49 Matching Annotations
  1. May 2019
    1. Cycles can be broken down into three main phases: Decision: the user is shown some options and takes a decision. Intention: the user approximates the interface that will serve to communicate the decision. Confirmation: the user communicates his decision to the computer.

      hm, makes sense. so you don't necessarily have to perform 'external' and potentially destructive actions with neural interface, it's fine to use a stronger signal to confirm, like speech or blink pattern or finger movement

  2. Apr 2019
    1. the vector potential changes the topology of the vacuum

      not sure if I understand that sentence, but it feels somewhat important

    2. The gauge field AAA is responsible that electrons moving on opposite sides around the solenoid also need to take different paths around the fiber bundle. In the picture above, the gauge field corresponds to the ramps that tell us how the phase factor of an electron changes as it moves through space.

      hm. so, if the electron goes around the solenoid twice (which it can with some probability), we have to count that in as well? That would be even bigger phase shift

    1. At 12 I would guzzle a bottle of Coke or Pepsi nearly every day. At 13, I wouldn’t touch the stuff with a ten foot pole, and I still won’t.

      huh, very similar to my perception

  3. Mar 2019
    1. It suffices to consider a 1+1-dimensional space-time ℝ×S1, in which the spatial direction is compactified to a circle of circumference 2π, rendering the momenta discrete.


    2. The classical equations of motion of a field are typically identical in form to the (quantum) equations for the wave-function of one of its quanta. For example, the Klein–Gordon equation is the classical equation of motion for a free scalar field, but also the quantum equation for a scalar particle wave-function.

      really? but it doesn't have wavefunction interpretation...

    1. He notes that however bad your carbon dioxide levels are during the day they’re probably much worse at night, when you shut yourself up in a small room, close all the doors and windows, and just breathe for like eight hours straight

      that's so true!

    1. It means that a "more elementary" way to look at an SO(3)SO(3)SO(3) rotation is to actually find a corresponding SU(2)SU(2)SU(2) transformation that acts on the spinors χχ\chi while the SO(3)SO(3)SO(3) rotation is just "inherited" and may be constructed as the transformation of a "tensor with two spinor indices" i.e. it is not quite elementary. As we will see, this is really the reason why the spin j=1/2j=1/2j=1/2, smaller than one unit (seemingly the smallest quantum), is possible.

      try to understand that, it seems important...

    1. Putting them into the Hamiltonian, we obtai

      hmm, in classical case they were commuting, whereas because operators are not commuting, we get the 1/2

    1. There is an obvious problem with this, that the Hamiltonian formulation isnot manifestly Lorentz invariant. However, we know it actually is because wederived it as an equivalent formulation of a Lorentz invariant theory.


  4. Feb 2019
    1. We think that a similar mechanism gives mass to the particles related to the weak force. At each spacetime point (country) there is some object (the analogue of gold) that has some orientation in the weak sphere. The details are more complicated because the symmetries correspond to rotations, and we will not describe it here. Essentially, the presence of this object means that the cost of exciting waves does not go to zero as the wavelength tends to zero. And this in turn means that the particles associated to the waves in the weak force field have a non-zero mass. If one sets the price of gold to one everywhere, then one is not free to do gauge transformations to further modify exchange rates. For this reason people sometimes say that the gauge symmetry is broken. This is conceptually misleading because the gauge symmetry is still present, if we remember that we need to also change the price of gold.


    1. We have said above that electromagnetic waves are associated to particles called photons, and that the mass of a photon is related to the energy it takes to excite a wave with a very long wave length. Using our analogy we have seen that this energy cost (the gain) goes to zero as the wavelength gets longer. This, essentially, is why the photon has no mass.


    1. ok, so he didn't finish the experiment yet, apparently

    2. Lavaan syntax

      what's that?

    3. I decided to get a Netatmo weather station device.


  5. Jan 2019
    1. So what if we had the power of these tools and what if we could drop this data into the blockchain and what if we said that human data privacy was a human right?

      that escalated quickly...

    1. Think something like “Photoshop for linear algebra”.

      TODO hmm. kinda like interpreter, which shows some context and suggests what you can do with an object?

