2216: Percent Milkfat

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Percent Milkfat
"So what's dark energy?" "Cosmologists and the FDA are both trying very hard to find out."
Title text: "So what's dark energy?" "Cosmologists and the FDA are both trying very hard to find out."


While cow milk contains a variable amount of fat (about 4.2%), whole milk from the store generally contains about 3.5% milkfat by weight according to the comic and some sources; other sources list similar but not identical numbers such as 3.25%.

Dairies commonly sell whole milk as well as products with less fat produced by removing milkfat. In the United States, there are three common products with less fat: 2% or "reduced fat" milk, 1% or "lowfat" milk, and "fat-free" or "skim" milk with 0 to 0.5% milkfat.

Since whole milk is labeled as "whole" milk and not as "3.5% milk," one might naively assume that whole milk is 100% milkfat, although this is not the case; 100% would be a product which is entirely milkfat (also known as butterfat), such as clarified butter or ghee. In milk, the remainder is mainly water along with proteins, lactose (a sugar), and other substances.

The comic analogizes this difference to the fact that physicists believe that "ordinary" matter constitutes only 5% of the actual mass-energy of the universe. Scientists predict the existence of another kind of matter known as "dark matter," invisible to our current instruments but exerting gravitational force on ordinary matter, which would constitute 85% of total matter and 27% of the universe's mass-energy, with the remainder an even less detectable and more mysterious "dark energy" accounting for the increasing speed of expansion of the universe.

Ponytail uses these quantities to "explain" the "missing" percentage in whole milk between the actual 3.5% and a potential 100% "whole." She actually uses the 27% as mentioned above for dark matter. She thus indicates that dark energy takes up the remaining 69.5% of the whole milk.

Ponytail is assuming that dark matter and dark energy are distributed uniformly throughout all pockets of the universe, no matter how small. This assumption is common in statistics and may have seemed appropriate since no one knows the proportion of dark matter or dark energy of an object as small as a milk carton (though a more sensible argument is that all matter is accounted for when considering the milk and the carton; no additional "dark" matter is necessary to explain the weight of the milk carton).

Cosmologists are working to better understand dark energy or another reason for the universe's accelerating expansion. The title text supposes that both cosmologists and the Food and Drug Administration (FDA), which regulates milk and other food items in the United States, are trying to understand the dark energy of the whole milk. In real life, the work of cosmologists and FDA scientists does not overlap at all.[citation needed]

Dark energy was recently mentioned in 2113: Physics Suppression, but before that milkfat and dark energy were actually mentioned in the same sentence in 2063: Carnot Cycle from almost a year before this comic, so the idea behind this comic is not new for Randall. Dark matter was mentioned back in 1758: Astrophysics and 2186: Dark Matter.


[Ponytail, raising her palm, and Cueball are talking.]
Ponytail: "2% milk" is 2% milkfat. But "whole milk" isn't 100% milkfat–it's 3.5%.
Cueball: Weird. What's the rest of it?
Ponytail: About 27% is dark matter. The remainder is dark energy.

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I've always called 2% milk "98% water". Also, these comics have been arriving really late this week; I hope Randall is doing alright. ProphetZarquon (talk) 00:19, 17 October 2019 (UTC)

Is the fact that the comic arrived later in the day responsible for the bottom of the page brokenly saying this is a "Thursday" comic? That doesn't seem editable in the normal wiki manner.

