Backward design Updated 2025-07-16
This is one of Ciro Santilli's most important principles.
Steve Jobs has a great quote about this. He's totally right on this one!
You've got to start with the customer experience and work backwards to the technology. You can't start with the technology and try to figure out where you're going to sell it.
Video 1.
Steve Jobs Insult Response excerpt from the 1997 WWDC
. Source. TODO understand the context of the question a bit better. It is something to do with an OpenDoc thing and Java.
Decide your goal first, and then do whatever is needed to how to reach it.
Don't start randomly learning tech, because that means you will waste a lot of time learning useless stuff.
There is of course some level chicken-and-egg paradox in this, as highlighted by Dilbert, since choosing an achievable goal in the first place requires some level of technical understanding.
Figure 1.
Dilbert cartoon about designing a nuclear power plant from user requirements (2002)
Source.
This cartoon illustrates well how when doing deep tech and fighting against the laws of physics, you can't just start from user requirements, but you also have to also think "what can we actually get done at all with this new technique".
The best research engineers are able to identify what is just on the cusp of the "possible", but which has the greatest value. This is the endless dance between the tech push, and the market/need pull.
However, it is much more common that people will get way too involved in learning useless stuff and lose sight of the useful end goals.
Rather, take an iterative approach:
There is some truth to the counter argument that "but if you don't spend a lot of time learning the basics, you can never find solutions".
However, these people underestimate your brain. The brain is beautiful, and human intuition is capable of generating interest towards the things that are actually useful to reach your goal. When you feel like learning something related to your goal, by all means, give yourself the time to do so. But this still be much more efficient than just learning random things that other people tell you to learn.
Bibliography:
Bacteria Updated 2025-07-16
Bad film Updated 2025-07-16
Many bad films have good aspects. They just didn't cross the elusive threshold of a good film.
Banheiros da USP Updated 2025-07-16
Semi-comical student website to review the toilets of the University of São Paulo. Some of the toilets had a reputation for being terrible.
One is reminded of Crushbridge.
Elliptic curve Updated 2025-07-16
An elliptic curve is defined by numbers and . The curve is the set of all points of the real plane that satisfy the Equation 1. "Definition of the elliptic curves"
Equation 1.
Definition of the elliptic curves
.
Figure 1.
Plots of real elliptic curves for various values of and
. Source.
Equation 1. "Definition of the elliptic curves" definies elliptic curves over any field, it doesn't have to the real numbers. Notably, the definition also works for finite fields, leading to elliptic curve over a finite fields, which are the ones used in Elliptic-curve Diffie-Hellman cyprotgraphy.
Lagrangian vs Hamiltonian Updated 2025-07-16
The key difference from Lagrangian mechanics is that the Hamiltonian approach groups variables into pairs of coordinates called the phase space coordinates:
This leads to having two times more unknown functions than in the Lagrangian. However, it also leads to a system of partial differential equations with only first order derivatives, which is nicer. Notably, it can be more clearly seen in phase space.
Laplace's equation Updated 2025-07-16
Like a heat equation but for functions without time dependence, space-only.
TODO confirm: does the solution of the heat equation always converge to the solution of the Laplace equation as time tends to infinity?
In one dimension, the Laplace equation is boring as it is just a straight line since the second derivative must be 0. That also matches our intuition of the limit solution of the heat equation.
web.math.pmf.unizg.hr/~duje/tors/rankhist.html gives a list with Elkies (2006) on top with:
TODO why this non standard formulation?
Largey Brage Updated 2025-07-16
The outcome of Larry Page and Sergey Brin performing a Dragon Ball fusion dance.
Both of them attended Montessori education at some point. Interesting! Mentioned in a talk by Sergey and highlighted at The Google Story.
But in 2023 they were somewhat pulled back in by the AI race and competition with ChatGPT.[ref]
As The Google Story puts it about Largey:
Scholarship was not just emphasized in their homes; it was treasured.
Ciro Santilli likes that.
Bell Labs Holmdel Complex Updated 2025-07-16
101 Crawfords Corner Rd Holmdel, NJ 07733 USA
It started with radio research apparently, including Karl Guthe Jansky.
They had a smaller building first: youtu.be/BPq_ZyOvbsg?t=51 and in 1962 opened the large new building.
Video 1.
Holmdel 20th Anniversary by AT&T Tech Channel (1982)
Source.
Video 2.
N.J.’s historic Bell Labs complex brought back to life as Bell Works by nj.com (2022)
Source. Shows the renewed building after the Bell Labs Holmdel Complex closure.
Bell Labs Murray Hill Updated 2025-07-16
600 Mountain Ave bldg 5, New Providence, NJ 07974, United States.
Became headquarters in 1967,
Drone footage: www.youtube.com/watch?v=z0Ld2KFjaC8 Bell LABS Headquarters Murray Hill NJ in 4K Drone Flight by ESTOUCHFPV (2017)
Notable inventions made there:
Bell test experiment Updated 2025-07-16
Some of the most remarkable ones seem to be:
Ben Bernanke Updated 2025-07-16
Bessel function Updated 2025-07-16
Shows up when trying to solve 2D wave equation on a circular domain in polar coordinates with separation of variables, where we have to decompose the initial condition in termes of a fourier-Bessel series, exactly like the Fourier series appears when solving the wave equation in linear coordinates.
For the same fundamental reasons, also appears when calculating the Schrödinger equation solution for the hydrogen atom.
Biochemistry Updated 2025-07-16
iubmb.onlinelibrary.wiley.com/doi/full/10.1002/bmb.2002.494030030067 Surprises and revelations in biochemistry: 1950-2000 by Perry A. Frey (2006). This should be worth a read.

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