.
Should it have anything more than a passing interest that the length of a average day changes on the order of parts per 10,000 per century
from the normal orbital variations?
Talking about that with you-know-who is like discussing relativity with Mr. Ed.
According to measurements made by the International Earth Rotation and Reference Systems Service, used for the graph I posted earlier, the length of a (sidereal) day reached a maximum in 1972, was about 2ms shorter by 1988, increased by about 1ms by 1993, then dropped by about 2ms to reach a minimum in 2003. Since then it has increased by about 1ms.
As I already stated, the rotation of the Earth is indeed gradually slowing as a result of tidal forces, but superimposed on this are fluctuations due to changes in the Earth's moment of inertia. These can be great enough to more than cancel out the tidal slowing over a timescale of decades so that, for a while, the Earth's rotation speed actually increases a little (as it did between, say, 1972 and 1988).
Since you have absolutely no idea what caused this study and how these time changes were measured you should not speak authoritatively about them. As I've said many times - most studies are not peer reviewed even when the claim is that they were. And most studies are eventually proven to be incorrect.
We cannot that accurately judge the length of a day because the variations caused both by the orbital variations of the Earth
Earth's orbit does not affect the length of day in any significant way.
Wake wrote:
and the fact that the Earth is not perfectly round
Again, it doesn't matter. The Earth could be cube for all it matters.
Wake wrote:
and does not have it's mass in a perfectly central location are not known.
If the mass of Earth was NOT at the center, YOU would be having a bad day! So would everyone else!
Wake wrote:
The core rotates at a different speed than the mantle so this changes the center of mass of the Earth.
Apparently you are clueless about hydrodynamics.
Wake wrote:
We CAN judge the tidal slowing through calculation of the retreat of the moon and that can be accurately judged by laser radar measurement.
Problematic. Tides are masked by things like storm surges and even minor barometric changes. We just use direct laser ranging these days. That is usefully accurate. The tolerances introduced by elevation changes in the reference points is ignored, however. A more accurate method is simply to measure the period of the Moon's orbit.
Wake wrote:
Do not give a lot of credence to studies that make silly claims about time periods of rotation of planets.
You probably should. We use that data to predict all kinds of astronomical events and who will get a chance to see them.
Data isn't a 'study'.
To a degree, Surface Detail is correct. Earth DOES vary in daylength on a day to day basis. Average increases in daylength vary slightly from year to year also. Where he makes his mistake is in assuming the Earth is speeding up (it isn't). This makes me suspect his dataset is not from a reliable source, despite his claims of the source.
We are still adding leap seconds every 2-3 years, now that we're caught up. That means the Earth is still slowing.
If the Earth was spinning faster as Surface Detail claims, we would have to REMOVE seconds from the year. We have never done that, nor needed to.
We started adding leap seconds since 1972 in almost every year. Now that we're caught up, we found that adding seconds this often overcompensated. We reduced that to every two years. Still too much. We stopped adding them entirely to allow synchronization again and started adding them every 2-3 years since then beginning in 2006.
The correct rate seems to be 1 second in about 2.5 years. We will probably adjust it further as we gain more accuracy.
The Parrot Killer
Debunked in my sig. - tmiddles
Google keeps track of paranoid talk and i'm not on their list. I've been evaluated and certified. - keepit
nuclear powered ships do not require nuclear fuel. - Swan
While it is true that fossils do not burn it is also true that fossil fuels burn very well - Swan
Edited on 25-10-2017 00:27 |
| 24-10-2017 23:51 |
Into the Night★★★★★
(21588) |
Surface Detail wrote:
Wake wrote:
Surface Detail wrote:
Wake wrote:
Surface Detail wrote:
Into the Night wrote:
Surface Detail wrote:
For example, the Earth is currently rotating faster than it was in 1970, so that a modern day is roughly 1ms shorter than it was then.
No, it is not. National time coordinate stations disagree with you.
Yes, it is. And no, they don't.
The simple fact that leap seconds have been added less frequently over the past decade than in the 1970s tells you that the Earth must be spinning faster now than it was then.
