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oriel36
2003-Sep-25, 02:41 PM
As I am not against the mainstream but I am for our astronomical heritage this posting belongs in this forum.


Grey wrote;"You're mistaken. I've been familiar with the equation of time for years. I well understand it's importance for comparing time as measured by a clock and time as measured by the Sun."

Look,the nature of the EoT is not for children,its principles are based on planetary meridian alignments with the Sun and really clever men were able to take advantage of these alignments by removing the natural inequality of a day via the astronomical correction.Perhaps a few here have heard how clocks act as rulers for solving the longitude problem but are not exactly sure how it was done using the Equation of Time,well as absolute time is one half of the Equation and this refers to a 24 clock day,it is easy enough to determine that relative time refers to the natural unequal day.

You see Grey they were making clock comparisons for centuries and these so-called clock comparisons for relativistic effects are a product of wishful thinking and especially as Newton defines the difference between absolute time and relative time as the Equation of Time.I said that you did'nt know up until a few weeks ago that Newton was refering to the very practical EoT,poor Albert and Mach had'nt a clue what its absolute and relative components refer to so you compare what Newton said with what Mach said.


Newton

"Absolute time, in astronomy, is distinguished from relative, by the equation or correlation of the vulgar time. For the natural days are truly unequal, though they are commonly considered as equal and used for a measure of time; astronomers correct this inequality for their more accurate deducing of the celestial motions." Principia


Mach: on Newton’s Absolute Time

“This absolute time can be measured by comparison with no motion; it has therefore neither a practical nor a scientific value; and no one is justified in saying that he knows aught about it. It is an idle metaphysical conception.”
Mach, Analyse der Empfindungen, 6th ed.

Mach being an idiot did'nt realise that there is no equable observed motion of the Sun corresponding to a 24 hour clock day,that is why we have the Equation of Time in the first place ,Newton knew the natural days are unequal which is why he refers relative time to external motion.You can modify Newton's absolute time to take into account that Foucault's pendulum at the poles,free of gravitational effects,registers 24 hours for axial rotation but I suspect you would rather stick with Mach and subsequently Albert.

Anyone else who is interested can jettison the dummy 'time' dimension ,rediscover the heritage of accurate clocks that were developed as rulers and perhaps for the first time appreceate the true intents and purpose of Newton's astronomical definitions of time,space and motion.


http://scienceview.berkeley.edu/VI/worksheet_longtutorial.html








Grey wrote;"However, you seem unable to understand that it has no bearing on the validity of relativity, or the lack thereof. The fact that Newton wrote soemthing down in the Principia does not mean that it was correct, or that no further insight onthe issue could be gained in the time since then."

Newton as an advisor to the Royal Longitude Board only thought that it was mechanically impossible to develop an accurate clock even though the principle of clocks as physical rulers of distance was well understood,neither you nor the Bad Astronomer will ever mention that clocks measure distance,you need it for the relativistic trash of " clocks measure time" and will be well pleased that participants won't look into the matter for in a roundabout way it leads all the way back to Newton's definition of the EoT as the difference between absolute time and relative time.




Grey wrote;" The validity of relativity is determined by whether it's predictions match observations, which they have done in every case yet tested. Regardless of whether you think it's a "silly concept", that silly concept describes the way the world actually works. You've yet to address this issue, though several people have brought it up."

Participants always have the option of going outside tonight and doing what Albert requests by using the path of Mars,Newton did not predict elliptical orbits,Kepler did by sorting out true motions from apparent motions,Albert just dumps Newton laws directly on to observation and comes up with elliptical orbits but only fools imagine this is the way astronomy worked.

"We must draw attention here to one of these deviations. According to
Newton's theory, a planet moves round the sun in an ellipse, which
would permanently maintain its position with respect to the fixed
stars, if we could disregard the motion of the fixed stars, themselves
and the action of the other planets under consideration. Thus, if we
correct the observed motion of the planets for these two influences,
and if Newton's theory be strictly correct, we ought to obtain for the
orbit of the planet an ellipse, which is fixed with reference to the
fixed stars" Albert the teletuby astronomer

Maybe the participant will then come inside and make a roaring fire with his/her relativity books and take up stamp collecting ,gardening or something as I've seen happen in sci.physics.

Grey wrote;"Except of course that the calculations from Newtonian mechanics turn out to conflict with observation, while those of relativity agree. Though scientists were reluctant to accept relativity, they did so because of the evidence. Despite your accusations to the contrary, mainstream views in science are not determined by a popularity contest, won by those that are the most charismatic speakers. They're determined by comparing the predictions of theory with observational fact."

Well that relativistic mantra is for lightweights,even when Newton was writting the Principia,non local geometric solutions for celestial motion were well established through the insight of Roemer.I have to laugh at how light speed is used in relativity in contrast to the very real affects that real astronomers observed (as opposed to pseudoastronomy seen today) even with their limited equipment.

http://dibinst.mit.edu/BURNDY/OnlinePubs/Roemer/index.html

BTW ;Of course Roemer used the Equation of Time or as Newton phrased it the difference between absolute time and relative time.

http://dibinst.mit.edu/BURNDY/OnlinePubs/Roemer/chapter3(part2).html

Grey wrote;"I fear that I'm starting to sound as much like a broken record player as you, since you keep making the same points, without addressing objections raised to them, so my responses can't change much. The visualizations are just a tool to help people unfamiliar with the mathematics understand a complex theory. If you have a problem with general relativity, show me why the mathematics is in error, or find experiments that invalidate its conclusions. That's the only way you'll be able to demonstrate scientifically that it's invalid, and if you do that, I'll either be persuaded by your arguments or I'll be able to find a flaw in your reasoning or evidence. Just calling those who accept relativity an "undisciplined bunch" who are "astronomically incompetent" and whose heads are full of "exotic nonsense" does not constitute a valid argument. "

I can point out to you that 4 years before the pictures of the rings of SN1987A emerged,I had worked out the geometry of stellar collapse,in other words I know why those rings are there.It is the only copyright I possess,one graphic representation refers to geometric nonperiodicity I used and the other graphic representation is exactly as the the rings appear with a ring of intersection.Insofar as it also refers to the geometry of stellar collapse beyond the supernova stage I can and certainly would not expose it to creatures who try to describe logical limits in terms of event horizons,singularities foamy space and heaven knows what .

You don't know why the rings of Sn1987a are present and how they relate to the geometry of stellar collapse and I am happy enough that you don't inquire for it is a matter of making local geometric connections with celestial objects,in other words it does'nt predict anything and is not a theory.It is bad enough to see theorists dither around with galaxies to have to watch more of the same with that supernova.

http://www.pacificnet.net/~sonia/cosmic/sn1987a-rings.jpg

Grey wrote;"Again, these aren't the "rough and tumble" sci.forums. This a place for rational discussion of ideas. If you want us to take your views seriously, you'll need to provide support for them and answer objections that others raise, rather than just insulting anyone who thinks differently. If you don't want anyone here to take your ideas seriously, then why are you posting here?"

The unmoderated sci.forums have their good points in that you won't find much ivory tower physics there although there is so much woo-woo physics that only a few posts are worth considering.There has been a shift lately away from the aether theories for this is where all the trouble began over a century ago,a dilution of what absolute and relative constitute to such an extent that it was easy for relativity to come along and tamper with Newton's definitions.Now you have the broken record going on for a century where space,time and motion is not absolute when nobody has the foggiest notion what the original division between absolute and relative refers to,you have to be an astronomer to understand it and frankly there is none here.

kilopi
2003-Sep-25, 02:50 PM
Look,the nature of the EoT is not for children
Careful there, oriel36, or you'll be left with sci.astro only.


Mach being an idiot

And you still insist this is mainstream?


