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View Full Version : Is there a globle time !?


Matter
Sep3-04, 03:39 AM
When I refer to time ,I mean the (tick, tock) clock type!
eg: it's 10:11 Friday morning 03-09-2004
I first considered this Q. in my teens. When on my first big adventure out into the world. I flew from one part of the world to another. There was a connecting flight in a third part of the world with a two hour layover.
On landing in the stopover airport I was surprised that although I literal had a two hour wait for my connecting flight. I had in fact landed an hour after I took off on my connecting flight.
:uhh: come to think of it, I haven't worn a wrist wach since! I don't really keep track of what day it is either! It really doesn't matter. Or does it?
Don't get me wrong I keep appointments and I am more often than not early. I eat when I am hungry and sleep when I'm tiered. But time as something I register! NO not really. I often only realise it's late because I've forgotten to buy milk and the shops closed. ( I drink to much coffee any how),so no matter!
Another point
When I'm on the net (as I am) chatting to someone ,whose time zone may be ten hours in front or behind of mine. Am i surposed to belive that Im sending or receiving messages from or to the past/future!
I think not. all that counts is 'here' and 'now'. :bugeye:

amwbonfire
Sep3-04, 07:46 AM
I don't think there can ever be a global time. At least not perfectly accurate.

Think about this: It's 10:00 here. Even if we synchronise EVERY place on Earth, there'll be a slight delay (due to the distances). So it's impossible to have perfectly synchronised time everywhere.

That's why we should revert to the old systems of sundials; using the sun to tell the time. Then we don't have to be accurate! :biggrin:

Gokul43201
Sep3-04, 09:15 AM
Our current system IS based (more or less) on sundials. The sun rises in the morning, reaches a maximum altitude around mid-day, and sets in the evening. Of course, if you lived in Rekjavik or Murmansk, you never really used a sundial in the first place.

If you did have a universal Global Time, then you'd have the sun rising at midnight in, say China and at mid-day in the US.

Monique
Sep3-04, 09:35 AM
Greenwich Mean Time, England (GMT) is international time, the basis of the world time clock. http://wwp.greenwichmeantime.com/

russ_watters
Sep3-04, 09:47 AM
Greenwich Mean Time, England (GMT) is international time, the basis of the world time clock. http://wwp.greenwichmeantime.com/ Time has always been a local phenomena based on the sun. Until the advent of rail travel, this wasn't an issue - time zones were invented largely to reconcile train scheduling in the 1800s. GMT became the referrence point for the time zones, but really has been the basis for much longer than that (though the French would disagree).

Matter, I'm not sure I understand your problem. If, for example, everyone synchronized their watches to GMT, that wouldn't be an improvement because the times of day are based on the position of the sun. Imagine the confusion if you went traveling - you would have no idea what time to get up in the morning. You wouldn't even know when "morning" was!

Vance
Sep3-04, 09:50 AM
When I refer to time ,I mean the (tick, tock) clock type!
eg: it's 10:11 Friday morning 03-09-2004
I first considered this Q. in my teens. When on my first big adventure out into the world. I flew from one part of the world to another. There was a connecting flight in a third part of the world with a two hour layover.
On landing in the stopover airport I was surprised that although I literal had a two hour wait for my connecting flight. I had in fact landed an hour after I took off on my connecting flight.
:uhh: come to think of it, I haven't worn a wrist wach since! I don't really keep track of what day it is either! It really doesn't matter. Or does it?
Don't get me wrong I keep appointments and I am more often than not early. I eat when I am hungry and sleep when I'm tiered. But time as something I register! NO not really. I often only realise it's late because I've forgotten to buy milk and the shops closed. ( I drink to much coffee any how),so no matter!
Another point
When I'm on the net (as I am) chatting to someone ,whose time zone may be ten hours in front or behind of mine. Am i surposed to belive that Im sending or receiving messages from or to the past/future!
I think not. all that counts is 'here' and 'now'. :bugeye:
Right now,
it is 11:44
in Japan,
and he should be
flying somewhere in
the sky!
or he might
be sleeping in
some hotel,
eating or shopping somewhere
in another country.
I will leave again
and this time I
will leave longer
than 2 weeks,
yes, Vienna and Rome,
you2 are so beautiful in
my dream, I will
see you by my own eyes in
a couple of days
after he comes back.
He will, tommorrow he will.
And I am not allowed
to visit you again,
but I will,
and I will do that on
October 1st.
See you, see you, see you again...