This is, of course, just a temporary aberration due to changes in the Earth's moment of inertia. In the long term, the Earth will continue its gradual slowing trend as angular momentum is transferred to the moon through tidal effects. In the future, ever-increasing numbers of leap seconds will be needed, assuming we continue using the same time system.
The day most assuredly is growing longer. But hardly enough to mention since the actual variations in the length of a day due to the orbit of the Earth are around 8 seconds per day shortest to longest.
Should it have anything more than a passing interest that the length of a average day changes on the order of parts per 10,000 per century
from the normal orbital variations?
Talking about that with you-know-who is like discussing relativity with Mr. Ed.
According to measurements made by the International Earth Rotation and Reference Systems Service, used for the graph I posted earlier, the length of a (sidereal) day reached a maximum in 1972, was about 2ms shorter by 1988, increased by about 1ms by 1993, then dropped by about 2ms to reach a minimum in 2003. Since then it has increased by about 1ms.
As I already stated, the rotation of the Earth is indeed gradually slowing as a result of tidal forces, but superimposed on this are fluctuations due to changes in the Earth's moment of inertia. These can be great enough to more than cancel out the tidal slowing over a timescale of decades so that, for a while, the Earth's rotation speed actually increases a little (as it did between, say, 1972 and 1988).
Since you have absolutely no idea what caused this study and how these time changes were measured you should not speak authoritatively about them. As I've said many times - most studies are not peer reviewed even when the claim is that they were. And most studies are eventually proven to be incorrect.
We cannot that accurately judge the length of a day because the variations caused both by the orbital variations of the Earth and the fact that the Earth is not perfectly round and does not have it's mass in a perfectly central location are not known. The core rotates at a different speed than the mantle so this changes the center of mass of the Earth.
We CAN judge the tidal slowing through calculation of the retreat of the moon and that can be accurately judged by laser radar measurement.
Do not give a lot of credence to studies that make silly claims about time periods of rotation of planets.
Seriously? You think the International Earth Rotation and Reference Systems Service is fabricating its measurements of the Earth's rotation? Why would they do such a thing? Is this another Marxist plot?
I don't think your numbers come from there. The national time coordinate stations disagree with it.
The Parrot Killer
Debunked in my sig. - tmiddles
Google keeps track of paranoid talk and i'm not on their list. I've been evaluated and certified. - keepit
nuclear powered ships do not require nuclear fuel. - Swan
While it is true that fossils do not burn it is also true that fossil fuels burn very well - Swan |
| 25-10-2017 00:05 |
Into the Night★★★★★
(21588) |
Wake wrote:
Surface Detail wrote:
Wake wrote:
Surface Detail wrote:
Wake wrote:
Surface Detail wrote:
Into the Night wrote:
Surface Detail wrote:
For example, the Earth is currently rotating faster than it was in 1970, so that a modern day is roughly 1ms shorter than it was then.
No, it is not. National time coordinate stations disagree with you.
Yes, it is. And no, they don't.
The simple fact that leap seconds have been added less frequently over the past decade than in the 1970s tells you that the Earth must be spinning faster now than it was then.
This is, of course, just a temporary aberration due to changes in the Earth's moment of inertia. In the long term, the Earth will continue its gradual slowing trend as angular momentum is transferred to the moon through tidal effects. In the future, ever-increasing numbers of leap seconds will be needed, assuming we continue using the same time system.
The day most assuredly is growing longer. But hardly enough to mention since the actual variations in the length of a day due to the orbit of the Earth are around 8 seconds per day shortest to longest.
Should it have anything more than a passing interest that the length of a average day changes on the order of parts per 10,000 per century
from the normal orbital variations?
Talking about that with you-know-who is like discussing relativity with Mr. Ed.
According to measurements made by the International Earth Rotation and Reference Systems Service, used for the graph I posted earlier, the length of a (sidereal) day reached a maximum in 1972, was about 2ms shorter by 1988, increased by about 1ms by 1993, then dropped by about 2ms to reach a minimum in 2003. Since then it has increased by about 1ms.
