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Cake day: June 12th, 2023

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  • The only fuel you can make from water is hydrogen. The RS-25 engines used on the SLS core stage and the Space Shuttle used liquid hydrogen, as did the J-2 engines on the second and third stage of the Saturn V (but not the first stage, which used RP-1 (kerosene) burning F-1 engine)

    Starship’s Raptor engines use liquid methane however. There are a bunch of tradeoffs between the different fuels, but generally liquid hydrogen is more difficult and expensive to deal with. With low cost reusability being one of the primary objectives of Starship, liquid methane was chosen as the best option. The fact that it can also be manufactured on Mars was also considered, since CO2 is abundant in Martian atmosphere.



  • Reagan was a union leader in the 40s and 50s, governor of California in the 60s, and elected president in 84 - he didn’t just go from acting to being president, he had a lot more political experience and track record than Trump.

    Sure he had charisma and was a good public speaker, but that’s pretty much what got Obama the presidency as well.








  • What is your source for this ? Recent polls show reunification support is still <2%, with about 6% open to reunification eventually but not now.

    In 2018, before the crackdown in HK, the reunification support was 3%, with 13% open to it eventually - the events in HK have definitely significantly eroded support for reunification in Taiwan.

    I have family in Taiwan and literally don’t know a single Taiwanese person that wants reunification with the PRC.


  • Early computers had very limited resources, RAM, storage, etc. (first computer I worked with only had 4k of RAM for example) It often made sense to only use the last 2 digits of the year as an optimization in many common tasks that computers were used for, as both the 1800s and the 2000s were far enough away that most basic date calculations worked fine. Also, the industry was changing rapidly, and few people expected their software to be used for more than a few years - certainly not for decades, so focus was usually on solving the immediate tasks as efficiently as possible, without much consideration for the distant future.

    However, it turned out that a lot of the code written in this period (70s and 80s) became “legacy code” that companies started relying on for far longer than was expected, to the point that old retired COBOL programmers were being hired for big $$ in late 90s to come and fix Y2K issues in code written decades ago. Many large systems had some critical ancient mainframe code somewhere along the dependency chains. On top of that, even stuff that was meant to handle Y2K was not always tested well, and all kinds of unexpected dependencies crept up where a small bug here, or some forgotten non-compliant library there could wreak havoc once date rolled over into the 2000s.

    A lot of the Y2K work was testing all the systems and finding all the places such bugs were hiding.



  • The first computer I used was a PDP-8 clone, which was a very primitive machine by today’s standards - it only had 4k words of RAM (hand-made magnetic core memory !) - you could actually do simple programming tasks (such as short sequences of code to load software from paper tape) by entering machine code directly into memory by flipping mechanical switches on the front panel of the machine for individual bits (for data and memory addresses)

    You could also write assembly code on paper, and then convert it into machine code by hand, and manually punch the resulting code sequence onto paper tape to then load into the machine (we had a manual paper punching device for this purpose)

    Even with only 4k words of RAM, there were actually multiple assemblers and even compilers and interpreters available for the PDP-8 (FOCAL, FORTRAN, PASCAL, BASIC) - we only had a teletype interface (that printed output on paper), no monitor/terminal, so editing code on the machine itself was challenging, although there was a line editor which you could use, generally to enter programs you wrote on paper beforehand.

    Writing assembly code is not actually the same as writing straight machine code - assemblers actually do provide a very useful layer of abstraction, such as function calls, symbolic addressing, variables, etc. - instead of having to always specify memory locations, you could use names to refer to jump points/loops, variables, functions, etc. - the assembler would then convert those into specific addresses as needed, so a small change of code or data structures wouldn’t require huge manual process of recalculating all the memory locations as a result, it’s all done automatically by the assembler.

    So yeah, writing assembly code is still a lot easier than writing direct machine code - even when assembling by hand, you would generally start with assembly code, and just do the extra work that an assembler would do, but by hand.



  • The history of Taiwan is quite a bit more complex than that, but the PRC (current government in mainland China) has never controlled Taiwan - it was never theirs.

    Taiwan was a Japanese colony from 1894 until 1945 when Japan was forced to hand it over to the ROC (the successor government to the Qing dynasty, which was the last time you could argue China controlled the island - the Qing managed to almost fully colonize it before losing it to the Japanese, although a lot of the mountainous parts of Taiwan were still mostly autonomous at that time and inhabited by aboriginal Taiwanese who continued to resist the Qing rule)

    The ROC takeover of the island is also seen as another colonization by many Taiwanese as well - the descendants of the Qing era colonists who were mostly Hokkien speakers from Fujian, while the ROC migration in 1949 was mostly Mandarin speakers from wider China, who fairly brutally imposed their rule over the island (see 4 decades of martial law, etc.)

    ROC managed to reform itself over time, and Taiwan is now a vibrant democratic country which is forging its new national identity where most people would prefer to be left alone to control their own affairs.