The key thing in a good system of units is to define units in a way that depends only on physical properties of nature.
Ideally (or basically necessarily?) the starting point generally has to be discrete phenomena, e.g.
- number of times some light oscillates per second
- number of steps in a quantum Hall effect or Josephson junction
What we don't want is to have macroscopic measurement artifacts, (or even worse, the size of body parts! Inset dick joke) as you can always make a bar slightly more or less wide. And even metals evaporate over time! Though the mad people of the Avogadro project still attempted otherwise well into the 2010s!
Standards of measure that don't depend on artifacts are known as intrinsic standards.
www.youtube.com/watch?v=0hfdSrK46EE How To Use A Minimoog Synthesizer by Doctor Mix (2020)
Software emulators:
Related to Leela Zero, a Go engine
Just like a classic programmer does not need to understand the intricacies of how transistors are implemented and CMOS semiconductors, the quantum programmer does not understand physical intricacies of the underlying physical implementation.
The main difference to keep in mind is that quantum computers cannot save and observe intermediate quantum state, so programming a quantum computer is basically like programming a combinatorial-like circuit with gates that operate on (qu)bits:
For this reason programming a quantum computer is much like programming a classical combinatorial circuit as you would do with SPICE, verilog-or-vhdl, in which you are basically describing a graph of gates that goes from the input to the output
For this reason, we can use the words "program" and "circuit" interchangeably to refer to a quantum program
Also remember that and there is no no clocks in combinatorial circuits because there are no registers to drive; and so there is no analogue of clock in the quantum system either,
Another consequence of this is that programming quantum computers does not look like programming the more "common" procedural programming languages such as C or Python, since those fundamentally rely on processor register / memory state all the time.
Quantum programmers can however use classic languages to help describe their quantum programs more easily, for example this is what happens in Qiskit, where you write a Python program that makes Qiskit library calls that describe the quantum program.
Quantum logic gates are needed for physical implementation Updated 2024-12-23 +Created 1970-01-01
One direct practical reason is that we need to map the matrix to real quantum hardware somehow, and all quantum hardware designs so far and likely in the future are gate-based: you manipulate a small number of qubits at a time (2) and add more and more of such operations.
While there are "quantum compilers" to increase the portability of quantum programs, it is to be expected that programs manually crafted for a specific hardware will be more efficient just like in classic computers.
TODO: is there any clear reason why computers can't beat humans in approximating any unitary matrix with a gate set?
This is analogous to what classic circuit programmers will do, by using smaller logic gates to create complex circuits, rather than directly creating one huge truth table.
The most commonly considered quantum gates take 1, 2, or 3 qubits as input.
The gates themselves are just unitary matrices that operate on the input qubits and produce the same number of output qubits.
For example, the matrix for the CNOT gate, which takes 2 qubits as input is:
1 0 0 0
0 1 0 0
0 0 0 1
0 0 1 0The final question is then: if I have a 2 qubit gate but an input with more qubits, say 3 qubits, then what does the 2 qubit gate (4x4 matrix) do for the final big 3 qubit matrix (8x8)? In order words, how do we scale quantum gates up to match the total number of qubits?
The intuitive answer is simple: we "just" extend the small matrix with a larger identity matrix so that the sum of the probabilities third bit is unaffected.
More precisely, we likely have to extend the matrix in a way such that the partial measurement of the original small gate qubits leaves all other qubits unaffected.
For example, if the circuit were made up of a CNOT gate operating on the first and second qubits as in:
0 ----+----- 0
|
1 ---CNOT--- 1
2 ---------- 2then we would just extend the 2x2 CNOT gate to:
TODO lazy to properly learn right now. Apparently you have to use the Kronecker product by the identity matrix. Also, zX-calculus appears to provide a powerful alternative method in some/all cases.
Transaction retries are inevitable, as some sQL isolation levels
Doesn't seem to have any simple built-in mechanism?
Nature is a black box, right?
You don't need to understand the from first principles derivation of every single phenomena.
And most important of all: you should not start learning phenomena by reading the from first principles derivation.
Instead, you should see what happens in experiments, and how matches some known formula (which hopefully has been derived from first principles).
Only open the boxes (understand from first principles derivation) if the need is felt!
E.g.:
- you don't need to understand everything about why SQUID devices have their specific I-V curve curve. You have to first of all learn what the I-V curve would be in an experiment!
- you don't need to understand the fine details of how cavity magnetrons work. What you need to understand first is what kind of microwave you get from what kind of input (DC current), and how that compares to other sources of microwaves
- lasers: same
Physics is all about predicting the future. If you can predict the future with an end result, that's already predicting the future, and valid.