As I already stated, the rotation of the Earth is indeed gradually slowing as a result of tidal forces, but superimposed on this are fluctuations due to changes in the Earth's moment of inertia. These can be great enough to more than cancel out the tidal slowing over a timescale of decades so that, for a while, the Earth's rotation speed actually increases a little (as it did between, say, 1972 and 1988).
Since you have absolutely no idea what caused this study and how these time changes were measured you should not speak authoritatively about them. As I've said many times - most studies are not peer reviewed even when the claim is that they were. And most studies are eventually proven to be incorrect.
We cannot that accurately judge the length of a day because the variations caused both by the orbital variations of the Earth and the fact that the Earth is not perfectly round and does not have it's mass in a perfectly central location are not known. The core rotates at a different speed than the mantle so this changes the center of mass of the Earth.
We CAN judge the tidal slowing through calculation of the retreat of the moon and that can be accurately judged by laser radar measurement.
Do not give a lot of credence to studies that make silly claims about time periods of rotation of planets.
Seriously? You think the International Earth Rotation and Reference Systems Service is fabricating its measurements of the Earth's rotation? Why would they do such a thing? Is this another Marxist plot?
No, But I think that their numbers don't mean very much. Tell me - why did coffee become poisonous, then healthy, then poisonous and now healthy again?
Do you think that was a plot or only science learning from it's mistakes? How long do you suppose it will be before coffee is dangerous again?
Heh. ALL foods are both healthy for you AND poisonous. If you eat only one thing to excess, you will have problems.
Wake wrote:
The lawsuits against Johnson and Johnson for marketing talcum powder have been thrown out.
Good. I can't imagine a more benign powder.
Wake wrote:
One study says that it causes cancer.
Another great example of a theory introduced that was never tested for the null hypothesis. It was not a scientific theory.
Wake wrote:
Well talc is used to prevent one type of cancer caused by the lungs sticking to the inside of their sack. They open you up and lubricate the lungs and sack with talc.
True. I also use it for tires. Best stuff around to lubricate inner tubes. Makes 'em smell nice too!
Wake wrote:
Will that treatment be found to cause cancer by some stupid study in the future causing law suits that could stop this treatment and cause the deaths from cancer in these sorts of cases?
People sue because they don't like the wart on someone's nose. We're a sue happy nation.
Wake wrote:
If you worship science you are looking upon a false God.
Science is not a religion. It is a set of falsifiable theories that describe nature. Any one of those theories could be destroyed at any time.
Wake wrote:
At least be aware that 2 milliseconds is about 2 x 10-^8.
WRONG. That's 20 nanoseconds, not 2 milliseconds. Get yer prefixes right, dude.
Wake wrote:
These are numbers that have extremely questionable meanings in the real world.
We commonly measure to nanoseconds. 20nS easily seen by a 50Mhz scope. We design radios and computers with numbers like these. You don't think radios and computers are real objects?
The Parrot Killer
Debunked in my sig. - tmiddles
Google keeps track of paranoid talk and i'm not on their list. I've been evaluated and certified. - keepit
nuclear powered ships do not require nuclear fuel. - Swan
While it is true that fossils do not burn it is also true that fossil fuels burn very well - Swan |
| 25-10-2017 00:10 |
Into the Night★★★★★
(21588) |
Surface Detail wrote:
The fact that these figures are used to determine when to add leap seconds
Not a fact. An argument. Learn what a 'fact' is. These figures are NOT used to determine when to add leap seconds.
Surface Detail wrote:
tends to indicate that they know what they're doing.
I doubt the source of your numbers come from where you say they come from.
Surface Detail wrote:
Or do you think that's all some sort of con too?
I think your graph is a con.
The Parrot Killer
Debunked in my sig. - tmiddles
Google keeps track of paranoid talk and i'm not on their list. I've been evaluated and certified. - keepit
nuclear powered ships do not require nuclear fuel. - Swan
While it is true that fossils do not burn it is also true that fossil fuels burn very well - Swan |
| 25-10-2017 00:43 |
Wake★★★★★
(4034) |
Surface Detail wrote: Given that you don't appear to understand how they measure the speed of rotation of the Earth, I hardly think you're in a position to dispute their figures. The fact that these figures are used to determine when to add leap seconds tends to indicate that they know what they're doing. Or do you think that's all some sort of con too?
