• Member Since 28th Oct, 2012
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Particle Physics and Pony Fiction Experimentalist


In a world where the movement of the sun and moon is down to the whims of alicorn princesses, other ways must be used to keep track of time. High up in the mountain above Canterlot, there lies an old abbey, home to the Order of the Time Turners, a monastic community of ponies founded by Starswirl the Bearded, who follow a strict timetable of daily duties to regulate the length of day and night. After following the same routine for over seven hundred years, things are about to change.

A tale of Equestria from the time before Luna’s exile, told by Doctor Hooves, with further commentary by Twilight Sparkle and the Cutie Mark Crusaders.

Chapters (7)
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Comments ( 100 )

A late request by the Show Jumpers League for an extra day to hold their annual gala was permitted one year in four (so-called leap years).

I shouldn't find that nearly as funny as I do.

The Minute cannot run slow by definition. It always runs at one minute per minute because it is what defines the minute. It is the absolute time standard, so it can't run slow. Instead your hourglass was running fast.

Well, there's dangerous thinking. If I shaved a few filings off of the official kilogram (back when there was one, of course,) would that make everything heavier?

Why would the Practical Scholar insist on using a base-10 system when he doesn't have fingers?

Given Equestria's highly magical nature, it's possible that lower solar exposure really is the cause of winter. Another possibility is conscious choice, whether Star Swirl's schedule or just ponies in general. When you have to manually change the seasons, the blame may rest with those ponies who helped with the Fall Finale.
Oh, who am I kidding? You're writing this. We both know what the answer will be. As long as the axis is tilted, geocentrism and heliocentrism have the same effect. Reference frames are a wonderful thing.

Spit takes are part of pony magic? Headcanon considered.

Oh, Twilight. :twilightsheepish:

I do love the various creation myths, and the cliffhanger. Looking forward to more.

Aww, I thought the Cutie Mark Crusaders were going to be sent back in time, with shenanigans resulting. Still, very interesting setup. I think there is an Asimov story where someone reinvents a method to do mathematics by hand after everyone has grown so reliant on calculators the skill has been lost. This feels similar; there is something pleasantly old-school about this story. I like the opening paragraph.

(And somewhere Applejack is grumbling to herself, "Where is that filly? Don't she know she got chores to do?")

“Keep—time?” Apple Bloom pulled a face. This was not a concept that the Apple family were familiar with, being more used to keeping apples, pigs, sheep, and track of the weather schedule and fruit price index.

Good lass.

Funny, clever, informative, and excellent world-building. Am very much "in" the story, would read more about this, perhaps a spin off where the CMC get sent back in time to the battle between the Order and Discord, with ensuing shenanigans (I am very much a fan of shenanigans). Meeting of Celestia and Luna surprisingly well-done, believable, comical. Poor moonfrogs. Would like to read Luna's terrible poetry.

Your footnotes are prettier than mine.

This is delightful.

“If you let the Doctor finish the story, you might learn how to get your cutie mark,” said Twilight.

Don't lie to the fillies, Twilight.

Five hundred years previously, the two sisters had stood together and yielded the elements of harmony to defeat Discord, the Master of Chaos.

"Wielded," presumably.

Ah, this is just fun to read. I really did not expect it to be so enjoyable. I'm looking forward to more.

I shall have to remember to have a snack with me for further chapters. I am not even sure I know what most of the foods are, but they sound nice.

An old earth pony legend told another, in which when the world was created, all animals lived in harmony in a beautiful garden. But ponies were expelled from this paradise for stealing apples.

The version I heard had dragons in it. But this is a story about telling lies....

“But how can we catch it,” said Ginger.

Question mark needed.


¡Yes! The military then makes manned missiles because people are cheaper than computers. I remember it.

A story about equine mathematics with the ponies using a different base would be nice. I nominate Balanced Ternary (Balanced Base3) and Sexagesimal (Base60) because they are my favorite bases.

I notice that you use Saturday and January. I always imagine the ponies having their own Calendar. Since the ponies have complete control of the sun and moon, their calendar can be completely regular. It might have 360 days because that is an highly composite number with 24 factors or 420 days because that is the least common multiple of all natural numbers upto 7 which also has 24 factors. It could be something else for some other reason.

Rappel reminds me about Lyra Silvertongue from His Dark Materials by Philip Pullman.

The 1st note explains the year-length (it started as the highly composite number 360), but I still do not get the metric system with its Base10, Saturday, and January. I imagine that ponies would use Planck-Units and their own base.

The cold could be from Windigoes.

The chandelier could be used as a periodic oscillator. One could use gears ratchets and escapements for counting swings and moving hands. One can provide energy via a windup spring.