You can modify Newton's absolute time to take into account that Foucault's pendulum at the poles,free of gravitational effects,registers 24 hours for axial rotation
23h 56m 4.10s (http://www.badastronomy.com/phpBB/viewtopic.php?p=56095&highlight=dictionary#56095)

oriel36
2003-Sep-25, 04:07 PM
You can modify Newton's absolute time to take into account that Foucault's pendulum at the poles,free of gravitational effects,registers 24 hours for axial rotation

Kilopi wrote; "23h 56m 4.10s"

Hey,you are the guys who are always blabbering on about experiments and observations and Foucault's pendulum tells you the Earth rotates once on its axis in 24 hours with the pendulum as a means to modify Newton's absolute time,Newton only said there may be no external motion to gauge a 24 hour day/absolute time and it was about 150 years after the Principia was written that Foucault came up with his pendulum.

http://www.phys-astro.sonoma.edu/people/students/baker/SouthPoleFoucault.html

This is the good stuff kids should be getting into but what chance have they ?.

They can learn how nature is full of geometric clues,why the spiral galaxies appear like hurricanes,why there are rings around supernova and all the other good stuff but it takes responsible people first like this following website.

http://www.mcs.surrey.ac.uk/Personal/R.Knott/Fibonacci/fibnat2.html

Whether you feel remorse or not,you are wrong and those who remain silent are no better.

kilopi
2003-Sep-25, 07:46 PM
Hey,you are the guys
I'm just one guy. :)


Whether you feel remorse or not,you are wrong and those who remain silent are no better.
Are you saying I'm wrong, that it's not 23h 56m 4.10s? Or that the guys who say it is 24 hours exactly are wrong?

AstroRockHunter
2003-Sep-25, 08:17 PM
oriel36:

For your backward audience, could you please state the Equation of Time??? I'm not totally familiar with it.

Thanks.

Grey
2003-Sep-25, 09:31 PM
For your backward audience, could you please state the Equation of Time??? I'm not totally familiar with it.

Thanks.
I'm not oriel, of course, but here (http://www.sundials.co.uk/equation.htm)'s a pretty straightforward site that gives a description of the issues involved in relating the sidereal day to the solar day. This (http://www.analemma.com/) is also an excellent site devoted to the equation of time.

oriel36
2003-Sep-26, 11:24 AM
AstroRockHunter wrote;"could you please state the Equation of Time??? I'm not totally familiar with it"

The Equation of Time is a table of figures,actually a table of minutes and seconds that astronomers and navigators applied each day to remove the natural inequality of a day beginning at noon and ending at noon.It is fairly easy to see how the navigators used the EoT using the determination of the Sun at noon to act as one end of a ruler and a clock fixed to a homeport as the other end of the ruler.

http://www.pbs.org/wgbh/nova/teachers/ideas/sammons/packet.html

The Equation of Time is not a formula and astronomers in Newton's era and navigators after him would have known precisely what Newton meant when he presented the difference between absolute time and relative time as the EoT but this is a lost history until recently when people started to rediscover clocks and how navigators used them.

"Absolute time, in astronomy, is distinguished from relative, by the equation or correlation of the vulgar time. For the natural days are truly unequal, though they are commonly considered as equal and used for a measure of time; astronomers correct this inequality for their more accurate deducing of the celestial motions." Principia

http://members.tripod.com/~gravitee/definitions.htm

There is little need to make it more complicated than it is however as you see, clocks were developed on the basis of the rotation of the Earth on its axis once in 24 hours while the relativistic guys are hellbent on saying it is 23 hours 56 minutes such as Grey's dumb post that the EoT corrects the Earth's motion wrt the Sun with the Earth's motion wrt the stars.


The following website puts the EoT is more complicated astronomical terms but here is where all the contemporary errors get jettisoned if the arguments are followed to their conclusion but as the components are so nebulous it may be short of impossible to make the necessary corrections.In this respect,nobody is 'backward',they are just unfamiliar with the EoT and why Newton expressed it as the difference between absolute time and relative time.


"An 'equation' did not then signify a formula, but rather a quantity, measured in minutes or degrees, whereby a mean value was improved, to obtain something nearer to its actual value. "

http://www.ucl.ac.uk/sts/nk/ntn.htm

Can you imagine the consequences if the motion of the primary planets was calculated off the rotation of the Earth as 23 hours 56 minutes with a cumulative loss of roughly 4 minutes for each rotation instead of the equable 24 hours for rotation ?.

oriel36
2003-Sep-26, 11:25 AM
AstroRockHunter wrote;"could you please state the Equation of Time??? I'm not totally familiar with it"

The Equation of Time is a table of figures,actually a table of minutes and seconds that astronomers and navigators applied each day to remove the natural inequality of a day beginning at noon and ending at noon.It is fairly easy to see how the navigators used the EoT using the determination of the Sun at noon to act as one end of a ruler and a clock fixed to a homeport as the other end of the ruler.

http://www.pbs.org/wgbh/nova/teachers/ideas/sammons/packet.html

The Equation of Time is not a formula and astronomers in Newton's era and navigators after him would have known precisely what Newton meant when he presented the difference between absolute time and relative time as the EoT but this is a lost history until recently when people started to rediscover clocks and how navigators used them.

"Absolute time, in astronomy, is distinguished from relative, by the equation or correlation of the vulgar time. For the natural days are truly unequal, though they are commonly considered as equal and used for a measure of time; astronomers correct this inequality for their more accurate deducing of the celestial motions." Principia

http://members.tripod.com/~gravitee/definitions.htm

There is little need to make it more complicated than it is however as you see, clocks were developed on the basis of the rotation of the Earth on its axis once in 24 hours while the relativistic guys are hellbent on saying it is 23 hours 56 minutes such as Grey's dumb post that the EoT corrects the Earth's motion wrt the Sun with the Earth's motion wrt the stars.


The following website puts the EoT is more complicated astronomical terms but here is where all the contemporary errors get jettisoned if the arguments are followed to their conclusion but as the components are so nebulous it may be short of impossible to make the necessary corrections.In this respect,nobody is 'backward',they are just unfamiliar with the EoT and why Newton expressed it as the difference between absolute time and relative time.


"An 'equation' did not then signify a formula, but rather a quantity, measured in minutes or degrees, whereby a mean value was improved, to obtain something nearer to its actual value. "

http://www.ucl.ac.uk/sts/nk/ntn.htm

Can you imagine the consequences if the motion of the primary planets was calculated off the rotation of the Earth as 23 hours 56 minutes with a cumulative loss of roughly 4 minutes for each rotation instead of the equable 24 hours for rotation ?.

oriel36
2003-Sep-26, 11:28 AM
AstroRockHunter wrote;"could you please state the Equation of Time??? I'm not totally familiar with it"

The Equation of Time is a table of figures,actually a table of minutes and seconds that astronomers and navigators applied each day to remove the natural inequality of a day beginning at noon and ending at noon.It is fairly easy to see how the navigators used the EoT using the determination of the Sun at noon to act as one end of a ruler and a clock fixed to a homeport as the other end of the ruler.

http://www.pbs.org/wgbh/nova/teachers/ideas/sammons/packet.html

The Equation of Time is not a formula and astronomers in Newton's era and navigators after him would have known precisely what Newton meant when he presented the difference between absolute time and relative time as the EoT but this is a lost history until recently when people started to rediscover clocks and how navigators used them.

"Absolute time, in astronomy, is distinguished from relative, by the equation or correlation of the vulgar time. For the natural days are truly unequal, though they are commonly considered as equal and used for a measure of time; astronomers correct this inequality for their more accurate deducing of the celestial motions." Principia

http://members.tripod.com/~gravitee/definitions.htm

There is little need to make it more complicated than it is however as you see, clocks were developed on the basis of the rotation of the Earth on its axis once in 24 hours while the relativistic guys are hellbent on saying it is 23 hours 56 minutes such as Grey's dumb post that the EoT corrects the Earth's motion wrt the Sun with the Earth's motion wrt the stars.