Given that I was a navigator I do know how rotation of the Earth is measured but by ALL means let's hear your version. You could be like nightmare and believe that the addition of a second to the time isn't to correct the time but because the earth is slowing.
Edited on 25-10-2017 00:58 |
| 25-10-2017 01:38 |
Into the Night★★★★★
(21588) |
Wake wrote:
Surface Detail wrote: Given that you don't appear to understand how they measure the speed of rotation of the Earth, I hardly think you're in a position to dispute their figures. The fact that these figures are used to determine when to add leap seconds tends to indicate that they know what they're doing. Or do you think that's all some sort of con too?
Given that I was a navigator I do know how rotation of the Earth is measured but by ALL means let's hear your version. You could be like nightmare and believe that the addition of a second to the time isn't to correct the time but because the earth is slowing.
The addition of a second to time is the result of the Earth rotating slower than our atomic clocks measure time as. The standard second is determined by an atomic clock, not the Earth's rotational speed, which does vary ever so slightly from day to day. Effectively then, it is because the Earth is slowing.
These variances are nothing like what Surface Detail is trying to claim, however.
The Parrot Killer
Debunked in my sig. - tmiddles
Google keeps track of paranoid talk and i'm not on their list. I've been evaluated and certified. - keepit
nuclear powered ships do not require nuclear fuel. - Swan
While it is true that fossils do not burn it is also true that fossil fuels burn very well - Swan |
| 25-10-2017 01:55 |
Surface Detail★★★★☆
(1673) |
Into the Night wrote:
Surface Detail wrote:
Wake wrote:
Surface Detail wrote:
Wake wrote:
Surface Detail wrote:
Into the Night wrote:
Surface Detail wrote:
For example, the Earth is currently rotating faster than it was in 1970, so that a modern day is roughly 1ms shorter than it was then.
No, it is not. National time coordinate stations disagree with you.
Yes, it is. And no, they don't.
The simple fact that leap seconds have been added less frequently over the past decade than in the 1970s tells you that the Earth must be spinning faster now than it was then.
This is, of course, just a temporary aberration due to changes in the Earth's moment of inertia. In the long term, the Earth will continue its gradual slowing trend as angular momentum is transferred to the moon through tidal effects. In the future, ever-increasing numbers of leap seconds will be needed, assuming we continue using the same time system.
The day most assuredly is growing longer. But hardly enough to mention since the actual variations in the length of a day due to the orbit of the Earth are around 8 seconds per day shortest to longest.
Should it have anything more than a passing interest that the length of a average day changes on the order of parts per 10,000 per century
from the normal orbital variations?
Talking about that with you-know-who is like discussing relativity with Mr. Ed.
According to measurements made by the International Earth Rotation and Reference Systems Service, used for the graph I posted earlier, the length of a (sidereal) day reached a maximum in 1972, was about 2ms shorter by 1988, increased by about 1ms by 1993, then dropped by about 2ms to reach a minimum in 2003. Since then it has increased by about 1ms.
As I already stated, the rotation of the Earth is indeed gradually slowing as a result of tidal forces, but superimposed on this are fluctuations due to changes in the Earth's moment of inertia. These can be great enough to more than cancel out the tidal slowing over a timescale of decades so that, for a while, the Earth's rotation speed actually increases a little (as it did between, say, 1972 and 1988).
Since you have absolutely no idea what caused this study and how these time changes were measured you should not speak authoritatively about them. As I've said many times - most studies are not peer reviewed even when the claim is that they were. And most studies are eventually proven to be incorrect.
We cannot that accurately judge the length of a day because the variations caused both by the orbital variations of the Earth and the fact that the Earth is not perfectly round and does not have it's mass in a perfectly central location are not known. The core rotates at a different speed than the mantle so this changes the center of mass of the Earth.
We CAN judge the tidal slowing through calculation of the retreat of the moon and that can be accurately judged by laser radar measurement.
Do not give a lot of credence to studies that make silly claims about time periods of rotation of planets.