Thanks. See this forum for discussion about footnotes.

Well Tuesday, at least, is cannon, as that is when Future Twilight came from. Nothing wrong with inventing a pony calendar of course, just that my game has always been using the pony world to parody our own.


If I shaved a few filings off of the official kilogram (back when there was one, of course,) would that make everything heavier?

The International Prototype Kilogram is still in use. And yes, if it shed a little material, then by definition everything else in the Universe would gain weight. That's why it is kept in a vault in Paris and only taken out a few times a century to calibrate other standards. This is the problem with defining a unit by a physical object (the kilogram is the only SI unit still defined this way), and the hope is that in the future the kilogram will be defined in a more fundamental way, perhaps as an integer number of atoms. But at the moment we can't count atoms as well as we can store a lump of platinum.

Good to find another Philip Pullman fan.


I wonder ¿whether the Dæmons of the CutieMarkCrusaders will ever settle?

Can you make an atomic clock in Equastria? Does magic make the passage of time variable, and therefore unmeasurable in an accurate and lasting sense? How long is an Equestrian day? How long is an equestrian year?

These are important questions.

I love the writing used to describe the setting. I can see myself on the meridian.


But, we already have an absolute method of defining the mass, without requiring a certain amount of matter.

The mass of one kilogram, is that point mass which, when an accurate clock is placed at 1 metre distance from it, slows by a relative fraction of a second to that of a clock placed at infinity. The fraction which I still havent calculated but must be in the definitions of Special and General Relativity.

Simply put, modern research atomic clocks are so accurate, they change due to the gravitational presence of the researcher. Therefore the researcher is entangling themselves in the observation of the time, giving both quantum and relativity effects simultaneously.

Well, everything else would weigh more kilograms, but the actual weight, calculated as a function of mass x acceleration from gravity, wouldn't change, would it?

The Abbess walked out of the hall and along the short passageway which led to the outside doorway. A steady stream of young novices, clad in brown hoods, were running outside. Among them the Dean caught sight of the fire-like red mane and green wings of her friend Median Measure—the Dean—descending another staircase.

I believe that one of those Deans is the Abbess. :twilightsheepish:

Aside from that, a wonderful story so far. Is it a good or a bad sign that those interruptions are starting to get slightly annoying already?


The weight would also change. Weight has SI units of N (= kg*m*s^-2), so if the kg changes so does the weight.

Now the physical effects in the world wouldn't change. If you hung an iron sphere massing 1 kg off a spring, maybe the spring stretches by 5 cm. After the kg changes, the iron sphere no longer masses 1 kg, and it's weight would no longer be 9.81 N, but the spring would still stretch by 5 cm. It's the labels that are changing.

Right, that's what I mean. The label would change, but not the actual magnitude of the 'weight' property.


The magnitude of the 'weight' property in what units, though? Weight isn't dimensionless. Its magnitude depends on the units you choose. I have an apple in my hand. What is the magnitude of its weight? Well, about 1, or .2, or around 100, or possibly even 8E-45. These are all realistic estimates of the magnitude of an apple's weight, but in different units (N, lbf, ponds, Planck force, respectively). It's not meaningful to talk about the magnitude of a dimensioned quantity without providing units. And if you do use units, if the unit changes, so does the magnitude.

What wouldn't change is relative weights (or masses), because [unit of weight]/[unit of weight] is dimensionless. A typical locomotive will still weigh about a hundred times as much as a typical car in any units, as long as you use the same ones for both.

And this visit would be especially fun as she was sharing it with her young friends who loved learning new things. She turned around and walked across the plaza to a stone parapet where the Cutie Mark Crusaders were admiring the view.

I cringed. Didn't Twilight learn from Discord and every other crusade?

Look, there's a process you've got to follow for capturing a mythical beast when you're just three fillies.

First, you build an enormous elaborate trap.

Then, the monster shows up where you weren't expecting and the trap fails hilariously.

Then, you run around for a while, ducking in and out of doors and passageways to try to lose it.

Then, you accidentally back into it and knock it into the last part of the trap that still works.

Also you should play in a band, just to be safe.

it's a reducio ad absurdum argument for why defining the kilogram in terms of a physical object is flawed, but it is technically true.

If we define the mass of something by how much it accelerates under a given force, relative to a standard mass of 1kg, then if the standard mass loses 5% of it's value, everything else in the universe become 5% heavier by definition

This is silly - but it's still a useful definition of the kilogram because the IPK actually keeps its value very well.

This story is about the absurd consequences of defining time using a water clock.

This is fine in theory, but it's not a practical way of defining the kilogram as you need to isolate your test mass from the gravitational field of everything else, which isn't possible. We need a way of weighing the kilogram which can be done in any laboratory and give the same result.