    1. Mathematicians say the set of left-invariant vector fields is the Lie algebra of GGG.

      so what?

    1. Here is a sound clip which first plays a 540.61 Hz tone paired with a perfect fifth (at 810.92 Hz), and then plays the same tone paired with 800 Hz, which is the interval referred to as "the wolf".

      annoying... I can't hear differences :(

    2. n comparison, a less simple ratio—here, 300 Hz and 573 Hz, related by a 100:191 ratio—will sound somewhat less pleasant when played together:

      fucking hell.. they both sound ok

    1. Two separate areas: structured notes area (think Evernote), and an unstructured, loose notes area (think Apple Notes or Simplenote).

      TODO hmm, that's a good idea

  6. Oct 2018
    1. fmap f readFn = Reader (\r -> f (runReader readFn r))

      basically, just pass the environment down the stream

  7. Sep 2018

      like particles filling up low energy states

    1. But as it is, even if many journalists are interested in raising awareness of police brutality, given their total lack of coordination there’s not much they can do. An editor can publish a story on Eric Garner, but in the absence of a divisive hook, the only reason people will care about it is that caring about it is the right thing and helps people. But that’s “charity”, and we already know from my blog tags that charity doesn’t sell. A few people mumble something something deeply distressed, but neither black people nor white people get interested, in the “keep tuning to their local news channel to get the latest developments on the case” sense.

      I guess the takeaway is: do not take their bait. Ignore completely, and if you do care, read about the subject. If you're involving in internet argument, you are not helping and wasting time, and also helping Moloch.

    2. For example, Immanuel Kant claims that if an axe murderer asks you where your best friend is, obviously intending to murder her when he finds her, you should tell the axe murderer the full truth, because lying is wrong. This is effective at showing how moral a person you are – no one would ever doubt your commitment to honesty after that – but it’s sure not a very good result for your friend.

      seriously? Maybe I shouldn't try to understand Kant then...

  8. Aug 2018
    1. This seems obvious to anyone who has rolled a ball, but it is not totally trivial to prove

      center of mass moves along the straight line?? unclear what means 'line through the origin is fixed'. E.g.consider a line which is Z axis. If we rotate it 45 degrees in YZ axis, it will clearly not be the same line.

  9. Jul 2018
    1. Now if we imagine all the possibilities (all 10 microstates) and we simply select one at random, it is clear that it most likely to be form "group ii." Since we can't tell the difference between the molecules, all of these microstates in group ii are the same.

      right. so basically if we have perfect information, entropy is always 0?

    1. Meditation positions, at least in the traditions I’ve been exposed to, are designed to build in mild to moderate physical discomfort, partly as a deterrent to spacing out or falling asleep and partly also, I suspect, to build in an incentive for contextualizing physical sensation.

      hmm, actually kinda makes sense. Average human was more flexible back then, so lotus was just mildly uncomf as opposed to very uncomf nowadays

  10. Jun 2017
    1. The main point seems to be disproportionately many people from Central European countries like Hungary and Germany, compared to either Eastern European countries like Poland and Russia or Western European countries like France and Britain.

      too small dataset..

    2. “Left to his own devices, he taught himself to read through mathematics texts that his parents left around their home. By the age of four, given a person’s age, he could calculate, in his head, how many seconds they had lived.”


    3. Okay. But I want to challenge this. During this era, formal education in Hungary began at age 10. By age ten, John von Neumann, greatest of the Hungarian supergeniuses, already spoke English, French, German, Italian, and Ancient Greek, knew integral and differential calculus, and could multiply and divide 8-digit numbers in his head.


  11. May 2017
    1. C♯ or D♭ (semitone; minor second)

      !!! semitoes are non-natural fractions

    2. The first and third sound much more related than the second sounds to either.

      do they?

    1. Being godlike is a good quality.


    2. Existence is a good quality.


    3. If A is good, then the opposite of A is bad

      too polar.

    4. So, for example, if I say that my counter being clean is a good thing, and my counter being clean necessarily forces my counter to smell nice, then smelling nice must also be a good thing.

      There might be some negative property due to counter being clean (e.g. not enoght bacteria, so your immunity gets suppressed). However, positivities might overweight negativities