Shady shady buyer of "vistomail.com". He sends emails as satoshi@vistomail.com without any disclaimers, Godlike.
He or someone with the same name is having some fun with the SEC: dockets.justia.com/docket/florida/flmdce/8:2023cv01638/416506 for "Securities Fraud".
The complaint: www.sec.gov/files/litigation/complaints/2023/comp25785.pdf (archive). Some pearls:
41. Elbanna told investors several other lies to gain investors’ trust. These included his claim that he had served in the U.S. Marines, when in reality he was discharged after just fifteen days of their thirteen-week recruit training. Elbanna claimed that he had worked at the U.S. National Security Agency (“NSA”). He further claimed that the NSA was aware of and participating in the Digital World Exchange enterprise. All of these claims were false.42. Perhaps most incredibly, after claiming that he had “been in blockchain technology since the beginning” and “in the cryptocurrency space almost since its inception” in the May 2018 and March 2019 Whitepapers, respectively, Elbanna told investors in a chat program in April 2019 that he “was one of the first 4 creators of BTC.” He went so far as to tell another investor that he was the pseudonymous inventor of bitcoin, Satoshi Nakamoto himself. These statements were also false. Elbanna later admitted that he was not involved in blockchain technology from its beginning, and that he “didn’t even really know much about crypto” in 2018, the year he launched the Digital World Exchange enterprise.
www.law360.com/articles/1803299/bogus-nsa-worker-to-pay-sec-2-2m-in-crypto-scam-case says he had to pay $2.2M to the SEC.
The documentary Bitconned from Netflix comes strongly to mind, www.imdb.com/title/tt30317302/. It is unbelieveable people would fall for that kind of thing, the founders are not even sophisticated. And on top of that he agrees to appear on a documentary!!! OMG.
Quantum Mechanics 12b - Dirac Equation II by ViaScience (2015)
Source. - youtu.be/tR6UebCvFqE?t=23 particle at rest
- youtu.be/tR6UebCvFqE?t=322 unidirectional movement without a potential
- youtu.be/tR6UebCvFqE?t=507 shows that observers in different frames of reference also see different spin. We are reminded of how magnetism is just a side effect of special-relativity.
- youtu.be/tR6UebCvFqE?t=549 Dirac equation solution for the hydrogen atom, final result only + mentions fine structure prediction.
It is hard for complex organisms to evolve because longer DNA means longer replication time Updated 2024-12-23 +Created 1970-01-01
Because DNA replication is a key limiting factor of bacterial replication time, such organisms are therefore strongly incentivized to have very minimal DNAs.
Power, Sex, Suicide by Nick Lane (2006) 7 "Why bacteria are simple" page 169 puts this nicely:
Bacteria replicate at colossal speed. [...] In two days, the mass of exponentially doubling E. coli would be 2664 times larger than the mass of the Earth.Luckily this does not happen, and the reason is that bacteria are normally half starved. They swiftly consume all available food, whereupon their growth is limited once again by the lack of nutrients. Most bacteria spend most of their lives in stasis, waiting for a meal. Nonetheless, the speed at which bacteria do mobilize themselves to replicate upon feeding illustrates the overwhelming strength of the selection pressures at work.
- www.raspberrypi.com/documentation/microcontrollers/c_sdk.html
- github.com/raspberrypi/pico-sdk
- github.com/raspberrypi/pico-examples The key hello world examples are:
Ubuntu 22.04 build just worked, nice! Much feels much cleaner than the Micro Bit C setup:
sudo apt install cmake gcc-arm-none-eabi libnewlib-arm-none-eabi libstdc++-arm-none-eabi-newlib
git clone https://github.com/raspberrypi/pico-sdk
cd pico-sdk
git checkout 2e6142b15b8a75c1227dd3edbe839193b2bf9041
cd ..
git clone https://github.com/raspberrypi/pico-examples
cd pico-examples
git checkout a7ad17156bf60842ee55c8f86cd39e9cd7427c1d
cd ..
export PICO_SDK_PATH="$(pwd)/pico-sdk"
cd pico-exampes
mkdir build
cd build
# Board selection.
# https://www.raspberrypi.com/documentation/microcontrollers/c_sdk.html also says you can give wifi ID and password here for W.
cmake -DPICO_BOARD=pico_w ..
