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time and clocks...

Posted by: Ekkehard Augustin - Tue Mar 29, 2005 5:28 pm
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time and clocks... 
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Post    Posted on: Tue Apr 05, 2005 3:00 pm
I will read three previous posts later - I have ready now the description I have been speaking of in my last post:

Mankind is using a time system that has been introduced thousands of years ago by the Babylonians. They divided the day into 24 hours, each our into 60 minutes and a minute into 60 seconds. In that system a day is defined as the time between two culminations of the sun. And as we know a year consists of 365,256 days – defined as the time between two movements of the sun through the ascending node.

This time system is sun-oriented which is quite reasonable because life depends on the light and warmth of the sun. This two is reflected by the four seasons of the year as they are shown by plants, flowers and animals too.

This element of the babylonian culture still is part of our culture too. The life of all humans and ist processes is organized and coordinated by this system.

But this system isn’t sufficiently exact and precise. So today time really is measured by atom clocks... – but seconds, minutes, hours and days are NOT defined by these clocks, NOT defined by the rate of collapses of atoms. There really is NO unit of time in general use that is defined as the time between two collapses of Caesium atoms. I don’t know of such a time system but it may exist in science – perhaps in physics especially. But is not in use in the public, in life. And the number of collapses of Caesium atoms per second is an odd number with decimals.

For the cultural reason mentioned above and for the reason that we all are used to using the babylonian system nobody ever will give up that system. Giving it up and introducing another for public use would be far too expensive and problematic and it would get no perception. The costs would be astronomical.

So normal average people would continue to apply the babylonian system – even if they will be living at another planet for a year or ten or so.

In other words at each planet a day would have 86400 seconds or 24 hours, at each planet an hour will have 60 minutes and at each planet a minute will have 60 seconds. The consequences are as follows:

If the numbers about the orbiting and rotation periods of Mercury, Venus, moon, Mars, Ceres, Callisto, Europa and Titan and Pluto are taken from Wikipedia and next the periods in earthian seconds are calculated – then the results are different to the babylonian length of an earthian day. But the people living at those planets will apply the babylonian system – so divide all the results by the babylonian amount of seconds per day and you get... the length of a second at those planets in earthian seconds: the mercurian second is 58.89583333 earthian seconds long, the venusian second 243.0076968 earthian seconds, the lunar second 27.61564815 earthian seconds, the martian second 1.278611111
earthian seconds, the ceresian second 0,405092593 earthian seconds (shorter!!!), the callistean second 16.90753852
earthian seconds, the europian second 3,639954148 earthian seconds, the titanian second 16,27777778 earthian seconds and the plutonian second 6,503287963 earthian seconds.

1.Consequently the use of babylonian units of time and terms like 15:45 o’clock will be extremely misleading in conversations between different planets if used in such conversations – regardless of the fact that it will be conversations by e-mail and not real time talks.

2. At each planet times of departures for another planet or arrivals from another planet have to be displayed using the baylonian system.

3. A supervising authority for control of interplanetary traffic would be totally confused by using the babylonian system.

4. Passengers will suffer by significantly changing speeds of life.

The babylonian system will work at Mars and perhaps Ceres only (and at Earth) – at all other planets the deviations from the earthian lengthes of the units are that significant that the people recognize them very early. At these planets the people will start to miss temporal orientation and this will impact health. To the minds orientation can be given easyly – to the body, to the biology of the people something has to be invented: this is a technological topic.

But my topic here is the traffic supervising authority. For this authority a standard system for all of the planets together has to be provided – and it must prevented very very urgently that someone will misunderstand that system as a planetary or earthian one. For this reason it shouldn’t be GMT or an earthian system no way – all expressions of time have to be recognized as time of the solar system. And the best idea to achieve that I currently have is to use the rotation period of the sun because that period is equal and the same wherever someone is in the solar system.

