• Member Since 28th Oct, 2012
  • offline last seen 36 minutes ago


Particle Physics and Pony Fiction Experimentalist

More Blog Posts369


Conservation of (Magical) Energy · 4:22pm July 19th

A key concept in Daring Do and the Inexplicable Artifact is the idea of the Conservation of Magical Energy. In the story Daring Do and Twilight Sparkle reason that the inexplicable artifact is inexplicable because it is absorbing enormous amounts of magic, apparently without doing anything. It isn’t actually written anywhere that magic works this way, but readers intuitively pick up that it must. It is shown in the show that magic is a finite measurable thing, which can be stored in giant cow bells, and transferred between magical creatures with less hassle than topping up your phone credit.

Neutrinos were reasoned to exist in the same way. The radioactive decays of some atoms apparently made energy disappear. Could this be a unique process that destroyed energy? There were good reasons not to believe such a heresy, so it was instead proposed that an invisible particle was being produced, which took away the missing energy. Twenty-six years later the neutrino was detected. These days we routinely search for more invisible particles by adding up all the energy coming out of high-energy proton collisions and comparing it to what we put in. Actually, it’s a bit more complicated, but you get the idea.

Why is the Conservation of Energy so undeniable that we prefer to invent new particles rather than consider that it might not be true? Physicists may claim it as one of our laws, but it is just as fundamental in chemistry and biology. It can seem like a statement of common sense. Most people can intuitively guess than you can’t build a perpetual motion machine by connecting a waterwheel to a pump to move the water back up to the top. But when an inventor presents you with a complicated diagram of hundreds of gear-wheels, proving it won’t work is more difficult.

The general mathematical proof was derived by mathematician Emmy Noether in 1915. Her biography is a story of battling for recognition in a sexist society, eventually succeeding, despite everything against her, due to persistence and being a genius. Albert Einstein said she was “the most significant creative mathematical genius thus far produced since the higher education of women began”. There is a long list of academic awards, institutions, fellowships, and other such things, named after her. And she has pony fan art:


Noether’s theorem states that a conservation law is linked to the fact that the laws of physics don’t change under a certain transformation or symmetry. Energy must be conserved as the laws of physics don’t change with time—the same equations describe the universe tomorrow, as describe it today. Other conservation laws are linked to different symmetries. The conservation of momentum is due to the fact that the laws of physics don’t change with your position in space. Conservation of angular momentum means that things obey the same rules when you pick them up and turn them around.

While no sensible scientist would doubt that energy must be conserved in a real experiment, it is trivial to break this rule in computer simulations. Once you have programmed a detailed model of all the physical interactions going on in a particle detector, one of the first things to do to test it would be to write a few lines of code to throw a virtual energetic particle in to see what happens. Then write a script to add up the total energy of all the particles in your simulation to check it is indeed conserved. If it isn’t, there must be a bug somewhere.

And what about in Equestria? There is no reason why magic has to follow the same rules. It is a made-up concept after all. Yet any script writer has to careful. Fans may be quite happy with the idea of flying ponies and unicorns turning apples into chickens, but there has to be some sort of rules. Violating the laws of physics is one thing, but violating the common-sense notion that you just can’t get something for nothing is quite another. Unless it involves a good gag involving Pinkie Pie or Discord.

While magical energy does seem to be conserved at a local level, it may not be a universal law. Magic is tied to all the friendship in Equestria. Friendship is not a conserved quantity, but can surely change over time depending on how nice ponies are being to one another? Maybe it is something else that is conserved. We hear that windigos are "winter spirits that feed off fighting and hatred.” If friendship is fuelling the magic, then, in the absence of friendship, the energy produces something else which nourishes these creatures?

And there is the small question of quite how changeling metabolism is supposed to work…

Join our Patreon to remove these adverts!
Comments ( 14 )

And she has pony fan art

That's how you know you've made it. :raritywink:

And there is the small question of quite how changeling metabolism is supposed to work…

Emotional energy does seem to be tied to magic: The magic of friendship, the windigoes' food source, the "hopeless magic" from Rainbow Roadtrip. Most creatures convert calories to thaums, to borrow terminology from Pratchett, which may carry an emotional charge as much as more familiar particles carry an electrical one. Changelings may perform that conversion in the other direction.

Other conservation laws are linked to different symmetries. The conservation of momentum is due to the fact that the laws of physics don’t change with your position in space. Conservation of angular momentum means that things obey the same rules when you pick them up and turn them around.

"Unicorns don't suddenly become more or less powerful if you move them from the ground to a balloon in the air, or change them from facing to west to facing to east!" :twilightsmile:

Maybe its a higher dimentional function. you can move lots of energy in and out of reality by prescessing it into a higher dimention with far less effort than trying to brute lift it there directly? the trick is finding a 4 dimentional gyroscope?

I have something I do not understand about the RECEPTION of Nöther's Theorem:

Physicists freaked out when they learned that one looses energy in an expanding universe, claiming that this violates conservation of energy. My response upon hearing this is "¡No Duh! The universe literally rolls up hill or, to put it another way, climbs out of its own gravitywell. ⸘Do not physicists remember that kinetic energy can convert to potential energy and vice versa‽" ¿Do I miss something?

