Microwave source by Ciro Santilli 40 Updated 2025-07-16
Microwave only found applications into the 1940s and 1950s, much later than radio, because good enough sources were harder to develop.
One notable development was the cavity magnetron in 1940, which was the basis for the original radar systems of World War II.
Microwave oven by Ciro Santilli 40 Updated 2025-07-16
Video 1.
How Microwaves Work by National MagLab (2017)
Source. A bit meh. Does not mention the word cavity magnetron!
Video 2. . Source. Cool demonstration of the standing waves in the cavity with cheese!
Not done yet as of 2020! Will be done one day for sure.
The most notable exception is the borrowing of 3d-orbital electrons to 4s as in chromium, leading to a 3d5 4s1 configuration instead of the 3d4 4s2 we would have with the rule. TODO how is that observed observed experimentally?
Tried a quick port to SQLite to get rid of annoying local databases for development, but failed, at c1c2cc4e448b279ff083272df1ac50d20c3304fa
npm install sqlite3 --save-dev
and
{
  "type": "sqlite",
  "database": "db.sqlite3",
  "entities": ["src/**/**.entity{.ts,.js}"],
  "synchronize": true
}
then:
npm start
fails with:
DataTypeNotSupportedError: Data type "timestamp" in "ArticleEntity.created" is not supported by "sqlite" database.
Attempt to hack it:
--- a/src/article/article.entity.ts
+++ b/src/article/article.entity.ts
@@ -20,10 +20,10 @@ export class ArticleEntity {
   @Column({default: ''})
   body: string;

-  @Column({ type: 'timestamp', default: () => "CURRENT_TIMESTAMP"})
+  @Column({ default: () => "CURRENT_TIMESTAMP"})
   created: Date;

-  @Column({ type: 'timestamp', default: () => "CURRENT_TIMESTAMP"})
+  @Column({ default: () => "CURRENT_TIMESTAMP"})
   updated: Date;
and after that it seems to run.
I can signup and login, terrible error reporting as usual, make sure to use long enough usernames/passwords.
However, article creation fails with:
Unhandled Rejection (TypeError): Cannot read property 'slug' of undefined
Video 1.
Fabry Perot Interferometer by JFC UCL (2016)
Source. Description only, reasonable animations. Considers the case of two nearby beam splitters.
Video 2.
Fabry-Perot Introduction by Williams College Physics (2020)
Source.
Shows a working device. Confocal optical cavity, one of the mirrors scans back and forward moved by a piezoelectric motor, this is called a "scanning Fabry-Perot interferometer".
Does not produce an interference pattern, only an on/off blob, which is then fed into an oscilloscope for analysis. The oscilloscope shows both the mirror displacement (which is given by a voltage) and the light detector output.
Video 3.
Aligning a Scanning Fabry-Perot Interferometer by University of South Florida (2016)
Source. Very detailed, and shows of some nice equipment and techniques.
Also webpack and Babel, looks promising!
As of 2021, last commit from 2017.
Running:
git clone https://github.com/Codaisseur/feathersjs-react-redux-ssr
cd feathersjs-react-redux-ssr
npm install
failed on Ubuntu 20.10 Node.js v14.15.3 with:
../src/create_string.cpp:17:37: error: no matching function for call to ‘v8::String::Utf8Value::Utf8Value(v8::Local<v8::Value>&)’
   17 |   v8::String::Utf8Value string(value);
      |                                     ^
Likely similar bullshit from: stackoverflow.com/questions/50111688/node-sqlite-node-gyp-build-error-no-member-named-forceset-in-v8object because the Node.js version is too new.
If I try nvm install v10
I Google error messages until reaching:
diff --git a/gulpfile.js b/gulpfile.js
index b931e06..24d2cc8 100644
--- a/gulpfile.js
+++ b/gulpfile.js
@@ -14,34 +14,34 @@ gulp.task('css', function() {
            .pipe(gulp.dest('./dist'))
 })
 