Seriously? You think the International Earth Rotation and Reference Systems Service is fabricating its measurements of the Earth's rotation? Why would they do such a thing? Is this another Marxist plot?
I don't think your numbers come from there. The national time coordinate stations disagree with it.
Do they really? Well let's have a link to their data so we can check for ourselves.
Edited on 25-10-2017 01:56 |
|
| 25-10-2017 02:04 |
Wake★★★★★
(4034) |
Surface Detail wrote:
Into the Night wrote:
Surface Detail wrote:
Wake wrote:
Surface Detail wrote:
Wake wrote:
Surface Detail wrote:
Into the Night wrote:
Surface Detail wrote:
For example, the Earth is currently rotating faster than it was in 1970, so that a modern day is roughly 1ms shorter than it was then.
No, it is not. National time coordinate stations disagree with you.
Yes, it is. And no, they don't.
The simple fact that leap seconds have been added less frequently over the past decade than in the 1970s tells you that the Earth must be spinning faster now than it was then.
This is, of course, just a temporary aberration due to changes in the Earth's moment of inertia. In the long term, the Earth will continue its gradual slowing trend as angular momentum is transferred to the moon through tidal effects. In the future, ever-increasing numbers of leap seconds will be needed, assuming we continue using the same time system.
The day most assuredly is growing longer. But hardly enough to mention since the actual variations in the length of a day due to the orbit of the Earth are around 8 seconds per day shortest to longest.
Should it have anything more than a passing interest that the length of a average day changes on the order of parts per 10,000 per century
from the normal orbital variations?
Talking about that with you-know-who is like discussing relativity with Mr. Ed.
According to measurements made by the International Earth Rotation and Reference Systems Service, used for the graph I posted earlier, the length of a (sidereal) day reached a maximum in 1972, was about 2ms shorter by 1988, increased by about 1ms by 1993, then dropped by about 2ms to reach a minimum in 2003. Since then it has increased by about 1ms.
As I already stated, the rotation of the Earth is indeed gradually slowing as a result of tidal forces, but superimposed on this are fluctuations due to changes in the Earth's moment of inertia. These can be great enough to more than cancel out the tidal slowing over a timescale of decades so that, for a while, the Earth's rotation speed actually increases a little (as it did between, say, 1972 and 1988).
Since you have absolutely no idea what caused this study and how these time changes were measured you should not speak authoritatively about them. As I've said many times - most studies are not peer reviewed even when the claim is that they were. And most studies are eventually proven to be incorrect.
We cannot that accurately judge the length of a day because the variations caused both by the orbital variations of the Earth and the fact that the Earth is not perfectly round and does not have it's mass in a perfectly central location are not known. The core rotates at a different speed than the mantle so this changes the center of mass of the Earth.
We CAN judge the tidal slowing through calculation of the retreat of the moon and that can be accurately judged by laser radar measurement.
Do not give a lot of credence to studies that make silly claims about time periods of rotation of planets.
Seriously? You think the International Earth Rotation and Reference Systems Service is fabricating its measurements of the Earth's rotation? Why would they do such a thing? Is this another Marxist plot?
I don't think your numbers come from there. The national time coordinate stations disagree with it.
Do they really? Well let's have a link to their data so we can check for ourselves.
A link? Really? You can't look this stuff up yourself?
Look up "solar time" as opposed to "clock time". |
| 25-10-2017 02:18 |
Surface Detail★★★★☆
(1673) |
Wake wrote:
Surface Detail wrote:
Into the Night wrote:
Surface Detail wrote:
Seriously? You think the International Earth Rotation and Reference Systems Service is fabricating its measurements of the Earth's rotation? Why would they do such a thing? Is this another Marxist plot?
I don't think your numbers come from there. The national time coordinate stations disagree with it.
Do they really? Well let's have a link to their data so we can check for ourselves.
A link? Really? You can't look this stuff up yourself?
Look up "solar time" as opposed to "clock time".