Monique
Sep3-04, 10:19 AM
Matter, I'm not sure I understand your problem. If, for example, everyone synchronized their watches to GMT, that wouldn't be an improvement because the times of day are based on the position of the sun. Imagine the confusion if you went traveling - you would have no idea what time to get up in the morning. You wouldn't even know when "morning" was!
Luckily we have time-zones now, before that every city used to have their own time based on the sun, which led to confusion if you visited a neighbouring city.

Monique
Sep3-04, 10:26 AM
For those who can read it (I'll give a summary later):Mijn vader is 17 maart 76 jaar geworden. In het Algemeen Handelsblad van zijn geboortedag in 1928 staat dat de zonsopgang destijds om 6:12 uur was en de zonsondergang om 18:06 uur. Op 17 maart 2004 kwam de zon om 6:49 uur op en ging onder om 18:48 uur. Hoe is deze grote verschuiving mogelijk?

Niet de zon, maar de tijd is verschoven, schrijft Rinke Hoekstra. ‘Vroeger had elke stad haar eigen tijd. Wanneer de zon ter plekke op zijn hoogste punt stond, was het twaalf uur ’s middags. Zo had je een Groningse, Utrechtse en een Amsterdamse tijd. Vanaf 1845 kregen steden door heel Nederland het advies om hun klok gelijk te zetten met de Amsterdamse. Die liep toen 19 minuten en 32 seconden voor op Greenwich. In 1937 werd de klok 28 seconden vooruit gezet, zodat we precies twintig minuten voorliepen op Greenwich. Op 16 mei 1940, toen Nederland onder Duits gezag was gekomen, werd verordonneerd dat de Duitse tijd aangehouden moest worden. Die klok liep veertig minuten voor op de Nederlandse.’
Die Midden-Europese Tijd (MET) hebben we nog steeds. ‘De zon staat daardoor om 12.00 uur op zijn hoogste punt boven de Duits-Poolse grens’, schrijft Arend Aantjes (Amersfoort). ‘In Nederland staat de zon om 12.40 uur op zijn hoogst. In de zomertijd komt hier nog een uurtje bij.’
Met die tijdscorrecties blijft er een paar minuten verschil in de genoemde tijden van 1928 en 2004, schrijft Mat Drummen, directeur Stichting De Koepel (Utrecht). ‘Dat is vermoedelijk te wijten aan de verschillende gebruikte bronnen. Geldt de gegeven tijd voor Utrecht of voor een andere plaats in Nederland?’
Voor een gedetailleerde beschrijving van de geschiedenis van onze tijd: www.phys.uu.nl/~vgent/wettijd/wettijd.htm

BobG
Sep3-04, 10:28 AM
Greenwich Mean Time, England (GMT) is international time, the basis of the world time clock. http://wwp.greenwichmeantime.com/

Monique is right. Greenwich Mean Time (aka Universal Standard Time or ZULU Time) is used in many jobs where you have to have to talk to folks all over the world.

But, speaking of sun dials brings up the point that, even locally, we use mean solar time instead of the true solar time. What will be the longest true solar day of 2004?

humanino
Sep3-04, 11:01 AM
Greenwich Mean Time (aka Universal Standard Time or ZULU Time) is used in many jobs where you have to have to talk to folks all over the world.

Usually, our US-Europe-Russia meetings occur at about 9h00am 10h00am US time so that it's the end of the afternoon for us in Europe. Then, if the meetings last too long, american don't care (it's just on their normal job hours). Back in Europe, we often have to stay afterhours because of this. Anyway, physicists always stay afterhours I guess. You know that joke about the physicist that get back home at 2h00 am, lipstick on his face, messy hair, female perfume on him.... and his wife goes : "Don't try to lie. I know you come from the lab" :rolleyes:

Am i surposed to belive that Im sending or receiving messages from or to the past/future!
I think not. all that counts is 'here' and 'now'. This is not a serious question, is it ? :wink:

BobG
Sep3-04, 11:05 AM
I don't think there can ever be a global time. At least not perfectly accurate.

Think about this: It's 10:00 here. Even if we synchronise EVERY place on Earth, there'll be a slight delay (due to the distances). So it's impossible to have perfectly synchronised time everywhere.