The Cavendish mass balance uses the same basic descriptin, that of idealised point masses and infinity, but then applies practicalities to end up with the final design.

In this case, the laboratory version would be a pair of atomic clocks spaced a known distance apart, with the 1kg mass placed the same distance away at one end, then at the other, given that 1kg mass equivalent of electric field strength, magnetic field strength, or electromagnetic energy is currently rather dangerous to attempt to confine.

Maybe a pair of MEMS Aluminium ion traps and a macro quantum dot stressed with a given energy density could be considered, but are more likely to havee to use nucleus transistion levels, gamma rays, to get the sensitivity needed.

Maybe trying to shield effects would lead to the discovery of placing the minaturised device inside a Bose Einstein bubble not only isolates it from quantum mechanical effects but also universal gravity, maybe it doesnt. Maybe it leads to discovery of how to make laboratory size BEC, for a given size of laboratory. Either way, trying to solve the first problem at hand often leads to new problems to solve, and solutions that can find all sorts of weird and wonderful, and often simle and mundane uses in civilisation, the home, and in childrens toys.

"So, why do they know exactly what those ponies were eating for dinner a thousand years ago?" :unsuresweetie:

"Let the Doctor continue the story." :facehoof:

On that note, this Order Of The Time Turners seems a lot like the wizards of the Unseen University.


On that note, this Order Of The Time Turners seems a lot like the wizards of the Unseen University.

This is because they are both based on an accurate description a fun caricature of Oxford/Cambridge dons.

Its actually a bit surprising that a water clock built high up on a mountain has never had this happen before. Though it is meticulously cared for.

Oh Twilight, you so adorable.

I really love the real, actual reason for the big, twice-daily ceremony.

The rest of the story too, that bit just stuck out as extra fun.

I can only assume Peony Poset is Pansy's descendant and Fluttershy's ancestor.

“Eeyup,” she said. “More than enough. The Practical Scholar sent the last order to the cider press, written using metric units. But they assumed it was in hogsheads. So we now have nine hundred and twenty barrels to drink up.”

Ahh, unit conversion mistakes, though in this case given the consequences it sound more like a feature than a bug.

Pendulum discovery via scared filly and swinging chandelier! Now we just need the Practical Scholar to shout eureka.

Apple Bloom, Scootaloo and Sweetie Belle all glared at Twilight, who stopped talking. She turned to the Doctor with a guilty face.


Heh, I literally actually gasped out loud when I got to the end of the chapter.

This is fun. It reminds me a lot of the Redwall series, which I greatly enjoyed when I was younger.

Ah... Brain Jacques Redwall... Cute little do-gooder mice defending their abbey home against invaders. I'm not reading that... It's undeniably, unquestionable, uncool... Then you pick it up to see what it's like and three hours later you're still reading. :pinkiehappy:

I'm eager to find out what partially-ordered sets have to do with systems of time and measurement. :twilightsmile:

Goodness, dragons are vexing. Challenging riddles, too.

So if I understand correctly, the effect of time temporarily stopping was to let everypony get an extra hour of sleep?

I wonder what this order thinks of daylight saving time.

I see that unicorns deciding it might be fun to try and hatch a dragon egg is hardly a modern problem. :twilightsheepish:

In fairness to Strombol, I suspect he serves as a very good guard for the abbey treasury.

But he insisted that it was his duty as a Fellow of the Order, and as a Noble Dragon, to stay in the abbey. He made his own allies, befriending the novices, especially the pretty unicorn mares, giving them little necklaces and other trinkets made from his gems so they all thought he was wonderful.

Hahaha, it seems that male dragons and female unicorns is also not a new development.

Green dragon? Purple spines? Hmn.

“It’s an old riddle,” said Twilight. “The answer is time.”

Thank you, Twilight, we never would have guessed. :ajbemused:

“And the answer to your riddle is tomorrow,” said the Abbess.

...do they tell any riddles that aren't time related?

Ahh, so not just dragons and unicorns, but dragons and white unicorns.

“We need a lava flow. There must be a volcano somewhere higher up the mountain. I could climb up and get it to erupt and direct some hot magma onto the ice, which would melt it...”


Wow. Yeah, a fission reaction probably would melt the ice.

Twilight's table manners are directly related to her distance from Ponyville, I see.

The Abbess disagreed with this interpretation of the regulations.

But he's following them to the letter, Abbess. :trollestia:

I'm not sure how the genetics of dragon scale coloration work, but Strombol seems to be related to Spike. Interesting.

