2 hours ago, toucana said:

The concept of “Three square meals” had another provenance dating from slightly before the industrial revolution, and derives from the serving time of meals onboard British naval warships in the later 18th and early 19th century. This in turn relates to the system of watch-keeping used in the British navy to this very day.

The crew of a ship are divided into two 'watches' called 'port' and 'starboard' who alternate on duty according to a pattern of seven watches. Five of the watches are of 4 hours duration, the other two from 4 p.m. to 6 p.m., and 6 p.m. to 8 p.m. are of 2 hours duration and are known as 'dog watches'. The purpose of 'dog-watches' is to force an uneven number of watches in a day to ensure the men are never on duty at the same time from day to day.

https://en.wikipedia.org/wiki/Watchkeeping

The time within a watch is marked by chiming the ship's bell every half-hour with a rising number of strokes up to '8 bells'  to mark the end of of a four hour  watch, or  '4 bells to mark the end of a 'dog'.

Middle Watch  -       00.00  - 04.00

Morning Watch        04.00 - 08.00

Forenoon Watch      08.00 - 12.00

Afternoon Watch     12.00 - 16.00

First Dog                 16.00 - 18.00

Second Dog            18.00 - 20.00

First Watch              20.00 - 24.00

In British warships around the time of Lord Nelson, breakfast was served at around 7.00 am (at “six bells” in the morning watch) and consisted of oatmeal porridge and ship’s biscuit.  Dinner was served around 11.30 am to midday (“seven bells” in the forenoon watch) and was the main meal of the day consisting of boiled salt beef, peas and  biscuit. Supper was served around 4 pm or 6pm catering for the men in the shorter ”dog watches”, and usually consisted of biscuits and cheese.

Sailors ate from square wooden trenchers with raised edges known as a “fiddle”. These tray like trenchers gave rise to the term “a square meal”, and the raised edges of the tray acted as a form of portion control. Having food piled higher than this edge was known as “being on the fiddle” - a punishable breach of naval discipline and rationing control.

https://collection.thedockyard.co.uk/objects/9066/square-plate

The British navy in the time of Nelson was famous for its strict watch-keeping, and a rota of meal times which ensured that  sailors were well-fed with “three square meals” per day.

Indeed, an artificial concept that humans can live with, that doesn't mean that it's the healthiest way to live.

13 hours ago, toucana said:

the raised edges of the tray acted as a form of portion control.

This was only secondary to keeping food on the plate instead of sliding off while in heavy seas.

On 11/20/2025 at 1:41 AM, npts2020 said:

This was only secondary to keeping food on the plate instead of sliding off while in heavy seas.

The mess tables were usually suspended by ropes from the ceiling in between the guns, and also had raised rims to help retain the trenchers and drinking vessels in heavy seas.

https://snr.org.uk/maritime-art/the-sailors-mess-c-1800/

The watch-keeping system of bells was based on the use of a 30 minute sandglass kept by the helmsman’s position. As soon as the sand ran out, the ship’s bell was rung and the sandglass was inverted to run again. In the days before the Harrison H4 marine chronometer was perfected (c.1773), this form of time-keeping in tandem with the magnetic compass and ‘chip log’ was the only way of estimating a ship’s longitude by dead-reckoning. - (Latitude could be found by taking sun-shots at noon with a sextant).

On 11/19/2025 at 11:56 AM, toucana said:

Sailors ate from square wooden trenchers with raised edges known as a “fiddle”. These tray like trenchers gave rise to the term “a square meal”, and the raised edges of the tray acted as a form of portion control. Having food piled higher than this edge was known as “being on the fiddle” - a punishable breach of naval discipline and rationing control.

Well +1 for the whole post I never knew any of that.

Thanks.

5 hours ago, studiot said:

Well +1 for the whole post I never knew any of that.

Thanks.

There is a fascinating book called Longitude by Dava Sobel (1995) which tells the story of John Harrison (1693-1776) an English clockmaker who invented the first reliable marine chronometer, and of his battles with the Commissioners of the Board of Longitude to collect a prize of £20,000 for solving what was widely regarded as one of the greatest scientific problems of the era - how to calculate a ship’s longitude when far out at sea.

https://en.wikipedia.org/wiki/Longitude_(book)

Harrison’s H4 marine chronometers ran accurately on GMT, and longitude was calculated by comparing this with a local clock time that was reset each day by a navigator taking noon-day shots with a sextant. A difference of four minutes corresponds to one degree of longitude. (The earth takes 24 hours to revolve 360 degrees, so one hour marks 1/24 of a revolution or 15 degrees, and 60/15 = 4).