The following website puts the EoT is more complicated astronomical terms but here is where all the contemporary errors get jettisoned if the arguments are followed to their conclusion but as the components are so nebulous it may be short of impossible to make the necessary corrections.In this respect,nobody is 'backward',they are just unfamiliar with the EoT and why Newton expressed it as the difference between absolute time and relative time.


"An 'equation' did not then signify a formula, but rather a quantity, measured in minutes or degrees, whereby a mean value was improved, to obtain something nearer to its actual value. "

http://www.ucl.ac.uk/sts/nk/ntn.htm

Can you imagine the consequences if the motion of the primary planets was calculated off the rotation of the Earth as 23 hours 56 minutes with a cumulative loss of roughly 4 minutes for each rotation instead of the equable 24 hours for rotation ?.

oriel36
2003-Sep-26, 11:30 AM
AstroRockHunter wrote;"could you please state the Equation of Time??? I'm not totally familiar with it"

The Equation of Time is a table of figures,actually a table of minutes and seconds that astronomers and navigators applied each day to remove the natural inequality of a day beginning at noon and ending at noon.It is fairly easy to see how the navigators used the EoT using the determination of the Sun at noon to act as one end of a ruler and a clock fixed to a homeport as the other end of the ruler.

http://www.pbs.org/wgbh/nova/teachers/ideas/sammons/packet.html

The Equation of Time is not a formula and astronomers in Newton's era and navigators after him would have known precisely what Newton meant when he presented the difference between absolute time and relative time as the EoT but this is a lost history until recently when people started to rediscover clocks and how navigators used them.

"Absolute time, in astronomy, is distinguished from relative, by the equation or correlation of the vulgar time. For the natural days are truly unequal, though they are commonly considered as equal and used for a measure of time; astronomers correct this inequality for their more accurate deducing of the celestial motions." Principia

http://members.tripod.com/~gravitee/definitions.htm

There is little need to make it more complicated than it is however as you see, clocks were developed on the basis of the rotation of the Earth on its axis once in 24 hours while the relativistic guys are hellbent on saying it is 23 hours 56 minutes such as Grey's dumb post that the EoT corrects the Earth's motion wrt the Sun with the Earth's motion wrt the stars.


The following website puts the EoT is more complicated astronomical terms but here is where all the contemporary errors get jettisoned if the arguments are followed to their conclusion but as the components are so nebulous it may be short of impossible to make the necessary corrections.In this respect,nobody is 'backward',they are just unfamiliar with the EoT and why Newton expressed it as the difference between absolute time and relative time.


"An 'equation' did not then signify a formula, but rather a quantity, measured in minutes or degrees, whereby a mean value was improved, to obtain something nearer to its actual value. "

http://www.ucl.ac.uk/sts/nk/ntn.htm

Can you imagine the consequences if the motion of the primary planets was calculated off the rotation of the Earth as 23 hours 56 minutes with a cumulative loss of roughly 4 minutes for each rotation instead of the equable 24 hours for rotation ?.

oriel36
2003-Sep-26, 11:39 AM
I apologise for the repeated sending of the posting whatever the reasons for it.

Kaptain K
2003-Sep-26, 05:17 PM
It is possible to delete your own posts. :o

Celestial Mechanic
2003-Sep-26, 05:19 PM
I apologise for the repeated sending of the posting whatever the reasons for it.
As the author you have the capability of editing any of your posts and that includes the option of deleting them. :)

kilopi
2003-Sep-26, 06:08 PM
I sent oriel36 an email about the delete option--but the delete option disappears when someone posts to the thread. Irony, eh?


Can you imagine the consequences if the motion of the primary planets was calculated off the rotation of the Earth as 23 hours 56 minutes with a cumulative loss of roughly 4 minutes for each rotation instead of the equable 24 hours for rotation ?.
But it is 23h 56m, unless you're talking geocentricity--and I know you're not, because you've said you are not against the mainstream.

Foucault's pendulum at the poles would rotate once each 23h 56m--those sort of experiments have been done.

Grey
2003-Sep-28, 05:34 AM
You see Grey they were making clock comparisons for centuries and these so-called clock comparisons for relativistic effects are a product of wishful thinking and especially as Newton defines the difference between absolute time and relative time as the Equation of Time.I said that you did'nt know up until a few weeks ago that Newton was refering to the very practical EoT,poor Albert and Mach had'nt a clue what its absolute and relative components refer to so you compare what Newton said with what Mach said.
Yes I know that's what you said. You were wrong. :) You have no basis for determining what I do and do not know about the Principia or the Equation of Time. And far from relativistic effects being wishful thinking, they were accepted only after a huge amount of corroboration.


You can modify Newton's absolute time to take into account that Foucault's pendulum at the poles,free of gravitational effects,registers 24 hours for axial rotation but I suspect you would rather stick with Mach and subsequently Albert.
Wait, I thought that you said if you modify Newton's ideas of absolute time, you invalidate half of the Equation of Time, and that's not acceptable. :)


Newton as an advisor to the Royal Longitude Board only thought that it was mechanically impossible to develop an accurate clock even though the principle of clocks as physical rulers of distance was well understood,neither you nor the Bad Astronomer will ever mention that clocks measure distance,you need it for the relativistic trash of " clocks measure time" and will be well pleased that participants won't look into the matter for in a roundabout way it leads all the way back to Newton's definition of the EoT as the difference between absolute time and relative time.
You know, clocks do measure time. They've been used to measure the passage of time long before they were used to determine longitude. The fact that knowing accurately what time it is, along with other information, allows you to determine where you are doesn't suddenly mean that clocks aren't useful as timekeeping devices. I'm not sure why you think it does.


Participants always have the option of going outside tonight and doing what Albert requests by using the path of Mars,Newton did not predict elliptical orbits,Kepler did by sorting out true motions from apparent motions,Albert just dumps Newton laws directly on to observation and comes up with elliptical orbits but only fools imagine this is the way astronomy worked.
Indeed. Of course, in one night you probably can't get an accurate measurement of the orbit of a planet. Still, as I've said, when astronomers do just this, they find out that Einstein's relativity predicts the positions of the planets more accurately than Newtonian mechanics. I'm afraid that's not really a point that you can successfully argue, unless you'd like to present an alternate theory to relativity that can account for the discrepancies from Newton's predictions.


I can point out to you that 4 years before the pictures of the rings of SN1987A emerged,I had worked out the geometry of stellar collapse,in other words I know why those rings are there.It is the only copyright I possess,one graphic representation refers to geometric nonperiodicity I used and the other graphic representation is exactly as the the rings appear with a ring of intersection.Insofar as it also refers to the geometry of stellar collapse beyond the supernova stage I can and certainly would not expose it to creatures who try to describe logical limits in terms of event horizons,singularities foamy space and heaven knows what .
Ah. So you predicted that rings would form in a supernova years before they were observed, but you're not going to show us your work because we wouldn't understand it. Remember, this is a supposed to be a rational discussion, so if you want to make a claim, you'll need to provide supporting evidence if you expect it to be given any weight.


Can you imagine the consequences if the motion of the primary planets was calculated off the rotation of the Earth as 23 hours 56 minutes with a cumulative loss of roughly 4 minutes for each rotation instead of the equable 24 hours for rotation ?
Solar noon to solar noon does average 24 hours, but one rotation is in fact 23 hours 56 minutes, 4.10 seconds, as kilopi has stated.

oriel36
2003-Sep-29, 10:59 AM
Grey wrote;"Solar noon to solar noon does average 24 hours, but one rotation is in fact 23 hours 56 minutes, 4.10 seconds, as kilopi has stated."

