gothinkster/realworld Updated 2025-07-16
Basically puts together every backend with Front-end web framework to create the exact same website.
The reference live demo can be found at: demo.realworld.io/#/ It is based on Angular.js as it links to: github.com/gothinkster/angularjs-realworld-example-app TODO backend?
There are however also live demos of other frontends, e.g.:
Note that all those frontends communicate with the same backend.
As of 2021 Devs are seemed a bit too focused on monetizing the project through their "how to use this project" premium tutorial, and documentation could be better: just getting the hello world of the most popular backend with the most popular frontend is not easy... come on.
github.com/gothinkster/realworld/issues/578 asks for community support, as devs have moved on since unfortunately.
Remember:
  • by default, the frontends hardcode the upstream public data API: https://conduit.productionready.io/api so you have to hack their code to match the port of the backend. And each backend can have a different port.
  • when you switch between backends, you must first manually clear client-side storage cookies/local new run will fail due to authentication issues!
Important missing things from the minimum base app:
First you should the most popular backend/frontend combination running, which is the most likely to be working. We managed to run on Ubuntu 20.10, React + Node.js Express.js as described at github.com/gothinkster/node-express-realworld-example-app/pull/116:
Then just:
npm install
npm start
on both server and client, and then visit the client URL: localhost:4100/
One cool thing is that the main repo has unified backend API tests:
git clone https://github.com/gothinkster/realworld
cd realworld
git checkout e7adc6b06b459e578d7d4a6738c1c050598ba431
cd api
APIURL=http://localhost:3000/api USERNAME="u$(date +%s)" ./run-api-tests.sh
so the per-repository tests are basically useless, and that single test can test everything for any backend! There is no frontend testing however: github.com/gothinkster/realworld/issues/269 so newb.
This is a good concept. For the ammount most people save, having a simple and easy to apply investment thesis is the best way to go.
Video 1.
All the financial advice you’ll ever need fits on a single index card
. Source.
Unlike the simple case of a matrix, in infinite dimensional vector spaces, the spectrum may be continuous.
The quintessential example of that is the spectrum of the position operator in quantum mechanics, in which any real number is a possible eigenvalue, since the particle may be found in any position. The associated eigenvectors are the corresponding Dirac delta functions.
Controlled quantum gate Updated 2025-07-16
Controlled quantum gates are gates that have two types of input qubits:
These gates can be understood as doing a certain unitary operation only if the control qubits are enabled or disabled.
The first example to look at is the CNOT gate.
Figure 1.
Generic controlled quantum gate symbol
. Source.
The black dot means "control qubit", and "U" means an arbitrary Unitary operation.
When the operand has a conventional symbol, e.g. the Figure "Quantum NOT gate symbol" for the quantum NOT gate to form the CNOT gate, that symbol is used in the operand instead.
For a detailed analysis of one transaction see: Nelson-Mandela.jpg.
Best guess so far, all in ASCII hex of output scripts:
Other Bitcon analysis:
There are a few possibilities:
csvtool Updated 2025-07-16
A compiled executable under /usr/bin/csvtool, has an Ubuntu 23.04 package: manpages.ubuntu.com/manpages/lunar/en/man1/csvtool.1.html
There seems to be no sane filtering mechanism however: stackoverflow.com/questions/46540752/using-csvtool-call-to-filter-csv-in-bash
Electronvolt Updated 2025-07-16
After the 2019 redefinition of the SI base units it is by definition exactly Joules.
Positive definite matrix Updated 2025-07-16
The dot product is a positive definite matrix, and so we see that those will have an important link to familiar geometry.
Alpha decay Updated 2025-07-16
Most of the helium in the Earth's atmosphere comes from alpha decay, since helium is lighter than air and naturally escapes out out of the atmosphere.
Wiki mentions that alpha decay is well modelled as a quantum tunnelling event, see also Geiger-Nuttall law.
As a result of that law, alpha particles have relatively little energy variation around 5 MeV or a speed of about 5% of the speed of light for any element, because the energy is inversely exponentially proportional to half-life. This is because:
  • if the energy is much larger, decay is very fast and we don't have time to study the isotope
  • if the energy is much smaller, decay is very rare and we don't have enough events to observe at all
Video 1.
Quantum tunnelling and the Alpha particle Paradox by Physics Explained (2022)
Source.

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