Hayflick limit by Ciro Santilli 35 Updated +Created
Subtitle editor by Ciro Santilli 35 Updated +Created
Readout (quantum computing) by Ciro Santilli 35 Updated +Created
NIST Atomic Spectra Database by Ciro Santilli 35 Updated +Created
Let's do a sanity check.
From there we can see for example the 1 to 2 lines:
  • 1s to 2p: 121.5673644608 nm
  • 1s to 2: 121.56701 nm TODO what does that mean?
  • 1s to 2s: 121.5673123130200 TODO what does that mean?
We see that the table is sorted from lower from level first and then by upper level second.
So it is good to see that we are in the same 121nm ballpark as mentioned at hydrogen spectral line.
TODO why I can't see 2s to 2p transitions there to get the fine structure?
Zeeman effect by Ciro Santilli 35 Updated +Created
Split in the spectral line when a magnetic field is applied.
Non-anomalous: number of splits matches predictions of the Schrödinger equation about the number of possible states with a given angular momentum. TODO does it make numerical predictions?
Anomalous: evidence of spin.
www.pas.rochester.edu/~blackman/ast104/zeeman-split.html contains the hello world that everyone should know: 2p splits into 3 energy levels, so you see 3 spectral lines from 1s to 2p rather than just one.
p splits into 3, d into 5, f into 7 and so on, i.e. one for each possible azimuthal quantum number.
It also mentions that polarization effects become visible from this: each line is polarized in a different way. TODO more details as in an experiment to observe this.
Video 1.
Experimental physics - IV: 22 - Zeeman effect by Lehrportal Uni Gottingen (2020)
Source.
This one is decent. Uses a cadmium lamp and an etalon on an optical table. They see a more or less clear 3-split in a circular interference pattern,
They filter out all but the transition of interest.
Video 2.
Zeeman Effect - Control light with magnetic fields by Applied Science (2018)
Source. Does not appear to achieve a crystal clear split unfortunately.
Light cone by Ciro Santilli 35 Updated +Created
A subset of Spacetime diagram.
The key insights that it gives are:
  • future and past are well defined: every reference frame sees your future in your future cone, and your past in your past cone
    Otherwise causality could be violated, and then things would go really bad, you could tell your past self to tell your past self to tell your past self to do something.
    You can only affect the outcome of events in your future cone, and you can only be affected by events in your past cone. You can't travel fast enough to affect.
    Two spacetime events with such fixed causality are called timelike-separated events.
  • every other event (to right and left, known as spacelike-separated events) can be measured to happen before or after your current spacetime event by different observers.
    But that does not violate causality, because you just can't reach those spacetime points anyways to affect them.
Figure 1.
Animation showing how space-separated events can be observed to happen in different orders by observers in different frames of reference
. Source.
Particle in a box by Ciro Santilli 35 Updated +Created
Two-state quantum system by Ciro Santilli 35 Updated +Created
Discrete quantum system model that can model both spin in the Stern-Gerlach experiment or photon polarization in polarizer.
Also known in quantum computing as a qubit :-)
Don't repeat yourself by Ciro Santilli 35 Updated +Created
Satoshi Dice by Ciro Santilli 35 Updated +Created
Claims provably fair. satoshidice.com/fair clarifies what that means: they prove fairness by releasing a hash of the seed before the bets, and the actual seed after the bets.
As mentioned in bitcoin.it, it functions basically as cryptocurrency tumbler in practice.
Hal Finney (computer scientist) by Ciro Santilli 35 Updated +Created
Ruby on Rails by Ciro Santilli 35 Updated +Created
The only reason why Ruby exists.
This web framework is pretty good as of 2020 compared to others, because it managed to gain a critical community size, and there's a lot of basic setup already done for you.
it is just big shame it wasn't written in Python or even better, Node.js, because learning Ruby is completely useless for anything else. As of 2020 for example, most Node.js web frameworks feel like crap compared to Rails, you just have to debug so much there.
Used in GitLab, which is why Ciro Santilli touched it.
SiFive by Ciro Santilli 35 Updated +Created
Leading RISC-V consultants as of 2020, they are basically trying to become the Red Hat of the semiconductor industry.
Human reproductive cue by Ciro Santilli 35 Updated +Created
Diode bridge by Ciro Santilli 35 Updated +Created
Dynamic random-access memory by Ciro Santilli 35 Updated +Created
DRAM is often shortened to just random-access memory.
Isra and Mi'raj by Ciro Santilli 35 Updated +Created
The truth will set you free by Ciro Santilli 35 Updated +Created

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