Rudimentary Geography Question 1

[StuM]

Originally Posted by waterman46

Yeah, that's why I qualified it by saying "if your clock had a calendar". Showing one day earlier is correct, I thought I made that clear, but perhaps not.

Nope, you still don't get it. You said:
"Each time you go into a new time zone you have to set your clock 1 hour earlier. If you traveled all the way around the world, you would end up setting your clock 24 hours earlier. If you didn't do that, and your clock also had a calendar, you'd find your calender was 24 hours, or one day, later than where it should be."


That is completely wrong.

If you didn't do that, your calendar would be correct.


By not changing your clock at all, its offset from UTC doesn't change.
By turning it back by an hour 24 times, it ends up 24 hours (1 day) earlier than UTC.

[El Pinguino]

I do so wish that people would refrain from typing in bold when they disagree with someone... it is akin to ALL CAPS.....

That said I can see what Waterman is saying... and to say that the spaniards didn't have aircraft is sheer pettiness ... explaining how this works does not have to be stuck in the pre-railway days before the coming of timetables...

I have a watch which shows the date.. its analog and all sorts of other fancy stuff...

If, when I am sailing west, I retard the time by 1 hour for every 15º of longitude it will get back to the original time after I have covered 360º.... 360º/15 = 24h

However, on my watch at least , it will not have adjusted the date... ie when the hands pass backwards through 00h00m the date will not 'lose a day'.... something to do with the internal gearing....
So I would arrive back in London or wherever I'm one day adrift in my date.

Now if I am heading east and am advancing my clock 1 hour every 15º it will advance the date by one day when the time passes through 00h00m... ie every second pass of the little hand past the 12....

So if Phineas Fogg had a day/date analog back in 1872 he would not have been confused about the date.

Mind you crossing the North Pacific and Americas he should have picked up a few hints re the changed date... train timetables in the US f'rinstance

Even though there was no 'Date Line' until the 1880s ships crossing from the Far East to the Americas ..and v/v .. or sailing ships with coal from Newcastle, NSW to Antofagasta and bringing guano back to the colonies from the Chincha Islands... had to deal with this issue every voyage...

Speaking of which... interesting factoid from the days of steam....
When merchant ships crossed the date line going from west to east they always seemed to gain a weekday... when losing a day on the east to west voyage it was always the Sunday that disappeared...

[SeanPatrick]

Originally Posted by El Pinguino

I do so wish that people would refrain from typing in bold when they disagree with someone... it is akin to ALL CAPS.....

I think that's what's intended. When I read bold text, the voice in my head gets slightly louder (and slightly higher in pitch) to indicate emphasis on the phrase in bold. The same way most people emphasize a phrase in actual speech.


When I read italics, I presume a slightly higher pitch - but no change in volume.


Everyone knows all caps is yelling.




PS


Bold italics is just a smidge below yelling.

[Benz]

Slightly related: in the novels of square riggers, you always read about them finding noon with the sextant--that is, local apparent noon. They would set their watches by it every day, while the chronometer was still on GMT. So then longitude could be worked out, and the ship's schedule could continue based on local time.

[StuM]

Originally Posted by SeanPatrick

I think that's what's intended. When I read bold text, the voice in my head gets slightly louder (and slightly higher in pitch) to indicate emphasis on the phrase in bold. The same way most people emphasize a phrase in actual speech.

Exactly.
In the absence of voice modulation/expression, the conventional method of drawing attention to key points in print is to mark it up in some way. Without markup, the reader has to guess where the intended emphasis lies - which can frequently lead to misinterpretation.

Basically there are four HTML tags designed for such markup: Bold <b>, Strong <strong>, Emphasis <em> and Italic <i> There are no "emphasis" or "strong" font styles the way their are bold and italic styles. Therefore the emphasis tag is rendered in an italic font and the strong tag in bold font by current browsers.


It's not a matter of disagreement, it's a matter of emphasis.


Personally, I prefer bold text to italics to show emphasis, but that's just me. (I tend to use italics for quotes) The only other practical alternative is to use different colours, but that has its own drawbacks since colours invoke different emotions in different people.

[El Pinguino]

Originally Posted by StuM

Which, unfortunately is completely incorrect
The early Spanish circumnavigators didn't have planes, "time zones" or phones.
Wrong! If you do nothing to your watch, ....

No...that is not good... even primary school teachers know that... or should...

You don't say Wrong!

You say... ' I think you may be mistaken... I would suggest that.....'

Just saying wrong! to a small child will scar them for life... say it to an adult and they will... well... your choice...

[El Pinguino]

Originally Posted by Benz

Slightly related: in the novels of square riggers, you always read about them finding noon with the sextant--that is, local apparent noon. They would set their watches by it every day, while the chronometer was still on GMT. So then longitude could be worked out, and the ship's schedule could continue based on local time.

That carried on until well into the 1930s.... and only died out after people( old phart captains?) became used to using radio time signals to correct their chronometers.