Participants can find out for themselves that the 24 hour clock was developed from the Equation of Time where the unequal natural day was reduced to an equable day,the rotation of the Earth is subsequently one rotation per 24 hours exactly.

As kids frequently this site,here is a useful site that should appeal to them if the Focault's pendulum sites look too complicated.

http://academic.brooklyn.cuny.edu/geology/leveson/core/linksa/findlong.html

Although the site does not mention the Equation of Time,without it ,it is impossible to determine location with clocks.The ingenousness of men is that they developed a way to reduce the unequal day to an equable day of 24 hours and fixed it to the geometry of the Earth.Here is Jack London's comment on the matter

http://sunsite.berkeley.edu/London/Writings/CruiseOfTheSnark/snark14.html

Now,if you cannot even work out what the rotation period of the Earth is,you can hardly go on to discuss other astronomical matters,unless you have'nt noticed you cannot base the motion of the primary planets on two different rotations of the Earth,one 24 hours exactly and the other 23 hours 56 minutes approx.

You are simply wrong,observation and experiment dictates that the Earth rotates underneath Foucault's pendulum 15 degrees per hour and 360 degrees in 24 hours.

http://www.phys-astro.sonoma.edu/people/students/baker/SouthPoleFoucault.html

oriel36
2003-Sep-29, 11:59 AM
Kilopi

The most important feature of basing the rotation period of the Earth using a 24 hour clock for the purpose of reducing the motions of the primary planets from the unequal natural day due to the Earth's axial and orbital rotations) to a equable day is that by applying the EoT in reverse it returns the motions of the planets to how we observe them by eye or by telescope.

I imagine that you have already noticed that there are two sets of figures out there that attribute different rotation periods for the Earth,one is 23 hrs 56 min while the other is 24 hours,I also suspect that others would have noticed it as well.As the Earth's rotation determines not only what we see in the night sky but the translation of the observed motions of the primary planets into heliocentric modelling or in other words the inferred true motions of the primary planets,astronomy cannot support two sets of figures on the most basic rotation of all,the axial rotation of the Earth,one has to be wrong if clocks are used to guage celestial motion.

The nature of astronomical investigation in today's world only affords that these forums are the only means to bring up these enormous lapses in reasoning and also to assure that no setpieces like relativity get dumped wholesale on humanity.

The numerous websites on Foucault's pendulum,clocks and the longitude problem and by association;Newton's definition of absolute/relative time are clear on the Earth's rotation as 24 hrs while the sidereal circumpolar stellar motion pins the rotation to 23 hrs 56 min.I will probably return to the matter at a later date but for the time being everyone has to live with this odd contradiction that should'nt really exist,it is based on the single rotation of the Earth so it is not unduly complicated.It gets rapidly complex when you base the motions of the primary planets on the Earth's rotation period and especially as relativity severs the EoT connection from clocks to the actual observed motions.

I really wish you could sense the importance of the material you are handling,where the errors crept in and the truly awful consequences for astronomy by dissolving the connection between the natural day and the 24 hr clock day.

AstroSmurf
2003-Sep-29, 12:13 PM
oriel36, have you heard of sidereal time?

Kaptain K
2003-Sep-29, 01:15 PM
It is said that "a little knowledge is a dangerous thing". ](*,)

Grey
2003-Sep-29, 01:25 PM
Now,if you cannot even work out what the rotation period of the Earth is,you can hardly go on to discuss other astronomical matters...
Careful, you may find this statement turning around and biting. :)


You are simply wrong,observation and experiment dictates that the Earth rotates underneath Foucault's pendulum 15 degrees per hour and 360 degrees in 24 hours.

http://www.phys-astro.sonoma.edu/people/students/baker/SouthPoleFoucault.html
Perhaps you didn't notice that they measured the period as 24 hours, ± 50 minutes. That is, the precision of the experiment was nowhere near sufficient to distinguish between a 24 hour period and a 23 hour, 56 minute period. More precise measurements of a Foucault pendulum's motion have been made, showing that the period is 23 hours, 56 minutes, divided by the sine of the latitude. Here (http://visite.artsetmetiers.free.fr/site_anglais/pendulum_museum_a.html)'s the one that was on originally display at the International Exhibition of Paris in 1855 (now at a church in Paris and still using the original wire, which is kind of cool from a historical standpoint, though they've changed the bob several times), which gives the period and latitude to the minute (31 hours, 47 minutes at the latitude 48° 50'). This gives a value for the rotation period of the Earth of 23 hours, 55.6 minutes ±0.8 minutes, assuming an error of 1 minute in both the latitude and period as stated.

[Edited to change "multiplied by the sine of the latitude" to "divided by..."; at least I went in the right direction when I worked out the example. :-? ]

russ_watters
2003-Sep-29, 01:53 PM
Round and round we go. The tenacity of everyone here is both impressive and sad: 8 people beating a dead horse and one who doesn't know its dead. However:
Perhaps you didn't notice that they measured the period as 24 hours, ± 50 minutes. That is, the precision of the experiment was nowhere near sufficient to distinguish between a 24 hour period and a 23 hour, 56 minute period. Things like this jump out at you and slap you so hard, I'm starting to wonder if maybe he really does know the horse has passed. The alternative of course is just as final.

oriel36
2003-Sep-30, 11:38 AM
Grey wrote;"Perhaps you didn't notice that they measured the period as 24 hours, ± 50 minutes. That is, the precision of the experiment was nowhere near sufficient to distinguish between a 24 hour period and a 23 hour, 56 minute period. More precise measurements of a Foucault pendulum's motion have been made, showing that the period is 23 hours, 56 minutes, divided by the sine of the latitude. Here's the one that was on originally display at the International Exhibition of Paris in 1855 (now at a church in Paris and still using the original wire, which is kind of cool from a historical standpoint, though they've changed the bob several times), which gives the period and latitude to the minute (31 hours, 47 minutes at the latitude 48° 50'). This gives a value for the rotation period of the Earth of 23 hours, 55.6 minutes ±0.8 minutes, assuming an error of 1 minute in both the latitude and period as stated."

It is customary to provide a counterexample and there are so many availible on the internet that we could in principle spend all our time just referencing that some have the rotation tied to sidereal motion of 23 hrs 56 min and others to clocks of 24 hours exactly.

http://www.eso.org/seaspace/navigation/navastro/navastro-5.html

Any two measurements taken along differing latitudes will indicate that the pendulum or rather the Earth rotates on its axis once in 24 hours, clocks are based on the reduction of the natural inequality of a day to this equality,artificial though it may be,it is fixed to the longitude coordinates of the Earth with the primary longitude meridian set at Greenwich.

If you wish to take issue with the institutions who reflect the rotation period as 24 hours,be my guest,the whole point of Foucault's pendulum is that it is the Earth rotating underneath the pendulum and 15 degrees per 1 hour or 360 degrees in 24 hours is in keeping with the development of clocks.

http://scienceview.berkeley.edu/VI/worksheet_longtutorial.html

As I mentioned to Kilopi,if you have two figures for the rotation of the Earth,one 23 hrs 56 min and the other 24 hours exactly,you have a problem on your hands for it is the rotation rate which determines the apparent motions of the primary planets and this is where it becomes intricate.

As you already know,it would have been impossible to accomplish heliocentric modelling via the unequal natural day, the EoT corrected observations to a 24 hour clock day but the compromise is that observations of the motion of the primary planets get reduced to modelling,there are no relative motions corresponding to the 24 hour clock but by reapplying the EoT in reverse,the correct observed motions would appear.It is always easier to frame the rotation period in terms of clocks and longitude before introducing the astronomical aspects,not necessarily for your benefit, but for the thorny ploblem of having two rotations rates whether you or I like them or not.

It may be difficult to see what I am up to but it was always a question for those willing to stick their necks out and start making connections between different areas of astronomy.