That's why we should revert to the old systems of sundials; using the sun to tell the time. Then we don't have to be accurate! :biggrin:

Just synchronize your watch to the time displayed on a GPS receiver while you're locked onto the satellites. Thanks to the method GPS uses to figure out where you are, your GPS receiver is likely to be the most accurate time piece you'll ever hold in your hand (at least while it's locked on to some satellites).

Matter
Sep4-04, 07:19 AM
No mentor!
I don't have any problems worth mentioning in PF. I was just thinking 'aloud'
the only Q I had (that was serious) was weather or not there was a Global time and I got the answer for that!
thanks :wink:

flexten
Sep5-04, 08:21 AM
And also:


\[
{\rm{ZULU}} \equiv Greenwich
\]


.

jimmy p
Sep6-04, 02:50 PM
I always thought that Zulu time was an hour ahead of GMT.

tribdog
Sep6-04, 03:51 PM
I always thought that whatever time it is where ever I am is the time it is, globally. Not that Im the most important person in the world, I'm just the most important person in my world.

Moonbear
Sep6-04, 05:29 PM
Back in Europe, we often have to stay afterhours because of this.

You have hours? To stay afterhours, that implies you have actual regular hours you work...do you really? :bugeye: Aha! Imposter! No REAL scientist would acknowledge such a thing existed as "after" hours! :rofl:

humanino
Sep6-04, 05:37 PM
You know what : when I come back home after 10 hours or more, I still can't help doing physics. The "Don't try to lie. I know you come from the lab" is a serious concern of mine.

But then, we have hours, because we have those "trade union" (not sure it is the right word) to protect us. If I did not have hours, my boss could force me to stay forever :surprised Once again, I admit that would not really be an issue for me, but for my social life. :yuck:

Monique
Sep6-04, 05:45 PM
They want to implement a 40 hour work week here in the Netherlands.. everyone is shocked.. that means putting in extra hours :surprised: At my previous position (in the US) I worked from 6 am until 6 pm and sure didn't get paid for all the extra hours :rolleyes:

jcsd
Sep6-04, 05:54 PM
I was born in Greenwich. That is why global time is measured from there.

humanino
Sep6-04, 06:03 PM
Hey Monique, what's up with post #8 ?
In France we have the so-called 35 hours a week, proposed by the previous governement. It is very good for people who do physically difficult jobs. But it is certainly not applied to engineers or equivalent jobs. Research is a way of life, so Moonbear is totally right. But people who chose their job on income criteria and now have to do the 50-hours must really like money :wink:

tribdog
Sep6-04, 08:09 PM
Why doesn't Greenwich rhyme with sandwich?

humanino
Sep7-04, 04:44 AM
Maybe Lord Sandwich came from Greenwich.
That would not explain anything though. :redface:

russ_watters
Sep7-04, 12:02 PM
Maybe Lord Sandwich came from Greenwich.
That would not explain anything though. :redface: I though Sandwich was an Earl?

Smurf
Sep7-04, 12:06 PM
I like that?

tribdog
Sep7-04, 08:43 PM
I though Sandwich was an Earl?
I thought a sandwich was a sandwich, but a Manwich was a meal.

jimmy p
Sep9-04, 02:49 PM
So what is a Greenwich?

tribdog
Sep9-04, 06:34 PM
So what is a Greenwich?
A biodegradable fairy?
a jealous gypsy?
an elf with the stomach flu?

The Bob
Sep10-04, 03:25 AM
Why doesn't Greenwich rhyme with sandwich?

They are said differently.

I though Sandwich was an Earl?

It was the Earl of Sandwich.

So what is a Greenwich?

A green witch but they missed the 't' out.

The Bob (2004 ©)

Anthony Shore
Sep11-04, 01:10 AM
Another point
When I'm on the net (as I am) chatting to someone ,whose time zone may be ten hours in front or behind of mine. Am i surposed to belive that Im sending or receiving messages from or to the past/future!
I think not. all that counts is 'here' and 'now'. :bugeye:

Ok, this was meant as a "silly" question, wasn't it? Time zones based on GMT as the central point for "universal standard time"...measurment of time based on position of sun...the sun does not appear to be in the same position globally as the planet is spherical so, what position the sun appears in on the western hemisphere will naturally be different on the eastern hemisphere and therefore the "local time" at a given location will be different...it is not a matter of "past or future" its a matter of where the sun appears to be at any given point on the planet and the "local time" is adjusted accordingly.