It's an interesting topic, but one that probably belongs in another thread

Apparently pendulums don't work well on a boat. 🤪

15 hours ago, TheVat said:

Apparently pendulums don't work well on a boat. 🤪

The pendulum clock was invented in 1657 by the Dutch mathematician Christiaan Huygens who thought his revolutionary new mechanism could be used to be build an accurate marine chronometer. He quickly found out otherwise when it was tested by his younger brother Lodewijk during a sea voyage to Spain in 1660.

https://en.wikipedia.org/wiki/Christiaan_Huygens

The rolling motion of a ship in heavy seas disturbed the pendulum, and rendered the chronometer no more accurate than conventional clocks of the period that could lose up to 15 minutes per day.

2 hours ago, toucana said:

The pendulum clock was invented in 1657 by the Dutch mathematician Christiaan Huygens who thought his revolutionary new mechanism could be used to be build an accurate marine chronometer. He quickly found out otherwise when it was tested by his younger brother Lodewijk during a sea voyage to Spain in 1660.

https://en.wikipedia.org/wiki/Christiaan_Huygens

The rolling motion of a ship in heavy seas disturbed the pendulum, and rendered the chronometer no more accurate than conventional clocks of the period that could lose up to 15 minutes per day.

Who knew eating would evolve into such a precious etymology...

20 hours ago, dimreepr said:

Who knew eating would evolve into such a precious etymology...

It all comes back to time-keeping, and how we as human beings synchronise and regulate our internal metabolic body clocks with the mechanical clocks and social systems of time management that we all need to live within.

There are certain strong physiological cues that predispose humans to take in nutrition at particular times of day. ‘Breakfast’ for example is so named because we quite literally need to break a fasting period of some 8 to 10 hours spent asleep (that’s etymology for you). The physiological cues that drive us towards the breakfast table are low blood sugar and raised levels of a hormone called ghrelin produced by the stomach.

A pineal hormone called melatonin is produced by the body at night as part of the human ‘circadian clock” and it functions as a sleep cue by building up after supper around two to three hours before we normally go to sleep. Melatonin also functions as an appetite regulator. Rising levels of melatonin stimulate the production of a hormone called leptin by the fat cells in our bodies, and that functions as an appetite suppressant.

https://revistapesquisa.fapesp.br/en/a-connection-between-sleep-and-hunger/

Melatonin levels fall steeply towards the end of the night, and as daylight returns, leptin production is replaced by that of ghrelin, as we awake, take breakfast, and prepare for our period of maximal activity in daylight hours once again.

Carefully timed oral doses of melatonin can be successfully used to counter jet-lag for this reason:

https://www.timeshifter.com/jet-lag/melatonin-for-jet-lag-type-dose-timing

3 hours ago, toucana said:

It all comes back to time-keeping, and how we as human beings synchronise and regulate our internal metabolic body clocks with the mechanical clocks and social systems of time management that we all need to live within.

Time-keeping is only for the worker's and the time and motion expert's.

A rigid approach that seems to exclude half the population, good for the early bird a complete fail for the owl.

Who knew what a bleak expectation that would be?

3 hours ago, dimreepr said:

Time-keeping is only for the worker's and the time and motion expert's.

A rigid approach that seems to exclude half the population, good for the early bird a complete fail for the owl.

I think you should do a little more research into Circadian Rhythms before being quite so dismissive about the role of 'time-keeping' in human biology.

Circadian Rhythms

Circadian rhythms are controlled by biological clocks located in organs and glands throughout the body, but all of these peripheral clocks are commanded by a “master clock” in a region of the brain called the suprachiasmatic nucleus (SCN).

In most adults and adolescents, this master clock operates on a cycle that’s slightly longer than 24 hours. In order to maintain alignment with the 24-hour rotation of the planet, the master clock must adjust by about 12 to 18 minutes every day. For this reason, it times circadian rhythms according to environmental cues known as “zeitgebers,” German for “timekeepers.”

Light and darkness are the most important and powerful zeitgebers. Other zeitgebers involved in circadian timing include :

• Meals

• Exercise

• Social interactions

• Daily routines

• Stress

These zeitgebers trigger the release of hormones in the brain and the delivery of chemical signals to body tissues. Thus, the master clock is able to effectively time vital body functions, such as the conversion of food into energy, fluctuations in body temperature, and when a person feels like sleeping or waking up.

https://www.sleepfoundation.org/circadian-rhythm

9 hours ago, toucana said:

There are certain strong physiological cues that predispose humans to take in nutrition at particular times of day. ‘Breakfast’ for example is so named because we quite literally need to break a fasting period of some 8 to 10 hours spent asleep (that’s etymology for you).