It’s known that travels between planets take days and months – and so it has to be considered if these may be a source of misunderstandings and confusions too. Using the planetary babylonian systems to measure the time between movements of the sun through the ascending node seen from each planet the mercurian year is 1,493637071
mercurian days and 0,004089288 earthian years long, the venusian year 0,924666185 venusian days and 0,002531556 earthian years, the lunar year 13,22641417 lunar days and 0,036211354 earthian years, the martian year 537,2861177 martian days and 1,470985056 earthian years, the ceresian year 4148,802103 ceresian days and 11,35861451 earthian years, the callistean year 256,2519077 callistean days and 0,701567962 earthian years, the europian year 1190,286697 europian days and 3,258773838 earthian years, the titanian year 660,9837128 titanian days and 1,809645051 earthian years and the plutonian year 13910,65574 plutonian days and 38,08467413 earthian years. There is the danger to increase confusion if the supervising authority wouldn’t use an independent solar system wide own standard defining a standard year and day.

Atomic clocks might provide a standard too perhaps but there may be effects on the time measured by a Caesium clock – effects from radiation, differences in gravity and velocity (relativistic effects). And the people are living by orientation by daylight and night – not by orientation by collapses of atoms. And the sun is one identical source of time measurement for all the people in the solar system – atomic clocks are not because one atomic clock cannot be seen by all these people together.

At each planet a local GMT can – and must - be applied. But the GMT of two or more planets will be equal only in a few special constellations. ...
...



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Post    Posted on: Tue Apr 05, 2005 3:12 pm
In general about time and changes: a new proposed time system C&T is a very good system, as I mentioned many months ago:
http://www.xprizenews.org/forum/viewtopic.php?t=952

Only too many people rejected it.

Especially the comment from Stefan on that topic:
Quote:
Bad idea, you can't just make a quick fix to the calendar. Sure, maybe for internal use it could help, but i dont see whats wrong with the current calendar. If you really want a good calendar, you should make something more stable, without any fixes in any years, that would be an advantage. The Newton month gives the same effect imo.

Showed to me that most people are NOT ready to accept it.
The C&T calender and time system, would have NO changes AT ALL, each year the same. (what Stefan really didn't knew I guess and just replied, because as so many people he's against the unknown).
He also mentioned the Newton month, this IS needed, because you can't end a day in the midday to start a new year again at 0 AM.
And Seasons have to be right.
We can never avoid a Newton week, cause a year is 0.25% too long or too short in day night cyclus of the earth, compared to the seaons.

But I do think we need a Date and Time system changes, because every year the same will:
1) Make things many times easier
2) Only changes need to be applied each year, instead of a total new planning
3) Events will be always at the same day.

The change to this system may cost a lot of money, but it offers on the long turn 10+ years a lot more profits. and make the world more advanced, less work, more results.

This is of course still calculated for "earth" with day and night cycles.

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Post    Posted on: Tue Apr 05, 2005 3:28 pm
Ekkehard Augustin wrote:
So today time really is measured by atom clocks... – but seconds, minutes, hours and days are NOT defined by these clocks, NOT defined by the rate of collapses of atoms.
Modern time REALLY IS defined by atomic clocks. Here is a quote from http://aa.usno.navy.mil/faq/docs/UT.html
"The International Bureau of Weights and Measures makes use of data from the timing laboratories to provide the international standard UTC which is accurate to approximately a nanosecond (billionth of a second) per day. The length of a UTC second is defined in terms of an atomic transition of the element cesium under specific conditions, and is not directly related to any astronomical phenomena. " (my emphasis)

This has been the standard since 1967.
http://tycho.usno.navy.mil/leapsec.html

Ekkehard Augustin wrote:
There really is NO unit of time in general use that is defined as the time between two collapses of Caesium atoms.
Yes there is! http://tycho.usno.navy.mil/systime.html
says, “the Systeme International (SI) second defined as the duration of 9,192,631,770 cycles of radiation corresponding to the transition between two hyperfine levels of the ground state of cesium 133.”
EVERY time system in the world is now based on Caesium atoms, including the time on your clock at home. You set your clock at home to the time on the radio or TV. The radio and TV station sets it's clock using short wave radio signals from international time services that use atomic clocks.

