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Private Notes
This video is about how to create muons in a particle accelerator via bombardment of heavy nuclei with protons, which results in creation of charged pions (plus and minus). The pions then decay into muons and mu neutrinos, and the muons then decay into electrons or positrons and more neutrinos. Muons also form in the upper atmosphere due to cosmic rays, and the uses of muons includes experimental tests of time dilation in special relativity, catalyzing muonic cold nuclear fusion, and more.
This video is about the cosmic distance scale and how we see objects farther away in space (ie at higher red shift) farther back in time because light takes time to reach us. Thus we can see not only stars and galaxies, but also the primordial stars & proto-galaxies, and even the remnants of the beginning of the universe itself: the CMB cosmic microwave background left over from the big bang.
This joke video is about how Internet Service Providers (aka ISPs, internet companies, telecommunications companies, etc) violate the basic axioms of Zermelo-Fraenkel set theory. Like the axiom of choice (sometimes Well-ordering theorem), the Axiom of extensionality, Axiom of regularity (also called the Axiom of foundation), Axiom schema of specification, Axiom of pairing, Axiom of union, Axiom schema of replacement, Axiom of infinity, Axiom of power set.
This video is about compressed air cans (aka gas dusters) and why they get cold when you spray them.
This video explains Shor’s Algorithm, a way to efficiently factor large pseudoprime integers into their prime factors using a quantum computer. The quantum computation relies on the number-theoretic analysis of the factoring problem via modular arithmetic mod N (where N is the number to be factored), and finding the order or period of a random coprime number mod N. The exponential speedup comes in part from the use of the quantum fast fourier transform which achieves interference among frequencies that are not related to the period (period-finding is the goal of the QFT FFT).
This video explains how Shor’s Algorithm factors the pseudoprime number 314191 into its prime factors using a quantum computer. The quantum computation relies on the number-theoretic analysis of the factoring problem via modular arithmetic mod N (where N is the number to be factored), and finding the order or period of a random coprime number mod N. The exponential speedup comes in part from the use of the quantum fast fourier transform which achieves interference among frequencies that are not related to the period (period-finding is the goal of the QFT FFT).
This video is about how I designed and made my own custom mute guitar pedal for my clip-on mic and piezo pickup on my violin (fiddle). The mic is an AT Pro35 phantom powered XLR condensor microphone, and the pickup is a Fishman V200 piezoelectric transducer. I got all of the parts from PartsExpress.
This video is about how little we know about the behavior of gravity at short length and distance scales, what the constraints are on the inverse square law/Newton's law of universal gravitation, at the human and microscopic and atomic scales. Only on solar system scales or larger do we have good constraints on Newton's law of gravitation.
This video is about the Portal Paradox - a paradox in the video game Portal (and Portal 2) regarding whether or not a companion cube passing through a moving portal plops out of the other end with no speed (velocity, momentum), or shoots out at high speed. It’s a question of conservation of momentum, relativity of velocities, wormholes, 3D printers and quantum teleportation, glitches, and more.
This video is about how Albert Einstein made a mistake when applying the Field Equations of General Relativity to cosmology (in particular, to a static, constant density universe), and solved the problem by introducing the cosmological constant, rather than allowing for a dynamic universe with a scale factor - that is, the Friedmann-Lemaitre-Robertson-Walker universe, first developed by Alexander Friedmann of Russia. Later, it was discovered by the Slipher and Hubble red-shift that the universe is indeed expanding, and even later, by Schwarz and company in 1998, that the expansion is accelerating - aka, dark energy. And the cosmological constant was re-introduced.
This video is about the length of a solar day vs a stellar day vs a mean standard day, what they all have to do with each other and the earth's orbit, eccentricity, axial tilt, and so on. Also, aliens and asteroids. It'll explain the equation of time, and why the longest day is in December. The lab will also show you what days are like on all the other planets - Mercury, Venus, Mars, Jupiter, Saturn, Uranus, Neptune, and even - though it's not a planet - Pluto.
The world's most entertaining and useless self-help guide, from the brilliant mind behind the wildly popular webcomic xkcd and the #1 New York Times bestsellers What If? and Thing Explainer
For any task you might want to do, there's a right way, a wrong way, and a way so monumentally complex, excessive, and inadvisable that no one would ever try it. How To is a guide to the third kind of approach. It's full of highly impractical advice for everything from landing a plane to digging a hole.
This video was made in collaboration with the US Census Bureau and fact-checked by Census Bureau scientists. Any opinions and errors are my own.
Cynthia Dwork (key inventor of Differential Privacy), giving a great intro talk about differential privacy
This video is about how Russian physicist Aleksandr Fridman corrected Albert Einstein about the expansion of the universe. Einstein thought that general relativity implied that space had to be static and unchanging, but he had made a technical error regarding the differentiation of the metric (in particular, I believe he mistook the determinant of the metric for a scalar rather than a tensor density of weight 2). Friedmann didn't make this differential geometric mistake, and the cosmologies he found from the Einstein Equations were more varied in their properties - they could be expanding, or contracting, or (with the cosmological constant), static.
This video is about two-photon (gamma-gamma) physics, and how photons can interact with each other - either mediated by a passing lepton, or gravitationally via lensing, or via vacuum fluctuation pair production of vertical particles (electron-positron pair, for example). This is the so-called "box diagram" feynman diagram.
This video is about why words flip left & right (aka horizontally) in a mirror but not up & down (aka vertically). The answer has to do with specular reflection, mirrors being like windows into another world (alternate universes, just with in and out flipped!), and transparency of the things we write on.
This video is about cutting, taping, and rearranging the periodic table into the Left Step form, the Mendeleev's flower form, the cake form, the wide form, the standard form, and so on. A great holiday craft!!