make -jThen we install the programs just like any other UF2 but plugging it in with BOOTSEL pressed and copying the UF2 over, e.g.:Note that there is a separate example for the W and non W LED, for non-W it is:
cp pico_w/blink/picow_blink.uf2 /media/$USER/RPI-RP2/cp blink/blink.uf2 /media/$USER/RPI-RP2/Also tested the UART over USB example:You can then see the UART messages with:
cp hello_world/usb/hello_usb.uf2 /media/$USER/RPI-RP2/screen /dev/ttyACM0 115200TODO understand the proper debug setup, and a flash setup that doesn't require us to plug out and replug the thing every two seconds. www.electronicshub.org/programming-raspberry-pi-pico-with-swd/ appears to describe it, with SWD to do both debug and flash. To do it, you seem need another board with GPIO, e.g. a Raspberry Pi, the laptop alone is not enough.
Course actually means "degree", not just one specific "course":
The course outline is given in a "handbook", a one or more PDF files that contain what people will learn and other practicalities. There is a full list of handbooks at: www.ox.ac.uk/students/academic/guidance/undergraduate/handbooks, but many of them are closed. The system is so closed that even the fucking course list is closed, e.g. all links at: www2.physics.ox.ac.uk/students/undergraduates are closed. Insane.
Please refer to Video "Linus Torvalds saying "Nvidia Fuck You" (2012)".
Does not happen every time, only some times. Can't figure out why. Usually happens when has suspended for a longer time.
bugs.launchpad.net/ubuntu/+source/nvidia-graphics-drivers-470/+bug/1946303 sounds like a likely report, Nvidia driver version 470, but can't find those error messages anywhere. The last line of:once was:which is when sleep starts.
journalctl -o short-precise -k -b -1PM: suspend entry (deep)This suggests that it is not a video bug then, seems that it is not waking up at all? Gotta try to SSH into it. OK. I did SSH into it, and that was fine, so it is just the video that won't start.
PM: suspend exitbugs.launchpad.net/ubuntu/+source/linux/+bug/1949977 is another possible bug, based on kernel version. I'm running 5.13, which is one of the failing versions on the report. Can't find any interesting dmesg though.
In another crash:had the following interesting lines:and there was a corresponding
journalctl -o short-precise -k -b -1nvidia-modeset: WARNING: GPU:0: Lost display notification (0:0x00000000); continuing.
[24307.640014] NVRM: GPU at PCI:0000:01:00: GPU-18af74bb-7c72-ff70-e447-87d48378ea20
[24307.640018] NVRM: Xid (PCI:0000:01:00): 79, pid=8828, GPU has fallen off the bus.
[24307.640021] NVRM: GPU 0000:01:00.0: GPU has fallen off the bus.
[24328.054022] nvidia-modeset: ERROR: GPU:0: The requested configuration of display devices (LGD (DP-4)) is not supported on this GPU.
[repeats several more times]
[24328.056767] nvidia-modeset: ERROR: GPU:0: The requested configuration of display devices (LGD (DP-4)) is not supported on this GPU.
[24328.056951] nvidia-modeset: ERROR: GPU:0: Failed to query display engine channel state: 0x0000927c:0:0:0x0000000f
[24328.056955] nvidia-modeset: ERROR: GPU:0: Failed to query display engine channel state: 0x0000927c:1:0:0x0000000f
[24328.056959] nvidia-modeset: ERROR: GPU:0: Failed to query display engine channel state: 0x0000927c:2:0:0x0000000f
[24328.056962] nvidia-modeset: ERROR: GPU:0: Failed to query display engine channel state: 0x0000927c:3:0:0x0000000f
[24328.056983] nvidia-modeset: ERROR: GPU:0: DP-4: Failed to disable DisplayPort audio stream-0
[24328.056992] nvidia-modeset: ERROR: GPU:0: Failed to query display engine channel state: 0x0000947d:0:0:0x0000000f/var/crash/_usr_sbin_gdm3.0.crash.Related "GPU has fallen off the bus": askubuntu.com/questions/868321/gpu-has-fallen-off-the-bus-nvidia
"Joachimsthal" is the German for it. Note how it is just near the modern frontier between Germany and the Czech Republic.
en.wikipedia.org/w/index.php?title=Uranium&oldid=1243907294#Pre-discovery_use:
In the early 19th century, the world's only known sources of uranium ore were these mines.
Apparently the region was a silver mining center:
Starting in the late Middle Ages, pitchblende was extracted from the Habsburg silver mines in Joachimsthal, Bohemia (now Jáchymov in the Czech Republic), and was used as a coloring agent in the local glassmaking industry
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