-gulp.task('css:watch', ['css'], function() {
+gulp.task('css:watch', gulp.series('css', function() {
   gulp.watch('app/styles/**/*.sass', ['css'])
-})
+}))
 
 gulp.task('moveAssets', function() {
   return gulp.src('./app/assets/**/*')
              .pipe(gulp.dest('./dist/assets'))
 })
 
-gulp.task('build:revAssets', ['css', 'moveAssets'], function() {
+gulp.task('build:revAssets', gulp.series('css', 'moveAssets', function() {
   var rev = new $.revAll()
   return gulp.src('./dist/**/*')
              .pipe(rev.revision())
              .pipe(gulp.dest('./dist/public'))
              .pipe(rev.manifestFile())
              .pipe(gulp.dest('./dist'))
-})
+}))
 
 gulp.task('build:cpServer', function() {
   return gulp.src('./app/**/*.{js,ejs}')
              .pipe(gulp.dest('./dist/server-build'))
 })
-gulp.task('build:revServer', ['build:cpServer'], function() {
+gulp.task('build:revServer', gulp.series('build:cpServer', function() {
   var manifest = gulp.src('./dist/rev-manifest.json')
   return gulp.src('./dist/server-build/{components,containers}/**/*')
              .pipe($.revReplace({ manifest: manifest }))
              .pipe(gulp.dest('./dist/server-build'))
-})
+}))
 
 gulp.task('build', function() {
   runSequence('build:revAssets', 'build:revServer')
diff --git a/package.json b/package.json
index bcb29c3..86bd593 100644
--- a/package.json
+++ b/package.json
@@ -67,7 +67,7 @@
     "redux-thunk": "^0.1.0",
     "request": "^2.79.0",
     "rewire": "^2.3.4",
-    "run-sequence": "^1.2.2",
+    "run-sequence": "^2.2.1",
     "serve-favicon": "^2.3.2",
     "socket.io-client": "^1.7.2",
     "superagent": "^1.4.0",
@@ -86,16 +86,16 @@
     "concurrently": "^2.0.0",
     "cross-env": "^1.0.7",
     "enzyme": "^2.3.0",
-    "gulp": "^3.9.0",
+    "gulp": "^4.0.2",
     "gulp-autoprefixer": "^3.1.0",
     "gulp-load-plugins": "^1.2.0",
     "gulp-rev": "^6.0.1",
-    "gulp-sass": "^2.1.1",
+    "gulp-sass": "4.1.0",
     "gulp-sourcemaps": "^1.6.0",
     "jsdom": "^7.0.1",
     "mocha": "^2.4.5",
     "nock": "^2.17.0",
-    "node-sass": "^3.4.2",
+    "node-sass": "^5.0.0",
     "nodemon": "^1.6.0",
     "react-addons-test-utils": "^15.3.2",
     "react-transform-catch-errors": "^1.0.0",
and the next problem is: stackoverflow.com/questions/48513573/gulp-error-gulp-hastask-is-not-a-function
MongoDB-based.
So once you install MongoDB, run with:
MONGODB_FEATHERS_REALWORLD=mongodb://localhost:27017/mydb npm start
Tests can be run with:
MONGODB_FEATHERS_REALWORLD=mongodb://localhost:27017/mydb npm run test
but there were 10 failures and 55 passes: github.com/randyscotsmithey/feathers-realworld-example-app/issues/3
hello_world_len points to the special st_shndx == SHN_ABS == 0xF1FF.
0xF1FF is chosen so as to not conflict with other sections.
st_value == 0xD == 13 which is the value we have stored there on the assembly: the length of the string Hello World!.
This means that relocation will not affect this value: it is a constant.
This is small optimization that our assembler does for us and which has ELF support.
If we had used the address of hello_world_len anywhere, the assembler would not have been able to mark it as SHN_ABS, and the linker would have extra relocation work on it later.

There are unlisted articles, also show them or only show them.