So yes .. they set their days from local apparent noon... which is why my 1960ish Nories has has speed / days run tables based on 22h to 26h days.....

[Wotname]

Originally Posted by StuM

"Contarini was the first European to give a correct explanation of this phenomenon"

Which implies that there was a "non-European" who worked it out before he did? Who? Enquiring minds want to know!

Insightful question however it raises many more. If it was reworded as "Contarini was the first person to give a correct explanation of this phenomenon", would it be implied that a non person worked it out earlier? Perhaps an albatross or a whale or some plankton even.

Further yet, is measuring time in days simply a human concept? If it was reworded as "Contarini was the first to give a correct explanation of this phenomenon", could it be assumed Contarini must be a person?

Enquiring minds want to know!

[El Pinguino]

Originally Posted by Wotname

Insightful question however it raises many more. If it was reworded as "Contarini was the first person to give a correct explanation of this phenomenon", would it be implied that a non person worked it out earlier? Perhaps an albatross or a whale or some plankton even.

Further yet, is measuring time in days simply a human concept? If it was reworded as "Contarini was the first to give a correct explanation of this phenomenon", could it be assumed Contarini must be a person?

Enquiring minds want to know!

The Moluccan in the crew... I think he came from Ternate.... was the first to complete a circumnavigation...

Did he go home to mum and say ' where's me sunday roast' and then think...'wot's going on here?' and then figure it all out? We shall never know....

[valhalla360]

A simple clock that would function accurately at sea was critical to the Brits ruling the seas.

Lattitude was fairly straight forward to determine by estimating the angle of celestial bodies above the norther (or southern) horizon. But without a way to determine Longitude, it limited how sailors could navigate. It was common to run north/south until you got to the latitude of your destination then turn east/west until you ran into your destination because you had no good method to estimate how far east/west you had traveled. This added distance, possibly poor weather and military predictability.

By setting a clock at a known longitude (say Greenwich), you could then compare to noon where you are by finding the time when the sun is at it's highest point in the sky. You would then know how many hours you were from Greenwich. (I'm oversimplifying to demonstrate the principal).

Now with both lattitude and longitude, you can determine your position. This allowed the Brits to take shortcuts saving time, using weather to better effect and allowed them to show up in surprising locations because they weren't as limited as their contemporaries.

[Lodesman]

Originally Posted by StuM

"Contarini was the first European to give a correct explanation of this phenomenon"

Which implies that there was a "non-European" who worked it out before he did? Who? Enquiring minds want to know!

It's given in the wiki:

Although the Arab geographer Abu'l-Fida (1273–1331) had predicted that circumnavigators would accumulate a one-day offset,[141] Cardinal Gasparo Contarini was the first European to give a correct explanation of the discrepancy

[StuM]

Originally Posted by Lodesman

It's given in the wiki:

Ah, yes. I see that now. That's right at the end of your first link, to Magellan. I didn't see it there, I was quoting from your second link to Gasparo Contarini which uses exactly the same phrase but without a reference to Abu'l-Fida.

[Lodesman]

Originally Posted by waterman46

Yeah, that's why I qualified it by saying "if your clock had a calendar". Showing one day earlier is correct, I thought I made that clear, but perhaps not.

I used to have a watch that showed not only time but date. I guess those have all gone the way of dinosaurs, or as some would have us believe, the same way as the CQR anchor!

Originally Posted by waterman46

Each time you go into a new time zone you have to set your clock 1 hour earlier. If you traveled all the way around the world, you would end up setting your clock 24 hours earlier. If you didn't do that, and your clock also had a calendar, you'd find your calender was 24 hours, or one day, later than where it should be.

I think you might be as confused by what you wrote, as the rest of us.

You correctly stated that if you set your clock 1 hour earlier as you pass through each time zone, then you would arrive with your clock set 24 hours earlier than the local clocks - unstated, the date on your clock would be 1 day earlier than the local clocks with dates. You then wrote "if you didn't do that", implying you didn't reset your clock with each passing time zone, then your calendar will be one day later than it should - if by "it should" you mean "incorrectly set to the wrong date" then you would be correct. However for most of us, having our watches displaying the actual date that is being observed at the location, that is where we think it should be. If I was to take off today (the 1st) on a 24-hr flight around the world, I will arrive back home on the 2nd - if I haven't touched my watch, it will show the 2nd; if I've turned the clock back every hour then I'll touch down at the same time I departed on the 1st (according to my watch), but it will be the 2nd.

[fivecapes]

Originally Posted by El Pinguino

The Moluccan in the crew... I think he came from Ternate.... was the first to complete a circumnavigation...

I think you meant Enrique was from Malacca (now Melaka) in Peninsular Malaysia, not Moluccas (Maluku) in East Indonesia.

[Lodesman]

Originally Posted by El Pinguino

The Moluccan in the crew... I think he came from Ternate.... was the first to complete a circumnavigation...

How do you get that? - They picked the Moluccan up in the Moluccas. There's no indication that he ever returned home, and certainly not until after the first 18 arrived in Seville - Manuel wasn't even one of them.