As an aside, I go back to work Monday, August 3rd. I shall probably get sick and die:

Our president acts like the AlphaMale of a troop of baboons:

  • Project Strength
  • Never Show Fear
  • Show No Weakness
  • Intimidate All Other Baboons

Wearing a mask and keeping distance would show fear and weakness; so now, he refuses. His followers emulate him. If we would just keep 2 meters apart and wear masks, the ReproductionNumber would be less than 1, but his followers refuse to wear masks and cough in the faces of others. As a result, we have over 100 thousand new infections daily and over 1 thousand deaths daily. I have a quote which summarizes everything:

"If we teach our children by example, we have only ourselves to blame for how they behave."
The Outer Limits

An example of a good leader is Prime Minister of New Zealand Jacinda Kate Laurell Ardern.

As far as we know.

If they draw on an ambient magic field that coagulates like gravity, they might be more powerful closer to the ground, albeit in a small amount as the atmosphere ends a relatively short distance above the ground. This might be what makes the moon an effective prison for a magical being: Less magic there to draw from.
Your second part is unrelated and so I'll not address it. As to the first, under Newtonian gravity you'd be right, but it's not quite that simple in General Relativity. The problem in GR is that you have to define what you mean by energy, since the self-gravitating energy does not enter the way kinetic and electromagnetic energy do. The full explanation is beyond the scope of this comment section, but suffice to say that under certain broad conditions it is not possible to rigorously define energy in a way that holds globally for the entire universe. However, I'm not sure what specifically you are referring to: under the Friedmann–Lemaître–Robertson–Walker metric energy cannot be easily said to be 'conserved', but that's because (global) energy is not well-defined under these circumstances. Energy is still locally conserved, as expected.

Addressing the original story, why does pony Noether have such a flat face?


Sorry for the confusion, but A car hit me last November, so I could not work. Pineta knew that, but I forgot to clarify it for others. It broke limbs, leaving me unable to work. The accident happened less than a month after my mother died. (nI am still not up to 100% and maybe never will be, but am healthy enough to work again. I am sorry for he confusion.

I work at a foodprocessing facility. If just 1 TrumpSupporter comes to work and coughs everyone could get sick. I am a diabetic male with A+ Blood; so now, I am wooried.

I have some advices:

  • Watch out for cars.
  • Resist the temptation to gorge oneself on sugar.*

* I have a sweet tooth. I burned out my pancreas by eating over 100 grams of sugar daily for decades. My Doctrix states that I did not ven have to give up sweets, but eat sweets with artificial sweeteners to avoid diabetes.

You might believe that I support a SodaPopTax, but you are wrong:

Those taxes are from idiots believing that it is the bubbles making SodaPop bad. They tax Diet SodaPop, while not taxing flat (noncarbonated) juices with scores of grams of added sugar. What they should do is tax added sugar, at, let us say, 1 cent per gram of added sugar. ¡That would be smart!


And she has pony fan art

That's how you know you've made it. :raritywink:

Wait — I thought you’d made it when “Weird Al” Yankovic did a parody of one of your songs…
…strike that.

There should be a gallery somewhere showing all the mathematicians and scientists who have made it in this way.

Good point about changelings. Interesting how we can't talk about the 'science of magic' for very long before we end up involving Pratchett.

Could there be some benefit to aligning your unicorn with the magnetic field, standing north-south rather than east-west?

I am pleased that you are well enough to be able to return to work and very much hope that you do not get sick and die. There is some encouragement that it looks like the alpha baboon is on track to lose bigly.

It takes a bit of time to get your head around the expansion of the universe - how dark energy can both hold it together and make it expand faster. And the truth is, there is a lot we still don't understand.


About the AlphaMaleBaboon, it is true that he does not do so well, in he polls, but he can still blowup the board:

To bring things back to ponies, in the story "Fallout: Equestria", posturing and overreaction over a coalshipment (the Zebras raised the price of coal in violation of contract because of increased costs, but the Equestrian military seized the coal claiming that it belongs to Equestria according to the original contract. Zebraica claimed that the seizing of the coal constituted an attack and declared war against Equestria. This happened a decade after Season # 1 in an alternate timeline.

When the war had raged a generation (25 years) and millions died, Zebraica was within an year of loosing the conventional war. Zebraica tried to obliterate Equestria using MegaSpells. The hope was that the 1st strike would destroy Equestria, leaving it incapable of retaliating with its own MegaSpells, thus snatching victory from the jaws of defeat. Equestria did manage a 2nd strike. In less than 1 hour, 90% of sapient beings in Equestria and Zebraica died. Within less than 1 year, over half of sapient beings died in other nations from the indirect effects of the MegaSpellExchange, for a total of over ⅔rds of all sapient beings dying on the planet within less than 1 year. The planet still has not recovered over 200 years in the future.

The Zebras blew up the board rather than loose the game. Trump might do likewise.

Or the magic field, if it's not uniform.

"Assume a uniform unicorn with magic strength of 1 kTh."

Login or register to comment
Join our Patreon to remove these adverts!