Ekkehard Augustin wrote:
And the number of collapses of Caesium atoms per second is an odd number with decimals.
NOT TRUE! No decimals are needed because the second is now DEFINED as EXACTLY 9,192,631,770 cycles. All astronomically based definitions are obsolete. As a result the length of the mean solar day is at present about 86,400.002 seconds instead of exactly 86,400 seconds.


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Post    Posted on: Wed Apr 06, 2005 9:51 am
Hello, campbelp2002,

I know that the definitions you are mentioning exist.

You are misunderstanding me because you read my post from the view of physics - which is not the view I am looking at the topic from.

I mentioned the Babylonians - I did it consciously. They were the people who defined the units of time to divide the day in and the units of time to divide the year in - and they defined these units as fractions of the day and the year.

If the Babylonians would have known that Caesium atoms collapse and that that occurs by a very very constant rate and permanently BEFORE they recognized the requirement of units of time - then they would have done so instead of using the culmination period or the period of one termination of orbit I think. And so I think too that they then would have NOT chosen a system based on the number 60. They wouldn't have chosen fractions of periods but they would simply have counted the collapses.

That's a cultural view, an organizational view and a coordinational view - but not a physical one. The method is a mathematical one and it is the work of astronomers - but the babylonian astronomers did it for religious reasons and motives (astrology for example). And religion and astrology and the like are cultural - not scientific.

In principle you are talking about the definition of measurement - not about the definition of the units.

You say that "Modern time REALLY IS defined by atomic clocks." - I know what you mean. But that I don't call a definition - I call it measurement and/or concept but not definition. A definition is something like "Time is ...", "A second is ..." - this doesn't have anything to do with the equipment to measure time or seconds: It is impossible to measure something that hasn't been defined previously because without definition it is unknown what to measure.

What you are quoting next to "Modern time.." is the definition of a size or length and it's a special one - but again it's not the definition of that "thing" that has this length or size.

To repeat it - I do know since long what you say but it's physics and the definitions are designed and optimized for purposes and goals of physics. And that really is not of relevance here - relevant here are definitions designed and optimized for purposes and goals of normal people of the future living throughout the whole solar system - people working there, spending vacations there and so on.

Regarding the number 9,192,631,770 - to me that is an odd number. May be that my understanding and/or use of the term "odd" is completely wrong - in German I would call that number "krumm" but it seems to be diffocult to translate it to English. 9,192.631,770 is "eine krumme Zahl", a "krumme" number. The number 10,000,000,000 is non-odd and I think that the Babylonians would have used that number instead of the second as time unit if they would have known the collapse of Caesium atoms and its stable rate etc. previous to the requirement to measure time.

You are right under the aspect of physics but that's not the aspect I am thinking about it here.



Hello, Sigurd,

Thank You Very Much for reminding to the thread you initiated earlier. I don't remember if I posted something there. It seems to me that I couldn't think about that time because the topic was too far off my thoughts then because of my work here in Hamburg. I am going to look and at my thoughts synoptically a little bit - may be that it will result in something interesting.



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Post    Posted on: Wed Apr 06, 2005 2:40 pm
To answer to the three posts I didn't respond to yet:

It's relatively easy and cheap to watch sun spots from Earth by amateur telescopes. Here in Germany I can buy such a telescope at a price of 300 Euros for example. The prices of atomic clocks I don't know but I think that I would have to pay significantly more than those 300 Euros for one atomic clock.