Oh, don't be so stupid. Whoever makes a claim has to give evidence for it. ITN claims he knows of data that disagree with the sourced graphs that I have posted. Unless he can back up his claim, I have no reason to believe him. |
| 25-10-2017 02:43 |
Wake★★★★★
(4034) |
Surface Detail wrote:
Wake wrote:
Surface Detail wrote:
Into the Night wrote:
Surface Detail wrote:
Seriously? You think the International Earth Rotation and Reference Systems Service is fabricating its measurements of the Earth's rotation? Why would they do such a thing? Is this another Marxist plot?
I don't think your numbers come from there. The national time coordinate stations disagree with it.
Do they really? Well let's have a link to their data so we can check for ourselves.
A link? Really? You can't look this stuff up yourself?
Look up "solar time" as opposed to "clock time".
Oh, don't be so stupid. Whoever makes a claim has to give evidence for it. ITN claims he knows of data that disagree with the sourced graphs that I have posted. Unless he can back up his claim, I have no reason to believe him.
If you don't know what the hell he's talking about how are you going to refute him? Especially when you don't know what the hell you're talking about. Clock time is more or less meaningless and that's what he's talking about. |
| 25-10-2017 03:30 |
Surface Detail★★★★☆
(1673) |
Wake wrote:
Surface Detail wrote:
Wake wrote:
Surface Detail wrote:
Into the Night wrote:
Surface Detail wrote:
Seriously? You think the International Earth Rotation and Reference Systems Service is fabricating its measurements of the Earth's rotation? Why would they do such a thing? Is this another Marxist plot?
I don't think your numbers come from there. The national time coordinate stations disagree with it.
Do they really? Well let's have a link to their data so we can check for ourselves.
A link? Really? You can't look this stuff up yourself?
Look up "solar time" as opposed to "clock time".
Oh, don't be so stupid. Whoever makes a claim has to give evidence for it. ITN claims he knows of data that disagree with the sourced graphs that I have posted. Unless he can back up his claim, I have no reason to believe him.
If you don't know what the hell he's talking about how are you going to refute him? Especially when you don't know what the hell you're talking about. Clock time is more or less meaningless and that's what he's talking about.
So far there is nothing to refute. ITN claims that he knows of data that contradict the graph I have referenced, but he hasn't shown me those data. Without some sort of evidence, his claim is worth nothing. That is how rational argument works. |
| 25-10-2017 04:25 |
Into the Night★★★★★
(21588) |
Wake wrote:
Surface Detail wrote:
Into the Night wrote:
Surface Detail wrote:
Seriously? You think the International Earth Rotation and Reference Systems Service is fabricating its measurements of the Earth's rotation? Why would they do such a thing? Is this another Marxist plot?
I don't think your numbers come from there. The national time coordinate stations disagree with it.
Do they really? Well let's have a link to their data so we can check for ourselves.
A link? Really? You can't look this stuff up yourself?
Look up "solar time" as opposed to "clock time".
That's actually not the reason for the leap second. Solar day varies throughout the year as a function of our orbit. Sidereal day does not vary much if at all (we can't measure that accurately). It is currently established at 23 hours, 56 minutes, and 4.09 seconds. Solar day lasts different times due to the speed of the Earth's orbit relative to the Sun.
The reason for the leap second is because we define the second using a Cesium clock, which doesn't care about the position of the Sun in the sky at any particular hour.
The Parrot Killer
Debunked in my sig. - tmiddles
Google keeps track of paranoid talk and i'm not on their list. I've been evaluated and certified. - keepit
nuclear powered ships do not require nuclear fuel. - Swan
While it is true that fossils do not burn it is also true that fossil fuels burn very well - Swan |
| 25-10-2017 05:23 |
Into the Night★★★★★
(21588) |
Surface Detail wrote:
Wake wrote:
Surface Detail wrote:
Wake wrote:
Surface Detail wrote:
Into the Night wrote:
Surface Detail wrote:
Seriously? You think the International Earth Rotation and Reference Systems Service is fabricating its measurements of the Earth's rotation? Why would they do such a thing? Is this another Marxist plot?
I don't think your numbers come from there. The national time coordinate stations disagree with it.
Do they really? Well let's have a link to their data so we can check for ourselves.
A link? Really? You can't look this stuff up yourself?
