Takes two AAA rechargeable batteries.
2021-08: rechargeable battery charges were in, nominal marked 1.2V nickel metal hydride, measured as 1.38V and 1.42V.
Reflections of the Moon on Erquan Updated 2025-07-16
Composed by Abing in 1949[ref]
Video 1.
Reflections of the Moon on Erquan with erhu solo performed Song Fei
. Source.
Although quotients look a bit real number division, there are some important differences with the "group analog of multiplication" of direct product of groups.
If a group is isomorphic to the direct product of groups, we can take a quotient of the product to retrieve one of the groups, which is somewhat analogous to division: math.stackexchange.com/questions/723707/how-is-the-quotient-group-related-to-the-direct-product-group
The "converse" is not always true however: a group does not need to be isomorphic to the product of one of its normal subgroups and the associated quotient group. The wiki page provides an example:
Given G and a normal subgroup N, then G is a group extension of G/N by N. One could ask whether this extension is trivial or split; in other words, one could ask whether G is a direct product or semidirect product of N and G/N. This is a special case of the extension problem. An example where the extension is not split is as follows: Let , and which is isomorphic to Z2. Then G/N is also isomorphic to Z2. But Z2 has only the trivial automorphism, so the only semi-direct product of N and G/N is the direct product. Since Z4 is different from Z2 × Z2, we conclude that G is not a semi-direct product of N and G/N.
TODO find a less minimal but possibly more important example.
I think this might be equivalent to why the group extension problem is hard. If this relation were true, then taking the direct product would be the only way to make larger groups from normal subgroups/quotients. But it's not.
Made four blisters on back of foot on first two days after walking a few hours on them, but then put on some tape on foot, and stopped hurting after that, so the shoe broke quickly.
Meal deal Updated 2025-07-16
x.com/Birdyword/status/1777591446612193667
A while ago a Singaporean taxi driver asked me what a UK hawker centre lunch might cost. I explained that there aren't any. He asked what office workers ate, and I explained the concept of Meal deals. And he looked at me with such a powerful combination of pity and revulsion.
Singaporean taxi drivers are the cutest.
Measure theory Updated 2025-07-16
Main motivation: Lebesgue integral.
The key idea, is that we can't define a measure for the power set of R. Rather, we must select a large measurable subset, and the Borel sigma algebra is a good choice that matches intuitions.
Mediocre Amateur Updated 2025-07-16
About 50k subscribers on 2021, which feels way too little for the video quality and quantity.
Ciro Santilli believes that this channel will go very far, certainly achieving 1M subscribers in they keep it for one or two more years. Update: it didn't, as of 2024, shame.
They are Utah-based, and they do many many amazing weekend trips. They mostly drive from home to some trailhead, and then climb up and down it the entire day.
No technical rock climbing, only bouldering, but they still manage to reach many amazing places, and there is a level of danger in many of their ascents.
They also often ski down the mountains when there is snow.
The cool thing about this channel is that as the name suggests, they are not professionals, and what they do can be done by anyone without working full time on it, as long as you have adequate preparation.
Medium (website) Updated 2025-07-16
While this has some of the metrics features that Ciro Santilli wants to implement for OurBigBook.com, it limits the number of articles your readeres can read.
How the fuck can you publish on a website that limits the number of views for your articles?!?! When all it has is static pages + some metrics?!?!
Evil. Just learn to use GitHub Pages for God's sake.
Ciro Santilli's knowledge hoarding Updated 2025-07-16
Ciro Santilli is a collector at heart. But a collector of knowledge.
His uncle, which Ciro rassembles in many ways, was like that. But he collected physical objects such as wines and stamps. Or even worse, objects that were meant to be collected such Panini soccer sticker albums! This Ciro looks down on.
With computers, knowledge takes no physical space and can be immediately shared with the hole world, and there is great beauty to that, as you can just keep collecting forever without filling up your house.
But of course, physical or not, all attachments futile.
Like other types collecting, once Ciro decides that "he must know everything about a given subject", he will keep coming back to that subject over and over. Not in a systematic way of course, since Ciro is a lazy bastard, but he will keep coming back for a very long time, and eventually become an expert at it.
Ciro Santilli's love advice Updated 2025-07-16
In the field of Love and Friendship, Ciro is a big believer in the merciless application of tit for tat. Never desire someone's love if you give and what comes back is not proportional. Cut your attempts to reach out immediately in such cases.
Never tell a woman you like her before she is in your bed.
If someone likes you and you don't like them as much, make that clear to them. Don't put this off, be it for compassion, curiosity, loneliness, or narcissism.
youtu.be/Sb0VHGnhX4M?t=174 from Video "Charles Bukowski Scandanavian TV interviews":
The way to get a woman is not to have money, not to look nice, not to have a nice personality. The way to get a woman, is to always be available, night or day. Any time you phone, you're there, or you're at the bar. They know that you are available at all times. It is very, very important to a woman.
When asked, Ciro likes to say that he speaks something between 1.5 and 3.5 languages in total, depending on how you count, because Portuguese, French and English are 99.99% the same, and Chinese is completely different but Ciro only knows about 50% of it if counted optimistically.
Memento mori Updated 2025-07-16
Figure 1.
Braque Family Triptych
. Source.
Figure 2.
"Vanitas" by Philippe de Champaigne (c. 1671)
Source.
Memory semantics Updated 2025-07-16
These are the rules which specify what different concurrent read/write memory accesses from different threads/processes can or cannot see.
Notable such set of rules include:
History Updated 2025-07-16
Chat programs that don't have a proper web-only operation and force you to have a mobile phone, e.g. WhatsApp.
Heck, even Signal, which is supposed to be super secure and good for your privacy, forces you to disclose your freaking cell phone to all contacts! lifehacker.com/how-to-use-signal-without-revealing-your-private-phone-1818996580
What is my phone breaks? What if I don't want to have a fucking phone? What if I move countries and have to change the fucking number? Also evil but less because done by all: chat programs that can't send you an email if you don't see the message in X minutes.
European Union, time to force those evil companies to use support open standards like XMPP?
The solution to "how to prevent spam" is simple: your ID is a public key that you own the private key for. If you start getting spammed, generate a new public key, and send it to all contacts, and dump the previous ID.

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