Iain Lambert
2003-Sep-30, 11:51 AM
If you wish to take issue with the institutions who reflect the rotation period as 24 hours,be my guest,the whole point of Foucault's pendulum is that it is the Earth rotating underneath the pendulum and 15 degrees per 1 hour or 360 degrees in 24 hours is in keeping with the development of clocks.


I'll not be quibbling with either of the institutions you've linked, as neither of them even contain the word "pendulum" on them, let alone claim that it rotates in anything other than the sidereal day.

Furthermore, lets look at what they actually do say:


As you know, the Earth performs one full rotation (360°) every 24 hours. Thus, it rotates 15° every hour.

In other words, Local Noon at two geographical locations which are separated by a longitudinal difference of 15° occurs with a time difference of 1 hour.

Yep, this looks true to me, as Local Noon obviously means its the Solar Day of 24 Hours. Similiarly, your Berkeley link is all about how to use the difference between local noon and GMT to determine latitude. And you get local noon from studying the position of what? Precisely.

Kaptain K
2003-Sep-30, 01:45 PM
...if you have two figures for the rotation of the Earth,one 23 hrs 56 min and the other 24 hours exactly,you have a problem on your hands...
No, it is you who has a problem! There are two different "days" being measured The sidereal day (The time between successive transits of a star - or other non solar system object). This is the 23h 56m time that is being referenced. The other is the solar day of 24h. This is the time between solar transits (noon to noon). The solar day is an average taken over a one year period. The EoT is the difference between the average solar day and the individual day. The individual days vary because of the ellipicity of the Earth's orbit. The Earth moves faster near perihelion and slower near aphelion.

kilopi
2003-Sep-30, 02:09 PM
As I mentioned to Kilopi,if you have two figures for the rotation of the Earth,one 23 hrs 56 min and the other 24 hours exactly,you have a problem on your hands for it is the rotation rate which determines the apparent motions of the primary planets and this is where it becomes intricate.
Yes, it does become intricate. I'm sure you can follow what I have to say below, though.


As you already know,it would have been impossible to accomplish heliocentric modelling via the unequal natural day, the EoT corrected observations to a 24 hour clock day but the compromise is that observations of the motion of the primary planets get reduced to modelling,there are no relative motions corresponding to the 24 hour clock but by reapplying the EoT in reverse,the correct observed motions would appear.

The Sun does not appear due south at the same time everyday, every 24 hours exactly. The difference is the equation of time. Using the equation of time, it's true we find that the average day is 24 hours, more or less exact.

However, in the heliocentric system, the Earth revolution about the Sun causes a progression of sunlight and night around the globe. If the Earth did not rotate at all as it went around the Sun, the hemispheres would still experience a solar day and night cycle. It would appear as if the Sun were rising in the west. Thus, the Earth loses a day as it revolves around the Earth. It actually rotates 366.25 times, but its revolution causes us to experience 365.25 days during one full revolution. Thus the length of an actual rotation is about 365.25/366.25 times 24 hours. That can be verified by observing the stars each night. My own telescope has a clock drive set to a sidereal rate to keep it aligned to the stars as I observe them.

365.25/366.25 times 24 hours is 23h 56m 4.1s


It may be difficult to see what I am up to but it was always a question for those willing to stick their necks out and start making connections between different areas of astronomy.
We'll see.

oriel36
2003-Sep-30, 02:23 PM
Kaptain K wrote;"No, it is you who has a problem! There are two different "days" being measured The sidereal day (The time between successive transits of a star - or other non solar system object). This is the 23h 56m time that is being referenced."

The other guy is wondering why they do not take the rotation of the local stars into account is cosmological modelling,the fact is that the sidereal choice for rotation of the Earth will give you the answer.

Now you possibly cannot figure out exactly why but I can tell you that the EoT which reflects kepler's second law allows you to recognise the heliocentric axis for the annual orbital motion of the Earth.The next rotation is the enormous leapt of the solar system around the galactic axis where it is all new rules and parameters necessary for cosmological modelling.

I have been tapping my fingers waiting for somebody to discuss cosmological modelling off the galactic axis but it is evident that even when somebody is greedy enough to circumvent the discussion and bring it up themselves,it generates a blank response with me around.So,go ahead and try and do it but the moment you do, you will be introducing the priviledged reference of the galactic axis and the local stars that rotate around it.

If you can't figure out the earth's rotation rate allied to clocks you would not be capable of working on the annual orbital rotation never mind the principle of its rotation around the galactic axis.Stick with 23 hours 56 minutes and the 'fixed stars' because that is all you will ever know.

AstroSmurf
2003-Sep-30, 03:13 PM
oriel36, your attitude is frankly unscientific. We are under no compulsion to accept anything you "tell" us unless you can demonstrate the logic behind it. All you've done so far is say "this is right, if you don't accept it you're stupid". This attitude has no place in science; the very basis of scientific reasoning is that you have to provide enough information for someone else to follow the logic. You have not done so.

To address the point, you seem to think that the coordinate system we should be using is one where the Earth rotates a full 360 degrees every 24 hours, or about 365.25 times each year. I'm not sure what your preferred rotational axis is, but I suspect it is one which is perpendicular to the ecliptic plane. This has very interesting consequences:
- The Sun and Earth are more or less fixed relative to each other; the only motions are due to eccentricity and the inclination of the Earth's rotational axis - in other words, what the Equation of Time is concerned with.
- The stars rotate one full turn every year around this axis (remember, they appear to rotate an extra degree each solar day, which sums up to an extra rotation during a year)
- Neither Newton nor Kepler's laws can be applied directly to the Earth; the Sun-Earth axis does not rotate in this coordinate syste, so there's no angular movement to balance the gravitational forces. If you wish to use Kepler's/Newton's laws, you need to use a different coordinate system (guess what it looks like).

Further, you are aware that the solar system does not follow a Keplerian, elliptic, orbit around the galactic center?

Kaptain K
2003-Sep-30, 08:13 PM
oriel36,

With every post you make, you demonstrate more and more exactly how much you do not know.

1) Although the Earth rotates around its own axis, it revolves around the Sun, which revolves around the center of the galaxy. This is not nitpicking. If you are going to discuss subjects in a field, you need to use the proper terminology.

2) You act like we are ignoring the motions of stars with respect to the Earth. If you look up the position of a star in a catalog, the coordinates will be given for a specific time. e.g RA xxh xxm xxs, Dec xxd xxm xxs (epoch 2000). This means that those were the coordinates at 0h GMT on Jan 01, 2000. If you need more precision, there are formulas for factoring in the precession of the Earth's axis, to give current coordinates. The catalog will also give proper motion vectors in RA and Dec for factoring in the stars motion against the the coordinate grid. For most uses, neither precession nor proper motion are critical to finding the object. But, if they are, the tools are available to factor them in.

3) You act like it is of "Earth shattering importance" that we seem to be ignoring the motion of the Sun around the galactic center. The Sun takes 220 million years to complete one orbit around the galaxy. When talking about the difference from one night to the next, one part in 80,353,372,000 can be safely ignored, in almost all circumstances. If the situation warrants, it too can be factored in when necessary.

SeanF
2003-Sep-30, 09:17 PM
Can you imagine the consequences if the motion of the primary planets was calculated off the rotation of the Earth as 23 hours 56 minutes with a cumulative loss of roughly 4 minutes for each rotation instead of the equable 24 hours for rotation ?.

Something about this just struck me.

Oriel . . . you have in previous posts mentioned the Equation of Time as being useful to "reduce the unequal day to an equable day of 24 hours." That seems to suggest that you understand that the Earth does not actually rotate exactly once every 24 hours but sometimes is ahead and sometimes behind, and the EoT compensates for that.

But if that's true, then how can you suggest that we should use a 24 hour rotation period to calculate the apparent motion of the planets? Wouldn't it be necessary to use the Earth's actual rotation time on the given day of the year to determine a celestial object's apparent motion on that day?