Look up "solar time" as opposed to "clock time".
Oh, don't be so stupid. Whoever makes a claim has to give evidence for it. ITN claims he knows of data that disagree with the sourced graphs that I have posted. Unless he can back up his claim, I have no reason to believe him.
If you don't know what the hell he's talking about how are you going to refute him? Especially when you don't know what the hell you're talking about. Clock time is more or less meaningless and that's what he's talking about.
So far there is nothing to refute. ITN claims that he knows of data that contradict the graph I have referenced, but he hasn't shown me those data. Without some sort of evidence, his claim is worth nothing. That is how rational argument works.
There is data for solar day variations, which is kept throughout each year and throughout the years. There is a also a record of the years we added leapseconds since 1972, when we first started doing it to 'catch up' on the difference between our atomic clocks and the sidereal time of Earth.
The mistake you are making is that sidereal day on Earth can vary due to polar precession, mass distribution, the effects of other bodies in space (not just the Moon!), and other unknown factors. For you to consider that the entire variation is due to mass distribution is the mistake.
At this point I accept the graph itself and retract my earlier position on your data source, but I do not accept your interpretation of it. The reason the Wikipedia graph looks suspiciously similar is because is the same graph from the same source. Like usual, Wikipedia has completely misinterpreted the graph. The article is wrong. It's examples like this that I usually discard Wikipedia on sight when someone quotes them.
Earth is not speeding up and the sidereal day length has not decreased.
Our current sidereal day is 23 hours, 56 minutes, and 4.09 seconds, increasing in length by 1-3 ms each year.
Yesterday's solar day was 24 hours and 0.0009913 seconds. Today's is expected to be 24 hours and 0.0008627 seconds. Solar days tend to get shorter now that Earth is heading toward perihelion, which will be reached on January 4th, at 2:17pm UTC. Our shortest solar day tends to be in the near the spring equinox as the Earth begins to slow down in earnest in orbit, climbing to our aphelion in July. Our longest ones tend to be in early fall as the Earth begins falling toward perihelion in earnest.
The Moon itself is the cause of most of the variations in the sidereal day, since the Moon's orbit is also elliptical. The distance from the Moon the Earth changes constantly, and that varies against the Earth's constantly changing distance from the Sun. It all depends on where you 'sync up' the yank on Earth.
If you examine your graph again, you will a sinusoidal pattern in it. That's orbital stuff, not mass distribution (which would not have such a pattern).
The Parrot Killer
Debunked in my sig. - tmiddles
Google keeps track of paranoid talk and i'm not on their list. I've been evaluated and certified. - keepit
nuclear powered ships do not require nuclear fuel. - Swan
While it is true that fossils do not burn it is also true that fossil fuels burn very well - Swan
Edited on 25-10-2017 05:27 |
| 25-10-2017 20:37 |
Wake★★★★★
(4034) |
Surface Detail wrote: So far there is nothing to refute. ITN claims that he knows of data that contradict the graph I have referenced, but he hasn't shown me those data. Without some sort of evidence, his claim is worth nothing. That is how rational argument works.
Look, when the horse's ass doesn't even understand that leap seconds are generally meant to correct clock time to solar time what is there to discuss with him. As I said before, it's like talking to Mr. Ed. |
| 25-10-2017 21:45 |
Into the Night★★★★★
(21588) |
Wake wrote:
Surface Detail wrote: So far there is nothing to refute. ITN claims that he knows of data that contradict the graph I have referenced, but he hasn't shown me those data. Without some sort of evidence, his claim is worth nothing. That is how rational argument works.
Look, when the horse's ass doesn't even understand that leap seconds are generally meant to correct clock time to solar time what is there to discuss with him. As I said before, it's like talking to Mr. Ed.
You post this right after I SAID the leap second is to correct clock time???
Pay attention dumbass.
The Parrot Killer
Debunked in my sig. - tmiddles
Google keeps track of paranoid talk and i'm not on their list. I've been evaluated and certified. - keepit
nuclear powered ships do not require nuclear fuel. - Swan
While it is true that fossils do not burn it is also true that fossil fuels burn very well - Swan |