One problem with an atomic clock is that they are to big to carry one like a conventional clock at my left arm - but very small displays for the left arm could be produced that can receive images by radio. These could be images taken by a cheap telescope and sent to that display as images are sent to handies. However I don't propose to do that really - the use of the rotation period of the sun as time standard I propose for use by the supervising authority that would be in charge to control and watch the traffic throughout the whole solar system. At the spaceports of the different planets there would be two clocks at least - one clock showing the planetary time of that time zoen of that planet and another clock showing the system-wide time the supervising authority is using. This would be required to inform the passengers about departure times and arrival times. Besides that the system-wide valid standard time would be used to translate the time of one planet into the time of another planet - to translate earthian seconds into martian seconds for example or to translate the earthian 15:40 o'clock into the martian counterpart valid that moment.

The example of our earthian time zones wouldn't work between two or more planets. The difference of time between two time zones at Earth is fix. Regardless of how late it is the difference between GMT and MET allways is one hour - but this wouldn't work between MET at Earth and a GMT of Mars. It would work in turn between a martian GMT and a martian MET. The reason are those I described in my long post yesterday. From time to time the earthian GMT will be equal to the martian one - but the date will be different between the two planets then. All that could - and will I suppose - cause trouble, confusion and chaos.

Sending signals from Earth to Mars that indicate time is faced to to problems at least:

1. It takes 180 seconds - or three minutes - until a single signal arrives at Mars if Mars is 54 million km away - I don't know this moment if Mars can be so close to Earth at all. But this means that the indicate time will be behind reality.

2. The distance between Earth and Mars is fluctuating by large scales because of different velocities and because of the high eccentricity of the martian orbit - the distnace varies between less than 60 million km and around 400 million km. So the time signal will deviate from reality by between less than 200 seconds and around 1333 seconds (between less than 3.333 minutes and around 22minutes 13 seconds)

That's inacceptable.

Observability I mentiond for one simple reason - many people consciously as well as unconsciously tend to read time from the position of the sun at the sky or from the degree of brightness of the sky. They do that especially in situation where no clock is available to them. They use it as a raw approximation the. One situation is when they are swimming in the ocean near the beach undressed and stripped of their clock from their left arm. Then their only orientation is the sun or the brightness of the sky. Another situation is when their clock is damaged and no other clock is available.

In space and at other planets it would be of use to enable such behaviour - it's simplifying life.

Not to forget - the speeds of sun spots are not variable. The rotation of sun is different at different solar latitudes and this causes different speeds of sun spots. But at a concrete single solar latitude the speed of rotation is constant and a sun spot moving at that latitude without leaving it has constant speed too.



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Post    Posted on: Wed Apr 06, 2005 3:09 pm
Ekkehard Augustin wrote:
Not to forget - the speeds of sun spots are not variable. The rotation of sun is different at different solar latitudes and this causes different speeds of sun spots. But at a concrete single solar latitude the speed of rotation is constant and a sun spot moving at that latitude without leaving it has constant speed too.
No, you can't depend on that. Sunspots appear and disappear, grow and shrink and change shape. Sunspots, or other features on the Sun cannot be used as a time standard, NO WAY.

(EDIT) This link mentions "Anomalous sunspot motions" and "solar differential rotation undergoes rapid changes "
http://adsabs.harvard.edu/cgi-bin/nph-b ... db_key=AST
Even at one latitude solar rotation is NOT constant.

Ekkehard Augustin wrote:
One problem with an atomic clock is that they are to big to carry one like a conventional clock at my left arm
But they ARE small enough for one person to carry and set on a small table. They ARE small enough to put three of them in a GPS satellite.

Ekkehard Augustin wrote:
It takes 180 seconds - or three minutes - until a single signal arrives at Mars
This problem is easily overcome. One way is to adjust the setting for the known light travel time. If you get the time signal from a source 180 light seconds away, just add 180 seconds to the value when setting your clock. It is very easy to know the exact light travel time between space craft, we do this already. For GPS satellites in LEO the error is less than 1 second but it is still large enough to be a problem if it is not compensated for exactly. The other way to overcome this problem is to physically take your clock to the time standard and set it there. This too is already done. On Earth, time standards agencies send people around the world with portable atomic clocks for the purpose of setting other clocks at different locations. Our space craft could set it’s clocks every time it arrives at a location with a standard clock. With an accuracy of 0.0000000001 seconds per day the clocks could go years between settings and still be more accurate than sunspot motions.