After all, you can't use a 24 hour rotational period to calculate the Sun's position every day (if you try to, you need to compensate with the EoT), so why would it work for Mars?

(Edited because I almost forgot:)

Stop ignoring me (http://www.badastronomy.com/phpBB/viewtopic.php?t=8207&start=14).

Iain Lambert
2003-Oct-01, 08:27 AM
Actually, thats a good point. What Oriel's real point is (if there indeed is one) is that he believes that we are giving insufficient importance to our motion through the galaxy. When his mighty galactic-centric model doesn't appear to have included the far, far larger influence of precession it is a serious problem.

oriel36
2003-Oct-01, 09:37 AM
What should I say,the Eot isolates the Earth's axial rotation to 24 hours,it is not difficult to understand.The observation of motion of the primary planets are influenced solely by the Earth's axial rotation and its annual orbital and as clocks were developed to remove the natural inequality in a day due to the combined effect of axial and orbital rotations.

So,in 2003 it appears that for whatever reasons,men are willing to bypass the only two influences that matter and homogenise it to circumpolar motion of the stars.Like it or not you have two figures for the rotation of the Earth,one built on clocks the other built on the 'fixed stars',the former 24 hours and the latter 23 hours 56 minutes.

So what !,those jokers in the early part of the 20th century had'nt a clue how the 24 hour day refers to the natural unequal day via the EoT and unless you live in a relativistic cave it is not difficult to figure out why accurate clocks were developed of axial rotation.The more you determine the rotation of the Earth via the 'fixed stars' the more you lot look like clowns,that is the price for following Albert.

Iain Lambert
2003-Oct-01, 10:10 AM
1) Ah. Now we're clowns. Its an improvement on idiots, but not much of one. On the other hand, I'm struggling so hard to resist doing a 'circular argument' gag that maybe you're right.

2) Its not that we don't know the whys and hows of clock innovation, its merely that most astromomers are more concerned with our position and viewing direction relative to the star we wish to look at, rather than the Sun. Solar observers will obviously be concentrating on where the Sun is, but then its not exactly difficult to spot.

kilopi
2003-Oct-01, 10:30 AM
So what !,those jokers in the early part of the 20th century had'nt a clue how the 24 hour day refers to the natural unequal day via the EoT and unless you live in a relativistic cave it is not difficult to figure out why accurate clocks were developed of axial rotation.The more you determine the rotation of the Earth via the 'fixed stars' the more you lot look like clowns,that is the price for following Albert.
Einstein did not establish that convention--that was put in place by astronomers long before he was born. When we say that the Earth rotates once every 23h 56m 4.10s, we are not following Eiinstein at all. He had nothing to do with it.

My last response. Ever. Unless we get an apology. :)

Kaptain K
2003-Oct-01, 10:59 AM
1)
...clocks were developed to remove the natural inequality in a day...
Clocks were developed to measure time! Sheesh! :roll:

2) Just in case you are not aware, there are 24 sidereal hours in a sidereal day - just as there are 24 solar hours in a solar day.

One more time:

We are talking about two different time scales here, each with its own units!

AstroSmurf
2003-Oct-01, 11:03 AM
I think your sig says it all, Kaptain K.

Iain Lambert
2003-Oct-01, 12:26 PM
As does yours.

SeanF
2003-Oct-01, 01:36 PM
What should I say,the Eot isolates the Earth's axial rotation to 24 hours,it is not difficult to understand.

So the Earth's axial rotation is not consistently 24 hours. Are you saying that the Earth's axial rotation changes throughout the year, that sometimes the Earth is rotating faster and other times slower?

The observation of motion of the primary planets are influenced solely by the Earth's axial rotation and its annual orbital and as clocks were developed to remove the natural inequality in a day due to the combined effect of axial and orbital rotations.
Clocks were developed to tell time. The day was divided into 24 equal hours because the solar day averages to 24 hours.

So,in 2003 it appears that for whatever reasons,men are willing to bypass the only two influences that matter and homogenise it to circumpolar motion of the stars.Like it or not you have two figures for the rotation of the Earth,one built on clocks the other built on the 'fixed stars',the former 24 hours and the latter 23 hours 56 minutes.

No, we have two figures for the length of a "day", one based relative to the Sun and the other based relative to the fixed stars.

So what !,those jokers in the early part of the 20th century had'nt a clue how the 24 hour day refers to the natural unequal day via the EoT and unless you live in a relativistic cave it is not difficult to figure out why accurate clocks were developed of axial rotation.The more you determine the rotation of the Earth via the 'fixed stars' the more you lot look like clowns,that is the price for following Albert.
Albert who? You can't mean Einstein, because he has nothing to do with the Equation of Time or the question of 24 hrs versus 23 hrs 56 mn 4 secs.

And, do I need to say it again? Why not? You're still ignoring me (http://www.badastronomy.com/phpBB/viewtopic.php?t=8207&start=14).

AstroRockHunter
2003-Oct-01, 05:29 PM
Oriel36 wrote:


Like it or not you have two figures for the rotation of the Earth,one built on clocks the other built on the 'fixed stars',the former 24 hours and the latter 23 hours 56 minutes.


Sorry, the 24 hour day was not built on clocks. It was built on the passage of the Sun across the sky. Clocks were built on this concept, not the other way around.

Anyway, it really dosen't matter.

oriel36
2003-Oct-02, 09:45 AM
Kilopi wrotre;"Einstein did not establish that convention--that was put in place by astronomers long before he was born. When we say that the Earth rotates once every 23h 56m 4.10s, we are not following Eiinstein at all. He had nothing to do with it. "

The guy misunderstood or did not know that absolute time/24 hour clock day has a mathematical relationship to the relative time/natural unequal day,that relationship is the EoT.

There is an incontrovertible relationship between clocks and geometry and especially the isolation of the rotation of the Earth in terms of 24 hrs exactly,if you adopt the convention that the rotation of the Earth is based on stellar circumpolar motion of 23 hrs 56 min,nothing will work,not timezones,not the calendar system,astronomy is wiped out and the best part of the development of clocks that stretches back millenia withers.

So now you find yourself at a level similar to the creationist or the geocentrist and believe me I do not correspond with intellects of that nature.It remains a clear choice,if you base the rate on 23 hrs 56 min you will be incorrect and will most certainly be a relativist,if the rotation rate is based on 24 hours,history supports it and Newton's awkward distinction between absolute time ( 24 hour clock day) and relative time (unequal natural day) becomes easy to understand and furthermore cannot be tampered with,experiments with Foucault's pendulum indicate the rotation of the Earth is 24 hours exactly when it is remembered what is doing the moving (hint;the ground beneath your feet).

If you cannot get the fundamental rotation of the axial rotation of the Earth right there is little sense in trying to deal with greater rotations.




if the guy who writes in big red letters ever manages to comprehend that only one rotation rate of the Earth is valid in terms of clocks,that one is 24 hours exactly for the history of the development of clocks supports it,it is fairly easy to understand

Kaptain K
2003-Oct-02, 11:10 AM
There is one rate of rotation of the Earth.
There are two different time systems.
Solar time - 24 solar hours = one solar day.
Sidereal time - 24 sidereal hours = one sidereal day.

One sidereal day = 23 solar hours, 56 solar minutes, 4.091 solar seconds.

One solar day = 24 sidereal hours, 3 sidereal minutes, 56.555 sidereal seconds.