And so we see the perils of letting the model reign over reality. It manages to be both more and less absurd when the model actually dictates reality, rather than just trying to predict it. Still, reforms will be needed, both in method and climate. The cooling trend seems to hint at some rather distressing possibilities. Either windigos are taking advantage of the sisters' strife or, even worse, Starswirl's model is flawed. :twilightoops:

Definitely looking forward to more.

Starwirls model was set up for a particular set of conditions, but if he failed the freindship spell, maybe he forgot, or didnt realise, to take into account the freindship of the sisters?

Imagine if Strombol had had teleport breath. well, thats one way of removing the ice from the cistern. Pity Celestia immediately ends up wearing it as a saddle. :twilightoops:

Which one of these genii is Harrison? three monstrosities, then something you carry in your hoof? Insane. :pinkiecrazy:

I was busy yesterday, but I am here now:

It seems that the timekeepers have 2 problems:

* Their reference clock is inaccurate and prone literally to freezing.
* Their world experiences global cooling. If they all die, they cannot keep time.

Strombol, is it? I see what you did there! :twistnerd: That one silly (B)Italian volcano that erupts ... regularly... and quite frequently! Ohoho!


Twilight, the thing you need to understand is absolutely nobody cares about what you have to say. At all.

Rap, Ginger Root, and Patina remind me about Roger Parslow and Lyra Silvertongue from "His Dark Materials", and the CutieMarkCrusaders.

The solution seems clear:

Given their technology, they can build a spring-driven Pendulum-Clock and keep it in a Climate-Controlled enclosure.

Typical, non linear fluid flows due to thermal, and shear, variations was the thing I specifically looked at in my degree course, and I forgot about it with the Minute. 1% variation per degree? Now what was it for treacle, between solid, and almost as flowing as water.

This is where the idea of the positive feedback comes from, where do you get the kick to keep the pendulum going, from the escapement that the pendulum moves, and generates a kick on escaping.

Dont ask me, Im just am freinds with an old clock repairer, and have trouble trying to understand electric motor, generator effects and back emf by virtual modeling.

Given Celestia and Luna, the water cooling might be one part in a physical realm, but Id still say it was windigo given the magical realm. :pinkiecrazy:

The basic idea that water clocks don't keep good time because the flow rate changes with temperature is simple, but when you look at the details, fluid mechanics is very complicated. According to wikipedia

Water is about 25 percent more viscous at 20 °C than at 30 °C, and a variation in temperature of one degree Celsius, in this "room temperature" range, produces a change of viscosity of about two percent. Therefore, a water clock that keeps good time at some given temperature would gain or lose about half an hour per day if it were one degree Celsius warmer or cooler. To make it keep time within one minute per day would require its temperature to be controlled within 1⁄30°C (about 1⁄17° Fahrenheit). There is no evidence that this was done in antiquity, so ancient water clocks (unlike the modern pendulum-controlled one described above) cannot have been reliably accurate by modern standards.

But I'm not sure that entirely true. Reports of Chinese water clocks suggest they kept much better time, so I wonder if with clever design they could have done much better. But these days we have lost the designs for such clocks, so we may never know for sure.

The verge-and-foliot mechanism was the principle behind the first mechanical clocks which were built in European monasteries in the middle ages. Here's a nice illustration:

I am a fan of Lyra and His Dark Materials, although similar ragamuffins come in many of my favourite books. I did once start writing a novel inspired by this - the idea was to write a similar fantasy story, but explain dark matter accurately. It wasn't very good - I wasn't such a good writer in those days - and I abandoned it after I had my laptop stolen and lost the file.

Well, that certainly explains that. Of course, then there comes the non-trivial matter of making a better Minute, and the leap from water clock to atomic isn't exactly feasible. Presumably, this will be where Rap shines. (Or where she shone. Flashback tenses get weird.)

5662291 their planet isn't cooling, exactly. Their nights are too long. Thier clock runs slower at night than during the day. The question is why this hasn't happened before. My guess is they had a cold snap, which caused ice in the steam and the longer night made it even colder and made the problem worse.

Atomic clocks are fun, but what happens when you lock the resonant loop of a clock through a long length of fibre using entanglement? A Time Loop clock?

I wonder if the tan Earth pony in the picture was wearing a red tie. After all, every story has a self insert? :pinkiehappy:

I take issue with that last line, you can't just ask people to pass the port, that's terribly gauche. The correct way is to say "Do you know the Bishop of York? Lovely fellow, but he always forgets to pass the port".

Well, that kinda depends on whether your primary objective is to intimidate a rival in a formal situation... or, you know, get your friend to push the bottle towards you.

Wow! It's complete! Congratulations, Pineta!

The Doctor smiled.

Farewell Strombol, old and faithful freind.


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