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Post    Posted on: Wed Apr 06, 2005 9:11 pm
Firs, Ekkehard, your math is very much wrong. Average timelag between here and Mars is about 20 minutes, not three.

Also, as campbelp2002 was kind enough to beat me to pointing out, the second is defined EVERYWHERE ON THE BLOODY PLANET in terms of the oscillations of the cesium atom, not in terms of any sort of astronomy -- anywhere, ever, period.

Yes, our time system was originally related to solar cycles. Currently, however, it is completely independent of solar cycles, and determined by the laws of nuclear physics.

Finally, I'm pretty sure tha NASA has defined Martian sols in terms of seconds, minutes, and hours -- considering the fact that the work shifts for the rover teams are organized in sols and not days.

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Post    Posted on: Thu Apr 07, 2005 9:16 am
It seems that I have to repeat a clarification first:

Whatever I said about the babylonian system and time units, clocks, time, seans, rotation periods etc. wasn't said in the meaning of physics nor in the meaning of astronomy - I don't look at it under the physical or astronomical aspect.

I am looking at it under the organizational and coordinational aspect. The babylonian system is in the mind of each human and it will be in his mind in the future too - nobody will accept the removal of it and its substitution by a non-babylonian system.

The whole life - scheduling meetings, scheduling vacation trips, timetables,when to leave home for work and when to sleep - is organized based on the babylonian time units and on a day of 24 hours, an hour of 60 minutes and a minute of 60 seconds. Each human is planning his day based on these units and each company too.

This is so at Earth and it will be so at Mars too and at Ceres also. At each planet the people - the workers and employees, the companies and authorities will divide the day into 24 hours, the hour into 60 minutes and the minute into 60 seconds.

At the spaceports the departures and the arrivals from other planets will be scheduled based on the babylonian units and the babylonian units - regardless at what planet you are. At each planet the day will be divided into 86400 seconds - regardless of the planet. The people will do so and they will refuse to do not. And this means that the people at Mars will use seconds, minutes and hours that are longer than the earthian ones. The difference in length will be a difference in the amount of collapses of Caesium atoms per second.

So at Earth a day will be 24 hours long - and at Mars too. Simply because the people will do so. The difference between 15:40 and 15:56 will be 16 minutes at Earth as well as at Mars - but the number of collapses of Caesium atoms will be different. Seen from the workers, employees, governmental authorities at both planets the same units and system are in use - and they will experience confusion because 16 minutes at Earth are passing by faster than at Mars.

The workers, employees, tourists and so on will DO AS IF time is measured astronomically - they unconsciously are used to do so. They don't know any rate of collapses of Caesium atoms per second. It's their behaviour what matters here - and they never will change that behaviour.

A supervising authority that controls the interplanetary traffic - like those authorities that control air traffic at Earth - needs one standard system with standard units that is valid throughout the whole system and this standard has to be that one that has the best chances to be accepted by the passengers of the vehicles too. These passengers will accept only a system and units that LOOK LIKE THEY WERE measured astronomically. Tourists and other travelers will best accept a system they can see by their own eyes - like they can see the change between daylight and night. And what can be seen best from each point or place throughout the solar system is the sun. The sun is rotating, its rotation is measured and thus its use may be similar familiar to the people as the daylight-night-circle is. Such people will be working for the supervising authority - not physicists, astronomers or other scientists. I know two of these people - called "Fluglotsen" in German - they never learned any science.

This all - behaviour of the people, what they are familiar to, what they will accept and what not etc. - is the reason I see why a new different standard is required in the future. This doesn't have anything to do with the real scientific measurement of time that I know of very well. And the number of collapses of atoms per second is far too abstrcat to the people - they never will become familiar to it.