AstroSmurf
2003-Oct-02, 11:46 AM
There is an incontrovertible relationship between clocks and geometry and especially the isolation of the rotation of the Earth in terms of 24 hrs exactly,if you adopt the convention that the rotation of the Earth is based on stellar circumpolar motion of 23 hrs 56 min,nothing will work,not timezones,not the calendar system,astronomy is wiped out and the best part of the development of clocks that stretches back millenia withers.
Rotation is defined only in terms of the coordinate system you adopt. You pick an "axis", a vector, and measure the angle of a point on the Earth's surface towards this axis - the rotational angle. The rotational period is the time it takes for this angle to go through a full 360 degrees.

It's perfectly possible to define a coordinate system where the Earth will rotate exactly once every 24 hours. What this means is that the "axis" defining the rotational angle is the Earth-Sun vector, slightly adjusted for effects of eccentricity and precession.

However, in such a coordinate system, the Sun will be more or less fixed relative to the Earth (barring effects from eccentricity and precession). If you comment on nothing else in this post, please address this point, oriel36 - this is a logical consequence of defining the rotation as being relative to the direction towards the Sun; since "one full rotation" is defined by when the same spot on the Earth is turned towards the Sun, the Sun is always in the same direction!

Therefore, the Earth will not be moving in a Keplerian orbit in such a coordinate system. Since all other planets do so to a high degree of precision, a special case would have to be formulated for the Earth.

Further, the stars would appear to be rotating slightly in such a frame, about 1 degree each day, and a Focault pendulum will also rotate along with the stars, as has been verified to a very high accuracy. If you still doubt this, I recommend contacting a physics department and asking them what the measurements actually indicate.

Taken together, this indicates that a closer approximation of an inertial frame is one where the Earth is moving in an elliptical orbit around the Sun, and where the stars are (more or less) fixed. In such a frame, the Earth rotates once every 23h 56 min, but since the Earth-Sun axis is also rotating slightly, the Earth will turn the same spot towards the Sun approximately every 24 hours.

As for calendars, timezones and so forth - they are connected to the solar day and hold no interest in astronomy.

Iain Lambert
2003-Oct-02, 12:09 PM
experiments with Foucault's pendulum indicate the rotation of the Earth is 24 hours exactly

No. (http://www.griffithobs.org/exhibits/Pendulum/pendulum.html)

They. (http://www.astro.louisville.edu/foucault/)

Do. (http://www.lns.cornell.edu/spr/2002-06/msg0042149.html)

Not. (http://www.abc.net.au/science/k2/pendulum/notes.htm)

Please (http://visite.artsetmetiers.free.fr/site_anglais/pendulum_museum_a.html) get this (http://www.friendsoftheharris.co.uk/features/pendulum/whatisitfor2.htm) into your head. (http://www.physics.usyd.edu.au/~jfellow/FOUCAULT/fpqvb.html)

Bored now.

oriel36
2003-Oct-02, 02:02 PM
Iain

Thanks for proving the point ,there are just as many websites giving the rotation rate as 24 hours as there are giving it as 23 hours 56 minutes.

Some of you websites give the rotation rate and compare it to the circumpolar motion of the 'fixed stars' but that's the whole point,the Earth rotates through 360 degrees in 24 hours ,15 degrees in 1 hour and 1 degree in 4 minutes so one has to go,that is where Albert and Mach got it so badly wrong.

http://www.sciam.com/article.cfm?articleID=00016A7C-5064-1E40-89E0809EC588EEDF

http://www.geospace-online.com/gol-en/sav/fic/sav-fic-pendule-en.htm#lumière

http://curious.astro.cornell.edu/timekeeping.php

http://www.sunlitdesign.com/infosearch/equivalence.htm

http://www.sunlitdesign.com/infosearch/geography.htm?indexref=2


The Bad Astronomer gets the priviledge of having to deal with two seperate figures for the rotation of the Earth while all the major institutions have a split view sometimes within their own websites.If Foucault's pendulum indicates anything other than 15 degrees for 1 hour or 360 degrees for 24 hours at the poles science is finished.You are not the right person to appreceate just how funny it is to link Foucault's pendulum to stellar circumpolar motion of 23 hours 56 min but I know you are dead serious.

http://www.physics.uoguelph.ca/foucault/foucault7.html

Funny,funny,maybe you can get the stop the Earth from rotating for those 4 minutes each day so you can isolate the axial rotation of the Earth to 23 hours 56 minutes.Defending Albert and his "influence of the motion of the fixed stars" for heliocentric modelling is a liability when the basic error is so simple to see,why bother appealing to scientists when everyone will have a good laugh at your expense,as far as I can tell there is no inclination to correct the matter so all this has to go somewhere else.

Iain Lambert
2003-Oct-02, 02:27 PM
Oh dear God not again. Why do I bother?

Right. Will you agree that there are 365-and-a-bit days in a year?

Will you agree that the Earth orbits the Sun?

Will you agree that this means that the Earth is in a different position on its orbit from one day to the next?

Even you link to Cornell's page (http://curious.astro.cornell.edu/timekeeping.php)

All astronomical objects pass across the sky through the meridian like the Sun due to the Earth's rotation. However, the Earth in addition to rotation around its axis, also revolves around the Sun. During the course of a year, due to its orbit, the Earth makes one additional rotation around the Sun. Hence relative to the stars, there is one extra rotation per year, and this amounts to a difference in the position of the stars in the sky by about four minutes of time, when viewed at the same time on two successive days.

Thus, relative to the stars, the Earth's rotation period is about 23 hours and 56 minutes (more accurately 23 hours, 56 minutes and 4.09 seconds), or 4 minutes less than 24 hours. This time period is called a sidereal day and clocks running at this rate indicate the sidereal time. The sidereal clock is defined to be 0 h at noon on Spring Equinox, and it coincides with the solar time at Autumn Equinox. The sidereal time is invaluable to amateur and professional astronomers to orient star maps to the sky and to point telescopes.

Please read the whole of a webpage before you cite it, or you'll end up looking even funnier than the rest of us.

Iain Lambert
2003-Oct-02, 02:33 PM
Actually, while we're quoting that page, the next paragraph is interesting as well, from the point of the "24 Hours, no more, no less" debate:


The time taken for Earth to complete one orbit around the Sun relative to the stars is called a sidereal year. However, we measure a year to be the period between two successive spring equinoxes, and this period is called a tropical year. The tropical year is about 20 minutes shorter than the sidereal year.


before going on to explain that the 20 minutes over a year is due to precession.

kilopi
2003-Oct-02, 02:45 PM
One sidereal day = 23 solar hours, 56 solar minutes, 4.091 solar seconds.
4.10 solar seconds (http://www.badastronomy.com/phpBB/viewtopic.php?p=56095#56095)

the 20 minutes over a year is due to precession.
Which is also the reason for the discrepancy between the two values (in the hundredths of a second!) for the sidereal day

Grey
2003-Oct-02, 03:21 PM
My last response. Ever. Unless we get an apology. :)
Okay. Kilopi, I'm really sorry that oriel seems incapable of understanding the rotation of the Earth, or the way a Foucault pendulum responds to it. I'm also sorry that he feels the need to call anyone who disagrees with him an "idiot", a "clown", or some other derogatory term. Oh, wait, maybe I wasn't the one you wanted an apology from. :D Maybe I should instead apologize for feeling the need to keep telling him that he's mistaken, when I suppose it should be obvious by now that he's either not ever going to get it, or he's being deliberately obtuse to provoke a response.