Where are these homes with people sleeping 8-10 hours that you speak of? Do such homes offer adoption programs? Are these residents like baby angels raised by puppies in a beachfront palace with no right angles?

Light teasing aside, it seems like routines make considerable difference in the overnight fasting period. Breakfast, as a zeitgeber, seems malleable. Though most people who try shifting to a brunch, moving the fast from twelve hours to sixteen, say, will hit a fairly hard wall at some point. While I benefit from my 16 hour hiatus, it didn't come easily, and I really need to find some food by 10-11 am.

Edited November 25Nov 25 by TheVat

12 hours ago, TheVat said:

Where are these homes with people sleeping 8-10 hours that you speak of? Do such homes offer adoption programs? Are these residents like baby angels raised by puppies in a beachfront palace with no right angles?

Light teasing aside, it seems like routines make considerable difference in the overnight fasting period. Breakfast, as a zeitgeber, seems malleable. Though most people who try shifting to a brunch, moving the fast from twelve hours to sixteen, say, will hit a fairly hard wall at some point. While I benefit from my 16 hour hiatus, it didn't come easily, and I really need to find some food by 10-11 am.

Infants need 11 to 17 hours of sleep per 24 hours, toddlers require 10 to 13 hours of sleep per day, and teenagers usually need 8 to 10 hours of sleep per night according to sleep research studies. It’s only older adults who commonly require 7 hours or less of sleep each night.

https://www.mayoclinic.org/healthy-lifestyle/adult-health/expert-answers/how-many-hours-of-sleep-are-enough/faq-20057898

What is really interesting however is that well up until the 18th century, many western people used to follow a biphasic pattern of sleep. Quite a number of written sources indicate that people often followed a pattern of “two sleeps” involving a night divided into two halves with a period of social activity in between.

https://www.bbc.co.uk/future/article/20220107-the-lost-medieval-habit-of-biphasic-sleep

People would take their ‘first sleep’ between 21:00 and 23:00, be active and be awake from 23:00 to 01:00 - a period of time also known as a ‘watch' (echoing the naval term  “middle watch’’), before taking a ‘second sleep’ that ended at dawn.

There is much discussion as to how and why people shifted over to a monophasic pattern of sleep from the early 19th century onwards. Industrial shift working, artificial illumination at home which encouraged people to stay up later by shifting the circadian sleep cues, and the invention of the alarm clock in 1787 have all been cited.

Edited November 26Nov 26 by toucana
Corrected spacing line 1 & 3.

21 hours ago, toucana said:

I think you should do a little more research into Circadian Rhythms before being quite so dismissive about the role of 'time-keeping' in human biology.

I'm not being dismissive of our biological clock, I'm suggesting it doesn't quiet match our quantum clock...

On 11/25/2025 at 9:53 AM, toucana said:

There are certain strong physiological cues that predispose humans to take in nutrition at particular times of day. ‘Breakfast’ for example is so named because we quite literally need to break a fasting period of some 8 to 10 hours spent asleep (that’s etymology for you).

Two points:

You can't have it both way's, it's either time or culture that drive our need to eat; hunger seems to be a healthier approach.

Breakfast has become a marketing exercise by the guy's that need to sell all the sugar (they don't need to grow), that's etymology for you... 😉

Just my personal evidence, but when I'm actually hungery, it's not a chocolate bar that I crave, it's a cooked horse...

6 hours ago, toucana said:

There is much discussion as to how and why people shifted over to a monophasic pattern of sleep from the early 19th century onwards. Industrial shift working, artificial illumination at home which encouraged people to stay up later by shifting the circadian sleep cues, and the invention of the alarm clock in 1787 have all been cited.

Why?

What's your point?

As far as I can tell, you've literally taken the title (of this topic) too literally, with all your naval gazing...

2 hours ago, dimreepr said:

I'm not being dismissive of our biological clock, I'm suggesting it doesn't quiet match our quantum clock...

What exactly is a  ‘quantum clock’ in this context, and which part of the humen anatomy do you think it resides in ?

I’’m wondering if you even realise that quantum clocks have to be laser cooled to near absolute zero in order to function ? Which part of the brain or human nervous system do you think functions at just above 0° Kelvin ?

