Developmental biology Updated +Created
Video 1.
Where is Anatomy Encoded in Living Systems? by Michael Levin (2022)
Source.
  • we are very far from full understanding. End game is a design system where you draw the body and it compiles the DNA for you.
  • some cool mentions of regeneration
Developmental genetics Updated +Created
How genes form bodies.
Video 1.
Developmental Genetics 1 by Joseph Ross (2020)
Source. Talks about homeobox genes.
Dharma name Updated +Created
法 (fa3) is the Chinese name for Dharma, and sometimes used as a way short way to refer to Buddhism.
Diamond Sutra Updated +Created
Differentiable manifold Updated +Created
TODO find a concrete numerical example of doing calculus on a differentiable manifold and visualizing it. Likely start with a boring circle. That would be sweet...
Diffie-Hellman key exchange Updated +Created
Based on the fact that we don't have a P algorithm for the discrete logarithm of the cyclic group as of 2020, but we do have an efficient algorithm for modular exponentiation. But nor do we have proof that one does not exist! Living on the edge as usual for public-key cryptography.
DigitalDreamDoor Updated +Created
Ahh, this brings good memories of Ciro Santilli's musical formative teenage years scouring the web for the best art humanity had ever produced in certain generes. And it still is a valuable resource as of the 2020's!
Digital electronic circuit Updated +Created
Digital Light Processing Updated +Created
Dilution refrigerator Updated +Created
Video 1.
This Is What A Helium Dilution refrigerator Is by Dietterich Labs (2019)
Source.
Dimension Updated +Created
Diophantine equation Updated +Created
Sometimes systems of Diophantine equations are considered.
Problems generally involve finding integer solutions to the equations, notably determining if any solution exists, and if infinitely solutions exist.
The general problem is known to be undecidable: Hilbert's tenth problem.
The Pythagorean triples, and its generalization Fermat's last theorem, are the quintessential examples.
Dipole antenna Updated +Created
Video 1.
Radio Wave Properties: Electric and Magnetic Dipole Antennae by Harvard Natural Sciences Lecture Demonstrations (2020)
Source. The dude lights bulbs on an antenna made of a single piece of copper, powered with EM radiation. Amazing.
Figure 1.
Dipole antenna receiver animation
. Source.
Figure 2.
Dipole antenna transmitter animation
. Source.
Dirac equation vs quantum electrodynamics Updated +Created
TODO: in high level terms, why is QED more general than just solving the Dirac equation, and therefore explaining quantum electrodynamics experiments?
Also, is it just a bunch of differential equation (like the Dirac equation itself), or does it have some other more complicated mathematical formulation, as seems to be the case? Why do we need something more complicated than
The main high level insight seems to be that The Dirac equation does not work for more than one electron.
Dirac Lagrangian Updated +Created
where:
Remember that is a 4-vetor, gamma matrices are 4x4 matrices, so the whole thing comes down to a dot product of two 4-vectors, with a modified by matrix multiplication/derivatives, and the result is a scalar, as expected for a Lagrangian.
Like any other Lagrangian, you can then recover the Dirac equation, which is the corresponding equations of motion, by applying the Euler-Lagrange equation to the Lagrangian.
Directional derivative Updated +Created
Discord email notifications Updated +Created
Discord is useless if you want to participate in more than one large group because of this. It is impossible to get email notification for selected threads you care about.

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