Second I wnat to answer to some details of the previous posts - but please wait until I find time to do so in this post by EDIT.



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EDIT:

Hello, campbelp2002,

the appearance and disappearance of sunspots doesn’t mean differences in the speed by which they are moving along a latitude.So this is no argument here. It would be an argument if I really wanted to measure time by observation of sunspots – but this in turn I don’t want to do. I don’t want to measure time by observation of the sunspots – it’s quite different:

1. It is possible to let the people experience time by sunspots like they experience time by the daylight-night-circle. And in difference to the different rotation periods of the planet the rotation of the sun – indicated by the sunspots – has the same speed regardless where you are in the solar system. And it’s observable for the people during flights too when they are not on any planet and cannot experience time by the daylight-night-circle.

2. The rotation period of the sun is known. So it could be divided into units. These units could be the babylonian ones or they could be metric ones. The period is measured in days etc. but there could be an agreement to divide the rotation period into 100 units, each unit into 10 subunits, these subunits again into 10 subsubunits and these into subsubsubunits too. The units would replace days, the subunits would replace hours, the subsubunits minutes and the subsubsubunits seconds. Perhaps they could be called rotons, chrons, michrons and sechrons – the last two would remind to minutes and seconds a little bit. These units and their whole system would be applied by the supervising authority for ist own purposes only and shown to the passengers and travelers to enable a trouble-free interplanetary communication about departures and arrivals. This should be done only in combination with translations into the times valid at the planet left and the planet to go to.

3. The rotation period that should be made use of is the rotation of the solar equator.

4. The measurement could be done by Caesium clocks if the effects of differences in gravitation and speed are known sufficiently by experiments.

Regarding the size and weight of atom clocks it is insufficient that I cannot carry them on my left arm. That I can do this is required and common use.

The problem with the 180 seconds simply is that the distance the signal has to go isn’t constant and very seldom repeated. So the time of travel of that signal isn’t constant too. The calculation consumes time and the computer doing the calculation needs his own independent internal clock. It tends to be very complicated this way – more complex than it would be if the people at the other planet apply the babylonian units and system to the rotation period of their planet.



Hello, spacecowboy,

I know that the average time light is travelling by from Earth to Mars is about 20 minutes but I didn’t speak of the average time required. Last year the Mars was very close to Earth for a few days – 56 million kilometers if I remember right. Light doesn’t need 20 minutes for this close distance. The farthest distance I know of is 400 million kilometers or more.

Time system, nuclear physics and astronomy – there seems to be a misunderstanding. What I call time system here in this thread is the hierarchy of year, day, hour, minute and second – I should have called that system of time units better. Sorry for not being that precise.

What astronomy has done formerly and what nuclear physics is doing today concerning time I never would call determination or definition – „definition“ seems to be worth an Off Topic-thread under the aspect of Philosophics perhaps. I would call it calibration or adjustment – these are required for exact and precise measurement. I don’t have in mind measurement, calibration or adjustment here – these are way off my thoughts here.

And I agree to your last point – I mentioned it myself in the beginning. NASA has defined Sols in difference to days - the definition of sols in terms of oscillations of the cesium atom is different to the definition of days in terms of those oscillations and so are the seconds, minutes and seconds of the Sols. The rover teams lived for a while as if they were at Mars.

The problems, troubles and confuses I am speaking of will occur concerning the time between departure from one planet and arrival at another because these two times will have quite different values in Sols and its hours etc. to their according values in days and its hours etc. And in the future there will be people living at Mars used to thinking in Sols but calling them days while the people at another planet will be used to thinking in Non-Sols but calling them days too. And if people of the one planet visit the others at the planet of these others – then the difference between Sols and the Non-Sols will cause problems of communication about departure times and arrival times. These should be avoided and could be avoided by a solar system-wide standard.

But the major problems the supervising authority will be faced to who has to act off any planet.


