Planet in the Solar System by Ciro Santilli 35 Updated +Created
Spontaneous parametric down-conversion by Ciro Santilli 35 Updated +Created
Phenomena that produces photons in pairs as it passes through a certain type of crystal.
You can then detect one of the photons, and when you do you know that the other one is there as well and ready to be used. two photon interference experiment comes to mind, which is the basis of photonic quantum computer, where you need two photons to be produced at the exact same time to produce quantum entanglement.
Video 1.
One Photon In, TWO Photons Out by JQInews (2010)
Source.
Mentions that this phenomena is useful to determine the efficiency of a single photon detector, as you have the second photon of the pair as a control.
Also briefly describes how the input energy and momentum must balance out the output energy and momentum of the two photons coming out (determined by the output frequency and angle).
Shows the crystal close up of the crystal branded "Cleveland Crystals Inc.". Mentions that only one in a billion photon gets scattered.
Also shows a photomultiplier tube.
Then shows their actual optical table setup, with two tunnels of adjustable angle to get photons with different properties.
Video 2.
How do you produce a single photon? by Physics World (2015)
Source.
Very short whiteboard video by Peter Mosley from the University of Bath, but it's worth it for newbs. Basically describes spontaneous parametric down-conversion.
One interesting thing he mentions is that you could get single photons by making your sunglasses thicker and thicker to reduce how many photons pass, but one big downside problem is that then you don't know when the photon is going to come through, that becomes essentially random, and then you can't use this technique if you need two photons at the same time, which is often the case, see also: two photon interference experiment.
XY sex-determination system by Ciro Santilli 35 Updated +Created
Michael Moritz by Ciro Santilli 35 Updated +Created
Video 1.
Michael Moritz interview by Stanford Graduate School of Business (2019)
Source. The dude is quirky.
so the solution is:
We notice that the solution has continuous spectrum, since any value of can provide a solution.
RNA-dependent RNA polymerase by Ciro Santilli 35 Updated +Created
Makes RNA from RNA.
Used in Positive-strand RNA virus to replicate.
I don't think it's present outside viruses. Well regulated organisms just transcribe more DNA instead.
Renormalization group by Ciro Santilli 35 Updated +Created
Raspberry Pi 2 by Ciro Santilli 35 Updated +Created
Protein complex by Ciro Santilli 35 Updated +Created
Hermite polynomials by Ciro Santilli 35 Updated +Created
14 1 hours 20 minute lectures.
The video resolution is extremely low, with images glued as he moves away from what he wrote :-) The beauty of the early Internet.
No-Nonsense Quantum Field Theory by Jakob Schwichtenberg (2020) by Ciro Santilli 35 Updated +Created
This book really tries to recall basic things to ensure that the reader will be able to understand the more advanced ones.
Sometimes it goes a little bit overboard, like defining what a function does several times.
But Ciro Santilli really prefers it when authors error on the side of obvious.
This is very widely used in courses as of 2020, it became kind of the default book.
Unfortunately, this approach bores Ciro Santilli to death. Or perhaps is too just advanced for him to appreciate. Either of those.
800+ pages.
Quantum Theory of Radiation by Fermi (1932) by Ciro Santilli 35 Updated +Created
Binary translation by Ciro Santilli 35 Updated +Created
RSA (cryptosystem) by Ciro Santilli 35 Updated +Created
Based on the fact that we don't have a P algorithm for integer factorization as of 2020. But nor proof that one does not exist!
The private key is made of two randomly generated prime numbers: and . How such large primes are found: how large primes are found for RSA.
The public key is made of:
  • n = p*q
  • a randomly chosen integer exponent between 1 and e_max = lcm(p -1, q -1), where lcm is the Least common multiple
Given a plaintext message m, the encrypted ciphertext version is:
c = m^e mod n
This operation is called modular exponentiation can be calculated efficiently with the Extended Euclidean algorithm.
The inverse operation of finding the private m from the public c, e and is however believed to be a hard problem without knowing the factors of n.
However, if we know the private p and q, we can solve the problem. As follows.
First we calculate the modular multiplicative inverse. TODO continue.
Position representation by Ciro Santilli 35 Updated +Created
A way to write the wavefunction such that the position operator is:i.e., a function that takes the wavefunction as input, and outputs another function:
If you believe that mathematicians took care of continuous spectrum for us and that everything just works, the most concrete and direct thing that this representation tells us is that:
the probability of finding a particle between and at time
equals:
Rayleigh-Jeans law by Ciro Santilli 35 Updated +Created
Derived from classical first principles, matches Planck's law for low frequencies, but diverges at higher frequencies.
Myers-Briggs Type_Indicator by Ciro Santilli 35 Updated +Created

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