I don't know the cause, or if they are related, but I was able to manually fix all that--even adding the appropriate categories that got left off. Trlkly (talk) 04:17, 17 October 2019 (UTC)
Randall was presenting his new book at a speech he gave in Berlin on the 15th of October. However being in Europe would make his comics more early, unless he has made an error with the cript doing the upload (mmoving time zone in the wrong direction) or he is uploading very early morning the next day. Alternatively he is just jet-lagged and his schedule is messed up. See the German Press release of the university he is visiting. He also advertised it on the header of the page, if the OS/Browser is set to German language. I wanted to put this on the wiki, but got no replies for it and hadn't had the time to do it on my own. --Lupo (talk) 06:26, 17 October 2019 (UTC)
Lupo, can you post an image of how it looks in the German version if there is a current version with different header? Also will it be possible that this is saved in a web archive? I would like to add it to the explanation, but without any kind of visual to show that it is indeed the case, it would be a bit thin as part of an explanation. I think it is an interesting information, but this page is about a US comic, so it should only be for the informational value, not something that needed to be fully included in the header text explanation. --Kynde (talk) 06:47, 17 October 2019 (UTC)
The announcement of his speech in Berlin has been replaced by a image of the German bookcover and the simple text (which is a link to the publishers shop), roughly translated as "In stores now". I am currently at work, but will look into getting a screenshot in the evening. Apperantly some IP-User has found a way to view the different localized versions at the talk page of the header, as I just noticed. --Lupo (talk) 07:08, 17 October 2019 (UTC)
There is also an anouncement of this, and of a tour across the UK last week at xkcd.com/how-to --Lupo (talk) 07:11, 17 October 2019 (UTC)

2% milk is called half-full in the Netherlands. As a child I once asked my mother why anybody would want to buy a milk carton that was only half full :-).

See that's marvelous. Lends a whole different meaning to "a glass half-full kinda guy"!
ProphetZarquon (talk) 02:46, 21 October 2019 (UTC)

The amount of milkfat in milk varies by the breed of cattle that produced it, along with individual variation. Holsteins are most often used for milk production because they can produce the greatest volume of milk, but other breeds, such as Jersey, produce less milk, but with higher milk fat, often up to 6% milkfat. Nutster (talk) 11:14, 17 October 2019 (UTC)

The proteins produced can vary by breed, too. Unfortunately for US consumers, there is a brand called "A2" that, due to carefully crafted intellectual property restrictions, is the sole interstate distributor of milk from some breeds of cows (that produce less, but for some people more digestible, milk).
ProphetZarquon (talk) 02:46, 21 October 2019 (UTC)

I am not entirely comfortable referring to dark energy as matter. 12:40, 17 October 2019 (UTC)

Per Einstein, energy and matter are interchangeable. Barmar (talk) 14:23, 17 October 2019 (UTC)
Energy and matter are NOT interchangeable! Energy and mass are interchangeable—- not the same thing at all. Matter is stuff that obeys the Pauli Exclusion Principle. 21:38, 17 October 2019 (UTC)
So most helium and lead are not matter? (Even mass number nuclei atomic are boson and does not obey the Pauli Exclusion Principle) 06:47, 18 October 2019 (UTC)
Forming a Bose-Einstein condensate is not the same as obeying the Pauli exclusion principle, but it can be if the component does. 17:41, 18 October 2019 (UTC)
It's not the fungibility, it's the commission. 15:27, 17 October 2019 (UTC)

I think we may need to start a list of things that are made up of dark matter: 1. Squirrels, 2. Milk 14:21, 17 October 2019 (UTC) Sam ...

3. Profit!
(Sorry, a list often needs more than two entries, or I can't help making a South Park reference.)
ProphetZarquon (talk) 02:46, 21 October 2019 (UTC)

If cosmologists and food scientists are working together, could we be getting close to a Grand Unified Theory? Barmar (talk) 14:23, 17 October 2019 (UTC)

If you can get Big Corn behind primordial black holes, you could ray-trace a giant ear of corn as a signal, perhaps as a form of communication to smaller earlier multiverses occupying your same space. However, it is questionable as to whether this hypothesis can be tested in a reasonable time frame by which to reply to the comments of Reviewer Two.

I've long been amused by the confusion over 2% milk, and have exactly had to point out to people before that real milk can't be 100%, but is only like 50% more than...okay, that's another pet peeve of mine, that when you tell someone that something is 50% more than 2% they can interpret that either as 3% or as 52%. Our mathematical notation could use some improvement. — Kazvorpal (talk) 18:54, 19 October 2019 (UTC)

Twenty four quart jars.
ProphetZarquon (talk) 02:46, 21 October 2019 (UTC)

There is a billboard near me that advertises local whole milk as 97% fat free. Completely accurate and I laugh every time I pass it. Cosumel (talk) 04:13, 17 November 2019 (UTC)