Asklemmy

There is (or at least used to be) a debug command to write-protect a hard drive. No idea what it's for or why such a thing exists, but you flip a certain bit from 0 to 1 and drive no write. I won $100 once at work with this knowledge. We had a training course about how much better the new version of windows at the time was and how much harder it was to break - so hard they'd pay $100 (in early 2000s money) to anyone who could unrecoverably break their demo windows install during the 10 minute presentation. The instructor (who worked for Microsoft) said he'd been doing this for 6 months and they'd never had to pay out that prize before, much less 30 seconds in.

Reign of Kings, a medieval online PvE survival game had a bug where the 360 rotation camera could be used in 3rd person mode to look inside of walls of other players. You could even access their chests if they built them against the wall (which they all did).

This meant that you could loot everyone’s bases without even breaking in. The game went through several major updates with this bug still in place. My brother and I used it extensively.

One day there is a major update and the release notes mention about how they have now finally fixed the “glitch where players items disappear from chests when placed near walls”.

Real G’s move in silence like lasagna.

From an old edition of the Pilot's Handbook of Aeronautical Knowledge:

An airplane's tire will hydroplane at a speed in knots equal to 9 times the square root of the tire pressure in PSI. So if your tires are inflated to 36 PSI, sq.rt 36 = 6 * 9 = 54 knots. If there is standing water on the runway, you will have no braking authority or steering control from the wheels, you will have to maintain control of the aircraft with the flight controls, and you cannot rely on short field stopping figures from the POH if it requires applying brakes above 54 knots.

I got that out of the 2003 edition; I don't know if it's in the current issue.

If you stare at the elbow of someone you are high-fiving, you'll never miss the high five.

Mammals generally get 1.5 billion heart beats in their lifetime regardless of size.

The great opera singer Enrico Caruso was the 18th of 21 children, only 3 of whom survived infancy.

Johann Sebastian Bach wrote an opera about coffee addiction.

The Russian composer Tchaikovsky was afraid his head would come off while conducting, so he would hold his chin with one hand while doing so.

The girlfriend of composer Erik Satie wore a corsage made of carrots, and she was a painter and liked to feed the paintings she made. Satie once threw her out the window but she survived.

“Bizarre” is the only word from the Basque language that is regularly used in the English language

(Can’t wait to be proven wrong in 5.. 4.. 3..)

Not sure if I can call this knowledge since I don't know if it's true, but I think I identified a couple of women from the 8th century CE who are mentioned in some Irish annals as actually being the same person. As far as I know there's next to no discussion of these women on the internet and there are basically no historical records of them, at least. So I guess if I'm right it's very obscure?

The women in question are Eithne ingen Bresail Bregh and Eithne ingen Cinadhon (and possibly also the legendary Eithne mother of Tuathal Techtmar)

Human blood is a valid substitute for eggs in baking.

ifupdown2 has a 15-character interface name limit, and the systemd predictable interface naming system uses the mac address for usb nics (giving them a 15-character name), so if you try to create a vlan subinterface of a usb nic using the standard interface.vlan naming scheme on a systemd host, it will fail, and you'll have to set up systemd network link files to rename the base interfaces to something shorter.

Wsl uses the 9p protocol from plan 9 to interact with windows and vice versa

The SR-71 used an Astroinertial Navigation System that used stars to keep the navigation information accurate as the plane flew over long distances. Normally an inertial navigation system degrades in accuracy over time and distance due to small errors building up and something called gyro drift. The NAS-14V2 used a catalog of known stars and a gimballed telescope to identify specific stars (even during a cloudy day) and determine the position of the stars in relation to the aircraft. Using this information the position of the aircraft can be used to revise the inertial navigation system's data every so often so the accuracy is much better.

There are two types of color E-ink displays:

One that uses a color filter on top of a regular black and white particle display, like in their Kaleido screens. This has a faster refresh rate like black and white displays, but the colors are muted and the screen’s “pure white” is much more gray than other displays.

One that uses four colored particles, cyan, magenta, yellow, and reflective white, like in their Gallery screens. This has a much slower refresh rate, but the colors are vivid and the screen’s “pure white” is just as good as a non-color screen.

There are also color transflective LCD screens from other companies that are sometimes marketed as “e-paper” or “paper like” that are fairly uninteresting.

And there are just straight up backlit LCD screens marketed as “e-paper” or “paper like” that are just not. XPPen just made one. I personally think this should be considered false advertising.

T-rex is closer temporally to humans than they were to Stegosaurus.

Hermeticism is the origin of most conspiracy theories if you dig deep enough. Truly the OG brainworm

Hm, I guess this is esoteric in the sense that most people aren’t interested in it?

Some clothes are made with what’s called ‘slub cotton’, which is cloth made from cotton thread that has irregular lumps jutting out of it. It gives the final woven fabric an interesting look, almost like static. If it’s done with bright or contrasting colors it can give a really interesting pop to the final item.

There is only one model structure that can be put on the category of small categories for which the weak equivalences coincide with honest equivalences of categories. It's called the Joyal-Tierney model structure. You can define the suspension of an object in any model category as the homotopy pushout to two terminals, then define an abstract notion of a sphere in any model category by setting the 0-sphere as the coproduct of two terminals and the (n+1)-sphere as the suspension of the n-sphere.

A small category is a CW-complex if and only if it is a groupoid.

There's a trick with our loan servicing XML imports. If you pre-encode the property address into a [Comment] tag inside the [CIF] section, the system auto-fills it in three different screens, even though none of them actually pull from that tag offcially. I don't know why it works, just that it does. Doesn't really save me more than about thirty seconds but when you're boarding dozens of loans per week, it can add up.

We don't know if π+e is irrational.

We don't know if π*e is irrational.

I'm Western esotericism, names have power beyond simply being signifiers for the thing they represent- they embody some part of the thing they represent. The word "fire" contains some intrinsic "fire-ness" but not the whole picture. After all, everyone has different names for the same thing. It is thought that everything has a "true name" that perfectly encapsulates all things about it in their entirety, and this true name could be found by intense study, meditation, or etymology. The Bible pays a lot of attention to names in this way. Adam, the first man, names all the animals. Genesis pays a lot of attention to the names of places, and a lot of stories in Genesis are essentially folk etymologies of locations. God's own name is of special importance, and its meaning was revealed to Moses by the Burning Bush. Even today Jews believe that even saying God's name is powerful and dangerous and that only the High Priest would be allowed to say it once every year during Yom Kippur. Jewish folklore says that even this name is merely a part of God's true name, and that Moses pronounced a longer more complete form of The Name to part the Red Sea, and some systems hold that there are even longer and even more complete forms that have been known to rabbis in the past.

The most efficient base for a number system is e.

We use base 10 with 0-9 digits and each position is a ten's place, and the efficiency being measured is the product of the number of digits and the length of digits needed to represent a number in a given range of values. So if we used base 2 binary instead of base 10 decimal we only need to remember 2 digits 0-1, but to represent most numbers we'll need more digits, 11 in base 10 is 1011 in base 2. On the other side we could use hexadecimal to write shorter numbers like 11 is B, but need to use more digits, 0-F digits where A-F are the 10-15 digits.

If you try to plot a function that minimizes the efficiency the minimum is at e. So you'd have digits 0-2 and e would be written as 10 since each position is an e's place.

My ICQ number...