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Joined 11 months ago
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Cake day: October 19th, 2023

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  • Other people have described the health effects, so I’ll describe the chemistry. Fats are made of long chains of carbon atoms surrounded by hydrogen atoms attached to a “head”, which is made of other elements or structures. Carbon atoms normally can make a total of 4 bonds. Hydrogen atoms can make 1 bond.

    Carbon being able to make 4 bonds means that in the chain of carbon and hydrogen atoms in fat molecules, each carbon atom makes a bond with the carbon atom before it in the chain, a bond with the carbon atom after it in the chain, and then bonds with two hydrogen atoms separately off to the side. This makes a total of 4 bonds. If all of the carbon atoms in the chain are like this, that’s “saturated fat”, because the chain of carbon is completely “saturated” with hydrogen atoms.

    (Hydrogen atoms are white, carbon atoms are black, oxygen atoms are red)

    Saturated fats have the often desirable property of being able to be tightly packed together, and thus are typically solid at room temperature. Butterfat is mostly saturated fat.

    However, carbon atoms can also make a double bond with other carbon atoms. If a particular carbon atom in the chain makes a double bond with the carbon atom before it, it could cause a bend in the chain of carbon atoms. In that case, it also means that those particular carbon atoms in the chain that have formed a double bond with each other only have 1 available bond left (after also forming a separate single bond with the carbon atom before or after it), so it can only bond with one hydrogen atom. These are, therefore, called “unsaturated fats”, and because they don’t pack together easily, they are typically liquid at room temperature.

    If there is a single double bond in the chain, it’s a monounsaturated fat.

    If there are two or more double bonds, it’s a polyunsaturated fat.

    Notice how the hydrogen atoms connected to the double-bonded carbon atoms in unsaturated fats can be connected to either the same side or the opposite sides of the two hydrogen atoms. If they’re on the same side, they are called cis-unsaturated fats. If they’re on opposite sides, they are trans-unsaturated fats, or trans fats in short.

    This is oleic acid, a cis monounsaturated fat commonly found in many vegetable oils:

    While this is vaccenic acid, a trans-monounsaturated fat. It is found naturally in butter and human milk and is not particularly bad for you:

    Note that this is NOT the same picture as the one I showed for saturated fat. The 7th and 8th carbon atoms from the left are double-bonded and, therefore, are each missing a hydrogen atom. The one remaining hydrogen atom on each is bonded on opposite sides.

    Note that trans-unsaturated fats are also pretty straight. This means that they can also pack together with saturated fats to make a solid product at room temperature.

    “Hydrogenation” is the process of adding hydrogen to unsaturated fats to saturate them. This means that liquid oil can be processed into a solid product. That’s how margarine and shortening are made. In previous years, partially hydrogenated oils that weren’t fully hydrogenated could leave substantial quantities of trans-unsaturated fats left in the product, but after health concerns, many countries’ food safety authorities banned these artificial trans fats. Fully hydrogenated fats consist of only saturated fats since they have been “fully” hydrogenated, and that is what food manufacturers have been doing instead.






  • Password is necessary for two-factor authentication. The factors of authentication are something you know (like a password), something you have (like a cell phone), and something you are (like a biometric).

    An example of three-factor authentication would be this—imagine a spy going into a secret bunker. They need to scan their iris, insert a key card, and then enter a passcode before the door opens. This has all three factors of authentication; the passcode is something they know, the key card is something they have, the iris scan is something they are.

    If it just sends a code to your phone, that’s one-factor authentication (something you have). Anyone with your phone can get into your account. Unless, of course, your phone hides its notifications and you have a screen lock. Then that’s actually two-factor authentication because you also need to know the phone PIN or have the biometric.

    If it just asks for a password, that’s one-factor authentication (something you know).

    If it asks for your password and then sends a code to your phone, which you need a fingerprint or face scan to unlock, you have achieved three-factor authentication.

    Edit: Interesting tidbit—in the USA, you can rent a mailbox at the post office to receive mail when you don’t want to give out your real address. Useful for privacy reasons. I’m sure they have similar things in other countries. These mailboxes come with a key. This is actually two-factor authentication, because the keys usually don’t have the mailbox number written on them! So you have to have the key and also have to know which mailbox among the hundreds at the post office it opens.


  • TOTP is standardised by RFC 6238 so all TOTP clients must comply with the standard and therefore work equally well. Pick the one whose UI you like the most and is otherwise good enough for your use case and personal preferences. It’s similar to arguments over CPU thermal paste—its presence or absence makes a much larger difference than the method of application.

    You do, however, want to pick something that is free and open-source and also popular. Google Authenticator (closed source) definitely is a functional TOTP client but you have to trust that the Google engineers have done a good job building a secure app. Since it’s Google, they probably have, but a principle in security is that you should not have to trust more people than absolutely necessary.








  • I think this might sound like a weird thing to say, but technical superiority isn’t enough to make a convincing argument for adoption. There are plenty of things that are undeniably superior but yet the case for adoption is weak, mostly because (but not solely because) it would be difficult to adopt.

    As an example, the French Republican Calendar (and the reformed calendar with 13 months) are both evidently superior to the Gregorian Calendar in terms of regularity but there is no case to argue for their adoption when the Gregorian calendar works well enough.

    Another example—metric time. Also proposed as part of the metric system around the same time as it was just gaining ground, 100 seconds in a minute and 100 minutes in an hour definitely makes more sense than 60, but it would be ridiculous to say that we should devote resources into switching to it.

    Final example—arithmetic in a dozenal (base-twelve) system is undeniably better than in decimal, but it would definitely not be worth the hassle to switch.

    For similar reasons, I don’t find the case for JPEG XL compelling. Yes, it’s better in every metric, but when the difference comes down to a measly one or two megabytes compared to PNG and WEBP, most people really just don’t care enough. That isn’t to say that I think it’s worthless, and I do think there are valid use cases, but I doubt it will unseat PNG on the Internet.