Notices by IntegralDuChemin (integralduchemin@qoto.org)

@freemo #QuantumPhysics #QuantumInformation #QuantumCryptography #Chemistry #Biochemistry #abortion #demography #womenonwaves #feminism #Linux #BSD #Psychopharmacology #ReactionKinetics #ReactionDynamics #Biophysics #ITSecurity #CriticalInfrastructure #Hacking

On my way to #Paris for that amazing #quantum #sensing conference at the #ENS. Delayed due to the strike but still feeling solidary with those striking.

For all the #nerds and #hackers among you - I highly recommend textfiles.com - a site containing thousands of files from the old times of BBS but some interesting things from the modern days as well.
For example try this - the Unix Haters Handbook - quite fun to read.

http://pdf.textfiles.com/books/ugh.pdf

Has anyone ever thought of constructing decentralized networks as concurrence to the internet? We could use radio frequencies to propagate data or even satellites. Or mesh networks. And if we restrict it to text files data transfer could be pretty easy, less harmful concerning viruses and could even be one-time-pad-encrypted. Referring to textfiles.com you can download a big part of the ancient American BBS network on a single telephone. It's some gigabytes in total (excluding pdfs).

Merge the past, commit the present, deploy the future!

What would you say if you met a woman as beautiful as Marilyn Monroe and as intelligent as Albert Einstein? #justcurious #peopleIwanttomeet

Are there #people or #companies financing/doing research in either theoretical quantum information, data science or machine learning who need a theoretical physicist who likes to play around with data and has a solid background in math?

@freemo I'm the path integral - interested in #physics, #math and #IT. I will post stuff about physics and perhaps comment on #German and #US #politics.
#introductions

Fun with spoons

How do you find the center of mass for any given geometry even if you have no idea on how to solve this analytically?

a) You can try some numerics.
b) You build a 3D replica and try to balance it on your fingertip. Works pretty well for spoons. Take a spoon, try to balance it -> yep, you found the COM.

Some more physics. You balance that spoon and add some small perturbations. Does the spoon hold? Congratulations, you just found a stable minimum.

How to describe this mathematically? -> Taylor series.
Dirty way - do a Taylor series expansion of the equation of motion around your extremum. Try to solve the differential equation with an ansatz combining two exponentials, one with a negative sign in the exponent, one with a positive one and both with different coefficients. The coefficients depend on the initial conditions but the exponents come from the solution of the differential equation.
If the exponent is imaginary you get a linear combination of cosine and sine functions. Congrats! For small perturbations your system will oscillate around the minimum but not leave it. You found a stable (maybe local) minimum.
Your exponent is real. Damn you found an unstable maximum. Try again.

@freemo Would be needing some new #followers as well.