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Post    Posted on: Thu Apr 07, 2005 12:34 pm
Here's what I was looking for!

See, the Martian Sol is defined in terms of seconds (hours and minutes are simply linear multiples of seconds, and not independent units), which are in turn defined as just-so-many-collapses-of-such-and-such-a-specific-Cesium-isotope.

Please note that much of that webpage is completely incomprehensible if you're not an astronomer (who are notoriously nitpicky about measuring time).

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Post    Posted on: Thu Apr 07, 2005 1:12 pm
OK, we agree that there are no technical problems.

The real issue is scheduling. How long should a day or a year be? Should a day on the Moon really be 4 weeks long or should we just use a regular 24 hour day? Should space craft in flight use Earth days and years or something else? You are proposing something else.

I propose solar system standard time (SSST) should be GMT (or UTC or similar time) because the Earth is, and will always be, the dominant location in this solar system. Space craft in flight, people on the Moon and people on every other object that does not have a natural day near 24 hours will also use GMT. Mars will use a 24 hour day of 86,400 Martian seconds. Like this:
http://marsrovers.jpl.nasa.gov/spotligh ... 40108.html

This system is simple, easy to use and only a little more confusing than the time zones on Earth. A system based on the 25 day solar rotation using new time units with names like rotons, chrons, michrons and sechrons is JUST CRAZY. Nobody will accept it. Not scientists, not space pilots and not Fluglotsen (I think this should be translated as “air traffic controller”), not nobody, not no how!


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Post    Posted on: Thu Apr 07, 2005 1:29 pm
Alright - what the people will accept and what not is opinion or imagnitaion only in the present. Because of being used to 24 hours etc., because of psychologics and similar reasons and because of causing orientation problems I suppose that the people woudn't accept Sols and days ending at a time that is a fraction of an hour - something like 24:31 for example. The orientation problems could be shown easyly by calculations.



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Location: Georgia Tech, Atlanta, GA
Post    Posted on: Thu Apr 07, 2005 10:00 pm
Hrm. The idea of using 24 Martian hours is definitely not out of the question, especially considering that over the course of a day, the difference in length will be hardly noticeable.

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Post    Posted on: Fri Apr 08, 2005 7:58 am
There is something to clarify:

By PM-communication to spacecowboy I detected a meaningful difference regarding clocks and time between the US and the UK at the one side and Germany and continental Europe at the other side.

In the US and the UK the AM/PM clock and time is common use - but in Germany, Austria, Switzerland and Liechtenstein and as far as I know in most of the european countries too the 24 hour-clock is in common use. The 12 hour-clock is in use too and fromerly it has been the major clock - but this 12 hour-clock is no explicit AM/PM-clock.

I know the difference between the two common uses and it's my fault no to take it into account - I simply wasn't aware of it.

It's a difference in culture...



Dipl.-Volkswirt (bdvb) Augustin (Political Economist)


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Post    Posted on: Fri Apr 08, 2005 12:20 pm
I'm not really all that sure how this would cause too much confusion.... The three people regularly commenting on this are you (Ekkehard), campbelp2002, and myself -- Sigurd was the last "other" poster, and that was three days ago -- and two of us are used to the idea of a 24-hour clock, and I'm sure that campbelp2002 is at least reasonably familiar with it.

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Post    Posted on: Fri Apr 08, 2005 12:37 pm
That's right.

I tend to think of the fact that we are talking in the public here and that there may be people reading all the threads and post without posting. To these people the post has been adressed mainly. Besides Sigurd Andy Hill at least has been posting here too.

The circumstance that each post is inserted after the last previous post tends to make the actual last post look as if were an answer to that last previous post even if that were not so really. A point I would have posted an improving proposal for in the according section if Sigurd weren't working on a new site already. I don't have the equipment and knowledges to take part in the development although he invited me.

So I don't propose improvements of the site currently.

...



Dipl.-Volkswirt (bdvb) Augustin (Political Economist)


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