Or are you perhaps using the expression ‘quantum clock’ as a metonym for all objective scientific methods of measuring and quantifying time  - in which case why not say so ?

I would refer you to the Sleep Foundation article I quoted from earlier which says:

"In most adults and adolescents, this master clock operates on a cycle that’s slightly longer than 24 hours. In order to maintain alignment with the 24-hour rotation of the planet, the master clock must adjust by about 12 to 18 minutes every day. For this reason, it times circadian rhythms according to environmental cues known as “zeitgebers,” German for “timekeepers.”

Biological clocks and zeitgeber cues are both involved - there is no either/or here - both are relevant.

The point of mentioning biphasic sleep patterns was to answer a humorous aside made by TheVat about typical patterns  of sleep duration, by pointing out that monophasic sleep appears to be a relatively modern cultural adaptation.

Edited November 26Nov 26 by toucana
corrected spelling of 'article'

14 hours ago, toucana said:

It’s only older adults who commonly require 7 hours or less of sleep each night.

Jesting about the "baby angels," as I'm sure you realized. Americans are notorious for their cultural tendencies towards sleep deprivation. The bit about biphasic sleep is interesting, and something my historian partner has delved into. I am inclined that direction myself, and will often split my sleep cycles now that I'm retired. One pleasure of the biphase night is remembering dreams better.

9 hours ago, dimreepr said:

As far as I can tell, you've literally taken the title (of this topic) too literally, with all your naval gazing...

Well, who doesn't enjoy watching the battleships as they glide into their docks?

18 hours ago, toucana said:

What exactly is a  ‘quantum clock’ in this context, and which part of the humen anatomy do you think it resides in ?

I’’m wondering if you even realise that quantum clocks have to be laser cooled to near absolute zero in order to function ? Which part of the brain or human nervous system do you think functions at just above 0° Kelvin ?

At risk of another neg, are you being deliberately obtuse?

Do you not realise that I'm drawing a distinction between time as we percieve it, and time that's imposed on us?

One is healthier for the bank balance, of one's boss, and the other is healthier for one...

13 hours ago, TheVat said:

Well, who doesn't enjoy watching the battleships as they glide into their docks?

Whatever floats ones boat... 😉

On 11/26/2025 at 10:51 PM, toucana said:

Or are you perhaps using the expression ‘quantum clock’ as a metonym for all objective scientific methods of measuring and quantifying time  - in which case why not say so ?

I would refer you to the Sleep Foundation article I quoted from earlier which says:

"In most adults and adolescents, this master clock operates on a cycle that’s slightly longer than 24 hours. In order to maintain alignment with the 24-hour rotation of the planet, the master clock must adjust by about 12 to 18 minutes every day. For this reason, it times circadian rhythms according to environmental cues known as “zeitgebers,” German for “timekeepers.”

Biological clocks and zeitgeber cues are both involved - there is no either/or here - both are relevant.

Relevant to what?

You seem to be missing the point of this thread, time is just an abstract number in terms of the fuel needed for the circadian rhythm to run smoothly.

It's like deciding to be a vegan, despite cheese...

4 hours ago, dimreepr said:

It's like deciding to be a vegan, despite cheese...

You presumably don't realise that there is such a thing as Vegan Cheese either - said to be quite tasty too.

https://en.wikipedia.org/wiki/Vegan_cheese

Why don't you go and eat a horse ? - your blood sugar seems to be on the blink atm.

18 hours ago, toucana said:

You presumably don't realise that there is such a thing as Vegan Cheese either - said to be quite tasty too.

https://en.wikipedia.org/wiki/Vegan_cheese

Why don't you go and eat a horse ? - your blood sugar seems to be on the blink atm.

Good joke, hmmm 🤔.

At least there's a point to mine, veganism, in this context, is an artificial human construct that isn't sustainable naturally.

I can't help but think that vegans are taking Buddhism to far, like the monks who stay awake as much as possible, to avoid crushing an innocent tick.

If one is interested in exploring the differences between human and nonhuman animals eating habits, you cannot ignore the impact of cooking/preparing meals vs eating organisms as they lie.

Edited December 10Dec 10 by LuckyR

1 hour ago, LuckyR said:

If one is interested in exploring the differences between human and nonhuman animals eating habits, you cannot ignore the impact of cooking/preparing meals vs eating organisms as they lie.

Wow! If only this thread had had a first page where this was extensively discussed.