Thanks for proving the point ,there are just as many websites giving the rotation rate as 24 hours as there are giving it as 23 hours 56 minutes.
Oriel, in case you hadn't noticed, it's clear that the websites giving a figure of 24 hours are targeted at children or people that aren't interested in that level of accuracy. For example, the Scientific American site you quote refers to the same Foucault pendulum I did the calculations (http://www.badastronomy.com/phpBB/viewtopic.php?p=147437#147437) for, showing a period of 23 hours, 55.6 minutes ±0.8 minutes. They quote it as 24 hours, but we know that's just an approximation, since I worked out the math (you're free to try to find an error in my math, if you'd like). But the article is talking about the "City of Children", part of the City of Science and Industry complex, so one wouldn't expect that they'd be concerned with the precise details of the pendulum in this article. Similarly, the second site you quoted is talking about Foucault's original experiment in Paris, but gives its period as "32 hours", when we know (http://visite.artsetmetiers.free.fr/site_anglais/pendulum_museum_a.html) it has to be about 31 hours, 47 minutes in Paris (give or take a minute or so; I don't know exactly how big Paris is, or where the museum is located relative to the Pantheon where Foucault originally performed his experiment). Clearly they aren't concerned with a precision of more than an hour or so.

Remember, if you want to show that it's 24 hours, not 23 hours, 56 minutes, you'll need to find an experiment with a sufficient level of precision to support the difference between those claims. I've done so, by finding an example of a pendulum with the period and latitude quoted to the minute. If you want to show that it's exactly 24 hours, and not just fairly close to 24 hours, you'll need to find an experiment that actually quotes the period to sufficient precision to support your claim. Since you've been so concerned with effects of galactic rotation on the position of objects, an effect that requires a great deal more precision to measure, this shouldn't be too difficult. Well, it wouldn't be too difficult if you were right. :D

oriel36
2003-Oct-02, 03:47 PM
Iain wrote;"Oh dear God not again. Why do I bother?

Right. Will you agree that there are 365-and-a-bit days in a year?

Will you agree that the Earth orbits the Sun?

Will you agree that this means that the Earth is in a different position on its orbit from one day to the next? "

Believe me,I have asked the same 'why bother' question every single day.

http://astrosun.tn.cornell.edu/courses/astro201/sidereal.htm

Here is your sidereal universe with your 'fixed star' in the middle,maybe it will get a guest appearance in a cartoon but it certainly has nothing to do with astronomy.Where is Kepler's second law of planetary motion expressed,what happened to the axial rotation of the Earth .

Why don't you try Kaptain K dual time measurement's with one rotation rate and screw the whole thing up together,it is enough that those intelligent enough to recognise that one rotation rate is set to accomodate the Mach/relativistic gr trash of the "influence of the motion of the 'fixed stars" on the motion of the primary planets.

Clocks were developed on a rotation rate of 24 hours where this rotation is allowed to drift against the natural alignments through applying the EoT,it has nothing to do with the stars fixed or not.

So you made your point and wish to stick with 23 hours 56 min for the rotation of the Earth to please those here but don't underestimate the ability of the wider population to appreceate why accurate clocks were developed as rulers of distance based on the 24 hour clock.

Iain Lambert
2003-Oct-02, 03:54 PM
Clocks were developed on a rotation rate of 24 hours where this rotation is allowed to drift against the natural alignments through applying the EoT,it has nothing to do with the stars fixed or not.


No-one, not a single person on the entire board has ever claimed anything different. You are trying to misrepresent our arguments, and then show that your misrepresentation is false. This does not invalidate our arguments, merely demonstrate that you cannot (or, far more likely will not) understand them.

Again: Will you agree that the Earth orbits the Sun?

AstroSmurf
2003-Oct-02, 04:01 PM
oriel36, the star in the middle of the pictures on the linked page is the Sun.
But simply answer Iain's questions - yes or no will suffice.

russ_watters
2003-Oct-02, 04:08 PM
Once again, the tenacity of all here is amazing. The horse has been beaten so badly that not only is he dead, he's unrecognizable as a horse.

You guys will never be able to get Oriel to accept that his facts are wrong, much less the conclusions he bases them on. Heck, he's probably got it backwards anyway (they usually do): the facts are chosen to fit the conclusion.

Pons and Flesichman tried to do the same thing - when their experiments showed nothing that looked anything like fusion they tried to redefine the word to fit their experiments.

AstroSmurf
2003-Oct-02, 04:18 PM
It would also help if he ever addressed a point directly instead of quoting it and then ignoring it completely in the "response".

SeanF
2003-Oct-02, 04:20 PM
I can't figure out why Oriel keeps coming back himself! He's ignoring (http://www.badastronomy.com/phpBB/viewtopic.php?t=8315&start=36) me twice (http://www.badastronomy.com/phpBB/viewtopic.php?t=8207&start=14) now.

I think he thinks if he keeps starting new topics, nobody will notice that he's not answering questions . . .

oriel36
2003-Oct-02, 04:49 PM
"oriel36 wrote:
Clocks were developed on a rotation rate of 24 hours where this rotation is allowed to drift against the natural alignments through applying the EoT,it has nothing to do with the stars fixed or not.



Iain wrote;"No-one, not a single person on the entire board has ever claimed anything different. You are trying to misrepresent our arguments, and then show that your misrepresentation is false. This does not invalidate our arguments, merely demonstrate that you cannot (or, far more likely will not) understand them."

Good,then you will have no problem with Newton who expresses the EoT as the difference between the the 24 hour day and the natural unequal day in terms of the difference between absolute time and relative time.

Now that you know that Newton was basing his definition on the Equation of Time,may be you can instruct your colleagues why astronomers had to make the correction from the unequal day to the equal day and how it was used for the purpose of navigation and the development of accurate clocks.



"Absolute time, in astronomy, is distinguished from relative, by the equation or correlation of the vulgar time. For the natural days are truly unequal, though they are commonly considered as equal and used for a measure of time; astronomers correct this inequality for their more accurate deducing of the celestial motions." Principia

http://members.tripod.com/~gravitee/definitions.htm

It is your priviledge not to deal with the matter but you can expect that it is easier to understand what the Equation of Time is and does than explain what relativity is and why the concept is entirely reckless in attempting to tamper with definitions he knew nothing of.People make up their own minds when the matter is made clearer,it does'nt take much,a bit of animation and graphics to carry the point of the EoT and how it ties in with geometry,astronomy and the development of clocks but when they come to relativity they get to see just how hopeless the premises were.

Iain Lambert
2003-Oct-02, 04:58 PM
One. Last. Time.

Please, for the love of God, try to actually defend your baseless arguments against what we actually say, not what you think we are saying. No-one is disagreeing with the EoT. However, no-one quite seems to grasp why you use it as such a blunt instrument to launch attacks on relativity. Or I shall have to conclude that the whole of your so-called argument equates to "lalala, I'm not listening", rather than just merely 90% of it.

AstroSmurf
2003-Oct-02, 05:04 PM
Don't flatter yourself, oriel36 - you've told us nothing new so far. Noone is "ignoring" the Equation of Time, it's just that we don't need it. While learning about the EoT was an intriguing detail, it's by no means vital to astronomy to be able to correct the "clock time" to get the position of the Sun. This is how it would be done; noone sets their watch by looking through a sextant any more - the precision is too low, so you'd apply the EoT in reverse if you for some reason needed the "vulgar time".

The trouble is that the corrections from the EoT do not suffice to correct for the anomalies we can observe. It's not that we're ignoring them in favor of a more obscure model, it's that even after applying the EoT to our observations, the results still do not match the predictions Newton's theory would indicate!

Emspak
2003-Oct-02, 05:35 PM
You know, reading these posts, um, I am sure glad you can all engage this guy.

I for one, was lost completely as to what he was talking about. Some of you cleared it up, tho. Good for you! I don't think I could have done it!

It got me to thinking, though. One of the basic misunderstandings that someone like oriel36 seems to have is that various equations and such are tools, and the right tool needs to be applied to the right job. For example, one could use a screwdriver to hammer nails, and it might work, but a hammer would be much better.

This seems to be a recurring theme among people who are pseudoscience enthusiasts. I remember myself having the same misconceptions -- when I was maybe 12 years old, and they were erased by some really serious study.

Oh well. Good luck, folks.

Kaptain K
2003-Oct-02, 06:28 PM
](*,)

I'm out of here. [-(