adrian_b

35 ms·

601.
by adrian_b 4mo ago
The computation in TFA is wrong. The incoming power is not the electrical power generated by the solar panels, but the entire power of the light that is absorbed by the solar panels and by the body of the satellite. Even with a perfectly re
602.
by adrian_b 4mo ago
Until now only energy sources based on radioactive decay have been used in space, which have very low power, but they can provide it for many decades. Nuclear fission reactors, similar to those used on submarines or ships, would enable very
603.
by adrian_b 4mo ago
There exist the so-called Sun-synchronous orbits, which exploit the precession effect caused by the fact that the Earth is not a sphere, to pass over the same point of the Earth at the same local hour. On a small subset of these Sun-synchro
604.
by adrian_b 4mo ago
No, it does not have any connection with symmetry whatsoever. Genome duplication has happened in many animal groups. Wherever it happens, it enables the descendants to evolve into having bodies that are bigger and more complex, because each
605.
by adrian_b 4mo ago
For the last year, there has been development work at several companies for products including HBF (high-bandwidth flash memory) as a supplement to HBM, in order to enable running inference for big LLMs at a reasonable cost, e.g. on one GPU
606.
by adrian_b 4mo ago
Open weights, like any other really big LLM. NVIDIA Nemotron 3 Ultra is a relatively big LLM for which a part of the training data is public, but not all of it. Nobody who has trained a really good and big LLM can afford to make public all
607.
by adrian_b 4mo ago
For about a half of year there have been cars with sodium-ion batteries, in China. As you say, for now they are more expensive, but it is expected that the price will drop quickly in the following years. Because they lose neither capacity n
608.
by adrian_b 4mo ago
As said in the parent Web page, lower energy efficiency, thus shorter range with the same battery. Another poster has mentioned that BMW also uses EESMs instead of permanent-motor magnets. BMW uses EESMs as the main motors, on the rear axle
609.
by adrian_b 4mo ago
Brushes are used everywhere for transmitting electrical current between two parts that have an unlimited relative motion. Brushes are typically made of graphite mixed with some binder. The graphite conducts the electrical current, but it al
610.
by adrian_b 4mo ago
A three-phase grid cannot drive a two-phase induction motor, like that invented by Tesla. In 1891, the three-phase induction motor was invented by Mikhail Dolivo-Dobrovolsky, combining the principles of the three-phase synchronous motor pre
611.
by adrian_b 4mo ago
Tesla had invented a kind of two-phase induction motor, but the three-phase induction motor that is the ancestor of the modern induction motors was invented in 1891 by Mikhail Dolivo-Dobrovolsky (working in Germany at AEG), who had also inv
612.
by adrian_b 4mo ago
This is mentioned in the parent page, where it is also mentioned that their disadvantage is a lower energy efficiency than either electrically-excited synchronous motors or permanent-magnet motors. The lower efficiency means a lower range f
613.
by adrian_b 4mo ago
Unfortunately, their Web page does not say a single word about the important problems of their motors. The electrically excited synchronous motors have been known forever, but they had not been used in EVs because of 2 disadvantages. The fi
614.
by adrian_b 5mo ago
It was not a bug, it was just another undocumented Apple feature. However, when a company sells a device, as opposed to providing it for lease, I do not believe that it has the right to not document any feature of the device that is relev
615.
by adrian_b 5mo ago
The boot flag was undocumented, like most features of Apple devices that are required knowledge for being able to port another operating system to them. Because of this lack of documentation, every release of a new version of Apple hardware
616.
by adrian_b 5mo ago
When a wave passes through different media, its frequency remains the same, but its velocity changes. The wavelength is the ratio between velocity and frequency, so it changes proportionally. If you multiply 36 kHz by 8326 m, you get a valu
617.
by adrian_b 5mo ago
This uses the same principle, but the traditional method required immense antennas and very high power radio transmitters. Such antennas and transmitters cannot be installed in a small submarine. Here a new kind of antenna is used, which is
618.
by adrian_b 5mo ago
Very low frequency radio waves is the traditional means of communication with military submarines, while submerged. However, this required huge antennas and very high power transmitters, so this was used mainly to transmit short messages fr
619.
by adrian_b 5mo ago
Yes, already for many years, I have also used par2create/par2verify for adding redundancy to archive files and repairing any corrupted files. However, I use both par2create and duplicate storage media, because duplicates that are prefe
620.
by adrian_b 5mo ago
> because we don't have to type type definitions Typing "type definitions" makes you type less, not more, because you type the definition only once, instead of writing many tests wherever values of that type are used. In a
621.
by adrian_b 5mo ago
This is not as uncommon as you may think. Avoiding "memory bugs" in C is trivial, but tedious, so too many C programmers fail to use an appropriate programming style. Nonetheless, there are some who have never encountered a "
622.
by adrian_b 5mo ago
I assume that the facts that have been disclosed in recent weeks about Israel spying on USA had been known much earlier by the US military and counterintelligence, but they have been "leaked" now by those who are against the propo
623.
by adrian_b 5mo ago
And how was std:copy implemented? Your answer is valid only for a programming language which assumes that the standard library is implemented in another language. C/C++ are supposed to be languages in which any program can be written,
624.
by adrian_b 5mo ago
The "void*" of C solves a frequently encountered problem, but it has an inappropriate and misleading name, because such a pointer points to something, it does not point to nothing. Moreover, it does not have a size. The correct so
625.
by adrian_b 5mo ago
Diminishing returns apply to ISA extensions only on average, not for individual applications. Most of the recent additions in processor instruction sets are intended for relatively niche applications. In such cases, other applications will
626.
by adrian_b 5mo ago
This is what you should always do when you know on which computers you will run the program, like I do when writing programs for my own computers. If you are a software vendor, or even just a contributor to some open-source program, you mus
627.
by adrian_b 5mo ago
The fragmentation of AVX-512 is a legacy problem. All the CPUs introduced after Ice Lake (Q3 2019), with the exception of Cooper Lake (Q2 2020; a server CPU with a modest installed base), which support any kind of AVX-512, support all the A
628.
by adrian_b 5mo ago
Obviously, as you assume, for ordinary fans it has already been much worse: https://www.bbc.com/news/articles/cx212p8r28eo Organizing any international events in USA is a huge, unforgivable mistake, when it is wel
629.
by adrian_b 5mo ago
Regarding operators, there are 3 distinct problems. One is to allow the use of simple mathematical symbols as names for functions, instead of allowing only alphanumeric identifiers. Most programming languages allow only a small fixed set of
630.
by adrian_b 5mo ago
From TFA: "in the United States, the incidence of advanced colorectal cancer has increased by about 3% each year since around 2010 in people between the ages of 20 and 49. In 2023, colorectal cancer became the leading cause of cancer d

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